Cormorant predation and the population dynamics of walleye and yellow perch in Oneida Lake

USGS Publications Warehouse

Rudstam, L. G.; VanDeValk, A.J.; Adams, C.M.; Coleman, J.T.H.; Forney, J.L.; Richmond, M.E.

2004-01-01

Double-crested Cormorants (Phalacrocorax auritus) increased dramatically in North America during the 1990s, providing the opportunity to study the effects of an increase of a top predator on an existing predator-prey system. In Oneida Lake, New York, USA, Double-crested Cormorants were first observed nesting in 1984 and had increased to over 360 nesting pairs by 2000. Concomitant with this increase in piscivorous birds was a decrease in the adult walleye (Stizostedion vitreum) and yellow perch (Perca flavescens) populations. Analysis of a 40-yr data series shows higher mortality of subadults (age 1-2 yr perch and age 1-3 yr walleye) for both species in the 1990s compared to the previous three decades. Cormorant diet was investigated from 1995 to 2000 using a combination of cast pellets, regurgitants, and stomach analysis. Walleye and yellow perch were a major portion of the cormorant diet during these years (40-82% by number). The number of subadult walleye and yellow perch consumed by cormorants suggests that the increase in subadult mortality can be explained by predation from cormorants. Mean mortality rates of adult percids attributed to cormorant predation were 1.1% per year for walleye and 7.7% per year for yellow perch. Our analysis suggests that predation by cormorants on subadult percids is a major factor contributing to the decline in both the walleye and the yellow perch populations in Oneida Lake. Other ecosystem changes (zebra mussels, lower nutrient loading, decrease in alternate prey) are not likely explanations because the potential mechanisms involved are not consistent with auxiliary data from the lake and would not affect subadult mortality. The likely impact of bird predation on percid populations in Oneida Lake occurs because cormorants feed on larger fish that are beyond the size range where compensatory mechanisms are important.

Reevaluation of a walleye (Sander vitreus) bioenergetics model

USGS Publications Warehouse

Madenjian, Charles P.; Wang, Chunfang

2013-01-01

Walleye (Sander vitreus) is an important sport fish throughout much of North America, and walleye populations support valuable commercial fisheries in certain lakes as well. Using a corrected algorithm for balancing the energy budget, we reevaluated the performance of the Wisconsin bioenergetics model for walleye in the laboratory. Walleyes were fed rainbow smelt (Osmerus mordax) in four laboratory tanks each day during a 126-day experiment. Feeding rates ranged from 1.4 to 1.7 % of walleye body weight per day. Based on a statistical comparison of bioenergetics model predictions of monthly consumption with observed monthly consumption, we concluded that the bioenergetics model estimated food consumption by walleye without any significant bias. Similarly, based on a statistical comparison of bioenergetics model predictions of weight at the end of the monthly test period with observed weight, we concluded that the bioenergetics model predicted walleye growth without any detectable bias. In addition, the bioenergetics model predictions of cumulative consumption over the 126-day experiment differed fromobserved cumulative consumption by less than 10 %. Although additional laboratory and field testing will be needed to fully evaluate model performance, based on our laboratory results, the Wisconsin bioenergetics model for walleye appears to be providing unbiased predictions of food consumption.

Are walleye from Lake Roosevelt contaminated with mercury?

USGS Publications Warehouse

Erwin, Martha L.; Munn, Mark D.

1997-01-01

To find out, scientists from the U. S. Geological Survey (USGS) tested walleye and other sport fish from the upper Columbia River and Franklin D. Roosevelt Lake (Lake Roosevelt), the largest reservoir in Washington and a popular fishing spot.Findings:Walleye had higher concentrations of mercury than other sport fish.Larger walleye had higher mercury concentrations than smaller walleye.Mercury concentrations in walleye fillets ranged from 0.11 to 0.44 parts per million (ppm). These concentrations do not exceed the current Federal standard (1.0 ppm of mercury) designed to protect the health of people who eat small amounts of fish.After reviewing these findings, the Washington State Department of Health concluded that people who regularly consume large amounts of Lake Roosevelt walleye may be at risk of adverse health effects from mercury and should limit their consumption of these fish.

The Effects of Simulated Live-release Walleye Tournaments on Survival and Blood Chemistry

USGS Publications Warehouse

Loomis, John H.; Schramm, Harold L.; Vondracek, Bruce C.; Gerard, Patrick D.; Chizinski, Christopher J.

2013-01-01

We examined the effects of acclimation water temperature,live-well (LW) water temperature,and LW dissolved oxygen (DO) concentration on survival of adult WalleyesSander vitreus subjected to simulated tournament conditions (angling,LW confinement,and weigh-in procedures) under controlled laboratory conditions. We tested three acclimation temperatures (12,18,and 24°C),and three LW temperature differentials (ΔT = −4,0,and +4°C) were tested at each acclimation temperature. Survival was monitored after 8 h of LW confinement and during a 5-d retention period in 1,700-L tanks. None of the Walleyes that were acclimated to 24°C and subjected to simulated tournament procedures survived the 5-d retention period; for fish subjected only to simulated angling at 24°C,survival during the 5-d retention period was 29%. Five-day survival was generally over 70% at acclimation temperatures of 12°C and 18°C,and we observed a significant interaction between acclimation temperature and ΔT; survival was greatest in LWs at −4°C ΔT for fish acclimated to 18°C and in LWs at +4°C ΔT for fish acclimated to 12°C. Best survival of Walleyes subjected to the stress of angling and tournament procedures was obtained at temperatures 6–8°C below the optimum temperature for adult Walleyes (i.e.,optimum = 20–22°C). Five-day survival exceeded 70% when LW DO was 5 or 12–15 mg/L (at an acclimation and LW temperature of 18°C),but survival was 0% when DO was 2 mg/L. Anglers may increase survival of Walleyes through careful manipulation of LW temperature and DO when ambient temperature is at or below 18°C,but high mortality of angled and LW-retained Walleyes should be expected when ambient water temperatures are 24°C or greater.

Walleye recruitment success is less resilient to warming water temperatures in lakes with abundant largemouth bass populations

USGS Publications Warehouse

Hansen, Gretchen J. A.; Midway, Stephen R.; Wagner, Tyler

2018-01-01

Lakes respond heterogeneously to climate, with implications for fisheries management. We analyzed walleye (Sander vitreus) recruitment to age-0 in 359 lakes in Wisconsin, USA, to (i) quantify the relationship between annual water temperature degree days (DD) and walleye recruitment success and (ii) identify the influence of lake characteristics — area, conductivity, largemouth bass (Micropterus salmoides) catch rates, and mean DD — on this relationship. The relationship between walleye recruitment and annual DD varied among lakes and was not distinguishable from zero overall (posterior mean = −0.11, 90% CI = −0.34, 0.15). DD effects on recruitment were negative in 198 lakes (55%) and positive in 161 (45%). The effect of annual DD was most negative in lakes with high largemouth bass densities, and, on average, the probability of recruitment was highest in large lakes with low largemouth bass densities. Conductivity and mean DD influenced neither recruitment nor the effect of annual DD. Walleye recruitment was most resilient to warming in lakes with few largemouth bass, suggesting that the effects of climate change depend on lake-specific food-web and habitat contexts.

Does behavioural thermoregulation underlie seasonal movements in Lake Erie walleye?

USGS Publications Warehouse

Raby, Graham D.; Vandergoot, Christopher; Hayden, Todd A.; Faust, Matthew D.; Kraus, Richard T.; Dettmers, John M.; Cooke, Steven J.; Zhao, Yingming; Fisk, Aaron T.; Krueger, Charles C.

2018-01-01

Thermoregulation is presumed to be a widespread determinant of behaviour in fishes, but has not often been investigated as a mechanism shaping long-distance migrations. We used acoustic telemetry and animal-borne thermal loggers to test the hypothesis that seasonal migration in adult walleye (Sander vitreus) in Lake Erie is size- and (or) sex-specific and related to behavioural thermoregulation. Female walleye migrated out of the warm, shallow western basin earlier than did males and were 1.8 times more likely to be detected on acoustic receivers in the deeper and cooler eastern basin. The few fish that remained in the western basin were restricted to a smaller range of higher temperatures (≥20 °C) than those that migrated to the central and eastern basins (∼16–21 °C). However, temperature records from walleye in the central basin were nearly indistinguishable from those in the eastern basin, suggesting thermal preferences alone could not explain migration to the eastern basin. As such, our effort to understand the mechanisms that cause migratory behaviours has generated mixed evidence on the role of temperature and that factors like foraging opportunities may have synergistic roles in the migration.

Food of young-of-the-year walleyes in Lake Erie

USGS Publications Warehouse

Wolfert, David R.

1966-01-01

Stomach contents were examined for 794 young-of-the-year (0-group) walleyes (Stizostedion vitreum vitreum) captured by trawls at 17 locations in western Lake Erie in June-November 1962. Food organisms were found in 92.5 percent of the stomachs. Food varied with geographic location and season of capture, but within areas and seasons, selection for certain species and sizes of prey was strong. Walleyes from the extreme western end of Lake Erie fed primarily on gizzard shad and alewives during the summer and shifted to emerald shiners during the fall. The stomach contents of walleyes from the Island region changed from mainly yellow perch during the summer to emerald shiners by the end of the year. Walleyes collected east of the Islands had consumed only smelt and yellow perch. The numbers of forage species caught with walleyes in trawls showed little correlation with the representation of these species in walleye stomachs. Walleyes fed on the smallest individuals of each species regardless of species preferences.

Walleye in Lake Erie and Lake St. Clair

USGS Publications Warehouse

Nepszy, S.J.; Davies, D.H.; Einhouse, D.; Hatch, R.W.; Isbell, G.; MacLennan, D.; Muth, K.M.

1991-01-01

The history and current status of walleye (Stizostedion vitreum vitreum) stocks in Lake Erie and Lake St. Clair are reviewed in relation to their exploitation by commercial and recreational fishermen, environmental factors, rehabilitation efforts, and community dynamics. Management initiatives and stock recovery under these processes are outlined. After the collapse of the fishery in 1957, the highly productive walleye stock of western Lake Erie remained depressed through the 1960s, while the eastern basin stock remained stable. Closure of the fishery for walleye from 1970-73 because of mercury contamination provided an opportunity for the development of an international interagency management plan. With quota management, the walleye stock in western Lake Erie responded well to limited exploitation, steadily increased, and expanded its range. As population expanded, growth began to decline and was more apparent in the young-of-the-year (YOY) in the 1970s, and in older walleye in the late 1970s and 1980s. At the turn of the century, commercial harvest of walleye in Lake St. Clair ranged from 12-127 tonnes annually. A relatively stable period from 1910-59 was followed by significantly increased harvests (100-150 t) in 1959-65. This increase was a result of increased commercial exploitation as well as an increased abundance of walleye. After the mercury contamination problem of 1970, angling effort and harvest was reduced but then gradually increased in Ontario waters from 37 t in 1973 to 62 t in 1988. The increased mean age of the stock during the early 1970s was due to a few strong year-classes (1970, 1972, and 1974) as well as a period of stable or reduced catch per unit effort. With the current mean age not reduced significantly, the stocks of walleye should continue to provide good yields.

Consumption dynamics of the adult piscivorous fish community in Spirit Lake, Iowa

USGS Publications Warehouse

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2004-01-01

At Spirit Lake, one of Iowa's most important fisheries, walleye Sander vitreus (formerly Stizostedion vitreum) is one of the most popular species with anglers. Despite a century of walleye stocking and management in Spirit Lake, walleye growth rate, size structure, and angler harvest continue to decline. Our purpose was to determine the magnitude and dynamics of walleye population consumption relative to those of other piscivorous species in Spirit Lake, which would allow managers to judge the feasibility of increasing the abundance, growth rate, and size structure of the walleye population. We quantified food consumption by the adult piscivorous fish community in Spirit Lake over a 3-year period. Data on population dynamics, diet, energy density, and water temperature from 1995 to 1997 were used in bioenergetics models to estimate total consumption by walleye, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieu, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus, and northern pike Esox lucius. Estimated annual consumption by the piscivorous community varied roughly fourfold, ranging from 154,752 kg in 1995 to 662,776 kg in 1997. Walleyes dominated total consumption, accounting for 68, 73, and 90% (1995-1997, respectively) of total food consumption. Walleyes were also the dominant consumers of fish, accounting for 76, 86, and 97% of piscivorous consumption; yellow perch followed, accounting for 16% of piscivorous consumption in 1995 and 12% in 1996. Yellow perch were the predominant fish prey species in all 3 years, accounting for 68, 52, and 36% of the total prey consumed. Natural reproduction is weak, so high walleye densities are maintained by intensive stocking. Walleye stocking drives piscivorous consumption in Spirit Lake, and yearly variation in the cannibalism of stocked walleye fry may be an important determinant of walleye year-class strength and angler success. Reducing walleye stocking intensity, varying stocking

Diet overlap and predation between largemouth bass and walleye in Wisconsin lakes using DNA barcoding to improve taxonomic resolution

USGS Publications Warehouse

Kelling, Craig J.; Isermann, Daniel A.; Sloss, Brian L.; Turnquist, Keith N.

2016-01-01

Over the last decade, the abundance of Largemouth Bass Micropterus salmoides has increased in many northern Wisconsin lakes, causing concern among anglers and biologists regarding the potential for Largemouth Bass to negatively affect populations of Walleye Sander vitreus through predation or competition for prey. Our objectives were to determine whether (1) diet overlap and predation occurred between adult Walleyes and Largemouth Bass in four northern Wisconsin lakes and (2) the use of DNA barcoding to reduce unidentifiable fish in diet samples affected conclusions regarding diet overlap. A single occurrence of Walleye predation was observed in the diets of 945 Largemouth Bass. Moderate to high diet overlap was observed between Largemouth Bass and Walleyes throughout much of the study period. The use of DNA barcoding reduced the amount of unidentified fish in diets to <1% and showed that failure to identify fish or fish parts can affect conclusions regarding diet overlap. Largemouth Bass predation is probably not a primary factor affecting Walleye abundance in the lakes we selected, but observed diet overlap suggests the potential for competition between the two species.

Laboratory evaluation of a walleye (Sander vitreus) bioenergetics model

USGS Publications Warehouse

Madenjian, C.P.; Wang, C.; O'Brien, T. P.; Holuszko, M.J.; Ogilvie, L.M.; Stickel, R.G.

2010-01-01

Walleye (Sander vitreus) is an important game fish throughout much of North America. We evaluated the performance of the Wisconsin bioenergetics model for walleye in the laboratory. Walleyes were fed rainbow smelt (Osmerus mordax) in four laboratory tanks during a 126-day experiment. Based on a statistical comparison of bioenergetics model predictions of monthly consumption with the observed monthly consumption, we concluded that the bioenergetics model significantly underestimated food consumption by walleye in the laboratory. The degree of underestimation appeared to depend on the feeding rate. For the tank with the lowest feeding rate (1.4% of walleye body weight per day), the agreement between the bioenergetics model prediction of cumulative consumption over the entire 126-day experiment and the observed cumulative consumption was remarkably close, as the prediction was within 0.1% of the observed cumulative consumption. Feeding rates in the other three tanks ranged from 1.6% to 1.7% of walleye body weight per day, and bioenergetics model predictions of cumulative consumption over the 126-day experiment ranged between 11 and 15% less than the observed cumulative consumption. ?? 2008 Springer Science+Business Media B.V.

Managing inherent complexity for sustainable walleye fisheries in Lake Erie

USGS Publications Warehouse

Roseman, Edward F.; Drouin, Richard; Gaden, Marc; Knight, Roger; Tyson, Jeff; Zhao, Yingming; Taylor, William W.; Lynch, Abigail J.; Léonard, Nancy J.

2012-01-01

In Lake Erie, Walleye (Sander vitreus vitreus) is king. The naturally occurring species is the foundation of commercial fishing operations on the Canadian side of the lake and is a much-prized sport fish on the American side. Management of Lake Erie walleye fisheries is complex and takes place in an inter-jurisdictional setting composed of resource agencies from the states of Michigan (MDNR), Ohio (ODNR), Pennsylvania (PFBC), and New York (NYDEC) and the province of Ontario (OMNR). The complexity of walleye management is exacerbated by interactions among environmental and ecological changes in Lake Erie, complex life-history characteristics of the species, public demand for walleye, and cultural/governance differences among managing groups and their respective constituents. Success of future management strategies will largely hinge upon our ability to understand these inherent complexities and to employ tactics that successfully accommodate stock productivity and human demand in a highly dynamic environment. In this report, we review the history of Lake Erie walleye management, outline the multi-jurisdictional process for international management of walleye, and discuss strategies to address challenges facing managers.

Interactions between commercial fishing and walleye pollock aggregations

NASA Astrophysics Data System (ADS)

Stienessen, Sarah; Wilson, Chris D.; Hallowed, Anne B.

2002-05-01

Scientists with the Alaska Fisheries Science Center are conducting a multiyear field experiment off the eastern side of Kodiak Island in the Gulf of Alaska to determine whether commercial fishing activities significantly affect the distribution and abundance of walleye pollock (Theragra chalcogramma), an important prey species of endangered Steller sea lions (Eumetopias jubatus). In support of this activity, spatio-temporal patterns were described for pollock aggregations. Acoustic-trawl surveys were conducted in two adjacent submarine troughs in August 2001. One trough served as a control site where fishing was prohibited and the other as a treatment site where fishing was allowed. Software, which included patch recognition algorithms, was used to extract acoustic data and generate patch size and shape-related variables to analyze fish aggregations. Important patch related descriptors included skewness, kurtosis, length, height, and density. Estimates of patch fractal dimensions, which relate school perimeter to school area, were less for juvenile than for adult aggregations, indicating a more complex school shape for adults. Comparisons of other patch descriptors were made between troughs and in the presence and absence of the fishery to determine whether trends in pollock aggregation dynamics were a result of the fishery or of naturally occurring events.

Sex difference in polybrominated diphenyl ether concentrations of walleyes

USGS Publications Warehouse

Madenjian, Charles P.; Trombka, Autumn W.; Rediske, Richard R.; Jude, David J.; O'Keefe, James P.

2012-01-01

Polybrominated diphenyl ether (PBDE) concentrations were determined for mature male and mature female walleyes (Sander vitreus) sampled from the Saginaw Bay population during 2007. PBDE concentrations in prey fish caught in the Saginaw River, the primary tributary to Saginaw Bay, and in Saginaw Bay during 2005 and 2007 also were determined. Mature male and mature female walleyes averaged 70.3 ng/g and 24.8 ng/g, respectively, in ΣPBDE, which was equal to the sum of concentrations of six PBDE congeners (BDE-28, BDE-47, BDE-99, BDE-100, BDE-153, and BDE-154). This sex difference was likely due to males spending more time in the Saginaw River system than females. Prey fish captured in the Saginaw River were roughly ten times higher in ΣPBDE than those caught in Saginaw Bay. BDE-47 was the predominant congener in both walleyes and prey fish, and this congener contributed about 50%, on average, to ΣPBDE. Congener profiles differed significantly between the two sexes of walleyes. In contrast, congener profiles of the prey fish did not differ significantly between the river-caught fish and the bay-caught fish. One plausible explanation for these congener profile results was that net trophic transfer efficiencies of PBDEs to walleyes from their prey were similar for all congeners except BDE-28, and that diet composition differed between the two sexes of walleyes.

Age structure and mortality of walleyes in Kansas reservoirs: Use of mortality caps to establish realistic management objectives

USGS Publications Warehouse

Quist, M.C.; Stephen, J.L.; Guy, C.S.; Schultz, R.D.

2004-01-01

Age structure, total annual mortality, and mortality caps (maximum mortality thresholds established by managers) were investigated for walleye Sander vitreus (formerly Stizostedion vitreum) populations sampled from eight Kansas reservoirs during 1991-1999. We assessed age structure by examining the relative frequency of different ages in the population; total annual mortality of age-2 and older walleyes was estimated by use of a weighted catch curve. To evaluate the utility of mortality caps, we modeled threshold values of mortality by varying growth rates and management objectives. Estimated mortality thresholds were then compared with observed growth and mortality rates. The maximum age of walleyes varied from 5 to 11 years across reservoirs. Age structure was dominated (???72%) by walleyes age 3 and younger in all reservoirs, corresponding to ages that were not yet vulnerable to harvest. Total annual mortality rates varied from 40.7% to 59.5% across reservoirs and averaged 51.1% overall (SE = 2.3). Analysis of mortality caps indicated that a management objective of 500 mm for the mean length of walleyes harvested by anglers was realistic for all reservoirs with a 457-mm minimum length limit but not for those with a 381-mm minimum length limit. For a 500-mm mean length objective to be realized for reservoirs with a 381-mm length limit, managers must either reduce mortality rates (e.g., through restrictive harvest regulations) or increase growth of walleyes. When the assumed objective was to maintain the mean length of harvested walleyes at current levels, the observed annual mortality rates were below the mortality cap for all reservoirs except one. Mortality caps also provided insight on management objectives expressed in terms of proportional stock density (PSD). Results indicated that a PSD objective of 20-40 was realistic for most reservoirs. This study provides important walleye mortality information that can be used for monitoring or for inclusion into

Selective food preferences of walleyes of the 1959 year class in Lake Erie

USGS Publications Warehouse

Parsons, John W.

1971-01-01

Stomachs were examined from 1,473 walleyes (Stizostedion vitreum vitreum) of the 1959 year class collected in western Lake Erie from June 1959 to October 1960. In the same period, the relative abundance and lengths of potential forage species were determined from trawl catches. The walleye fed almost entirely on fish. In 1959 the food was dominated first (in June and July) by yellow perch (Perca flavescens) and then, in sequence, by spottail shiners (Notropis hudsonius) and emerald shiners (Notropis atherinoides). In 1960, the walleyes fed mostly on yearling spottail shiners and emerald shiners in the spring and summer but young alewives (Alosa pseudoharengus) became the dominant food in the fall. The length of forage fish increased with the length of walleyes and walleyes of a given length usually ate forage fish within a restricted range of lengths. This size preference was shown by walleyes of the same length in the same and different months. The increased in length of forage fish with length of walleye was not proportionate. Walleyes 2.5 inches long ate forage fish 0.44 times their length whereas walleyes 15.5 inches long ate forage fish only 0.28 times their length. The diet of the walleyes changed according to species and lengths of forage fish available. Since young of several species hatched in different months and grew at different rates, abundance and suitability as forage sometimes changed rapidly.

Genetic contribution of hatchery fish to walleye stocks in Saginaw Bay, Michigan

USGS Publications Warehouse

Todd, Thomas N.; Haas, Robert C.; Schramm, Harold L.; Piper, Robert G.

1995-01-01

Stocks of walleye (Stizostedion vitreum) were severely depressed in Saginaw Bay in the 1970s. In 1979, the Michigan Department of Natural Resources began intensive stocking of walleye fingerlings to bolster fish populations. Subsequent to stocking, the walleye fishery has recovered. The study objective was to determine if recovery was due to the stocking program or natural reproduction. Inherent genetic differences between hatchery fish and endemic walleyes were used to determine the effect and contribution of hatchery fish to Saginaw Bay.

Influence of variable rainbow smelt and gizzard shad abundance on walleye diets and growth

USGS Publications Warehouse

Fincel, Mark J.; Dembkowski, Daniel J.; Chipps, Steven R.

2014-01-01

Prey availability influences growth and condition of walleye (Sander vitreus) in large systems. In Lake Oahe, South Dakota, rainbow smelt (Osmerus mordax) and gizzard shad (Dorosoma cepedianum) are primary prey of walleye, but their abundance varies substantially year to year. To evaluate the influence of gizzard shad and rainbow smelt on walleye diets and growth in Lake Oahe, we compared recent estimates of walleye diets and growth in 2008 through 2010 with those from the late 1990s and early 2000s. Walleye diets differed seasonally with increased piscivory in July and October. In 2008, gizzard shad were the dominant prey item of walleye, representing about 60% of the diets by weight; however, by 2009, gizzard shad declined appreciably in the diet (22%) and were completely absent from walleye diets by 2010. Conversely, rainbow smelt abundance represented 12%, 27%, and 90% of walleye diets by weight in 2008, 2009 and 2010, respectively. Changes in growth corresponded to changes in diets, with the slowest growth occurring when gizzard shad were dominant in the diets and increasing growth every year thereafter. Because gizzard shad are only available during short periods (<3 months) in late summer, walleye can only achieve about 50% of their annual maintenance energy requirements from this prey source. Conversely, rainbow smelt, which are available and consumed year round, provide a continuous energy source that contributes to high growth rates. Nonetheless, when abundant, gizzard shad may provide an important subsidy to Lake Oahe walleye during periods of low rainbow smelt abundance.

First evidence of egg deposition by walleye (Sander vitreus) in the Detroit River

USGS Publications Warehouse

Manny, B.A.; Kennedy, G.W.; Allen, J.D.; French, J. R. P.

2007-01-01

The importance of fish spawning habitat in channels connecting the Great Lakes to fishery productivity in those lakes is poorly understood and has not been adequately documented. The Detroit River is a reputed spawning and nursery area for many fish, including walleye (Sander vitreus) that migrate between adjacent Lakes Erie and St. Clair. During April–May 2004, near the head of the Detroit River, we collected 136 fish eggs from the bottom of the river on egg mats. We incubated the eggs at the Great Lakes Science Center until they hatched. All eleven larvae that hatched from the eggs were identified as walleye. These eggs and larvae are the first credible scientific evidence that walleye spawn in the Detroit River. Their origin might be a stock of river-spawning walleye. Such a stock of walleye could potentially add resilience to production by walleye stocks that spawn and are harvested in adjacent waters.

Thiamine and fatty acid content of walleye tissue from three southern U.S. reservoirs

USGS Publications Warehouse

Honeyfield, D.C.; Vandergoot, C.S.; Bettoli, P.W.; Hinterkopf, J.P.; Zajicek, J.L.

2007-01-01

We determined the thiamine concentration in egg, muscle, and liver tissues of walleyes Sander vitreus and the fatty acid content of walleye eggs from three southern U.S. reservoirs. In two Tennessee reservoirs (Dale Hollow and Center Hill), in which there were alewives Alosa pseudoharengus in the forage base, natural recruitment of walleyes was not occurring; by contrast in Lake James Reservoir, North Carolina, where there were no alewives, the walleye population was sustained via natural recruitment. Female walleye tissues were collected and assayed for thiamine (vitamin B1) and fatty acid content. Thiamine pyrophosphate was found to be the predominant form of thiamine in walleye eggs. In 2000, mean total egg thiamine concentrations were similar among Center Hill, Dale Hollow, and Lake James reservoirs (2.13, 3.14, and 2.77 nmol thiamine/g, respectively). Egg thiamine concentration increased as maternal muscle (r 2 = 0.73) and liver (r2 = 0.68) thiamine concentration increased. Walleye egg thiamine does not appear to be connected to poor natural reproduction in Tennessee walleyes. Threadfin shad Dorosoma petenense, which are found in all three reservoirs, had higher thiaminase activity than alewives. Six fatty acids differed among the walleye eggs for the three reservoirs. Two were physiologically important fatty acids, arachidonic acid (20:4[n-6]) and docosahexaenoic acid (22:6[n-3]), which are important eicosanoid precursors involved in the regulation of biological functions, such as immune response and reproduction. ?? Copyright by the American Fisheries Society 2007.

Acoustic telemetry reveals large-scale migration patterns of walleye in Lake Huron

USGS Publications Warehouse

Hayden, Todd A.; Holbrook, Christopher; Fielder, David G.; Vandergoot, Christopher S.; Bergstedt, Roger A.; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron.

Acoustic telemetry reveals large-scale migration patterns of walleye in Lake Huron.

PubMed

Hayden, Todd A; Holbrook, Christopher M; Fielder, David G; Vandergoot, Christopher S; Bergstedt, Roger A; Dettmers, John M; Krueger, Charles C; Cooke, Steven J

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron.

Predation on walleye eggs by fish on reefs in western Lake Erie

USGS Publications Warehouse

Roseman, E.F.; Taylor, W.W.; Hayes, D.B.; Jones, A.L.; Francis, J.T.

2006-01-01

We examined diets of fishes from gillnet and egg pump collections conducted on reefs in western Lake Erie during walleye (Sander vitreus) egg incubation periods from 1994–1999 and 2004 to assess incidence of walleye eggs in fish diets. We collected no potential egg predators in samples taken in 1994 but from 1995–1999 and in 2004 we caught 22 different species of fish on reefs in addition to spawning walleye. In most years, white perch (Morone americana) stomachs contained more walleye eggs than any other species on the reefs averaging 253 eggs per stomach. We also found lower numbers of walleye eggs in the stomachs of channel catfish (Ictalurus punctatus; 53 eggs/stomach), johnny darter (Etheostoma nigrum; 2 eggs/stomach), logperch (Percina caprodes; 10 eggs/stomach), quillback (Carpiodes cyprinus; 184 eggs/stomach), rock bass (Ambloplites rupestris; 3 eggs/stomach), round goby (Neogobius melanostomus; 4 eggs/stomach), sculpin (Cottidae; 21 eggs/stomach), silver chub (Macrhybopsis storeriana; 3 eggs/stomach), spottail shiner (Notropis hudsonius; 14 eggs/stomach), trout-perch (Percopsis omiscomaycus; 30 eggs/stomach), white sucker (Catastomus commersonii; 20 eggs/stomach), and yellow perch (Perca flavescens; 181 eggs/stomach). Similar to other studies of predation on walleye eggs, our results indicate that prolonged incubation periods increase the potential for egg loss due to predation.

Acoustic Telemetry Reveals Large-Scale Migration Patterns of Walleye in Lake Huron

PubMed Central

Hayden, Todd A.; Holbrook, Christopher M.; Fielder, David G.; Vandergoot, Christopher S.; Bergstedt, Roger A.; Dettmers, John M.; Krueger, Charles C.; Cooke, Steven J.

2014-01-01

Fish migration in large freshwater lacustrine systems such as the Laurentian Great Lakes is not well understood. The walleye (Sander vitreus) is an economically and ecologically important native fish species throughout the Great Lakes. In Lake Huron walleye has recently undergone a population expansion as a result of recovery of the primary stock, stemming from changing food web dynamics. During 2011 and 2012, we used acoustic telemetry to document the timing and spatial scale of walleye migration in Lake Huron and Saginaw Bay. Spawning walleye (n = 199) collected from a tributary of Saginaw Bay were implanted with acoustic tags and their migrations were documented using acoustic receivers (n = 140) deployed throughout U.S. nearshore waters of Lake Huron. Three migration pathways were described using multistate mark-recapture models. Models were evaluated using the Akaike Information Criterion. Fish sex did not influence migratory behavior but did affect migration rate and walleye were detected on all acoustic receiver lines. Most (95%) tagged fish migrated downstream from the riverine tagging and release location to Saginaw Bay, and 37% of these fish emigrated from Saginaw Bay into Lake Huron. Remarkably, 8% of walleye that emigrated from Saginaw Bay were detected at the acoustic receiver line located farthest from the release location more than 350 km away. Most (64%) walleye returned to the Saginaw River in 2012, presumably for spawning. Our findings reveal that fish from this stock use virtually the entirety of U.S. nearshore waters of Lake Huron. PMID:25506913

Development of eighteen microsatellite loci in walleye (Sander vitreus)

USGS Publications Warehouse

Coykendall, D. Katharine; Morrison, Cheryl L.; Stott, Wendylee; Springmann, Marcus J.

2014-01-01

A suite of tri- and tetra-nucleotide microsatellite loci were developed for walleye (Sander vitreus) from 454 pyrosequencing data. Eighteen of the 50 primer sets tested amplified consistently in 35 walleye from two lakes on Isle Royale, Lake Superior: Chickenbone Lake and Whittlesey Lake. The loci displayed moderate levels of allelic diversity (average 5.5 alleles/locus) and heterozygosity (average 35.8 %). Levels of genetic diversity were sufficient to produce unique multi-locus genotypes and detect phylogeographic structuring as individuals assigned back to their population of origin. Cross-species amplification within S. canadensis(sauger) was successful for 15 loci, and 11 loci were diagnostic to species. The loci characterized here will be useful for detecting fine-scale spatial structuring, resolving the taxonomic status of Sander species and sub-species, and detecting walleye/sauger hybrids.

Temporal trends of mercury concentrations in Wisconsin walleye (Sander vitreus), 1982-2005.

PubMed

Rasmussen, Paul W; Schrank, Candy S; Campfield, Patrick A

2007-11-01

The Wisconsin Department of Natural Resources has monitored mercury (Hg) in several species of fish since the early 1970s primarily for fish consumption advisory purposes. We selected skin-on fillets of walleye (Sander vitreus) from inland lakes collected over the years 1982-2005 to assess temporal trends of Hg concentrations. While individual lakes are of interest, sample sizes, and unbalanced collections across fish lengths, seasons, or years prevent estimates of temporal trends of walleye Hg concentrations within most lakes. We evaluated temporal trends over all lakes using mixed effects models (3,024 records from 421 lakes). Relationships between Hg concentrations and a suite of lake chemistry, morphometry, and other variables were also explored. Hg concentrations generally increased with walleye length but the relationship varied among lakes. The best-fitting mixed effects models suggested that the overall rate of change in walleye Hg across all lakes in the dataset varied with latitude. Hg in walleye decreased 0.5% per year in northern lakes, increased 0.8% in southern lakes, and remained constant in middle latitude lakes over the period of 1982-2005. Season of collection was also an important predictor variable. Hg concentrations were highest in walleye captured in the spring and lowest in the fall. Other variables such as gender, lake area, and total alkalinity were also important predictors.

Environmental DNA assays for the sister taxa sauger (Sander canadensis) and walleye (Sander vitreus)

PubMed Central

Carim, Kellie J.; Ruggles, Michael; McKelvey, Kevin S.; Young, Michael K.; Schwartz, Michael K.

2017-01-01

Sauger (Sander canadensis) and walleye (S. vitreus) are percid fishes that naturally co-occur throughout much of the eastern United States. The native range of sauger extends into the upper Missouri River drainage where walleye did not historically occur, but have been stocked as a sport fish. Sauger populations have been declining due to habitat loss, fragmentation, and competition with non-native species, such as walleye. To effectively manage sauger populations, it is necessary to identify areas where sauger occur, and particularly where they co-occur with walleye. We developed quantitative PCR assays that can detect sauger and walleye DNA in filtered water samples. Each assay efficiently detected low quantities of target DNA and failed to detect DNA of non-target species with which they commonly co-occur. PMID:28441436

Factors associated with mortality of walleyes and saugers caught in live-release tournaments

USGS Publications Warehouse

Schramm, Harold; Vondracek, Bruce C.; French, William E.; Gerard, Patrick D.

2010-01-01

We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to measure postrelease mortality) was 0–97%. Mortality was generally low in events conducted when water temperatures were below 14°C but substantially higher in events when water temperatures were above 18°C. The mortality of reference fish suggests that capture by electrofishing and minimal handling when the water temperature exceeds 19°C results in high mortality of walleyes that is largely the result of the thermal conditions immediately after capture. Mortality was not related to the size of the tournaments (number of boats), the total number or weight of walleyes weighed in, or the mean number or weight of walleyes weighed in per boat. Mortality was positively related to the depth at which walleyes were caught and the live-well temperature and negatively related to the live-well dissolved oxygen concentration. Surface water temperature was the best predictor of mortality, and models were developed to predict the probability of prerelease and postrelease mortality of 10, 20, and 30% or less of tournament-caught walleyes due to water temperature.

Factors influencing mercury concentrations in walleyes in northern Wisconsin lakes

USGS Publications Warehouse

Wiener, J.G.; Martini, R.E.; Sheffy, T.B.; Glass, G.E.

1990-01-01

The authors examined relations between mercury concentrations in walleyes Stizostedion vitreum and the characteristics of clear-water Wisconsin lakes, which spanned a broad range of pH values (5.0-8.1) and acid- neutralizing capacities (-9 to 1,017 mu eq/L). Total concentrations of mercury in axial muscle tissue of walleyes (total length, 25-56 cm) varied from 0.12 to 1.74 mu g/g wet weight. Concentrations were greatest in fish from the eight lakes with pH less than 7.0; concentrations in these fish equaled or exceeded 0.5 mu g/g in 88% of the samples analyzed and 1.0 mu g/g in 44%. In the five lakes with pH of 7.0 and above, concentrations exceeded 0.5 mu g/g in only 1 of 21 walleyes. Multiple regression revealed that lake pH and total length of fish accounted for 69% of the variation in mercury concentration in walleyes. Regression models with total length and either waterborne calcium or acid-neutralizing capacity as independent variables accounted for 67% of the variation in concentration.

Factors associated with initial mortality of Walleye and Sauger caught in live-release tournaments

USGS Publications Warehouse

Schramm, Harold L.; Vondracek, Bruce C.; French, William E.; Gerard, Patrick D.

2010-01-01

We measured the initial mortality (fish judged nonreleasable at weigh-in), prerelease mortality (fish judged nonreleasable 1–2 h after weigh-in [which includes initial mortality]), and postrelease mortality (fish that died during a 5-d retention in net-pens) in 14 live-release tournaments for walleye Sander vitreus conducted in April–October 2006 and April–July 2007 in lakes and rivers in Michigan, Minnesota, North Dakota, South Dakota, and Wisconsin. Among the 14 events, initial mortality was 0–28%, prerelease mortality was 3–54%, and postrelease mortality was 0–100%; the mortality of reference fish (walleyes ≥31 cm long that were captured by electrofishing and held in net-pens with tournament-caught walleyes to measure postrelease mortality) was 0–97%. Mortality was generally low in events conducted when water temperatures were below 14°C but substantially higher in events when water temperatures were above 18°C. The mortality of reference fish suggests that capture by electrofishing and minimal handling when the water temperature exceeds 19°C results in high mortality of walleyes that is largely the result of the thermal conditions immediately after capture. Mortality was not related to the size of the tournaments (number of boats), the total number or weight of walleyes weighed in, or the mean number or weight of walleyes weighed in per boat. Mortality was positively related to the depth at which walleyes were caught and the live-well temperature and negatively related to the live-well dissolved oxygen concentration. Surface water temperature was the best predictor of mortality, and models were developed to predict the probability of prerelease and postrelease mortality of 10, 20, and 30% or less of tournament-caught walleyes due to water temperature.

A population genetic window into the past and future of the walleye Sander vitreus: relation to historic walleye and the extinct “blue pike” S. v. “glaucus”

PubMed Central

2014-01-01

Background Conserving genetic diversity and local adaptations are management priorities for wild populations of exploited species, which increasingly are subject to climate change, habitat loss, and pollution. These constitute growing concerns for the walleye Sander vitreus, an ecologically and economically valuable North American temperate fish with large Laurentian Great Lakes' fisheries. This study compares genetic diversity and divergence patterns across its widespread native range using mitochondrial (mt) DNA control region sequences and nine nuclear DNA microsatellite (μsat) loci, examining historic and contemporary influences. We analyze the genetic and morphological characters of a putative endemic variant– “blue pike” S. v. “glaucus” –described from Lakes Erie and Ontario, which became extinct. Walleye with turquoise-colored mucus also are evaluated, since some have questioned whether these are related to the “blue pike”. Results Walleye populations are distinguished by considerable genetic divergence (mean FST mtDNA = 0.32 ± 0.01, μsat = 0.13 ± 0.00) and substantial diversity across their range (mean heterozygosity mtDNA = 0.53 ± 0.02, μsat = 0.68 ± 0.03). Southern populations markedly differ, possessing unique haplotypes and alleles, especially the Ohio/New River population that houses the oldest haplotype and has the most pronounced divergence. Northern formerly glaciated populations have greatest diversity in Lake Erie (mean heterozygosity mtDNA = 0.79 ± 0.00, μsat = 0.72 ± 0.01). Genetic diversity was much less in the historic Lake Erie samples from 1923–1949 (mean heterozygosity mtDNA = 0.05 ± 0.01, μsat = 0.47 ± 0.06) than today. The historic “blue pike” had no unique haplotypes/alleles and there is no evidence that it comprised a separate taxon from walleye. Turquoise mucus walleye also show no genetic differentiation from other sympatric walleye and

Influence of Physiochemical and watershed characteristics on mercury concentration in walleye, Sander vitreus, M.

USGS Publications Warehouse

Hayer, Cari-Ann; Chipps, Steven R.; Stone, James J.

2011-01-01

Elevated mercury concentration has been documented in a variety of fish and is a growing concern for human consumption. Here, we explore the influence of physiochemical and watershed attributes on mercury concentration in walleye (Sander vitreus, M.) from natural, glacial lakes in South Dakota. Regression analysis showed that water quality attributes were poor predictors of walleye mercury concentration (R2 = 0.57, p = 0.13). In contrast, models based on watershed features (e.g., lake level changes, watershed slope, agricultural land, wetlands) and local habitat features (i.e., substrate composition, maximum lake depth) explained 81% (p = 0.001) and 80% (p = 0.002) of the variation in walleye mercury concentration. Using an information theoretic approach we evaluated hypotheses related to water quality, physical habitat and watershed features. The best model explaining variation in walleye mercury concentration included local habitat features (Wi = 0.991). These results show that physical habitat and watershed features were better predictors of walleye mercury concentration than water chemistry in glacial lakes of the Northern Great Plains.

The effect of oil sands tailings pond sediments on embryo-larval walleye (Sander vitreus).

PubMed

Raine, J C; Turcotte, D; Tumber, V; Peru, K M; Wang, Z; Yang, C; Headley, J V; Parrott, J L

2017-10-01

Walleye (Sander vitreus) are a commercially important North American fish species that inhabit the Athabasca River. This river flows through the Athabasca oil sands where natural sources of bitumen erode from the McMurray formation. Little information is available on responses of walleye embryos to oil sands tailings pond sediments in a laboratory setting. The current study describes the design and implementation of a daily-renewal bioassay to assess the potential effects of tailings pond sediments from the Athabasca oil sands area on walleye development. Developing walleye embryos were exposed to increasing concentrations of two tailings pond sediments (collected in the Athabasca oil sands area) until the completion of yolk absorption in control fish. Sediments from the tailings pond represent a mixture of polycyclic aromatic hydrocarbons (PAHs) and alkylated PAHs. During the 31 day exposure, the walleye were examined for mortalities, weight, length and developmental abnormalities to provide an initial evaluation of the effects of the oil sands tailings pond sediments. Walleye embryo survival differed between the tailings pond sediments, and survival decreased with increasing sediment concentration. Alkylated PAH content differed between the two tailings pond sediments and lower embryo survival corresponded to higher total and alkylated PAH content. Tailings pond sediment-exposed walleye exhibited a delay in development, as well as increased percentages of larvae with heart and yolk sac edema, and cranial and spinal malformations. These abnormalities in development are often associated with PAH and alkylated PAH exposure. This study provides an exposure design that can be used to assess sediment toxicity to early developmental stages of a fish species not commonly tested in the lab, and lays the groundwork for future studies with this and other difficult-to-culture species. These results offer information on the potential effects of tailings pond sediments

Factors influencing recruitment of walleye and white bass to three distinct early ontogenetic stages

USGS Publications Warehouse

DeBoer, Jason A.; Pope, Kevin L.

2015-01-01

Determining the factors that influence recruitment to sequential ontogenetic stages is critical for understanding recruitment dynamics of fish and for effective management of sportfish, particularly in dynamic and unpredictable environments. We sampled walleye (Sander vitreus) and white bass (Morone chrysops) at 3 ontogenetic stages (age 0 during spring: ‘age-0 larval’; age 0 during autumn: ‘age-0 juvenile’; and age 1 during autumn: ‘age-1 juvenile’) from 3 reservoirs. We developed multiple linear regression models to describe factors influencing age-0 larval, age-0 juvenile and age-1 juvenile walleye and white bass abundance indices. Our models explained 40–80% (68 ± 9%; mean ± SE) and 71%–97% (81 ± 6%) of the variability in catch for walleye and white bass respectively. For walleye, gizzard shad were present in the candidate model sets for all three ontogenetic stages we assessed. For white bass, there was no unifying variable in all three stage-specific candidate model sets, although walleye abundance was present in two of the three white bass candidate model sets. We were able to determine several factors affecting walleye and white bass year-class strength at multiple ontogenetic stages; comprehensive analyses of factors influencing recruitment to multiple early ontogenetic stages are seemingly rare in the literature. Our models demonstrate the interdependency among early ontogenetic stages and the complexities involved with sportfish recruitment.

Variation in annual production of copepods, euphausiids, and juvenile walleye pollock in the southeastern Bering Sea

NASA Astrophysics Data System (ADS)

Sigler, Michael F.; Napp, Jeffrey M.; Stabeno, Phyllis J.; Heintz, Ronald A.; Lomas, Michael W.; Hunt, George L.

2016-12-01

We synthesize recent research on variation in annual production of copepods (Calanus spp.), euphausiids (Thysanoessa spp.), and juvenile walleye pollock (Gadus chalcogrammus) in the southeastern Bering Sea. We reach five conclusions: 1) the timing of the spring bloom is more important than the amount of annual primary production for the transfer of primary to secondary production (i.e., timing matters); 2) summer and fall, not just spring, matter: organisms must maximize energy intake devoted to somatic growth and storage of lipids and minimize energy expenditures during each season; 3) stored lipids are important for the overwinter survival of both zooplankton and age-0 walleye pollock; 4) variation in ice extent and timing of ice retreat affect the spatial distributions of phytoplankton, zooplankton, and age-0 walleye pollock; when these spatial distributions match in late-ice-retreat years, the annual production of copepods, euphausiids, and juvenile walleye pollock often increases (i.e., location matters); 5) if years with late ice retreat, which favor copepod, euphausiid, and juvenile walleye pollock production, occur in succession, top-down control increases. These conclusions help to explain annual variation in production of copepods, euphausiids and juvenile walleye pollock. Copepods and euphausiids often are more abundant in cold years with late ice retreat than in warm years with early ice retreat due to bloom timing and the availability of ice algae during years with late ice retreat. As a consequence, age-0 walleye pollock consume lipid-enriched prey in cold years, better preparing them for their first winter and their overwinter survival is greater. In addition, there is a spatial match of primary production, zooplankton, and age-0 walleye pollock in cold years and a mismatch in warm years.

Relationships among walleye population characteristics and genetic diversity in northern Wisconsin Lakes

USGS Publications Warehouse

Waterhouse, Matthew D.; Sloss, Brian L.; Isermann, Daniel A.

2014-01-01

The maintenance of genetic integrity is an important goal of fisheries management, yet little is known regarding the effects of management actions (e.g., stocking, harvest regulations) on the genetic diversity of many important fish species. Furthermore, relationships between population characteristics and genetic diversity remain poorly understood. We examined relationships among population demographics (abundance, recruitment, sex ratio, and mean age of the breeding population), stocking intensity, and genetic characteristics (heterozygosity, effective number of alleles, allelic richness, Wright's inbreeding coefficient, effective population size [Ne], mean d2 [a measure of inbreeding], mean relatedness, and pairwise population ΦST estimates) for 15 populations of Walleye Sander vitreus in northern Wisconsin. We also tested for potential demographic and genetic influences on Walleye body condition and early growth. Combinations of demographic variables explained 47.1–79.8% of the variation in genetic diversity. Skewed sex ratios contributed to a reduction in Ne and subsequent increases in genetic drift and relatedness among individuals within populations; these factors were correlated to reductions in allelic richness and early growth rate. Levels of inbreeding were negatively related to both age-0 abundance and mean age, suggesting Ne was influenced by recruitment and generational overlap. A negative relationship between the effective number of alleles and body condition suggests stocking affected underlying genetic diversity of recipient populations and the overall productivity of the population. These relationships may result from poor performance of stocked fish, outbreeding depression, or density-dependent factors. An isolation-by-distance pattern of genetic diversity was apparent in nonstocked populations, but was disrupted in stocked populations, suggesting that stocking affected genetic structure. Overall, demographic factors were related to genetic

Diet Overlap and Predation between Smallmouth Bass and Walleye in a North Temperate Lake

Treesearch

Aaron P. Frey; Michael A. Bozek; Clayton J. Edwards; Steve P. Newman

2003-01-01

Walleye (Stizostedion vitreum vitreum) and smallmouth bass (Micropterus dolomieu) diets from Big Crooked Lake, Wisconsin were examined to assess the degree of diet overlap and predation occurring between these species in an attempt to deternine whether walleye influence smallmouth bass recruitment, which is consistently low...

Toxicity of TFM lampricide to early life stages of walleye

USGS Publications Warehouse

Seelye, J.G.; Marking, L.L.; King, E.L.; Hanson, L.H.; Bills, T.D.

1987-01-01

The authors studied the effects of the lampricide 3-trifluoromethyl-4-nitrophenol (TFM) on gametes, newly fertilized eggs, eyed eggs, larvae, and swim-up fry of the walleye Stizostedion vitreum . When gametes from sexually mature walleyes were stripped into solutions of TFM, no effects were observed during the fertilization process at concentrations up to 3.0 mg/L - three times the concentration lethal to 99.9% of larval sea lampreys Petromyzon marinus held 12 h (LC99.9) under the same test conditions. Newly fertilized eggs likewise were unaffected during water hardening by concentrations of TFM that were lethal to sea lamprey ammocoetes. Eyed eggs, sac fry, and swim-up fry yielded LC25 values that were 2.5 to 5 times greater than the 12-h LC99.9 for sea lamprey ammocoetes. The data thus indicated that all of the early life stages of walleyes tested were considerably more resistant than sea lamprey ammocoetes to TFM, and that it is unlikely they would be adversely affected by standard stream treatments to kill sea lamprey ammocoetes.

Competitive interactions between walleye (Sander vitreus) and smallmouth bass (Micropterus dolomieu) under various controlled conditions

USGS Publications Warehouse

Wuellner, M.R.; Graeb, B.D.S.; Willis, D.W.; Galster, B.J.; Selch, T.M.; Chipps, S.R.

2011-01-01

The range of smallmouth bass (Micropterus dolomieu) is expanding northward, creating new interactions with native predators, including walleye (Sander vitreus). We used a series of experiments to investigate competition between walleye (WAE) and smallmouth bass (SMB) at different life stages and light conditions, identified behaviors that allowed one fish to outcompete another, and evaluated whether prey switching mitigated competitive interactions. Juvenile and adult SMB appeared to outcompete WAE when fed during the daytime; neither species dominated when fed near dusk. Attack rates and capture efficiencies of both species were similar with an intra- or interspecific competitor, but SMB often exploited prey before the competitor had a chance to feed (exploitative competition) or displayed agonistic behaviors toward a potential competitor (interference competition). Prey selectivity of WAE or SMB did not differ when by themselves or with a potential competitor. These results indicate that SMB could outcompete WAE under limiting prey conditions due to the aggressive nature of SMB, but resources may be partitioned at least along a temporal scale. ?? 2011 Taylor & Francis.

Selection of prey by walleyes in the Ohio waters of the central basin of Lake Erie, 1985-1987

USGS Publications Warehouse

Wolfert, David R.; Bur, Michael T.

1992-01-01

Walleyes (Stizostedion vitreum vitreum) were collected at five locations in the central basin of Lake Erie in 1985-87. The contents of the fishes' stomachs were examined to identify the species of prey. The seasonal availability of potential prey was determined from sampling with trawl tows. Food electivity indexes for young-of-the-year (YOY) and older walleyes were calculated. Electivity indexes changed monthly in YOY walleyes that consumed mostly YOY gizzard shads (Dorosoma cepedianum) in July and fed moderately on gizzard shads, but more on smelts (Osmerus mordax), in August. In September and October YOY walleyes did not consume YOY white perch (Morone americana). During October, they continued to eat YOY gizzard shads moderately but consumed mostly emerald shiners (Notropis atherinoides). Older walleys were highly partial to YOY gizzard shads, emerald shiners, and smelts and consumed no YOY white perch. The numbers of YOY yellow perch (Perca flavescens) in stomachs were limited. Prey selection by walleyes in the central basin was species-specific irrespective of abundance of prey.

Comparisons between consumption estimates from bioenergetics simulations and field measurements for walleyes from Oneida Lake, New York

USGS Publications Warehouse

Lantry, B.F.; Rudstam, L. G.; Forney, J.L.; VanDeValk, A.J.; Mills, E.L.; Stewart, D.J.; Adams, J.V.

2008-01-01

Daily consumption was estimated from the stomach contents of walleyes Sander vitreus collected weekly from Oneida Lake, New York, during June-October 1975, 1992, 1993, and 1994 for one to four age-groups per year. Field rations were highly variable between weeks, and trends in ration size varied both seasonally and annually. The coefficient of variation for weekly field rations within years and ages ranged from 45% to 97%. Field estimates were compared with simulated consumption from a bioenergetics model. The simulation averages of daily ration deviated from those of the field estimates by -20.1% to +70.3%, with a mean across all simulations of +14.3%. The deviations for each time step were much greater than those for the simulation averages, ranging from -92.8% to +363.6%. A systematic trend in the deviations was observed, the model producing overpredictions at rations less than 3.7% of body weight. Analysis of variance indicated that the deviations were affected by sample year and week but not age. Multiple linear regression using backwards selection procedures and Akaike's information criterion indicated that walleye weight, walleye growth, lake temperature, prey energy density, and the proportion of gizzard shad Dorosoma cepedianum in the diet significantly affected the deviations between simulated and field rations and explained 32% of the variance. ?? Copyright by the American Fisheries Society 2008.

Efficacy of oxytetracycline hydrochloride bath immersion to control external columnaris disease on walleye and channel catfish fingerlings

USGS Publications Warehouse

Rach, J.J.; Johnson, Aaron H.; Rudacille, J.B.; Schleis, S.M.

2008-01-01

The efficacy of oxytetracycline hydrochloride (OTC-HCl) in controlling external columnaris disease caused by Flavobacterium columnare on fingerling walleyes Sander vitreus and channel catfish Ictalurus punctatus was evaluated in two on-site hatchery trials. Microscopic examination of skin scrapings before treatment confirmed the presence of bacteria with characteristics indicative of F. columnare.in separate trials, walleyes (4.4 g) and channel catfish (1.5 g) were exposed to 60-min static bath treatments of OTC-HCl at 0, 10, and 20 mg/L (walleyes) or 0, 10, 20, and 40 mg/L (channel catfish) on three consecutive days. Each treatment regimen was tested in triplicate, and each replicate contained either 30 walleyes or 55 channel catfish. Posttreatment presumptive disease diagnosis indicated that F. columnare was the disease agent causing the mortality in both species of fish. Walleye survival at 10 d posttreatment was greater in the 10- and 20-mg/L treatment groups than in the control group; however, only the 10-mg/L treatment significantly (P < 0.05) increased walleye survival in comparison with controls. In the channel catfish trial, survival at 10 d posttreatment was significantly (P < 0.05) greater for all OTC-HCl treatment groups relative to controls. Results from these trials indicated that OTC-HCl treatments effectively reduced mortality in walleyes (10 mg/L only) and channel catfish infected with F. columnare. ?? Copyright by the American Fisheries Society 2008.

Distribution and population genetics of walleye and sauger

USGS Publications Warehouse

Haponski, Amanda E.; Sloss, Brian L.

2014-01-01

Conserving genetic diversity and local adaptations are management priorities for wild populations of exploited species, which increasingly are subject to climate change, habitat loss, and pollution. These constitute growing concerns for the walleye Sander vitreus, an ecologically and economically valuable North American temperate fish with large Laurentian Great Lakes' fisheries. This study compares genetic diversity and divergence patterns across its widespread native range using mitochondrial (mt) DNA control region sequences and nine nuclear DNA microsatellite (μsat) loci, examining historic and contemporary influences. We analyze the genetic and morphological characters of a putative endemic variant– “blue pike” S. v. “glaucus” –described from Lakes Erie and Ontario, which became extinct. Walleye with turquoise-colored mucus also are evaluated, since some have questioned whether these are related to the “blue pike”.

Spawning site fidelity and apparent annual survival of walleye (Sander vitreus) differ between a Lake Huron and Lake Erie tributary

USGS Publications Warehouse

Hayden, Todd A.; Binder, Thomas; Holbrook, Christopher; Vandergoot, Christopher; Fielder, David G.; Cooke, Steven J.; Dettmers, John M.; Krueger, Charles C.

2018-01-01

Fidelity to spawning habitats can maximise reproductive success of fish by synchronising movements to sites of previous recruitment. To determine the role of reproductive fidelity in structuring walleye Sander vitreus populations in the Laurentian Great Lakes, we used acoustic telemetry combined with Cormack–Jolly–Seber capture–recapture models to estimate spawning site fidelity and apparent annual survival for the Tittabawassee River in Lake Huron and Maumee River in Lake Erie. Walleye in spawning condition were tagged from the Tittabawassee River in Lake Huron and Maumee River in Lake Erie in 2011–2012. Site fidelity and apparent annual survival were estimated from return of individuals to the stream where tagged. Site fidelity estimates were higher in the Tittabawassee River (95%) than the Maumee River (70%) and were not related to sex or fish length at tagging. Apparent annual survival of walleye tagged in the Tittabawassee did not differ among spawning seasons but was higher for female than male walleye and decreased linearly as fish length increased. Apparent annual survival of walleye tagged in the Maumee River did not differ among spawning seasons but was higher for female walleye than male walleye and increased linearly as fish length increased. Greater fidelity of walleye tagged in the Tittabawassee River than walleye tagged in the Maumee River may be related to the close proximity to the Maumee River of other spawning aggregations and multiple spawning sites in Lake Erie. As spawning site fidelity increases, management actions to conserve population structure require an increasing focus on individual stocks.

Residue depletion of oxytetracycline from fillet tissues of northern pike and walleye

USGS Publications Warehouse

Bernardy, Jeffry A.; Vue, Chue; Gaikowski, Mark P.; Stehly, Guy R.; Gingerich, William H.; Moore, Allen

2003-01-01

The broad-spectrum antibacterial drug oxytetracycline (OTC) is used in the U.S. to treat certain diseases in salmonids and catfish. This study was conducted to support an extension of the OTC label to include all cool-water fish species cultured at U.S. public aquaculture facilities by satisfying human food safety requirements. Juvenile northern pike (Esox lucius; mean weight: 117 g) and walleye (Stizostedion vitreum; mean weight: 59 g) were fed OTC-medicated diets near the maximum legal treatment rate (82.7 mg OTC-HCl/kg fish/day for 10 days) and near the lower limit of the water temperature range for most disease outbreaks in these species (14 and 16 °C, respectively). Two trials were conducted simultaneously with northern pike, one using commercially medicated feed and the other using on-site OTC top-coated feed. A third trial was performed with walleye using on-site OTC top-coated feed. Fillet tissues were collected and OTC free base (OTC-base) concentrations were determined by high performance liquid chromatography. The maximum mean OTC-base concentrations in the fillet tissue were 319 ng/g in northern pike (skinless) and 721 ng/g in walleye (skin-on), both well below the current tolerance limit of 2000 ng/g OTC-base. The log-linear loss of OTC-base from the fillet tissues was monophasic, with terminal phase half-lives of 5.9 days in northern pike fed commercial medicated feed, 6.7 days in northern pike fed top-coated feed, and 10.5 days in walleye fed top-coated feed. The data supported a zero withdrawal time in juvenile northern pike and walleye fed OTC at the approved dose level for 10 days at water temperatures down to 14 and 16 °C respectively.

Response of walleye and yellow perch to water-level fluctuations in glacial lakes

USGS Publications Warehouse

Dembkowski, D.J.; Chipps, Steven R.; Blackwell, B. G.

2014-01-01

The influence of water levels on population characteristics of yellow perch, Perca flavescens (Mitchill), and walleye, Sander vitreus (Mitchill), was evaluated across a range of glacial lakes in north-eastern South Dakota, USA. Results showed that natural variation in water levels had an important influence on frequently measured fish population characteristics. Yellow perch abundance was significantly (P<0.10) greater during elevated water levels. Yellow perch size structure, as indexed by the proportional size distribution of quality- and preferred-length fish (PSD and PSD-P), was significantly greater during low-water years, as was walleye PSD. Mean relative weight of walleye increased significantly during high-water periods. The dynamic and unpredictable nature of water-level fluctuations in glacial lakes ultimately adds complexity to management of these systems.

Environmental DNA assays for the sister taxa aauger (Sander canadensis) and walleye (Sander vitreus)

Treesearch

Joseph C. Dysthe; Kellie J. Carim; Michael Ruggles; Kevin S. McKelvey; Michael K. Young; Michael K. Schwartz

2017-01-01

Sauger (Sander canadensis) and walleye (S. vitreus) are percid fishes that naturally co-occur throughout much of the eastern United States. The native range of sauger extends into the upper Missouri River drainage where walleye did not historically occur, but have been stocked as a sport fish. Sauger populations have been declining due to habitat loss, fragmentation,...

Interactions between walleyes and smallmouth bass in a Missouri River reservoir with consideration of the influence of temperature and prey

USGS Publications Warehouse

Wuellner, Melissa R.; Chipps, Steven R.; Willis, David W.; Adams, Wells E.

2010-01-01

Walleyes Sander vitreus are the most popular fish among South Dakota anglers, but smallmouth bass Micropterus dolomieu were introduced to provide new angling opportunities. Some walleye anglers have reported reductions in the quality of walleye fisheries since the introduction of smallmouth bass and attribute this to the consumption of young walleyes by smallmouth bass and competition for shared prey resources. We quantified the diets of walleyes and smallmouth bass in the lower reaches of Lake Sharpe (a Missouri River reservoir), calculated the diet overlap between the two predators, and determined whether they partitioned shared prey based on size. We also quantified walleye diets in the upper reach of the reservoir, which has a different prey base and allowed us to compare the growth rates of walleyes within Lake Sharpe. Age-0 gizzard shad Dorosoma cepedianum composed a substantial proportion of the diets of both predators, regardless of location, for most of the growing season; the patterns in shad vulnerability appeared to drive the observed patterns in diet overlap. Smallmouth bass appeared to consume a smaller size range of gizzard shad than did walleyes, which consumed a wide range. Smallmouth bass consumed Sander spp. in some months, but in very low quantities. Given that global climate change is expected to alter the population and community dynamics in Great Plains reservoirs, we also used a bioenergetics approach to predict the potential effects of limiting prey availability (specifically, the absence of gizzard shad and rainbow smelt Osmerus mordax) and increased water temperatures (as projected from global climate change models) on walleye and smallmouth bass growth. The models indicated that the absence of rainbow smelt from the diets of walleyes in upper Lake Sharpe would reduce growth but that the absence of gizzard shad would have a more marked negative effect on both predators at both locations. The models also indicated that higher

Effect of diet processing method and ingredient substitution on feed characteristics and survival of larval walleye, Sander vitreus

USGS Publications Warehouse

Barrows, F.T.; Lellis, W.A.

2006-01-01

Two methods were developed for the production of larval fish diets. The first method, microextrusion marumerization (MEM), has been tested in laboratory feeding trials for many years and produces particles that are palatable and water stable. The second method, particle-assisted rotational agglomeration (PARA), produced diets that have lower density than diets produced by MEM. Each method was used to produce diets in the 250- to 400- and 400- to 700-??m range and compared with a reference diet (Fry Feed Kyowa* [FFK]) for feeding larval walleye in two experiments. The effect of substituting 4% of the fish meal with freeze-dried artemia fines was also investigated. In the first experiment, 30-d survival was greater (P < 0.05) for fish fed a diet produced by PARA without Artemia (49.1.0%) than for fish fed the same diet produced by MEM (27.6%). The addition of Artemia to a diet produced by MEM did not increase survival of larval walleye. Fish fed the reference diet had 24.4% survival. In the second experiment, there was an effect of both processing method and Artemia supplementation, and an interaction of these effects, on survival. Fish fed a diet produced by PARA without Artemia supplementation had 48.4% survival, and fish fed the same diet produced by MEM had only 19.6% survival. Inclusion of 4% freeze-dried Artemia improved (P < 0.04) survival of fish fed MEM particles but not those fed PARA particles. Fish fed FFK had greater weight gain than fish fed other diets in both experiments. Data indicate that the PARA method of diet processing produces smaller, lower density particles than the MEM process and that diets produced by the PARA process support higher survival of larval walleye with low capital and operating costs. ?? Copyright by the World Aquaculture Society 2006.

Spatial and temporal genetic analysis of Walleyes in the Ohio River

USGS Publications Warehouse

Page, Kevin S.; Zweifela, Richard D.; Stott, Wendylee

2017-01-01

Previous genetic analyses have shown that Walleyes Sander vitreus in the upper Ohio River comprise two distinct genetic strains: (1) fish of Great Lakes origin that were stocked into the Ohio River basin and (2) a remnant native strain (Highlands strain). Resource agencies are developing management strategies to conserve and restore the native strain within the upper reaches of the Ohio River. Hybridization between strains has impacted the genetic integrity of the native strain. To better understand the extent and effects of hybridization on the native strain, we used mitochondrial DNA and microsatellite markers to evaluate the spatial (river sections) and temporal (pre- and poststocking) genetic diversity of Ohio River Walleyes. Contemporary Lake Erie Walleyes and archival museum specimens collected from the Ohio River basin were used for comparison to contemporary Ohio River samples. Although there was evidence of hybridization between strains, most of the genetic diversity within the Ohio River was partitioned by basin of origin (Great Lakes versus the Ohio River), with greater similarity among river sections than between strains within the same section. Results also suggested that the native strain has diverged from historical populations. Furthermore, notable decreases in measures of genetic diversity and increased relatedness among native-strain Walleyes within two sections of the Ohio River may be related to stocking aimed at restoration of the Highlands strain. Our results suggest that although the Highlands strain persists within the Ohio River, it has diverged over time, and managers should consider the potential impacts of future management practices on the genetic diversity of this native strain.

Changes in growth and maturity of walleyes associated with stock rehabilitation in western Lake Erie, 1964-1983

USGS Publications Warehouse

Muth, Kenneth M.; Wolfert, David R.

1986-01-01

The precipitous decline in abundance of walleyes (Stizostedion vitreum vitreum) in western Lake Erie during the 1960s caused major concerns for the future of this resource. Mercury contamination in walleyes in 1970 resulted in a moratorium on commercial fishing in United States and Canadian waters. The opportunity arose for resource agencies to develop a plan for rehabilitation of the walleye stocks, and quota management for walleyes was begun in 1976. After 8 years, the resource had recovered dramatically and the estimated standing stock in 1983 was more than three times that in 1976. In the mid-1970s, however, certain detrimental changes suggested that self-regulatory mechanisms were occurring. The growth rate declined gradually but rather consistently. Growth changes were most evident for young-of-the-year (YOY), yearlings, and 2-year-old fish, which usually constituted more than 80% of the standing stock in 1976-1983. Average lengths of YOY fish decreased by nearly 50 mm (from about 240 mm in 1961 to 190 mm in 1983). Average lengths and weights of yearling and older fish began to decline after 1975 and decreased markedly after 1980. Historically, growth of walleyes in western Lake Erie exceeded that reported for many walleye populations in other waters. Another sign of self-regulation was an increasing delay in the onset of maturity. Most (usually more than 90%) of the yearling males were sexually mature each fall before 1979, but this percentage decreased to only 32 by fall 1983. Usually 80% or more of the age-II females were mature each fall during the 1960s and early 1970s, but this percentage decreased rapidly to only 7 by fall 1983. Prey fish populations declined somewhat in the early 1980s, and their ability to sustain the high abundance of walleyes is a great concern to resource managers.

Selectivity evaluation for two experimental gill-net configurations used to sample Lake Erie walleyes

USGS Publications Warehouse

Vandergoot, Christopher S.; Kocovsky, Patrick M.; Brenden, Travis O.; Liu, Weihai

2011-01-01

We used length frequencies of captured walleyes Sander vitreus to indirectly estimate and compare selectivity between two experimental gill-net configurations used to sample fish in Lake Erie: (1) a multifilament configuration currently used by the Ohio Department of Natural Resources (ODNR) with stretched-measure mesh sizes ranging from 51 to 127 mm and a constant filament diameter (0.37 mm); and (2) a monofilament configuration with mesh sizes ranging from 38 to 178 mm and varying filament diameter (range = 0.20–0.33 mm). Paired sampling with the two configurations revealed that the catch of walleyes smaller than 250 mm and larger than 600 mm was greater in the monofilament configuration than in the multifilament configuration, but the catch of 250–600-mm fish was greater in the multifilament configuration. Binormal selectivity functions yielded the best fit to observed walleye catches for both gill-net configurations based on model deviances. Incorporation of deviation terms in the binormal selectivity functions (i.e., to relax the assumption of geometric similarity) further improved the fit to observed catches. The final fitted selectivity functions produced results similar to those from the length-based catch comparisons: the monofilament configuration had greater selectivity for small and large walleyes and the multifilament configuration had greater selectivity for mid-sized walleyes. Computer simulations that incorporated the fitted binormal selectivity functions indicated that both nets were likely to result in some bias in age composition estimates and that the degree of bias would ultimately be determined by the underlying condition, mortality rate, and growth rate of the Lake Erie walleye population. Before the ODNR switches its survey gear, additional comparisons of the different gill-net configurations, such as fishing the net pairs across a greater range of depths and at more locations in the lake, should be conducted to maintain congruence in

Quantity, structure, and habitat selection of natural spawning reefs by walleyes in a north temperate lake: A multiscale analysis

USGS Publications Warehouse

Raabe, Joshua K.; Bozek, Michael A.

2012-01-01

Spawning habitat, the cornerstone of self-sustaining, naturally reproducing walleyeSander vitreus populations, has received limited quantitative research. Our goal was to quantitatively describe the structure and quantity of natural walleye spawning habitat and evaluate potential selection of habitat in Big Crooked Lake, Wisconsin. In 2004 and 2005, we located and delineated walleye egg deposition polygons through visual snorkel and scuba surveys. We also delineated recently deposited, adhesive egg patches daily along one spawning reef in 2005. To determine habitat selection, we quantified and compared spawning and lakewide available habitat at different scales. In both years, walleyes used similar spawning habitat, including three geomorphic types: linear shorelines, a point bar, and an island. Walleyes used only 14% of the entire lake shoreline and 39% of the shoreline comprised of gravel (6.4–76.0 mm), cobble (76.1–149.9 mm), or coarser substrates for spawning in 2005, indicating selection of specific spawning habitat. Lakewide, walleyes spawned close to shore (outer egg deposition polygon boundary mean distance = 2.7 m), in shallow water (outer egg deposition polygon boundary mean depth = 0.3 m), and over gravel substrate (percent coverage mean = 64.3) having low embeddedness (mean = 1.30). Our best nearshore (0–13-m) resource selection function predicted an increase in the relative probability of egg deposition with the increasing abundance of gravel, cobble, and rubble (150.0–303.9-mm) substrates and a decrease with increasing distance from shore and water depth (89.9% overall correct classification). Adhesive egg patches confirmed that walleyes actively chose nearshore, shallow-water, and coarse-substrate spawning habitat. The quantitative habitat information and predictive models will assist biologists in developing walleye spawning reef protection strategies and potentially aid in designing and evaluating artificial spawning reefs.

Residue depletion of oxytetracycline from fillet tissues of northern pike and walleye

USGS Publications Warehouse

Bernardy, J.A.; Vue, C.; Gaikowski, M.P.; Stehly, G.R.; Gingerich, W.H.; Moore, A.

2003-01-01

Iowa Department of Natural Resources Fisheries Bureau,Rathbun Research,15053 Hatchery Place,Moravia, IA 52571-8933,USA The broad-spectrum antibacterial drug oxytetracycline (OTC) is used in the U.S. to treat certain diseases in salmonids and catfish. This study was conducted to support an extension of the OTC label to include all cool-water fish species cultured at U.S. public aquaculture facilities by satisfying human food safety requirements. Juvenile northern pike (Esox lucius; mean weight: 117 g) and walleye (Stizostedion vitreum; mean weight: 59 g) were fed OTC-medicated diets near the maximum legal treatment rate (82.7 mg OTC-HCl/kg fish/day for 10 days) and near the lower limit of the water temperature range for most disease outbreaks in these species (14 and 16??C, respectively). Two trials were conducted simultaneously with northern pike, one using commercially medicated feed and the other using on-site OTC top-coated feed. A third trial was performed with walleye using on-site OTC top-coated feed. Fillet tissues were collected and OTC free base (OTC-base) concentrations were determined by high performance liquid chromatography. The maximum mean OTC-base concentrations in the fillet tissue were 319 ng/g in northern pike (skinless) and 721 ng/g in walleye (skin-on), both well below the current tolerance limit of 2000 ng/g OTC-base. The log-linear loss of OTC-base from the fillet tissues was monophasic, with terminal phase half-lives of 5.9 days in northern pike fed commercial medicated feed, 6.7 days in northern pike fed top-coated feed, and 10.5 days in walleye fed top-coated feed. The data supported a zero withdrawal time in juvenile northern pike and walleye fed OTC at the approved dose level for 10 days at water temperatures down to 14 and 16??C respectively. Published by Elsevier Science B.V.

Interannual and Spatial Variability in Maturity of Walleye Pollock Gadus chalcogrammus and Implications for Spawning Stock Biomass Estimates in the Gulf of Alaska

PubMed Central

Kruse, Gordon H.; Dorn, Martin W.

2016-01-01

Catch quotas for walleye pollock Gadus chalcogrammus, the dominant species in the groundfish fishery off Alaska, are set by applying harvest control rules to annual estimates of spawning stock biomass (SSB) from age-structured stock assessments. Adult walleye pollock abundance and maturity status have been monitored in early spring in Shelikof Strait in the Gulf of Alaska for almost three decades. The sampling strategy for maturity status is largely characterized as targeted, albeit opportunistic, sampling of trawl tows made during hydroacoustic surveys. Trawl sampling during pre-spawning biomass surveys, which do not adequately account for spatial patterns in the distribution of immature and mature fish, can bias estimated maturity ogives from which SSB is calculated. Utilizing these maturity data, we developed mixed-effects generalized additive models to examine spatial and temporal patterns in walleye pollock maturity and the influence of these patterns on estimates of SSB. Current stock assessment practice is to estimate SSB as the product of annual estimates of numbers at age, weight at age, and mean maturity at age for 1983-present. In practice, we found this strategy to be conservative for a time period from 2003–2013 as, on average, it underestimates SSB by a 4.7 to 11.9% difference when compared to our estimates of SSB that account for spatial structure or both temporal and spatial structure. Inclusion of spatially explicit information for walleye pollock maturity has implications for understanding stock reproductive biology and thus the setting of sustainable harvest rates used to manage this valuable fishery. PMID:27736982

A biophysical model of Lake Erie walleye (Sander vitreus) explains interannual variations in recruitment

USGS Publications Warehouse

Zhao, Yingming; Jones, Michael L.; Shuter, Brian J.; Roseman, Edward F.

2009-01-01

We used a three-dimensional coupled hydrodynamic-ecological model to investigate how lake currents can affect walleye (Sander vitreus) recruitment in western Lake Erie. Four years were selected based on a fall recruitment index: two high recruitment years (i.e., 1996 and 1999) and two low recruitment years (i.e., 1995 and 1998). During the low recruitment years, the model predicted that (i) walleye spawning grounds experienced destructive bottom currents capable of dislodging eggs from suitable habitats (reefs) to unsuitable habitats (i.e., muddy bottom), and (ii) the majority of newly hatched larvae were transported away from the known suitable nursery grounds at the start of their first feeding. Conversely, during two high recruitment years, predicted bottom currents at the spawning grounds were relatively weak, and the predicted movement of newly hatched larvae was toward suitable nursery grounds. Thus, low disturbance-based egg mortality and a temporal and spatial match between walleye first feeding larvae and their food resources were predicted for the two high recruitment years, and high egg mortality plus a mismatch of larvae with their food resources was predicted for the two low recruitment years. In general, mild westerly or southwesterly winds during the spawning-nursery period should favour walleye recruitment in the lake.

Spatial heterogeneity of mercury bioaccumulation by walleye in Franklin D. Roosevelt Lake and the upper Columbia River, Washington

USGS Publications Warehouse

Munn, M.D.; Short, T.M.

1997-01-01

We examined mercury concentration in muscle of walleye Stizostedion vitreum from three reaches in Franklin D. Roosevelt Lake, a reservoir on the Columbia River, and from the upper Columbia River, an area contaminated by wastes from metal mining and associated processing activities. Our objectives were to describe the relation between size and age of walleyes and tissue concentrations of mercury and to compare mercury concentrations within a single reservoir system among spatially segregated cohorts. Overall, mercury concentrations in walleye muscle ranged from 0.11 to 0.44 mg/kg (wet weight) and were positively correlated with age, weight, and length of the fish. Mercury concentrations in walleyes varied spatially within the system; the highest concentrations were in fish from the lower and middle reaches of the reservoir. Condition factor of age-2+ fish was inversely related to tissue concentration of mercury and was lower in fish from the lower and middle reaches than in fish from the upper reach. Spatial patterns in condition factor and mercury in walleyes were unrelated to concentrations of total mercury in surficial bed sediments, which ranged from less than 0.05 to 2.8 mg/kg (dry weight). We suggest that the observed spatial differences in the concentrations of mercury in walleyes may be attributed to the fish preferring to spawn and forage in specific areas where the bioavailability of mercury varies due to local differences in the physical and chemical environment.

Walleye age estimation using otoliths and dorsal spines: Preparation techniques and sampling guidelines based on sex and total length

USGS Publications Warehouse

Dembkowski, Daniel J.; Isermann, Daniel A.; Koenigs, Ryan P.

2017-01-01

We used dorsal spines and otoliths from 735 Walleye Sander vitreus collected from 35 Wisconsin water bodies to evaluate whether 1) otolith and dorsal spine cross sections provided age estimates similar to simpler methods of preparation (e.g., whole otoliths and dorsal spines, cracked otoliths); and 2) between-reader precision and differences between spine and otolith ages varied in relation to total length (TL), sex, and growth rate. Ages estimated from structures prepared using simpler techniques were generally similar to ages estimated using thin sections of dorsal spines and otoliths, suggesting that, in some instances, much of the additional processing time and specialized equipment associated with thin sectioning could be avoided. Overall, between-reader precision was higher for sectioned otoliths (mean coefficient of variation [CV] = 3.28%; standard error [SE] = 0.33%) than for sectioned dorsal spines (mean CV = 9.20%; SE = 0.56%). When using sectioned otoliths for age assignment, between-reader precision did not vary between sexes or growth categories (i.e., fast, moderate, slow), but between-reader precision was higher for females than males when using sectioned dorsal spines. Dorsal spines were generally effective at replicating otolith ages for male Walleye <450 mm TL and female Walleye <600 mm TL, suggesting that dorsal spines can be used to estimate ages for male Walleye <450 mm TL and female Walleye <600 mm TL. If sex is unknown, we suggest dorsal spines be used to estimate ages for Walleye <450 mm TL, but that otoliths be used for fish >450 mm TL. Our results provide useful guidance on structure and preparation technique selection for Walleye age estimation, thereby allowing biologists to develop sampling guidelines that could be implemented using information that is always (TL) or often (sex) available at the time of fish collection.

Fall diets of red-breasted merganser (Mergus serrator) and walleye (Sander vitreus) in Sandusky Bay and adjacent waters of western Lake Erie

USGS Publications Warehouse

Bur, M.T.; Stapanian, M.A.; Bernhardt, G.; Turner, M.W.

2008-01-01

Although published studies indicate the contrary, there is concern among many sport anglers that migrating red-breasted mergansers (Mergus serrator) and other waterbirds pose a competitive threat to sport fish species such as walleye (Sander vitreus) in Lake Erie. We quantified the diet of autumn-migrant mergansers and walleye during 1998-2000 in Sandusky Bay and adjacent waters of western Lake Erie. We hypothesized that the diets of both predators would be similar in species composition, but because of different foraging ecologies their diets would differ markedly in size of prey consumed. In addition to predator samples, we used trawl data from the same general area as an index of prey availability. We found that mergansers fed almost exclusively on fish (nine species). Gizzard shad (Dorosoma cepedianum), emerald shiner (Notropis atherinoides) and round goby (Neogobius melanostomus) were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Walleye fed exclusively on fish: gizzard shad, alewife (Alosa psuedoharengus) and emerald shiner were consumed in the greatest numbers, most frequently and comprised the greatest biomass. Diet overlap between mergansers and walleye was 67% by weight and 66% by species frequency. Mean total lengths of gizzard shad, emerald shiner and round goby found in walleye stomachs exceeded those captured in trawls by 47%, on average. Mean total lengths of gizzard shad, emerald shiner and round goby were greater in walleye stomachs than in merganser stomachs. Mean total lengths of emerald shiner and round goby were less in merganser stomachs than in trawls. Our results suggest that although the diets of walleye and mergansers overlapped considerably, mergansers generally consumed smaller fish than walleye. Given the abundance and diversity of prey species available, and the transient nature of mergansers on Lake Erie during migration, we conclude that competition for food between these species is minimal.

Effects of recruitment, growth, and exploitation on walleye population size structure in northern Wisconsin lakes

USGS Publications Warehouse

Hansen, Michael J.; Nate, Nancy A.

2014-01-01

We evaluated the dynamics of walleye Sander vitreus population size structure, as indexed by the proportional size distribution (PSD) of quality-length fish, in Escanaba Lake during 1967–2003 and in 204 other lakes in northern Wisconsin during 1990–2011. We estimated PSD from angler-caught walleyes in Escanaba Lake and from spring electrofishing in 204 other lakes, and then related PSD to annual estimates of recruitment to age-3, length at age 3, and annual angling exploitation rate. In Escanaba Lake during 1967–2003, annual estimates of PSD were highly dynamic, growth (positively) explained 35% of PSD variation, recruitment explained only 3% of PSD variation, and exploitation explained only 7% of PSD variation. In 204 other northern Wisconsin lakes during 1990–2011, PSD varied widely among lakes, recruitment (negatively) explained 29% of PSD variation, growth (positively) explained 21% of PSD variation, and exploitation explained only 4% of PSD variation. We conclude that population size structure was most strongly driven by recruitment and growth, rather than exploitation, in northern Wisconsin walleye populations. Studies of other species over wide spatial and temporal ranges of recruitment, growth, and mortality are needed to determine which dynamic rate most strongly influences population size structure of other species. Our findings indicate a need to be cautious about assuming exploitation is a strong driver of walleye population size structure.

Environmental factors affecting the strength of walleye (Stizostedion vitreum vitreum) year-classes in western Lake Erie, 1960-70

USGS Publications Warehouse

Busch, Wolf-Dieter N.; Scholl, Russell L.; Hartman, Wilbur L.

1975-01-01

Commercial production of walleyes (Stizostedion vitreum vitreum) from western Lake Erie declined from 5.9 million pounds in 1956 to 140,000 pounds by 1969. Since 1956, marked irregularity in year-class success has developed. Only four year-classes were considered good during 1959–70. The rate and regularity of water warming during the spring spawning and incubation periods in 1960–70 had a positive effect on the density of egg deposits and the resulting year-class strength. Rates of warming were not themselves detrimental, but rather the extended length of the incubation period in cool springs increased the exposure of eggs to such negative influences as dislodgment from the spawning reefs by strong current action generated by spring storms, or siltation and low oxygen tensions. The annual brood stock size had much less influence on year-class strength than did water temperature. Reproductive success was unrelated to fluctuations in size of suitable reef spawning area caused by changes in water level. Apparently the usable spawning area at any water level is more than adequate to serve the limited walleye brood stocks.

Identification, movement, growth, mortality, and exploitation of walleye stocks in Lake St. Clair and the western basin of Lake Erie

USGS Publications Warehouse

Haas, Robert C.; Fabrizio, Mary C.; Todd, Thomas N.

1988-01-01

The harvest of walleye by sport and commercial fisheries in lakes St. Clair and Erie is under a cooperative management program involving several states and two countries. In this report we present the results of a long-term tag-recapture study as well as corroborative evidence of stock discreteness fromstudies of population characteristics such as growth and allelic frequencies of walleye in these waters. Walleye were tagged in the spring from 1975-87 in lakes St. Clair and Erie. Tag-recapture data indicate a general tendency for walleye to move northward after tagging. Walleye tagged in Lake St. Clair had higher recovery rates and lower survival rates than walleye tagged in Lake Erie. A reward-tag study in Lake St. Clair provided an estimate of a non-reporting rate of approximately 33% which is comparable to rates in the literature for other species. Data from the Ontario commercial (gill-net) fishery, Michigan Department of Natural Resources trap-net surveys, and sport fisheries from western Lake Erie and Lake St. Clair were analyzed with a catch-at-age model which permitted estimation of population abundance (12.2 to 34.5 million fish), fishing mortality rate (0.19 to 0.37), and annual survival rate (0.57 to 0.68). It appears that exploitation rates for the sport fishery in the western basin exceeded those of the commercial fishery from 1978-82. In recent years (1983-87), exploitation rates were comparable. Average abundance and catch of walleye in the western basin were 12.2 million and 3.4 million fish in 1978-82; average abundance and catch in 1983-87 were 34.5 and 5.2 million fish. We found good agreement between the estimate of the harvest from creel surveys and that from the catch-at-age model for Lake Erie. Walleye abundance and harvest in Lake St. Clair were 10% of the values for the western basin of Lake Erie. Two discrete stocks were delineated be analysis of allelic frequencies of samples from Lake St. Clair and Lake Erie spawning populations. These

Development of a stock-recruitment model and assessment of biological reference points for the Lake Erie walleye fishery

USGS Publications Warehouse

Zhao, Yingming; Kocovsky, Patrick M.; Madenjian, Charles P.

2013-01-01

We developed an updated stock–recruitment relationship for Lake Erie Walleye Sander vitreus using the Akaike information criterion model selection approach. Our best stock–recruitment relationship was a Ricker spawner–recruit function to which spring warming rate was added as an environmental variable, and this regression model explained 39% of the variability in Walleye recruitment over the 1978 through 2006 year-classes. Thus, most of the variability in Lake Erie Walleye recruitment appeared to be attributable to factors other than spawning stock size and spring warming rate. The abundance of age-0 Gizzard Shad Dorosoma cepedianum, which was an important term in previous models, may still be an important factor for Walleye recruitment, but poorer ability to monitor Gizzard Shad since the late 1990s could have led to that term failing to appear in our best model. Secondly, we used numerical simulation to demonstrate how to use the stock recruitment relationship to characterize the population dynamics (such as stable age structure, carrying capacity, and maximum sustainable yield) and some biological reference points (such as fishing rates at different important biomass or harvest levels) for an age-structured population in a deterministic way.

The movement, heterogeneity, and rate of exploitation of walleyes in northern Green Bay, Lake Michigan, as determined by tagging

USGS Publications Warehouse

Crowe, Walter R.; Karvelis, Ernest G.; Joeris, Leonard S.

1963-01-01

The Michigan waters of northern Green Bay are an important center for commercial and sport fishing. This 400-square-mile area has supported a commercial fishery for many years but the development of the intensive sport fishery is more recent, mostly since World War II. The commercial fishery is based on several species, whereas anglers are particularly interested in the walleye, Stizostedion v. vitreum. Broad objectives of tagging studies initiated in September 1957 were to obtain information on the heterogeneity, movement, and exploitation of the walleye population of northern Green Bay. The statistical data on the commercial fishery are very sound but other information on the Green Bay walleye has been sketchy.

Rates of consumption of juvenile salmonids and alternative pray fish by northern squawfish, walleyes, smallmouth bass, and channel catfish in John Day Reservoir, Columbia River

USGS Publications Warehouse

Vigg, Steven; Poe, Thomas P.; Prendergast , Linda A.; Hansel, Hal C.

1991-01-01

Adult northern squawfish Ptychocheilus oregonensis, walleyes Stizostedion vitreum, smallmouth bass Micropterus dolomieu, and channel catfish Ictalurus punctatus were sampled from four regions of John Day Reservoir from April to August 1983–1986 to quantify their consumption of 13 species of prey fish, particularly seaward-migrating juvenile Pacific salmon and steelhead (Oncorhynchus spp.). Consumption rates were estimated from field data on stomach contents and digestion rate relations determined in previous investigations. For each predator, consumption rates varied by reservoir area, month, time of day, and predator size or age. The greatest daily consumption of salmonids by northern squawfish and channel catfish (0.7 and 0.5 prey/predator) occurred in the upper end of the reservoir below McNary Dam. Greatest daily predation by walleyes (0.2 prey/predator) and smallmouth bass (0.04) occurred in the middle and lower reservoir. Consumption rates of all predators were highest in July, concurrent with maximum temperature and abundance of juvenile salmonids. Feeding by the predators tended to peak after dawn (0600–1200 hours) and near midnight (2000–2400). Northern squawfish below McNary Dam exhibited this pattern, but fed mainly in the morning hours down-reservoir. The daily ration of total prey fish was highest for northern squawfish over 451 mm fork length (> 13.2 mg/g predator), for walleyes 201–250 mm (42.5 mg/g), for smallmouth bass 176–200 mm (30.4 mg/g), and for channel catfish 401–450 mm (17.1 mg/g). Averaged over all predator sizes and sampling months (April–August), the total daily ration (fish plus other prey) of smallmouth bass (28.7 mg/ g) was about twice that of channel catfish (12.6), northern squawfish (14.1), and walleyes (14.2). However, northern squawfish was clearly the major predator on juvenile salmonids.

Do water level fluctuations influence production of walleye and yellow perch young-of-the-year in large northern lakes?

USGS Publications Warehouse

Larson, James H.; Staples, David F.; Maki, Ryan P.; Vallazza, Jon M.; Knights, Brent C.; Peterson, Kevin E.

2016-01-01

Many ecological processes depend on the regular rise and fall of water levels (WLs), and artificial manipulations to WL regimes can impair important ecosystem services. Previous research has suggested that differences in WL between late summer and early spring may alter the suitability of shoals used by Walleyes Sander vitreus for spawning. Other species, such as the Yellow Perch Perca flavescens, are unlikely to be affected in the same way by WL fluctuations because their spawning requirements are quite different. We used 11–23 years of data from six northern Minnesota lakes to assess the effects of WL fluctuations on the abundances of young-of-the-year (age-0) Walleyes and Yellow Perch. In two lakes (Rainy Lake and Lake Kabetogama), a change in WL management occurred in 2000, after which these lakes saw increased age-0 Walleye abundance, while the other study lakes experienced decreases or no change. Rainy Lake and Lake Kabetogama also had increases in age-0 Yellow Perch, but another study lake did also. We used partial least-squares regression to assess whether WL metrics were associated with variation in age-0 Walleye and Yellow Perch abundances, but WL metrics were seldom associated with age-0 abundance for either species. Our analysis suggested a potential influence of WL regulation on age-0 Walleye abundance, but we found no evidence that early spring access to spawning shoals was the mechanism by which this occurred.

Fecundity of walleyes in western Lake Erie, 1966 and 1990-91

USGS Publications Warehouse

Muth, Kenneth M.; Ickes, Brian S.

1993-01-01

Ovaries were collected from walleyes (Stizostedion vitreum vitreum) in western Lake Erie just prior to spawning in 1990 and 1991 to determine current fecundity. Results were compared with fecundity determined in 1966 prior to stock rehabilitation when walleye abundance was lower and fish size at age was greater. Fecundity estimates determined from 121 fish aged 3-10 ranged from 53,000 to 426,000 eggs per female. Increases in egg production correlated with increases in length and weight, and weight accounting for most of the variability. In 1990-91 the mean egg production of the dominant age groups of spawners (ages 4 to 8) was approximately 25% lower than fishes of similar age in 1966. The mean egg diameter in 1990-91 (1.63 mm) was not related to the size or age of the fish and was not significantly smaller than the egg diameter in 1966 (1.72 mm).

Comparing catch orientation among Minnesota walleye, northern pike, and bass anglers

USGS Publications Warehouse

Schroeder, Susan A.; Fulton, David C.

2013-01-01

We compared the catch orientations of Minnesota walleye (Sander vitreus), northern pike (Esox lucius), largemouth bass (Micropterus salmoides), and smallmouth bass (Micropterus dolomieu) anglers. Results were derived from 2009, 2010, and 2012 surveys of anglers targeting these different species. Consistent with previous research, we identified four dimensions of anglers’ catch orientation: (a) catching something, (b) catching big fish, (c) catching many fish, and (d) keeping fish. Walleye anglers were the most motivated to keep fish, while northern pike anglers were more oriented toward catching big fish. Largemouth bass anglers, and to a lesser extent smallmouth bass anglers, were also oriented toward catching big fish. Bass anglers reported the lowest interest in keeping fish. An orientation to keep fish was negatively related to more restrictive management actions, regardless of species. A stronger orientation to catch big fish was associated with support for increased harvest restrictions only for northern pike and smallmouth bass.

Walleye Sander vitreus performance, water quality, and waste production in replicated recirculation aquaculture systems when feeding a low phosphorus diet without fishmeal versus a traditional fishmeal-based diet

USDA-ARS?s Scientific Manuscript database

Walleye Sander vitreus is a popular sport- and food-fish in areas surrounding the Great Lakes. Walleye are mainly provided as food-fish by limited capture fisheries, but have potential for profitable production to market-size in recirculation aquaculture systems (RAS). Walleye are piscivorous with a...

Histopathology of repeated, intermittent exposure of chloramine-T to walleye (Sander vitreum) and (Ictalurus punctalus) channel catfish

USGS Publications Warehouse

Gaikowski, M.P.; Densmore, Christine L.; Blazer, V.S.

2009-01-01

Chloramine-T (Cl-T) has been used safely and effectively to control bacterial gill disease in salmonids at a maximum exposure regimen of up to four consecutive, once-daily exposures administered for 60??min at 20??mg/L. However, data to document safe treatment concentrations of Cl-T are lacking for freshwater-reared fish other than salmonids. We report the histopathology resultant from the administration of 12 consecutive, once-daily, 180-min static immersion baths of 0, 20, 50, or 80??mg Cl-T/L to walleye (20????C) and channel catfish (27????C). Twelve fish of each species were euthanized immediately before the first exposure (initial controls) and then after the twelfth exposure and 7 and 14??days after the twelfth exposure. Only initial controls and fish euthanized immediately after the twelfth exposure were processed for histological review because of the general lack of exposure-related lesions in exposed fish. The only exposure-related histological changes were in the spleen where significantly greater erythrocyte swelling and necrosis was observed in channel catfish exposed at 80??mg/L relative to exposure at 0??mg/L; similar histological changes were insignificant for walleye, though there appeared to be a shift in the general category of histological change with degenerative changes (necrosis, etc.) observed following exposure at 50 or 80??mg/L compared to the inflammatory and hemodynamic changes (congestion, leukocyte infiltrate, etc.) observed in walleye exposed at 0 or 20??mg/L. The only significant change in peripheral blood cytology was that walleye fingerlings exposed at 80??mg/L had significantly fewer mature red blood cells and significantly more immature red blood cells per oil-immersion field than controls. The histopathological changes observed following exposure to Cl-T under an exaggerated exposure regimen suggest that walleye or channel catfish therapeutically exposed to Cl-T will not have treatment-related histological changes.

Efficacy of hydrogen peroxide in controlling mortality associated with saprolegniasis on walleye, white sucker, and paddlefish eggs

USGS Publications Warehouse

Gaikowski, M.P.; Rach, J.J.; Drobish, M.; Hamilton, J.; Harder, T.; Lee, L.A.; Moen, C.; Moore, A.

2003-01-01

The efficacy of hydrogen peroxide in controlling saprolegniasis on eggs of walleye Stizostedion vitreum, white sucker Catostomus commersoni, and paddlefish Polyodon spathula was evaluated at four private, state, and federal production hatcheries participating in an Investigational New Animal Drug efficacy study (experiment 1; walleyes) and in a laboratory-based miniature egg jar incubation system (experiment 2; walleyes, white suckers, and paddlefish). Naturally occurring fungal infestations (saprolegniasis) were observed on eggs in both experiments. Confirmatory diagnosis of infested eggs from one hatchery in experiment 1 identified the pathogen as Saprolegnia parasitica. During experiment 1, eggs were treated daily for 15 min with either 0, 500, or 750 mg/L of hydrogen peroxide, and one trial compared a 500-mg/L hydrogen peroxide treatment with a formalin treatment at 1,667 mg/L. Saprolegniasis infestation was observed in control egg jars, whereas treatment with either formalin or hydrogen peroxide virtually eliminated the infestation. Hydrogen peroxide treatments of 500 mg/L either increased egg hatch or were as effective as physical removal of infested eggs in controlling mortality. Although treatment with formalin at 1,667 mg/L significantly increased the percent eye-up of walleye eggs compared with that of those treated with hydrogen peroxide at 500 mg/L, the difference was only 1.9-2.6%. In experiment 2, noneyed eggs were treated for 15 min every other day with 0, 283, 565, or 1,130 mg/L of hydrogen peroxide until the viable eggs hatched. Saprolegniasis infestation engulfed most control eggs, whereas infestation of treated eggs was either reduced or not visible. Hydrogen peroxide significantly increased egg hatch for all three species tested in experiment 2. Although hydrogen peroxide treatments as low as 283 mg/L significantly increased walleye and white sucker hatch, treatments between 500 and 1,000 mg/L are more likely to be effective in production egg

Dynamics of the recovery of the western Lake Erie walleye (Stizostedion vitreum vitreum) stock

USGS Publications Warehouse

Hatch, Richard W.; Nepszy, Stephen J.; Muth, Kenneth M.; Baker, Carl T.

1987-01-01

After its 1957 collapse under intensive fishing and environmental stresses, the walleye (Stizostedion vitreum vitreum) stock of western Lake Erie remained low throughout the 1960s. A moratorium on both sport and commercial fishing, resulting from the 1970 discovery of mercury concentrations in walleye flesh, provided an opportunity for the development of an international interagency management plan. The quota management plan developed depended on sequential projection of the fishable stock on the basis of estimated annual recruitment and reports of total withdrawals from the stock. The fishery reopened gradually and quota management (including allocation among jurisdictions) was implemented in 1976. The stock, which had been gradually increasing as a result of relatively strong year-classes produced in 1970, 1972, and 1974, responded well to limited exploitation and produced a record year-class in 1977. Quotas were exceeded in 1978-80, but the stock continued to improve to the extent that the recommended rate of exploitation was increased in 1980 and again in 1981. As the population expanded, growth began to decline; the decline became apparent in young-of-the-year in the early 1970s and in older walleyes in the late 1970s. This trend toward progressively slower growth, which continued in the 1977 and subsequent year-classes, was accompanied by an increase in length at sexual maturity and a decrease in the percentage of female walleyes reaching sexual maturity at age III. As a net result of these changes, the proportion of mature females in the stock (an index of stock fecundity) decreased slightly during the interval 1975-84, while the estimated biomass of the standing stock rose from 9 000 to nearly 26 000 t. Both sport and commercial catches increased markedly after 1980 in Lake Erie's central basin.

Relationships among condition indices, feeding and growth of walleye in Lake Erie

USGS Publications Warehouse

Hartman, K.J.; Margraf, F.J.

2006-01-01

Condition indices are often used as surrogates of fish health, growth, and feeding and to compare ecological well-being among fish populations. In an effort to identify easily measured indices, growth and food consumption were compared with gonadal-somatic index, liver-somatic index (LSI), fat-somatic index and relative weight (Wr) for ages 1-3 walleye, Sander vitreus (Mitchill), in Lake Erie from 1986 to 1988. The LSI and Wr were significantly correlated with growth rate or food consumption, but correlations were too small to be considered biologically meaningful. Furthermore, no consistent relationships between condition indices and growth or consumption were found among combinations of fish age and season. None of the indices are considered reliable surrogates for more laborious estimates of growth and food consumption for Lake Erie walleye. Significant relationships between Wr and relative abundance of key prey species warrant further investigation. ?? 2006 Blackwell Publishing Ltd.

Feeding ecology of the walleye (Percidae, Sander vitreus), a resurgent piscivore in Lake Huron (Laurentian Great Lakes) after shifts in the prey community

USGS Publications Warehouse

Pothoven, Steven A.; Madenjian, Charles P.; Höök, Tomas O.

2017-01-01

Recovering populations of piscivores can challenge understanding of ecosystem function due to impacts on prey and to potentially altered food webs supporting their production. Stocks of walleye (Percidae, Sander vitreus), an apex predator in the Laurentian Great Lakes, crashed in the mid‐1900s. Management efforts led to recovery by 2009, but recovery coincided with environmental and fish community changes that also had implications for the feeding ecology of walleye. To evaluate potential changes in feeding ecology for this apex predator, we assessed diets in the main basin of Lake Huron and in Saginaw Bay, a large embayment of Lake Huron, during 2009–2011. Walleye switched their diets differently in the main basin and Saginaw Bay, with non‐native round goby (Gobiidae, Neogobius melanostomus) and rainbow smelt (Osmeridae, Osmerus mordax) more prevalent in diets in the main basin, and invertebrates, yellow perch (Percidae,Perca flavescens) and gizzard shad (Clupeidae, Dorosoma cepedianum) more prevalent in diets in the bay. Feeding strategy plots indicated that there was a high degree of individual specialisation by walleye in the bay and the main basin. Bioenergetic simulations indicated that walleye in Saginaw Bay need to consume 10%–18% more food than a walleye that spends part or all of the year in the main basin, respectively, in order to achieve the same growth rate. The differences in diets between the bay and main basin highlight the flexibility of this apex predator in the face of environmental changes, but changes in diet can alter energy pathways supporting piscivore production.

Walleye dermal sarcoma virus Orf B functions through receptor for activated C kinase (RACK1) and protein kinase C

DOE Office of Scientific and Technical Information (OSTI.GOV)

Daniels, Candelaria C.; Rovnak, Joel; Quackenbush, Sandra L.

2008-06-05

Walleye dermal sarcoma virus is a complex retrovirus that is associated with walleye dermal sarcomas that are seasonal in nature. Fall developing tumors contain low levels of spliced accessory gene transcripts A and B, suggesting a role for the encoded proteins, Orf A and Orf B, in oncogenesis. In explanted tumor cells the 35 kDa Orf B accessory protein is localized to the cell periphery in structures similar to focal adhesions and along actin stress fibers. Similar localization was observed in mammalian cells. The cellular protein, receptor for activated C kinase 1 (RACK1), bound Orf B in yeast two-hybrid assaysmore » and in cell culture. Sequence analysis of walleye RACK1 demonstrated high conservation to other known RACK1 sequences. RACK1 binds to activated protein kinase C (PKC). Orf B associates with PKC{alpha}, which is constitutively activated and localized at the membrane. Activated PKC promoted cell survival, proliferation, and increased cell viability in Orf B-expressing cells.« less

Squamous epithelial proliferation induced by walleye dermal sarcoma retrovirus cyclin in transgenic mice

PubMed Central

Lairmore, Michael D.; Stanley, James R.; Weber, Stacy A.; Holzschu, Donald L.

2000-01-01

Walleye dermal sarcoma (WDS) is a common disease of walleye fish in the United States and Canada. These proliferative lesions are present autumn through winter and regress in the spring. Walleye dermal sarcoma virus (WDSV), a retrovirus distantly related to other members of the family Retroviridae, has been etiologically linked to the development of WDS. We have reported that the D-cyclin homologue [retroviral (rv) cyclin] encoded by WDSV rescues yeast conditionally deficient for cyclin synthesis from growth arrest and that WDSV-cyclin mRNA is present in developing tumors. These data strongly suggest that the rv-cyclin plays a central role in the development of WDS. To test the ability of the WDSV rv-cyclin to induce cell proliferation, we have generated transgenic mice expressing the rv-cyclin in squamous epithelia from the bovine keratin-5 promoter. The transgenic animals were smaller than littermates, had reduced numbers of hair follicles, and transgenic females did not lactate properly. Following injury the transgenic animals developed severe squamous epithelial hyperplasia and dysplasia with ultrastructural characteristics of neoplastic squamous epithelium. Immunocytochemistry studies demonstrated that the hyperplastic epithelium stained positive for cytokeratin and were abnormally differentiated. Furthermore, the rv-cyclin protein was detected in the thickened basal cell layers of the proliferating lesions. These data are the first to indicate that the highly divergent WDSV rv-cyclin is a very potent stimulator of eukaryotic cell proliferation and to demonstrate the potential of a cyclin homologue encoded by a retrovirus to induce hyperplastic skin lesions. PMID:10811912

Effects of light conditions and temperature gradients on vertical migration behavior of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma)

NASA Astrophysics Data System (ADS)

Flanders, K. R.; Laurel, B.

2016-02-01

Early life stages of marine fishes must maximize growth while minimizing vulnerability to predators. Larval stages in particular are subject to ocean currents, but encounter favorable habitats by adjusting their vertical position in the water column. The investigation of environmental cues that change larval fish behavior is therefore crucial to understanding larval drift and dispersal modeling, and subsequently population structure and connectivity. In this study, the behavioral responses of larval Arctic cod (Boreogadus saida) and walleye pollock (Gadus chalcogramma) in a vertical water column were examined. Two prominent environmental variables, light and temperature, were manipulated over 3 h during observational trials. Light intensity was studied at two levels (1.484 x 101 μE m-2 s-1 ; 2.54 x102 μE m-2 s-1), and a diel effect was studied through the removal of light after 2 h. Light intensity did not significantly impact the position of either species in a vertical water column. However, a significant difference by species was apparent when all light levels were considered: the mean position of Arctic cod was closer to the surface of the water than that of walleye pollock. The effect of temperature through the introduction of a thermocline (range 5.6°C - 1.5°C) was limited to walleye pollock given the Arctic cod larvae were surface oriented across all light treatments. However, the thermocline did not significantly impact the relative change in position from light to dark in walleye pollock, likely because they were also surface oriented in control treatments. These results could be incorporated into future larval dispersal and survival models, particularly in Alaskan and Arctic waters, to investigate changes in species distributions resulting from global warming impacts. These results also indicate population structures of Arctic cod and walleye pollock could be affected, which may be reflected in ecosystem and trophic interactions. Because Arctic cod

To Harvest a Walleye. Student Guide and Teacher Guide. OEAGLS Investigation 16.

ERIC Educational Resources Information Center

Leach, Susan; And Others

Designed to introduce basic ecological relationships in a lake community, this investigation uses a Lake Erie food chain involving people and walleye as an example. The first activity is a board game in the form of a biomass pyramid; students begin with 1000 kilograms of algae and attempt to reach the "harvest" with at least a kilogram…

Evaluation of the Efficacy of Iodophor Disinfection of Walleye and Northern Pike Eggs to Eliminate Viral Hemorrhagic Septicemia Virus

USGS Publications Warehouse

Tuttle-Lau, M.T.; Phillips, K.A.; Gaikowski, M.P.

2009-01-01

Viral hemorrhagic septicemia virus (VHSv) is a serious fish pathogen that has been responsible for large-scale fish kills in the Great Lakes since 2005. It causes high mortality and resulting outbreaks have severe economic consequences for aquaculture. Iodophor disinfection of salmonid eggs is a standard hatchery practice to reduce the risk of pathogen transfer during gamete collection ('spawning') operations and is thus a leading candidate for reducing VHSv transmission during and after spawning of nonsalmonid fishes. However, before it is incorporated by hatcheries during nonsalmonid fish spawning efforts, its safety and effectiveness needs to be evaluated. The USGS Fact Sheet 2009-3107, 'Evaluation of the Efficacy of Iodophor Disinfection of Walleye and Northern Pike Eggs to Eliminate Viral Hemorrhagic Septicemia Virus' presents the results of a study to assess the effectiveness of iodophor disinfection for eliminating VHSv (strain IVb) from fertilized eggs of walleye and northern pike intentionally challenged with VHSv following egg fertilization. Walleye and northern pike egg survival (hatch) following iodophor egg disinfection also was assessed.

Lake Sturgeon, Lake Whitefish, and Walleye egg deposition patterns with response to fish spawning substrate restoration in the St. Clair–Detroit River system

USGS Publications Warehouse

Fischer, Jason L.; Pritt, Jeremy J.; Roseman, Edward; Prichard, Carson G.; Craig, Jaquelyn M.; Kennedy, Gregory W.; Manny, Bruce A.

2018-01-01

Egg deposition and use of restored spawning substrates by lithophilic fishes (e.g., Lake Sturgeon Acipenser fulvescens, Lake Whitefish Coregonus clupeaformis, and Walleye Sander vitreus) were assessed throughout the St. Clair–Detroit River system from 2005 to 2016. Bayesian models were used to quantify egg abundance and presence/absence relative to site-specific variables (e.g., depth, velocity, and artificial spawning reef presence) and temperature to evaluate fish use of restored artificial spawning reefs and assess patterns in egg deposition. Lake Whitefish and Walleye egg abundance, probability of detection, and probability of occupancy were assessed with detection-adjusted methods; Lake Sturgeon egg abundance and probability of occurrence were assessed using delta-lognormal methods. The models indicated that the probability of Walleye eggs occupying a site increased with water velocity and that the rate of increase decreased with depth, whereas Lake Whitefish egg occupancy was not correlated with any of the attributes considered. Egg deposition by Lake Whitefish and Walleyes was greater at sites with high water velocities and was lower over artificial spawning reefs. Lake Sturgeon eggs were collected least frequently but were more likely to be collected over artificial spawning reefs and in greater abundances than elsewhere. Detection-adjusted egg abundances were not greater over artificial spawning reefs, indicating that these projects may not directly benefit spawning Walleyes and Lake Whitefish. However, 98% of the Lake Sturgeon eggs observed were collected over artificial spawning reefs, supporting the hypothesis that the reefs provided spawning sites for Lake Sturgeon and could mitigate historic losses of Lake Sturgeon spawning habitat.

Validation of a side-scan sonar method for quantifying walleye spawning habitat availability in the littoral zone of northern Wisconsin Lakes

USGS Publications Warehouse

Richter, Jacob T.; Sloss, Brian L.; Isermann, Daniel A.

2016-01-01

Previous research has generally ignored the potential effects of spawning habitat availability and quality on recruitment of Walleye Sander vitreus, largely because information on spawning habitat is lacking for many lakes. Furthermore, traditional transect-based methods used to describe habitat are time and labor intensive. Our objectives were to determine if side-scan sonar could be used to accurately classify Walleye spawning habitat in the nearshore littoral zone and provide lakewide estimates of spawning habitat availability similar to estimates obtained from a transect–quadrat-based method. Based on assessments completed on 16 northern Wisconsin lakes, interpretation of side-scan sonar images resulted in correct identification of substrate size-class for 93% (177 of 191) of selected locations and all incorrect classifications were within ± 1 class of the correct substrate size-class. Gravel, cobble, and rubble substrates were incorrectly identified from side-scan images in only two instances (1% misclassification), suggesting that side-scan sonar can be used to accurately identify preferred Walleye spawning substrates. Additionally, we detected no significant differences in estimates of lakewide littoral zone substrate compositions estimated using side-scan sonar and a traditional transect–quadrat-based method. Our results indicate that side-scan sonar offers a practical, accurate, and efficient technique for assessing substrate composition and quantifying potential Walleye spawning habitat in the nearshore littoral zone of north temperate lakes.

Managing Ich infections of walleye cultured in a surface water supply with copper sulfate

USDA-ARS?s Scientific Manuscript database

Ichthyophthirius multifiliis infests walleye during growout at Rathbun Fish Hatchery (RFH). Daily flow-through formalin treatments (45-50 ppm for 9 h) were applied to prevent Ich outbreaks, and this contributed to 25% ($35,000) of fish production costs during the grow-out period. Research to decre...

Comparison of two viewing methods for estimating largemouth bass and walleye ages from sectioned otoliths and dorsal spines

USGS Publications Warehouse

Wegleitner, Eric J.; Isermann, Daniel A.

2017-01-01

Many biologists use digital images for estimating ages of fish, but the use of images could lead to differences in age estimates and precision because image capture can produce changes in light and clarity compared to directly viewing structures through a microscope. We used sectioned sagittal otoliths from 132 Largemouth Bass Micropterus salmoides and sectioned dorsal spines and otoliths from 157 Walleyes Sander vitreus to determine whether age estimates and among‐reader precision were similar when annuli were enumerated directly through a microscope or from digital images. Agreement of ages between viewing methods for three readers were highest for Largemouth Bass otoliths (75–89% among readers), followed by Walleye otoliths (63–70%) and Walleye dorsal spines (47–64%). Most discrepancies (72–96%) were ±1 year, and differences were more prevalent for age‐5 and older fish. With few exceptions, mean ages estimated from digital images were similar to ages estimated via directly viewing the structures through the microscope, and among‐reader precision did not vary between viewing methods for each structure. However, the number of disagreements we observed suggests that biologists should assess potential differences in age structure that could arise if images of calcified structures are used in the age estimation process.

Tobacco Retail Outlet Density and Young Adult Tobacco Initiation

PubMed Central

Pearson, Jennifer L.; Anesetti-Rothermel, Andrew; Xiao, Haijun; Kirchner, Thomas R.; Vallone, Donna

2016-01-01

Background: A growing body of evidence indicates that the density of tobacco retail outlets around the home residence may influence tobacco use among youth and adults. The purpose of this study was to examine the impact of neighborhood tobacco retail outlet density on young adult initiation of different tobacco product types. Methods: Cross-sectional data from a 2013 nationally representative sample of young adults aged 18–34 was examined in relation to a 2012 geocoded listing of all outlets likely to sell tobacco in the United States. Separate multivariable logistic regression analyses examined associations between neighborhood outlet density and past 6 months first use of cigarettes, non-cigarette combustible products, and noncombustible products among adults aged 18–24 and 25–34. Results: Outlet density was significantly associated with recent initiation of cigarettes and other combustibles, but this impact varied for younger and older groups. Increased density was significantly associated with a higher likelihood of initiating cigarette use among adults aged 25–34 (OR = 3.75, 95% CI = 1.18, 11.90), and of initiating non-cigarette combustible use among 18–24 year olds (OR = 3.16, 95% CI = 1.03, 9.74). There was no impact of outlet density on recent noncombustible product initiation among either group. Conclusion: This study is the first to examine the impact of tobacco outlet density on young adult initiation of cigarettes and other tobacco products. Findings demonstrate that residential neighborhood outlet density is associated with recent initiation of combustible products and this effect varies by product type and age. The tobacco outlet environment may be a critical factor in promoting young adult tobacco use initiation. PMID:25666816

Infection of the walleye, Stizostedion v. vitreum, of western Lake Erie with Bothriocephalus cuspidatus (Cooper)

USGS Publications Warehouse

Wolfert, David R.; Applegate, Vernon C.; Allison, Leonard N.

1967-01-01

In recent years appreciable changes have taken place in the biota and physiochemical conditions in Lake Erie. The accelerated eutrophication of the lake has been accompanied by the near disappearance of several fish species, e.g., blue pike (Stizostedion vitreum glaucum), lake herring (Coregonus artedi), lake trout (Salvelinus namaycush), sauger (Stizostedion canadense), and whitefish (Coregonus clupeaformis). Interest in the biology of the remaining species has increased as means have been sought to preserve their numbers in the lake. This report, which describes the caecal and intestinal parasites of the walleye, Stizostedion vitreum vitreum, is a contribution to the natural history of this fish in western Lake Erie. This study concerns: the type and degree of intestinal parasitic infestations in a single year class of walleyes during their first 3 years of life; seasonal changes in the incidence and maturity of the dominant parasite Bothriocephalus cuspidatus; and the effects of the infestations on the physical condition of the host.

Neurocysticercosis presenting as isolated wall-eyed monocular internuclear ophthalmoplegia with contraversive ocular tilt reaction.

PubMed

Chandran, Suresh R; Balakrishnan, Rojith K; Umakanthan, K; Govindarajan, K

2012-01-01

Neurocysticercosis is a common tropical infection presenting with neurological signs. It commonly presents as seizures but various other focal neurological presentations have been reported. Though neurocysticercosis have been reported to present as isolated internuclear ophthalmoplegia, we report the first case of neurocysticercosis presenting as wall-eyed monoocular internuclear ophthalmoplegia syndrome with contraversive ocular tilt reaction.

Neurocysticercosis presenting as isolated wall-eyed monocular internuclear ophthalmoplegia with contraversive ocular tilt reaction

PubMed Central

Chandran, Suresh R; Balakrishnan, Rojith K; Umakanthan, K; Govindarajan, K

2012-01-01

Neurocysticercosis is a common tropical infection presenting with neurological signs. It commonly presents as seizures but various other focal neurological presentations have been reported. Though neurocysticercosis have been reported to present as isolated internuclear ophthalmoplegia, we report the first case of neurocysticercosis presenting as wall-eyed monoocular internuclear ophthalmoplegia syndrome with contraversive ocular tilt reaction. PMID:22346205

Safety of oxytetracycline (Terramycin TM-100F) administered in feed to hybrid striped bass, walleyes, and yellow perch

USGS Publications Warehouse

Gaikowski, M.P.; Wolf, J.C.; Schleis, S.M.; Gingerich, W.H.

2003-01-01

Oxytetracycline (Terramycin TM-100F, a medicated premix containing oxytetracycline at 220 g/kg) is approved in the United States to control certain systemic bacterial diseases of salmon and catfish when fed at a rate of 55-82.5 mg per kilogram of bodyweight per day for 10 d. Although oxytetracycline may also control certain systemic bacterial infections in coolwater or scaled warmwater fish, no safety data for such species are available. Our objective was to determine the safety of oxytetracycline administered in feed at nominal doses of 0, 82.5, 248, or 413 mg??kg-1??d-1 to yellow perch Perca flavescens and hybrid striped bass (striped bass Morone saxatilis x white bass M. chrysops) for 10 d and to walleye Sander vitreus (formerly Stizostedion vitreum) for 20 d. Yellow perch and hybrid striped bass consumed 50% to 100% of the diet, whereas walleye feed consumption was occasionally less than 50% of the diet. Feed or fecal material was present in the gastrointestinal tract of all necropsied walleyes except for one control fish. The single growth effect was that hybrid striped bass offered a nominal dose of 413 mg??kg-1??d-1 were significantly smaller than untreated controls. Oxytetracycline-related histopathological findings were limited to walleyes and were of low severity. The histopathological findings included decreased hematopoietic-lymphopoietic (H&L) tissue in the anterior kidneys, diffuse hyperplasia of the gill filament epithelium, and a decreased prevalence of fish with eosinophilic droplets in their renal tubular epithelial cells. Although the incidence of decreased H&L tissue tended to increase in proportion to oxytetracycline dose, this finding was statistically significant only for fish that received a nominal dose of 413 mg??kg-1??d-1. Given the pathogenicity of the types of bacteria that are controlled by oxytetracycline treatment and the long history of its use in major aquaculture species, the relative risk of the minor oxytetracycline

HOT CELL BUILDING, TRA632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA ...

Library of Congress Historic Buildings Survey, Historic Engineering Record, Historic Landscapes Survey

HOT CELL BUILDING, TRA-632. CONTEXTUAL VIEW ALONG WALLEYE AVENUE, CAMERA FACING EASTERLY. HOT CELL BUILDING IS AT CENTER LEFT OF VIEW; THE LOW-BAY PROJECTION WITH LADDER IS THE TEST TRAIN ASSEMBLY FACILITY, ADDED IN 1968. MTR BUILDING IS IN LEFT OF VIEW. HIGH-BAY BUILDING AT RIGHT IS THE ENGINEERING TEST REACTOR BUILDING, TRA-642. INL NEGATIVE NO. HD46-32-1. Mike Crane, Photographer, 4/2005 - Idaho National Engineering Laboratory, Test Reactor Area, Materials & Engineering Test Reactors, Scoville, Butte County, ID

Non-lethal sampling of walleye for stable isotope analysis: a comparison of three tissues

USGS Publications Warehouse

Chipps, Steven R.; VanDeHey, J.A.; Fincel, M.J.

2012-01-01

Stable isotope analysis of fishes is often performed using muscle or organ tissues that require sacrificing animals. Non-lethal sampling provides an alternative for evaluating isotopic composition for species of concern or individuals of exceptional value. Stable isotope values of white muscle (lethal) were compared with those from fins and scales (non-lethal) in walleye, Sander vitreus (Mitchill), from multiple systems, size classes and across a range of isotopic values. Isotopic variability was also compared among populations to determine the potential of non-lethal tissues for diet-variability analyses. Muscle-derived isotope values were enriched compared with fins and depleted relative to scales. A split-sample validation technique and linear regression found that isotopic composition of walleye fins and scales was significantly related to that in muscle tissue for both δ13C and δ15N (r2 = 0.79–0.93). However, isotopic variability was significantly different between tissue types in two of six populations for δ15N and three of six populations for δ13C. Although species and population specific, these findings indicate that isotopic measures obtained from non-lethal tissues are indicative of those obtained from muscle.

ALTERED SERUM SEX STEROIDS AND VITELLOGENIN INDUCTION IN WALLEYE (STIZOSTEDION VITREUM) COLLECTED NEAR A METROPOLITAN SEWAGE TREATMENT PLANT

EPA Science Inventory

Feral, male walleye collected from the Mississippi River below the St. Paul metropolitan sewage treatment plant (STP) contained measurable levels of the estrogen-inducible, female egg protein, vitellogenin. These same fish showed significantly decreased serum androgen and signifi...

Using cumulative diet data and stable isotope analysis to determine trophic position of walleye Sander vitreus in a large, complex system

USGS Publications Warehouse

Fincel, Mark J.; James, Daniel A.; Chipps, Steven R.; Davis, Blake A.

2014-01-01

Diet studies have traditionally been used to determine prey use and food web dynamics, while stable isotope analysis provides for a time-integrated approach to evaluate food web dynamics and characterize energy flow in aquatic systems. Direct comparison of the two techniques is rare and difficult to conduct in large, species rich systems. We compared changes in walleye Sander vitreus trophic position (TP) derived from paired diet content and stable isotope analysis. Individual diet-derived TP estimates were dissimilar to stable isotope-derived TP estimates. However, cumulative diet-derived TP estimates integrated from May 2001 to May 2002 corresponded to May 2002 isotope-derived estimates of TP. Average walleye TP estimates from the spring season appear representative of feeding throughout the entire previous year.

Water-quality assessment of the Upper Mississippi River Basin, Minnesota and Wisconsin- Polychlorinated biphenyls in common carp and walleye fillets, 1975-95

USGS Publications Warehouse

Lee, Kathy E.; Anderson, Jesse P.

1998-01-01

Median PCB concentrations in common carp and walleye at individual sites were greatest during 1975-79 and 1980-87, and least during 1988-95 at most sites. Most of the river segments exhibited over 80 percent decline in median PCB concentrations in common carp and walleye between the 1975-79 and 1988-95 time periods. The results from these temporal analyses were similar to those of other studies in the United States and in Minnesota and Wisconsin that reported a significant downward trend in PCB concentrations in fish. Although, PCB concentrations have decreased during 1975-95, low concentrations of PCBs still remain in the aquatic environment despite the fact that PCBs were banned nearly 20 years ago.

Including independent estimates and uncertainty to quantify total abundance of fish migrating in a large river system: walleye (Sander vitreus) in the Maumee River, Ohio

USGS Publications Warehouse

Pritt, Jeremy J.; DuFour, Mark R.; Mayer, Christine M.; Kocovsky, Patrick M.; Tyson, Jeffrey T.; Weimer, Eric J.; Vandergoot, Christopher S.

2013-01-01

Walleye (Sander vitreus) in Lake Erie is a valuable and migratory species that spawns in tributaries. We used hydroacoustic sampling, gill net sampling, and Bayesian state-space modeling to estimate the spawning stock abundance, characterize size and sex structure, and explore environmental factors cuing migration of walleye in the Maumee River for 2011 and 2012. We estimated the spawning stock abundance to be between 431,000 and 1,446,000 individuals in 2011 and between 386,400 and 857,200 individuals in 2012 (95% Bayesian credible intervals). A back-calculation from a concurrent larval fish study produced an estimate of 78,000 to 237,000 spawners for 2011. The sex ratio was skewed towards males early in the spawning season but approached 1:1 later, and larger individuals entered the river earlier in the season than smaller individuals. Walleye migration was greater during low river discharge and intermediate temperatures. Our approach to estimating absolute abundance and uncertainty as well as characterization of the spawning stock could improve assessment and management of this species, and our methodology is applicable to other diadromous populations.

Unimodal relationship between small-scale barnacle recruitment and the density of pre-existing barnacle adults.

PubMed

Scrosati, Ricardo A; Ellrich, Julius A

2017-01-01

Recruitment is a key demographic process for population persistence. This paper focuses on barnacle ( Semibalanus balanoides ) recruitment. In rocky intertidal habitats from the Gulf of St. Lawrence coast of Nova Scotia (Canada), ice scour is common during the winter. At the onset of intertidal barnacle recruitment in early May (after sea ice has fully melted), mostly only adult barnacles and bare substrate are visible at high elevations in wave-exposed habitats. We conducted a multiannual study to investigate if small-scale barnacle recruitment could be predicted from the density of pre-existing adult barnacles. In a year that exhibited a wide adult density range (ca. 0-130 individuals dm -2 ), the relationship between adult density and recruit density (scaled to the available area for recruitment, which excluded adult barnacles) was unimodal. In years that exhibited a lower adult density range (ca. 0-40/50 individuals dm -2 ), the relationship between adult and recruit density was positive and resembled the lower half of the unimodal relationship. Overall, adult barnacle density was able to explain 26-40% of the observed variation in recruit density. The unimodal adult-recruit relationship is consistent with previously documented intraspecific interactions. Between low and intermediate adult densities, the positive nature of the relationship relates to the previously documented fact that settlement-seeking larvae are chemically and visually attracted to adults, which might be important for local population persistence. Between intermediate and high adult densities, where population persistence may be less compromised and the abundant adults may limit recruit growth and survival, the negative nature of the relationship suggests that adult barnacles at increasingly high densities stimulate larvae to settle elsewhere. The unimodal pattern may be especially common on shores with moderate rates of larval supply to the shore, because high rates of larval supply may

Comparative population genetic structure and diversity of Yellow Perch and Walleye: Broad- and fine-scale patterns across North America

USDA-ARS?s Scientific Manuscript database

The yellow perch Perca flavescens and the walleye Sander vitreus are native North American percid fishes, which have considerable fishery and ecological importance across their wide geographic ranges. Over the past century, they were stocked into new habitats, often with relative disregard for conse...

Maternal Anthropometry and Mammographic Density in Adult Daughters.

PubMed

Michels, Karin B; Cohn, Barbara A; Goldberg, Mandy; Flom, Julie D; Dougan, Marcelle; Terry, Mary Beth

2016-11-01

We examined the relation between maternal anthropometry and mammographic density in the adult daughter using prospectively collected data. Our study included a total of 700 mother-daughter dyads participating in an adult follow-up of women born in 2 US birth cohorts: the Child Health and Development Study and the Boston, Massachusetts, and Providence, Rhode Island sites of the National Collaborative Perinatal Project. We observed an increased percent breast density at a mean age of 43.1 years in the daughters of mothers who gained 5 kg or less during pregnancy compared with mother-daughter pairs in which the mother gained 5 to 10 kg (β = 4.8, 95% confidence interval: 1.0 to 8.6). The daughters of mothers who were overweight at the time of conception (prepregnancy BMI ≥25) and who gained >5 kg during pregnancy had a lower percent density (β = -3.2, 95% confidence interval: -6.2 to -0.2) compared with mothers with a BMI <25 at conception who gained >5 kg. We did not find any strong and consistent patterns between maternal anthropometry and the daughter's breast density, a strong predictor of breast cancer risk. A modest association between low gestational weight gain and increased breast density 40 years later in the daughter was observed, even after accounting for adult body size, and if confirmed, possible mechanisms need to be further elucidated. Copyright © 2016 by the American Academy of Pediatrics.

Sequence and Transcriptional Analyses of the Fish Retroviruses Walleye Epidermal Hyperplasia Virus Types 1 and 2: Evidence for a Gene Duplication

PubMed Central

LaPierre, Lorie A.; Holzschu, Donald L.; Bowser, Paul R.; Casey, James W.

1999-01-01

Walleye epidermal hyperplasia virus types 1 and 2 (WEHV1 and WEHV2, respectively) are associated with a hyperproliferative skin lesion on walleyes that appears and regresses seasonally. We have determined the complete nucleotide sequences and transcriptional profiles of these viruses. WEHV1 and WEHV2 are large, complex retroviruses of 12,999 and 13,125 kb in length, respectively, that are closely related to one another and to walleye dermal sarcoma virus (WDSV). These walleye retroviruses contain three open reading frames, orfA, orfB, and orfC, in addition to gag, pol, and env. orfA and orfB are adjacent to one another and located downstream of env. The OrfA proteins were previously identified as cyclin D homologs that may contribute to the induction of cell proliferation leading to epidermal hyperplasia and dermal sarcoma. The sequence analysis of WEHV1 and WEHV2 revealed that the OrfB proteins are distantly related to the OrfA proteins, suggesting that orfB arose by gene duplication. Presuming that the precursor of orfA and orfB was derived from a cellular cyclin, these genes are the first accessory genes of complex retroviruses that can be traced to a cellular origin. WEHV1, WEHV2, and WDSV are the only retroviruses that have an open reading frame, orfC, of considerable size (ca. 130 amino acids) in the leader region preceding gag. While we were unable to predict a function for the OrfC proteins, they are more conserved than OrfA and OrfB, suggesting that they may be biologically important to the viruses. The transcriptional profiles of WEHV1 and WEHV2 were also similar to that of WDSV; Northern blot analyses detected only low levels of the orfA transcripts in developing lesions, whereas abundant levels of genomic, env, orfA, and orfB transcripts were detected in regressing lesions. The splice donors and acceptors of individual transcripts were identified by reverse transcriptase PCR. The similarities of WEHV1, WEHV2, and WDSV suggest that these viruses use

Recent changes in the walleye fishery of northern Green Bay and history of the 1943 year class

USGS Publications Warehouse

Pycha, Richard L.

1961-01-01

Production, fishing intensity, and availability of walleyes (Stizostedion vitreum vitreum) fluctuated widely in the commercial fishery of northern Green Bay in 1929-57. The catch ranged from 16,000 pounds (8 percent of average for the 1929-53 base period) in 1942 to 1,294,000 pounds (633 percent) in 1950. The index of fishing intensity ranged from 17 (1941) to 400 (1950) and that of abundance from 47 (1929) to 222 (1955). Production and fishing intensity were consistently above average in 1947-57; abundance exceeded the average in 8 of these years. The fishery statistics and records of age and size composition of commercial landings of walleyes in the spring and fall fishing seasons of 1949-58 (scale samples were taken from a total of 1,631 fish) were the basis for a study of recent changes in the walleye fishery with particular reference to the effects of fluctuations in the strength of year classes. The 1943 year class, by a wide margin, exceeded all others in the estimated total number (1,173,000 fish) and weight (3,355,000 pounds) contributed to commercial landings. This year class was a major factor in the sharp rise in production and abundance after 1945 and the all-time record catch of 1950. In contrast, certain other year classes (1945, 1946, 1948) have contributed totals as small as 16,000 to 52,000 pounds. The abundance of the 1950, 1951, and 1952 year classes approached or exceeded that of the 1943 year class at the lesser ages (through the IV group), but these more recent classes disappeared from the fishery so rapidly that their total contributions were relatively low. The indicated increase of mortality in the middle 1950's cannot be attributed to increase in the rate of commercial exploitation. Evidence is offered that the heightened mortality rate resulted from expansion of the sport fishery.

Proximate composition and energy density of some North Pacific forage fishes

USGS Publications Warehouse

van Pelt, Thomas I.; Piatt, John F.; Lance, Brian K.; Roby, Daniel D.

1997-01-01

Mature pelagic forage fish species (capelin, sand lance, squid) had greater lipid concentrations than juvenile age-classes of large demersal and pelagic fish species (walleye pollock, Pacific cod, Atka mackerel, greenling, prowfish, rockfish, sablefish). Myctophids preyed on by puffins have at least twice as much lipid per gram compared to mature capelin, sand lance and squid, and an order of magnitude greater lipid concentrations than juvenile forage fish. Energy density of forage fishes was positively correlated with lipid content, and negatively correlated with water, ash-free lean dry mass (mostly protein), and ash contents.

Estimating peer density effects on oral health for community-based older adults.

PubMed

Chakraborty, Bibhas; Widener, Michael J; Mirzaei Salehabadi, Sedigheh; Northridge, Mary E; Kum, Susan S; Jin, Zhu; Kunzel, Carol; Palmer, Harvey D; Metcalf, Sara S

2017-12-29

As part of a long-standing line of research regarding how peer density affects health, researchers have sought to understand the multifaceted ways that the density of contemporaries living and interacting in proximity to one another influence social networks and knowledge diffusion, and subsequently health and well-being. This study examined peer density effects on oral health for racial/ethnic minority older adults living in northern Manhattan and the Bronx, New York, NY. Peer age-group density was estimated by smoothing US Census data with 4 kernel bandwidths ranging from 0.25 to 1.50 mile. Logistic regression models were developed using these spatial measures and data from the ElderSmile oral and general health screening program that serves predominantly racial/ethnic minority older adults at community centers in northern Manhattan and the Bronx. The oral health outcomes modeled as dependent variables were ordinal dentition status and binary self-rated oral health. After construction of kernel density surfaces and multiple imputation of missing data, logistic regression analyses were performed to estimate the effects of peer density and other sociodemographic characteristics on the oral health outcomes of dentition status and self-rated oral health. Overall, higher peer density was associated with better oral health for older adults when estimated using smaller bandwidths (0.25 and 0.50 mile). That is, statistically significant relationships (p < 0.01) between peer density and improved dentition status were found when peer density was measured assuming a more local social network. As with dentition status, a positive significant association was found between peer density and fair or better self-rated oral health when peer density was measured assuming a more local social network. This study provides novel evidence that the oral health of community-based older adults is affected by peer density in an urban environment. To the extent that peer density

Concentrations of mercury and other trace elements in walleye, smallmouth bass, and rainbow trout in Franklin D. Roosevelt Lake and the upper Columbia River, Washington, 1994

USGS Publications Warehouse

Munn, M.D.; Cox, S.E.; Dean, C.J.

1995-01-01

Three species of sportfish--walleye, smallmouth bass, and rainbow trout--were collected from Franklin D. Roosevelt Lake and the upstream reach of the Columbia River within the state of Washington, to determine the concentrations of mercury and other selected trace elements in fish tissue. Concentrations of total mercury in walleye fillets ranged from 0.11 to 0.44 milligram per kilogram, with the higher concentrations in the larger fish. Fillets of smallmouth bass and rainbow trout also contained mercury, but generally at lower concentrations. Other selected trace elements were found in fillet samples, but the concentrations were generally low depending on species and the specific trace element. The trace elements cadmium, copper, lead, and zinc were found in liver tissue of these same species with zinc consistently present in the highest concentration.

Inter-class competition in stage-structured populations: effects of adult density on life-history traits of adult and juvenile common lizards.

PubMed

San-Jose, Luis M; Peñalver-Alcázar, Miguel; Huyghe, Katleen; Breedveld, Merel C; Fitze, Patrick S

2016-12-01

Ecological and evolutionary processes in natural populations are largely influenced by the population's stage-structure. Commonly, different classes have different competitive abilities, e.g., due to differences in body size, suggesting that inter-class competition may be important and largely asymmetric. However, experimental evidence states that inter-class competition, which is important, is rare and restricted to marine fish. Here, we manipulated the adult density in six semi-natural populations of the European common lizard, Zootoca vivipara, while holding juvenile density constant. Adult density affected juveniles, but not adults, in line with inter-class competition. High adult density led to lower juvenile survival and growth before hibernation. In contrast, juvenile survival after hibernation was higher in populations with high adult density, pointing to relaxed inter-class competition. As a result, annual survival was not affected by adult density, showing that differences in pre- and post-hibernation survival balanced each other out. The intensity of inter-class competition affected reproduction, performance, and body size in juveniles. Path analyses unravelled direct treatment effects on early growth (pre-hibernation) and no direct treatment effects on the parameters measured after hibernation. This points to allometry of treatment-induced differences in early growth, and it suggests that inter-class competition mainly affects the early growth of the competitively inferior class and thereby their future performance and reproduction. These results are in contrast with previous findings and, together with results in marine fish, suggest that the strength and direction of density dependence may depend on the degree of inter-class competition, and thus on the availability of resources used by the competing classes.

Contaminant trends in lake trout and walleye from the Laurentian Great Lakes

USGS Publications Warehouse

DeVault, David S.; Hesselberg, Robert J.; Rodgers, Paul W.; Feist, Timothy J.

1996-01-01

Trends in PCBs, DDT, and other contaminants have been monitored in Great Lakes lake trout and walleye since the 1970s using composite samples of whole fish. Dramatic declines have been observed in concentrations of PCB, ΣDDT, dieldrin, and oxychlordane, with declines initially following first order loss kinetics. Mean PCB concentrations in Lake Michigan lake trout increased from 13 μg/g in 1972 to 23 μg/g in 1974, then declined to 2.6 μg/g by 1986. Between 1986 and 1992 there was little change in concentration, with 3.5 μg/g observed in 1992. ΣDDT in Lake Michigan trout followed a similar trend, decreasing from 19.2 μg/g in 1970 to 1.1 μg/g in 1986, and 1.2 μg/g in 1992. Similar trends were observed for PCBs and ΣDDT in lake trout from Lakes Superior, Huron and Ontario. Concentrations of both PCB and ΣDDT in Lake Erie walleye declined between 1977 and 1982, after which concentrations were relatively constant through 1990. When originally implemented it was assumed that trends in the mean contaminant concentrations in open-lake fish would serve as cost effective surrogates to trends in the water column. While water column data are still extremely limited it appears that for PCBs in lakes Michigan and Superior, trends in lake trout do reasonably mimic those in the water column over the long term. Hypotheses to explain the trends in contaminant concentrations are briefly reviewed. The original first order loss kinetics used to describe the initial decline do not explain the more recent leveling off of contaminant concentrations. Recent theories have examined the possibilities of multiple contaminant pools. We suggest another hypothesis, that changes in the food web may have resulted in increased bioaccumulation. However, a preliminary exploration of this hypothesis using a change point analysis was inconclusive.

Bone mineral density in adults with Down syndrome.

PubMed

Carfì, A; Liperoti, R; Fusco, D; Giovannini, S; Brandi, V; Vetrano, D L; Meloni, E; Mascia, D; Villani, E R; Manes Gravina, E; Bernabei, R; Onder, G

2017-10-01

This study analyzed data of bone mineral density (BMD) from a large cohort of adults with Down syndrome (DS). BMD was found to decrease with age more rapidly in these subjects than in the general population, exposing adults with DS to an increased risk of osteoporosis and bone fracture. Down syndrome (DS) in adulthood presents with a high prevalence of osteoporosis. However, in DS, bone mineral density (BMD) can be underestimated due to short stature. Furthermore, the rate of age-related decline in BMD and its association with gender in DS has been rarely evaluated or compared with the general population. The present study is aimed at assessing the variation of BMD with age and gender in a sample of adults with DS and to compare these data with those of the general population, after adjusting for anthropometric differences. Adults with DS, aged 18 or older, were assessed dual-energy-X-ray-absorptiometry (DXA) at the femoral neck and at the lumbar spine. They were compared with the general population enrolled in the National Health and Nutrition Examination Survey (NHANES) 2009-2010 dataset. Bone mineral apparent density (BMAD) was calculated for each individual. DXA was evaluated in 234 subjects with DS (mean age 36.93 ± 11.83 years, ranging from 20 to 69 years; 50.4% females). In the lumbar spine both mean BMD (DS 0.880 ± 0.141 vs. NHANES 1.062 ± 0.167, p < 0.001) and BMAD (DS 0.138 ± 0.020 vs. NHANES 0.152 ± 0.020, p < 0.001) were significantly lower in the DS sample than in the NAHNES cohort. The same trend was observed at the femoral neck in both BMD (DS 0.658 ± 0.128 vs. NHANES 0.835 ± 0.137, p < 0.001) and BMAD (DS 0.151 ± 0.030 vs. NHANES 0.159 ± 0.028, p<0.001). Age was associated with lower femoral neck BMAD in both samples; importantly, this association was significantly stronger in the DS sample. In the lumbar spine region, no significant association between BMAD and age could be observed in both samples. Adults with DS

Maternal influences on thiamine status of walleye Sander vitreus ova.

PubMed

Wiegand, M D; Johnston, T A; Brown, L R; Brown, S B; Casselman, J M; Leggett, W C

2011-03-01

Concentrations of the various forms of thiamine (vitamin B(1) ) were determined in walleye Sander vitreus ova from three central North American lakes. Total thiamine concentrations in ova from Lake Winnipeg S. vitreus were approximately three times greater (mean 12 nmol g(-1) ) than in those from Lakes Erie or Ontario. The percentage of thiamine in the active form (thiamine pyrophosphate, TPP) was highest in Lake Ontario ova (mean 88%) and lowest in those from Lake Winnipeg (mean 70%). Neither ova total thiamine concentration nor per cent ova thiamine as TPP showed any consistent relationships with maternal age, size, morphometric condition, somatic lipid concentrations or liver lipid concentrations. Ova total thiamine concentration, however, was negatively related to ovum size in some populations, as well as among populations, and was positively related to liver total thiamine concentration. Maternal transfer of thiamine to ova appears to be independent of female ontogenetic or conditional state in S. vitreus. © 2011 The Authors. Journal of Fish Biology © 2011 The Fisheries Society of the British Isles.

Dietary energy density and body weight in adults and children: a systematic review.

PubMed

Pérez-Escamilla, Rafael; Obbagy, Julie E; Altman, Jean M; Essery, Eve V; McGrane, Mary M; Wong, Yat Ping; Spahn, Joanne M; Williams, Christine L

2012-05-01

Energy density is a relatively new concept that has been identified as an important factor in body weight control in adults and in children and adolescents. The Dietary Guidelines for Americans 2010 encourages consumption of an eating pattern low in energy density to manage body weight. This article describes the systematic evidence-based review conducted by the 2010 Dietary Guidelines Advisory Committee (DGAC), with support from the US Department of Agriculture's Nutrition Evidence Library, which resulted in this recommendation. An update to the committee's review was prepared for this article. PubMed was searched for English-language publications from January 1980 to May 2011. The literature review included 17 studies (seven randomized controlled trials, one nonrandomized controlled trial, and nine cohort studies) in adults and six cohort studies in children and adolescents. Based on this evidence, the 2010 Dietary Guidelines Advisory Committee concluded that strong and consistent evidence in adults indicates that dietary patterns relatively low in energy density improve weight loss and weight maintenance. In addition, the committee concluded that there was moderately strong evidence from methodologically rigorous longitudinal cohort studies in children and adolescents to suggest that there is a positive association between dietary energy density and increased adiposity. This review supports a relationship between energy density and body weight in adults and in children and adolescents such that consuming diets lower in energy density may be an effective strategy for managing body weight. Copyright © 2012 Academy of Nutrition and Dietetics. Published by Elsevier Inc. All rights reserved.

The Effects of Phonotactic Probability and Neighborhood Density on Adults' Word Learning in Noisy Conditions

PubMed Central

Storkel, Holly L.; Lee, Jaehoon; Cox, Casey

2016-01-01

Purpose Noisy conditions make auditory processing difficult. This study explores whether noisy conditions influence the effects of phonotactic probability (the likelihood of occurrence of a sound sequence) and neighborhood density (phonological similarity among words) on adults' word learning. Method Fifty-eight adults learned nonwords varying in phonotactic probability and neighborhood density in either an unfavorable (0-dB signal-to-noise ratio [SNR]) or a favorable (+8-dB SNR) listening condition. Word learning was assessed using a picture naming task by scoring the proportion of phonemes named correctly. Results The unfavorable 0-dB SNR condition showed a significant interaction between phonotactic probability and neighborhood density in the absence of main effects. In particular, adults learned more words when phonotactic probability and neighborhood density were both low or both high. The +8-dB SNR condition did not show this interaction. These results are inconsistent with those from a prior adult word learning study conducted under quiet listening conditions that showed main effects of word characteristics. Conclusions As the listening condition worsens, adult word learning benefits from a convergence of phonotactic probability and neighborhood density. Clinical implications are discussed for potential populations who experience difficulty with auditory perception or processing, making them more vulnerable to noise. PMID:27788276

The Effects of Phonotactic Probability and Neighborhood Density on Adults' Word Learning in Noisy Conditions.

PubMed

Han, Min Kyung; Storkel, Holly L; Lee, Jaehoon; Cox, Casey

2016-11-01

Noisy conditions make auditory processing difficult. This study explores whether noisy conditions influence the effects of phonotactic probability (the likelihood of occurrence of a sound sequence) and neighborhood density (phonological similarity among words) on adults' word learning. Fifty-eight adults learned nonwords varying in phonotactic probability and neighborhood density in either an unfavorable (0-dB signal-to-noise ratio [SNR]) or a favorable (+8-dB SNR) listening condition. Word learning was assessed using a picture naming task by scoring the proportion of phonemes named correctly. The unfavorable 0-dB SNR condition showed a significant interaction between phonotactic probability and neighborhood density in the absence of main effects. In particular, adults learned more words when phonotactic probability and neighborhood density were both low or both high. The +8-dB SNR condition did not show this interaction. These results are inconsistent with those from a prior adult word learning study conducted under quiet listening conditions that showed main effects of word characteristics. As the listening condition worsens, adult word learning benefits from a convergence of phonotactic probability and neighborhood density. Clinical implications are discussed for potential populations who experience difficulty with auditory perception or processing, making them more vulnerable to noise.

Movement and Harvest of Fish in Lake Saint Clair, Saint Clair River, and Detroit River

DTIC Science & Technology

1985-01-01

a creel survey of the angling fishery , a trap net survey, and a tagging study of the adult fish community . The study area encompassed all of...River does not support a winter walleye fishery (C. Baker, ODNR, personal communication ). Yellow perch,-Yellow perch, like walleyes, are considered best...two basic forms: affecting the adult fish community directly, or interfering with the winter angling fishery . The fish community might be affected

The effects of regional angling effort, angler behavior, and harvesting efficiency on landscape patterns of overfishing.

PubMed

Hunt, Len M; Arlinghaus, Robert; Lester, Nigel; Kushneriuk, Rob

2011-10-01

We used a coupled social-ecological model to study the landscape-scale patterns emerging from a mobile population of anglers exploiting a spatially structured walleye (Sander vitreus) fishery. We systematically examined how variations in angler behaviors (i.e., relative importance of walleye catch rate in guiding fishing site choices), harvesting efficiency (as implied by varying degrees of inverse density-dependent catchability of walleye), and angler population size affected the depletion of walleye stocks across 157 lakes located near Thunder Bay (Ontario, Canada). Walleye production biology was calibrated using lake-specific morphometric and edaphic features, and angler fishing site choices were modeled using an empirically grounded multi-attribute utility function. We found support for the hypothesis of sequential collapses of walleye stocks across the landscape in inverse proportionality of travel cost from the urban residence of anglers. This pattern was less pronounced when the regional angler population was low, density-dependent catchability was absent or low, and angler choices of lakes in the landscape were strongly determined by catch rather than non-catch-related attributes. Thus, our study revealed a systematic pattern of high catch importance reducing overfishing potential at low and aggravating overfishing potential at high angler population sizes. The analyses also suggested that density-dependent catchability might have more serious consequences for regional overfishing states than variations in angler behavior. We found little support for the hypotheses of systematic overexploitation of the most productive walleye stocks and homogenized catch-related qualities among lakes sharing similar access costs to anglers. Therefore, one should not expect anglers to systematically exploit the most productive fisheries or to equalize catch rates among lakes through their mobility and other behaviors. This study underscores that understanding landscape

Spatial match-mismatch between juvenile fish and prey provides a mechanism for recruitment variability across contrasting climate conditions in the eastern Bering Sea.

PubMed

Siddon, Elizabeth Calvert; Kristiansen, Trond; Mueter, Franz J; Holsman, Kirstin K; Heintz, Ron A; Farley, Edward V

2013-01-01

Understanding mechanisms behind variability in early life survival of marine fishes through modeling efforts can improve predictive capabilities for recruitment success under changing climate conditions. Walleye pollock (Theragra chalcogramma) support the largest single-species commercial fishery in the United States and represent an ecologically important component of the Bering Sea ecosystem. Variability in walleye pollock growth and survival is structured in part by climate-driven bottom-up control of zooplankton composition. We used two modeling approaches, informed by observations, to understand the roles of prey quality, prey composition, and water temperature on juvenile walleye pollock growth: (1) a bioenergetics model that included local predator and prey energy densities, and (2) an individual-based model that included a mechanistic feeding component dependent on larval development and behavior, local prey densities and size, and physical oceanographic conditions. Prey composition in late-summer shifted from predominantly smaller copepod species in the warmer 2005 season to larger species in the cooler 2010 season, reflecting differences in zooplankton composition between years. In 2010, the main prey of juvenile walleye pollock were more abundant, had greater biomass, and higher mean energy density, resulting in better growth conditions. Moreover, spatial patterns in prey composition and water temperature lead to areas of enhanced growth, or growth 'hot spots', for juvenile walleye pollock and survival may be enhanced when fish overlap with these areas. This study provides evidence that a spatial mismatch between juvenile walleye pollock and growth 'hot spots' in 2005 contributed to poor recruitment while a higher degree of overlap in 2010 resulted in improved recruitment. Our results indicate that climate-driven changes in prey quality and composition can impact growth of juvenile walleye pollock, potentially severely affecting recruitment variability.

Vulnerability of age-0 pallid sturgeon Scaphirhynchus albus to predation; effects of predator type, turbidity, body size, and prey density

USGS Publications Warehouse

French, William E.; Graeb, Brian D. S.; Chipps, Steven R.; Klumb, Robert A.

2014-01-01

Predation can play an important role in the recruitment dynamics of fishes with intensity regulated by behavioral (i.e., prey selectivity) and/or environmental conditions that may be especially important for rare or endangered fishes. We conducted laboratory experiments to quantify prey selection and capture efficiency by three predators employing distinct foraging strategies: pelagic piscivore (walleye Sander vitreus); benthic piscivore (flathead catfish Pylodictis olivaris) and generalist predator (smallmouth bass Micropterus dolomieu) foraging on two size classes of age-0 pallid sturgeon: large (75–100 mm fork length [FL]) and small (40–50 mm FL). Experiments at high (> 70 nephalometric turbidity units [NTU]) and low (< 5 NTU) turbidity for each predator were conducted with high and low densities of pallid sturgeon and contrasting densities of an alternative prey, fathead minnow Pimephales promelas. Predator behaviors (strikes, captures, and consumed prey) were also quantified for each prey type. Walleye and smallmouth bass negatively selected pallid sturgeon (Chesson’s α = 0.04–0.1) across all treatments, indicating low relative vulnerability to predation. Relative vulnerability to predation by flathead catfish was moderate for small pallid sturgeon (α = 0.44, neutral selection), but low for large pallid sturgeon (α = 0.11, negative selection). Turbidity (up to 100 NTU) did not affect pallid sturgeon vulnerability, even at low density of alternative prey. Age-0 pallid sturgeon were easily captured by all predators, but were rarely consumed, suggesting mechanisms other than predator capture efficiency govern sturgeon predation vulnerability.

Impact of Adult Weight, Density, and Age on Reproduction of Tenebrio molitor (Coleoptera: Tenebrionidae)

USDA-ARS?s Scientific Manuscript database

The impact of adult weight, age, and density on reproduction of Tenebrio molitor L. (Coleoptera: Tenebrionidae) was studied. The impact of adult weight on reproduction was determined in two ways: 1) counting the daily progeny of individual adult pairs of known weight and analyzing the data with line...

Gill tissue reactions in walleye Stizostedion vitreum vitreum and common carp Cyprinus carpio to glochidia of the freshwater mussel Lampsilis radiata siliquoidea

USGS Publications Warehouse

Waller, D.L.; Mitchell, L.G.

1989-01-01

The glochidia of many freshwater mussels, which are obligate parasites on the gills, fins, and other body parts of specific fishes, attach to a suitable host, become encapsulated, and develop to the free-living juvenile stage. Using light and electron microscopy we compared gill tissue reactions in a suitable host (walleye Stizostedion vitreum vitreum) and unsuitable host (common carp Cyprinus carpio) infected with Lampsilis radiata siliquoidea. Encapsulation of glochidia on walleye gills was completed by 6 h post-infection at 20 to 22°C. Capsular formation and compaction were accompanied by a general increase in epithelioid cells. Fibrotic material appeared in capsules at about 48 h and virtually filled capsular cells from about Day 5 to Day 11 post-infection. Liberation of juvenile mussels was accompanied by thinning of the capsule from about Day 11 to Day l7. Although glochidia attached to the gills of common carp, few became encapsulated. By 48 h post-infection, preliminary capsular growth was evident and necrotic cells and cellular debris appeared at the edges of the growth. However, all glochidia were sloughed from carp gills by 60 h. Host specificity of L. radiata siliquoidea apparently depended on a combination of the attachment response of glochidia, differences in the encapsulation process, and tissue reactions in the fish.

Walleye dermal sarcoma virus: expression of a full-length clone or the rv-cyclin (orf a) gene is cytopathic to the host and human tumor cells.

PubMed

Xu, Kun; Zhang, Ting Ting; Wang, Ling; Zhang, Cun Fang; Zhang, Long; Ma, Li Xia; Xin, Ying; Ren, Chong Hua; Zhang, Zhi Qiang; Yan, Qiang; Martineau, Daniel; Zhang, Zhi Ying

2013-02-01

Walleye dermal sarcoma virus (WDSV) is etiologically associated with a skin tumor, walleye dermal sarcoma (WDS), which develops in the fall and regresses in the spring. WDSV genome contains, in addition to gag, pol and env, three open reading frames (orfs) designated orf a (rv-cyclin), orf b and orf c. Unintegrated linear WDSV provirus DNA isolated from infected tumor cells was used to construct a full-length WDSV provirus clone pWDSV, while orf a was cloned into pSVK3 to construct the expression vector porfA. Stable co-transfection of a walleye cell line (W12) with pWDSV and pcDNA3 generated fewer and smaller G418-resistant colonies compared to the control. By Northern blot analysis, several small transcripts (2.8, 1.8, 1.2, and 0.8 kb) were detected using a WDSV LTR-specific probe. By RT-PCR and Southern blot analysis, three cDNAs (2.4, 1.6 and 0.8 kb) were identified, including both orf a and orf b messenger. Furthermore stable co-transfection of both a human lung adenocarcinoma cell line (SPC-A-1) and a cervical cancer cell line (HeLa) with pcDNA3 and ether porfA or pWDSV also generated fewer and smaller G418-resistant colonies. We conclude that expression of the full-length WDSV clone or the orf a gene inhibits the host fish and human tumor cell growth, and Orf A protein maybe a potential factor which contributes to the seasonal tumor development and regression. This is the first fish provirus clone that has been expressed in cell culture system, which will provide a new in vitro model for tumor research and oncotherapy study.

Larval Population Density Alters Adult Sleep in Wild-Type Drosophila melanogaster but Not in Amnesiac Mutant Flies

PubMed Central

Chi, Michael W.; Griffith, Leslie C.; Vecsey, Christopher G.

2014-01-01

Sleep has many important biological functions, but how sleep is regulated remains poorly understood. In humans, social isolation and other stressors early in life can disrupt adult sleep. In fruit flies housed at different population densities during early adulthood, social enrichment was shown to increase subsequent sleep, but it is unknown if population density during early development can also influence adult sleep. To answer this question, we maintained Drosophila larvae at a range of population densities throughout larval development, kept them isolated during early adulthood, and then tested their sleep patterns. Our findings reveal that flies that had been isolated as larvae had more fragmented sleep than those that had been raised at higher population densities. This effect was more prominent in females than in males. Larval population density did not affect sleep in female flies that were mutant for amnesiac, which has been shown to be required for normal memory consolidation, adult sleep regulation, and brain development. In contrast, larval population density effects on sleep persisted in female flies lacking the olfactory receptor or83b, suggesting that olfactory signals are not required for the effects of larval population density on adult sleep. These findings show that population density during early development can alter sleep behavior in adulthood, suggesting that genetic and/or structural changes are induced by this developmental manipulation that persist through metamorphosis. PMID:25116571

Larval Population Density Alters Adult Sleep in Wild-Type Drosophila melanogaster but Not in Amnesiac Mutant Flies.

PubMed

Chi, Michael W; Griffith, Leslie C; Vecsey, Christopher G

2014-08-11

Sleep has many important biological functions, but how sleep is regulated remains poorly understood. In humans, social isolation and other stressors early in life can disrupt adult sleep. In fruit flies housed at different population densities during early adulthood, social enrichment was shown to increase subsequent sleep, but it is unknown if population density during early development can also influence adult sleep. To answer this question, we maintained Drosophila larvae at a range of population densities throughout larval development, kept them isolated during early adulthood, and then tested their sleep patterns. Our findings reveal that flies that had been isolated as larvae had more fragmented sleep than those that had been raised at higher population densities. This effect was more prominent in females than in males. Larval population density did not affect sleep in female flies that were mutant for amnesiac, which has been shown to be required for normal memory consolidation, adult sleep regulation, and brain development. In contrast, larval population density effects on sleep persisted in female flies lacking the olfactory receptor or83b, suggesting that olfactory signals are not required for the effects of larval population density on adult sleep. These findings show that population density during early development can alter sleep behavior in adulthood, suggesting that genetic and/or structural changes are induced by this developmental manipulation that persist through metamorphosis.

Lower leg muscle density is independently associated with fall status in community-dwelling older adults.

PubMed

Frank-Wilson, A W; Farthing, J P; Chilibeck, P D; Arnold, C M; Davison, K S; Olszynski, W P; Kontulainen, S A

2016-07-01

Muscle density is a risk factor for fractures in older adults; however, its association with falls is not well described. After adjusting for biologically relevant confounding factors, a unit decrease in muscle density was associated with a 17 % increase in odds of reporting a fall, independent of functional mobility. Falls are the leading cause of injury, disability, and fractures in older adults. Low muscle density (i.e., caused by muscle adiposity) and functional mobility have been identified as risk factors for incident disability and fractures in older adults; however, it is not known if these are also independently associated with falls. The purpose of this study was to explore the associations of muscle density and functional mobility with fall status. Cross-sectional observational study of 183 men and women aged 60-98 years. Descriptive data, including a 12-month fall recall, Timed Up and Go (TUG) test performance, lower leg muscle area, and density. Odds ratio (OR) of being a faller were calculated, adjusted for age, sex, body mass index, general health status, diabetes, and comorbidities. Every mg/cm(3) increase in muscle density (mean 70.2, SD 2.6 mg/cm(3)) independently reduced the odds of being a faller by 19 % (OR 0.81 [95 % CI 0.67 to 0.97]), and every 1 s longer TUG test time (mean 9.8, SD 2.6 s) independently increased the odds by 17 % (OR 1.17 [95 % CI 1.01 to 1.37]). When both muscle density and TUG test time were included in the same model, only age (OR 0.93 [95 % CI 0.87 to 0.99]) and muscle density (OR 0.83 [95 % CI 0.69 to 0.99]) were independently associated with fall status. Muscle density was associated with fall status, independent of functional mobility. Muscle density may compliment functional mobility tests as a biometric outcome for assessing fall risk in well-functioning older adults.

Three-dimensional temporal and spatial distribution of adult Rhyzopertha dominica in stored wheat and corn under different temperatures, moisture contents, and adult densities.

PubMed

Jian, Fuji; Larson, Ron; Jayas, Digvir S; White, Noel D G

2012-08-01

Three-dimensional temporal and spatial distributions of adult Rhyzopertha dominica (F.) at adult densities of 1.0, 5.0, and 10.0 adults per kg grain and at 20 +/- 1, 25 +/- 1, and 30 +/- 1 degrees C were determined in 1.5 t bins filled with wheat (Triticum aestivum L.) with 11.0 +/- 0.8, 13.0 +/- 0.6, and 15.0 +/- 0.5% moisture content (wet basis) or corn (Zea mays L.) with 13.0 +/- 0.2% moisture content (wet basis). At each of five sampled locations, grain was separated into three 15-kg vertical layers, and adult numbers in each layer were counted. Inside both corn and wheat, adults did not prefer any location in the same layer except at high introduced insect density in wheat. The adults were recovered from any layer of the corn and >12, 65, and 45% of adults were recovered in the bottom layer of the corn at 20, 25, and 30 degrees C; respectively. However, <1% of adults were recovered in the bottom layer of wheat. Numbers of adults correlated with those in adjacent locations in both vertical and horizontal directions, and the temporal continuous property existed in both wheat and corn. Adults had highly clumped distribution at any grain temperature and moisture content. This aggregation behavior decreased with the increase of adult density and redistribution speed. Grain type influenced their redistribution speed, and this resulted in the different redistribution patterns inside wheat and corn bulks. These characterized distribution patterns could be used to develop sampling plans and integrated pest management programs in stored grain bins.

Estimated loss of juvenile salmonids to predation by northern squawfish, walleyes, and smallmouth bass in John Day Reservoir, Columbia River

USGS Publications Warehouse

Rieman, Bruce E.; Beamesderfer, Raymond C.; Vigg, Steven; Poe, Thomas P.

1991-01-01

We estimated the loss of juvenile salmonids Oncorhynchus spp. to predation by northern squawfish Ptychocheilus oregonensis, walleyes Stizostedion vitreum, and smallmouth bass Micropterus dolomieu in John Day Reservoir during 1983–1986. Our estimates were based on measures of daily prey consumption, predator numbers, and numbers of juvenile salmonids entering the reservoir during the April–August period of migration. We estimated the mean annual loss was 2.7 million juvenile salmonids (95% confidence interval, 1.9–3.3 million). Northern squawfish were responsible for 78% of the total loss; walleyes accounted for 13% and smallmouth bass for 9%. Twenty-one percent of the loss occurred in a small area immediately below McNary Dam at the head of John Day Reservoir. We estimated that the three predator species consumed 14% (95% confidence interval, 9–19%) of all juvenile salmonids that entered the reservoir. Mortality changed by month and increased late in the migration season. Monthly mortality estimates ranged from 7% in June to 61% in August. Mortality from predation was highest for chinook salmon O. tshawytscha, which migrated in July and August. Despite uncertainties in the estimates, it is clear that predation by resident fish predators can easily account for previously unexplained mortality of out-migrating juvenile salmonids. Alteration of the Columbia River by dams and a decline in the number of salmonids could have increased the fraction of mortality caused by predation over what it was in the past.

Diet dynamics of the adult piscivorous fish community in Spirit Lake, Iowa, USA 1995-1997

USGS Publications Warehouse

Liao, H.; Pierce, C.L.; Larscheid, J.G.

2002-01-01

Diets of adults of six important piscivorous fish species, black crappie Pomoxis nigromaculatus, largemouth bass Micropterus salmoides, northern pike Esox lucius, smallmouth bass Micropterus dolomieui, walleye Stizostedion vitreum, and yellow perch Perca flavescens were quantified in Spirit Lake, Iowa, USA from May to October in 1995-1997. Forty-one prey taxa were found in the diets of these species, including 19 species of fish. The most important prey taxa overall were yellow perch, amphipods and dipterans. Diets of northern pike and walleye were dominated by yellow perch. Largemouth bass diets included large percentages of both yellow perch and black bullhead Ameiurus melas. Smallmouth bass diets included large percentages of both yellow perch and crayfish. Black crappie and yellow perch diets were dominated by invertebrates, primarily amphipods and dipterans. There were pronounced differences in diets among species, among size classes within species and over time. Most of the dominant prey taxa we documented in the diets of piscivorous species were in accordance with previous studies, but a few deviated significantly from expectations. Many of the temporal diet changes were asynchronous among piscivorous species and size classes, suggesting different responses to common prey resources over time.

Stock-specific advection of larval walleye (Sander vitreus) in western Lake Erie: Implications for larval growth, mixing, and stock discrimination

USGS Publications Warehouse

Fraker, Michael E.; Anderson, Eric J.; May, Cassandra J.; Chen, Kuan-Yu; Davis, Jeremiah J.; DeVanna, Kristen M.; DuFour, Mark R.; Marschall, Elizabeth A.; Mayer, Christine M.; Miner, Jeffery G.; Pangle, Kevin L.; Pritt, Jeremy J.; Roseman, Edward F.; Tyson, Jeffrey T.; Zhao, Yingming; Ludsin, Stuart A

2015-01-01

Physical processes can generate spatiotemporal heterogeneity in habitat quality for fish and also influence the overlap of pre-recruit individuals (e.g., larvae) with high-quality habitat through hydrodynamic advection. In turn, individuals from different stocks that are produced in different spawning locations or at different times may experience dissimilar habitat conditions, which can underlie within- and among-stock variability in larval growth and survival. While such physically-mediated variation has been shown to be important in driving intra- and inter-annual patterns in recruitment in marine ecosystems, its role in governing larval advection, growth, survival, and recruitment has received less attention in large lake ecosystems such as the Laurentian Great Lakes. Herein, we used a hydrodynamic model linked to a larval walleye (Sander vitreus) individual-based model to explore how the timing and location of larval walleye emergence from several spawning sites in western Lake Erie (Maumee, Sandusky, and Detroit rivers; Ohio reef complex) can influence advection pathways and mixing among these local spawning populations (stocks), and how spatiotemporal variation in thermal habitat can influence stock-specific larval growth. While basin-wide advection patterns were fairly similar during 2011 and 2012, smaller scale advection patterns and the degree of stock mixing varied both within and between years. Additionally, differences in larval growth were evident among stocks and among cohorts within stocks which were attributed to spatiotemporal differences in water temperature. Using these findings, we discuss the value of linked physical–biological models for understanding the recruitment process and addressing fisheries management problems in the world's Great Lakes.

Dietary Energy Density in the Australian Adult Population from National Nutrition Surveys 1995 to 2012.

PubMed

Grech, Amanda Lee; Rangan, Anna; Allman-Farinelli, Margaret

2017-12-01

It is hypothesized that the observed proliferation of energy-dense, nutrient-poor foods globally is an important contributing factor to the development of the obesity epidemic. However, evidence that the population's dietary energy density has increased is sparse. The World Cancer Research Fund recommends that dietary energy density be <1.25 kcal/g to prevent weight gain. The aim of this research was to determine whether the dietary energy density of the Australian population has changed between 1995 and 2012. A secondary analysis of two cross-sectional Australian national nutrition surveys from 1995 and 2011/2012 was conducted. Participants of the surveys included adults aged 18 years and older (1995 n=10,986 and 2011/2012 n=9,435) completing 24-hour dietary recalls, including a second recall for a subset of the population (10.4% in 1995 and 64.6% in 2011/2012). Outcome measures included the change in dietary energy density (calculated as energy/weight of food [kcal/g] for food only) between surveys. The National Cancer Institute method for "estimating ratios of two dietary components that are consumed nearly every day" was used to determine the usual distribution and the percentage of participants reporting energy density <1.25 kcal/g. The mean (standard deviation) dietary energy density was 1.59 (0.26) kcal/g and 1.64 (0.32) kcal/g (P<0.0001) in 1995 and 2011/2012, respectively, with 13% and 5% (P<0.0001) of the population meeting dietary energy-density recommendations. For those aged 70 years and older, the percentage with energy density <1.25 kcal/g decreased from 22% to 6% (P<0.0001) for men and from 33% to 11% (P<0.0001) for women in 1995 and 2011/2012, respectively. Among those aged 18 to 29 years, 1% of men in both surveys (P=0.8) and 4% of women in 1995 and 2% in 2011/2012 (P=0.01) reported energy density <1.25 kcal/g. Dietary energy density has increased between the two surveys and few people consumed low energy-dense diets in line with recommendations

Calf muscle density is independently associated with physical function in overweight and obese older adults.

PubMed

Scott, David; Shore-Lorenti, Catherine; McMillan, Lachlan B; Mesinovic, Jakub; Clark, Ross A; Hayes, Alan; Sanders, Kerrie M; Duque, Gustavo; Ebeling, Peter R

2018-03-01

To determine whether associations of calf muscle density with physical function are independent of other determinants of functional decline in overweight and obese older adults. This was a secondary analysis of a cross-sectional study of 85 community-dwelling overweight and obese adults (mean±SD age 62.8±7.9 years; BMI 32.3±6.1 kg/m2; 58% women). Peripheral quantitative computed tomography assessed mid-calf muscle density (66% tibial length) and dual-energy X-ray absorptiometry determined visceral fat area. Fasting glucose, Homeostatic Model Assessment of Insulin Resistance (HOMA-IR) and C-reactive protein (CRP) were analysed. Physical function assessments included hand grip and knee extension strength, balance path length (computerised posturography), stair climb test, Short Physical Performance Battery (SPPB) and self-reported falls efficacy (Modified Falls Efficacy Scale; M-FES). Visceral fat area, not muscle density, was independently associated with CRP and fasting glucose (B=0.025; 95% CI 0.009-0.042 and B=0.009; 0.001-0.017, respectively). Nevertheless, higher muscle density was independently associated with lower path length and stair climb time, and higher SPPB and M-FES scores (all P⟨0.05). Visceral fat area, fasting glucose and CRP did not mediate these associations. Higher calf muscle density predicts better physical function in overweight and obese older adults independent of insulin resistance, visceral adiposity or inflammation.

Childhood factors associated with mammographic density in adult women.

PubMed

Lope, Virginia; Pérez-Gómez, Beatriz; Moreno, María Pilar; Vidal, Carmen; Salas-Trejo, Dolores; Ascunce, Nieves; Román, Isabel González; Sánchez-Contador, Carmen; Santamariña, María Carmen; Carrete, Jose Antonio Vázquez; Collado-García, Francisca; Pedraz-Pingarrón, Carmen; Ederra, María; Ruiz-Perales, Francisco; Peris, Mercé; Abad, Soledad; Cabanes, Anna; Pollán, Marina

2011-12-01

Growth and development factors could contribute to the development of breast cancer associated with an increase in mammographic density. This study examines the influence of certain childhood-related, socio-demographic and anthropometric variables on mammographic density in adult woman. The study covered 3574 women aged 45-68 years, participating in breast cancer-screening programmes in seven Spanish cities. Based on a craniocaudal mammogram, blind, anonymous measurement of mammographic density was made by a single radiologist, using Boyd's semiquantitative scale. Data associated with the early stages of life were obtained from a direct survey. Ordinal logistic regression and generalised linear models were employed to estimate the association between mammographic density and the variables covered by the questionnaire. Screening programme was introduced as a random effects term. Age, number of children, body mass index (BMI) and other childhood-related variables were used as adjustment variables, and stratified by menopausal status. A total of 811 women (23%) presented mammographic density of over 50%, and 5% of densities exceeded 75%. Our results show a greater prevalence of high mammographic density in women with low prepubertal weight (OR: 1.18; 95% CI: 1.02-1.36); marked prepubertal height (OR: 1.25; 95% CI: 0.97-1.60) and advanced age of their mothers at their birth (>39 years: OR: 1.28; 95% CI: 1.03-1.60); and a lower prevalence of high mammographic density in women with higher prepubertal weight, low birth weight and earlier menarche. The influence of these early-life factors may be explained by greater exposure to hormones and growth factors during the development of the breast gland, when breast tissue would be particularly susceptible to proliferative and carcinogenic stimulus.

Fluctuations in production and abundance of commercial species in the Red Lakes, Minnesota, with special reference to changes in the walleye population

USGS Publications Warehouse

Smith, Lloyd L.; Krefting, Laurits W.

1954-01-01

The Red Lakes in northwestern Minnesota comprise 275,000 acres of water which support a commercial fishery producing up to 1.5 million pounds of fish per year. Walleye, Stizostedion vitreum vitreum (Mitchill), and yellow perch, Perca flavescens (Mitchill), are the principal species. Statistics for the past 37 years have been analyzed and fluctuations in the abundance of the important species calculated for the 24-year period, 1930–1953. The fishing is carried on exclusively with 3 1/2-inch-mesh (extension measure) gill nets by Chippewa Indians and the catch is marketed through a cooperative fishery enterprise. There have been wide fluctuations in the abundance of principal species but, although fishing effort has increased greatly during the past few years no trends have developed. Changes in walleye abundance have been shown to be independent of changes or levels of fishing effort, and to be determined by strength of individual year classes. Gear competition has no effect on abundance estimates. Strength of year classes is not correlated with size of brood stock, abundance of competing species, or amount of hatchery fish planted. Weather conditions cannot be correlated with observed changes in strength of year classes. Implications for management include provision of adequate prediction of abundance, and annual adjustment of fishing practices to make greatest use of the available stock. Gear limitations should be designed to secure harvest at optimum size of fish and to provide a suitable economic status for the fisherman.

Total and High-Density Lipoprotein Cholesterol in Adults with Mental Retardation.

ERIC Educational Resources Information Center

Rimmer, James H.; Kelly, Luke E.

1990-01-01

The study evaluated the total cholesterol and high density lipoprotein cholesterol of 40 adults (mean age 37.5 years) with mental retardation residing at an intermediate care facility. Results indicated that 59 percent of the males and 68 percent of the females were at moderate to high risk for coronary heart disease. (DB)

Localization and seasonal variation of blue pigment (sandercyanin) in walleye (Sander vitreus)

USGS Publications Warehouse

Schaefer, Wayne; Schmitz, Mark; Blazer, Vicki S.; Ehlinger, Tim; Berges, John

2015-01-01

Several fish species, including the walleye (Sander vitreus), have “yellow” and “blue” color morphs. In S. vitreus, one source of the blue color has been identified as a bili-binding protein pigment (sandercyanin), found in surface mucus of the fish. Little is known about the production of the pigment or about its functions. We examined the anatomical localization and seasonal variation of sandercyanin in S. vitreus from a population in McKim Lake, northwestern Ontario, Canada. Skin sections were collected from 20 fish and examined histologically. Mucus was collected from 306 fish over 6 years, and the amount of sandercyanin was quantified spectrophotometrically. Sandercyanin was found solely on dorsal surfaces of the fish and was localized to novel cells in the epidermis, similar in appearance to secretory sacciform cells. Sandercyanin concentrations were significantly higher in fish collected in summer versus other seasons. Yellow and blue morphs did not differ in amounts of sandercyanin, suggesting that the observed blue color, in fact, arises from lack of yellow pigmentation in blue morphs. The function of the sandercyanin remains unclear, but roles in photoprotection and countershading are consistent with available data.

Association between sleep duration, insomnia symptoms and bone mineral density in older Puerto Rican adults

USDA-ARS?s Scientific Manuscript database

Objective: To examine the association between sleep patterns (sleep duration and insomnia symptoms) and total and regional bone mineral density (BMD) among older Boston Puerto Rican adults. Materials/Methods: We conducted a cross-sectional study including 750 Puerto Rican adults, aged 47–79 y livi...

Bone Density in Adolescents and Young Adults with Autism Spectrum Disorders

ERIC Educational Resources Information Center

Ekhlaspour, Laya; Baskaran, Charumathi; Campoverde, Karen Joanie; Sokoloff, Natalia Cano; Neumeyer, Ann M.; Misra, Madhusmita

2016-01-01

Patients with autism spectrum disorder (ASD) are at increased risk for fracture, and peri-pubertal boys with ASD have lower bone mineral density (BMD) than controls. Data are lacking regarding BMD in older adolescents with ASD. We compared BMD using dual-energy X-ray absorptiometry in 9 adolescents/young adults with ASD against 9 typically…

Locus Coeruleus Neuron Density and Parkinsonism in Older Adults without Parkinson’s Disease

PubMed Central

Buchman, Aron S.; Nag, Sukriti; Shulman, Joshua M.; Lim, Andrew S.P.; VanderHorst, Veronique G.J.M.; Leurgans, Sue E.; Schneider, Julie A.; Bennett, David A.

2013-01-01

Objective Prior work has showed that nigral neuron density is related to the severity of parkinsonism proximate to death in older persons without a clinical diagnosis of Parkinson’s disease (PD). We tested the hypothesis that neuron density in other brainstem aminergic nuclei is also related to the severity of parkinsonism. Design We studied brain autopsies from 125 deceased older adults without PD enrolled in the Memory and Aging Project, a clinical-pathologic investigation. Parkinsonism was assessed with a modified version of the Unified Parkinson’s Disease Rating Scale (UPDRS). We measured neuron density in the substantia nigra, ventral tegmental area, locus coeruleus and dorsal raphe; and postmortem indices of Lewy body Alzheimer’s disease and cerebrovascular pathologies. Results Mean age at death was 88.0 and global parkinsonism was 14.8 (SD=9.50). In a series of regression models which controlled for demographics and neuron density in the substantia nigra, neuron density in the locus coeruleus (Estimate, −0.261, S.E., 0.117, p=0.028) but not in the ventral tegmental area or dorsal raphe was associated with the severity of global parkinsonism proximate to death. These findings were unchanged in models which controlled for post-mortem interval, whole brain weight and other common neuropathologies including Alzheimer’s disease and Lewy body pathology and cerebrovascular vascular pathologies. Conclusion In older adults without a clinical diagnosis of PD, neuron density in locus coeruleus nuclei is associated with the severity of parkinsonism and may contribute to late-life motor impairments. PMID:23038629

Adult trees cause density-dependent mortality in conspecific seedlings by regulating the frequency of pathogenic soil fungi.

PubMed

Liang, Minxia; Liu, Xubing; Gilbert, Gregory S; Zheng, Yi; Luo, Shan; Huang, Fengmin; Yu, Shixiao

2016-12-01

Negative density-dependent seedling mortality has been widely detected in tropical, subtropical and temperate forests, with soil pathogens as a major driver. Here we investigated how host density affects the composition of soil pathogen communities and consequently influences the strength of plant-soil feedbacks. In field censuses of six 1-ha permanent plots, we found that survival was much lower for newly germinated seedlings that were surrounded by more conspecific adults. The relative abundance of pathogenic fungi in soil increased with increasing conspecific tree density for five of nine tree species; more soil pathogens accumulated around roots where adult tree density was higher, and this greater pathogen frequency was associated with lower seedling survival. Our findings show how tree density influences populations of soil pathogens, which creates plant-soil feedbacks that contribute to community-level and population-level compensatory trends in seedling survival. © 2016 John Wiley & Sons Ltd/CNRS.

Bone mineral density of vegetarian and non-vegetarian adults in Taiwan.

PubMed

Wang, Yuh-Feng; Chiu, Jainn-Shiun; Chuang, Mei-Hua; Chiu, Jing-Er; Lin, Chin-Lon

2008-01-01

Diet is thought to be one of the leading causes of bone mineral loss in aging people. In this study, we explored the potential impact of a vegetarian diet on bone mineral density (BMD) in adult Taiwanese men and women. This was a cross-sectional study of the relationship between diet (vegetarian versus non-vegetarian) and BMD and the incidence of osteoporosis. Bone mineral density was determined in a cohort of 1865 adult male and female patients who underwent routine examination in a regional teaching hospital in Taiwan between February 2003 and February 2004. Subjects with definite vertebral problems, known osteopathy, or poor posture were excluded. Dual-energy X-ray absorptiometry (DEXA) was used to determine BMD, on the right hip in men and on lumbar vertebrae L2 to L4 in women. The subjects were grouped according to sex and diet, and were then stratified by age within each of the four groups. The outcome measures were the BMD value and the incidence of osteopenia or osteoporosis according to defined criteria. Bone mineral density gradually declined with increasing age in Taiwanese men, while Taiwanese women showed a precipitous decrease in BMD after the 5th decade. However, no statistical differences in BMD were observed between vegetarians and non-vegetarians of either sex. The proportion of subjects with osteopenia or osteoporosis also appeared comparable between vegetarians and non-vegetarians of either sex. BMD shows an age-related decline in Taiwanese men and women, and eating a vegetarian diet does not appear to affect this decline.

Whole-brain grey matter density predicts balance stability irrespective of age and protects older adults from falling.

PubMed

Boisgontier, Matthieu P; Cheval, Boris; van Ruitenbeek, Peter; Levin, Oron; Renaud, Olivier; Chanal, Julien; Swinnen, Stephan P

2016-03-01

Functional and structural imaging studies have demonstrated the involvement of the brain in balance control. Nevertheless, how decisive grey matter density and white matter microstructural organisation are in predicting balance stability, and especially when linked to the effects of ageing, remains unclear. Standing balance was tested on a platform moving at different frequencies and amplitudes in 30 young and 30 older adults, with eyes open and with eyes closed. Centre of pressure variance was used as an indicator of balance instability. The mean density of grey matter and mean white matter microstructural organisation were measured using voxel-based morphometry and diffusion tensor imaging, respectively. Mixed-effects models were built to analyse the extent to which age, grey matter density, and white matter microstructural organisation predicted balance instability. Results showed that both grey matter density and age independently predicted balance instability. These predictions were reinforced when the level of difficulty of the conditions increased. Furthermore, grey matter predicted balance instability beyond age and at least as consistently as age across conditions. In other words, for balance stability, the level of whole-brain grey matter density is at least as decisive as being young or old. Finally, brain grey matter appeared to be protective against falls in older adults as age increased the probability of losing balance in older adults with low, but not moderate or high grey matter density. No such results were observed for white matter microstructural organisation, thereby reinforcing the specificity of our grey matter findings. Copyright © 2016 Elsevier B.V. All rights reserved.

Link between Food Energy Density and Body Weight Changes in Obese Adults

PubMed Central

Stelmach-Mardas, Marta; Rodacki, Tomasz; Dobrowolska-Iwanek, Justyna; Brzozowska, Anna; Walkowiak, Jarosław; Wojtanowska-Krosniak, Agnieszka; Zagrodzki, Paweł; Bechthold, Angela; Mardas, Marcin; Boeing, Heiner

2016-01-01

Regulating the energy density of food could be used as a novel approach for successful body weight reduction in clinical practice. The aim of this study was to conduct a systemic review of the literature on the relationship between food energy density and body weight changes in obese adults to obtain solid evidence supporting this approach. The search process was based on the selection of publications in the English language listed in public databases. A meta-analysis was performed to combine individual study results. Thirteen experimental and observational studies were identified and included in the final analysis. The analyzed populations consist of 3628 individuals aged 18 to 66 years. The studies varied greatly in terms of study populations, study design and applied dietary approaches. The meta-analysis revealed a significant association between low energy density foods and body weight reduction, i.e., −0.53 kg when low energy density foods were eaten (95% CI: −0.88, −0.19). In conclusions, this study adds evidence which supports the energy density of food as a simple but effective measure to manage weight in the obese with the aim of weight reduction. PMID:27104562

Serum bicarbonate and bone mineral density in US adults.

PubMed

Chen, Wei; Melamed, Michal L; Abramowitz, Matthew K

2015-02-01

Chronic metabolic acidosis leads to bone mineral loss and results in lower bone mineral density (BMD), which is a risk factor for osteoporosis-related fractures. The effect of low-level metabolic acidosis on bone density in the general population is unknown. Cross-sectional study. 9,724 nationally representative adults 20 years or older in NHANES (National Health and Nutrition Examination Survey) 1999-2004. Serum bicarbonate level. Lumbar and total BMD, as well as low lumbar and total bone mass, defined as 1.0 SD below the sex-specific mean value of young adults. BMD was measured by dual-energy x-ray absorptiometry and serum bicarbonate was measured in all participants. Both men and women with lower serum bicarbonate levels were more likely to be current smokers and had higher body mass index and estimated net endogenous acid production. There was a significant linear trend across quartiles of serum bicarbonate with lumbar BMD in the total population, as well as in sex-specific models (P=0.02 for all 3 models, P=0.1 for interaction). For total BMD, a significant association was seen with serum bicarbonate level for women but not men (P=0.02 and P=0.1, respectively; P=0.8 for interaction), and a significant association was seen for postmenopausal women but not premenopausal women (P=0.02 and P=0.2, respectively; P=0.5 for interaction). Compared with women with serum bicarbonate levels <24mEq/L, those with serum bicarbonate levels ≥27mEq/L had 0.018-g/cm(2) higher total BMD (95% CI, 0.004-0.032; P=0.01) and 31% lower odds of having low total bone mass (OR, 0.68; 95% CI, 0.46-0.99; P=0.049). Cross-sectional study using a single measurement of serum bicarbonate. Subgroup differences are not definitive. Lower serum bicarbonate levels are associated with lower BMD in US adults. Further studies should examine whether serum bicarbonate levels should be incorporated into the diagnostic assessment and management of osteoporosis. Copyright © 2015 National Kidney Foundation

Serum Bicarbonate and Bone Mineral Density in US Adults

PubMed Central

Chen, Wei; Melamed, Michal L.; Abramowitz, Matthew K.

2014-01-01

Background Chronic metabolic acidosis leads to bone mineral loss and results in lower bone mineral density (BMD), which is a risk factor for osteoporosis-related fractures. The effect of low-level metabolic acidosis on bone density in the general population is unknown. Study Design Cross-sectional study. Setting & Participants 9,724 nationally representative adults aged 20 years or older in the National Health and Nutrition Examination Survey 1999-2004. Factor Serum bicarbonate level. Outcomes Lumbar and total BMD as well as low lumbar and total bone mass defined as 1.0 SD below sex-specific mean of young adults. Measurements BMD was measured by dual-energy X-ray absorptiometry and serum bicarbonate levels were measured in all participants. Results Both men and women with lower serum bicarbonate levels were more likely to be current smokers and had higher body mass index and estimated net endogenous acid production. There was a significant linear trend across quartiles of serum bicarbonate with lumbar BMD among the total population as well as in sex-specific models (p=0.02 for all three models, p=0.1 for interaction). For total BMD, a significant association was seen with serum bicarbonate levels among women but not men (p=0.02 and p=0.1, respectively; p=0.8 for interaction); and a significant association was seen among post-menopausal women but not pre-menopausal women (p=0.02 and p=0.2, respectively; p=0.5 for interaction). Compared to women with serum bicarbonate level <24 mEq/L, those with serum bicarbonate ≥27 mEq/L had 0.018 g/cm2 higher total BMD (95% CI, 0.004-0.032; p=0.01) and had 31% lower odds of having low total bone mass (OR, 0.68; 95% CI, 0.46-0.99; p=0.05). Limitations Cross-sectional study using a single measurement of serum bicarbonate level. The subgroup differences are not definitive. Conclusions Lower serum bicarbonate levels are associated with lower BMD in US adults. Further studies should examine whether serum bicarbonate levels should be

Increased energy density of the home-delivered lunch meal improves 24-hour nutrient intakes in older adults.

PubMed

Silver, Heidi J; Dietrich, Mary S; Castellanos, Victoria H

2008-12-01

As food intake declines with aging, older adults develop energy and nutrient inadequacies. It is important to design practical approaches to combat insufficient dietary intakes to decrease risk for acute and chronic diseases, illness, and injury. Manipulating the energy density of meals has improved energy intakes in institutional settings, but the effects on community-residing older adults who are at nutrition risk have not been investigated. The aim of this study was to determine whether enhancing the energy density of food items regularly served in a home-delivered meals program would increase lunch and 24-hour energy and nutrient intakes. In a randomized crossover counterbalanced design, 45 older adult Older American Act Nutrition Program participants received a regular and enhanced version of a lunch meal on alternate weeks. The types of foods, portion sizes (gram weight), and appearance of the lunch meal was held constant. Consumption of the enhanced meal increased average lunch energy intakes by 86% (P<0.001) and 24-hour energy intakes by 453 kcal (from 1,423.1+/-62.2 to 1,876.2+/-78.3 kcal, P<0.001). The 24-hour intakes of several key macronutrients and micronutrients also improved. These data suggest that altering the energy density of regularly served menu items is an effective strategy to improve dietary intakes of free-living older adults.

Latent Profiles of Macronutrient Density and their Association with Mobility Limitations in an Observational Longitudinal Study of Older U.S. Adults.

PubMed

Bishop, N J; Zuniga, K E; Lucht, A L

2018-01-01

Our first objective was to estimate empirically-derived subgroups (latent profiles) of observed carbohydrate, protein, and fat intake density in a nationally representative sample of older U.S. adults. Our second objective was to determine whether membership in these groups was associated with levels of, and short term change in, physical mobility limitations. Measures of macronutrient density were taken from the 2013 Health Care and Nutrition Study, an off-year supplement to the Health and Retirement Study, which provided indicators of physical mobility limitations and sociodemographic and health-related covariates. 3,914 community-dwelling adults age 65 years and older. Percent of daily calories from carbohydrate, protein, and fat were calculated based on responses to a modified Harvard food frequency questionnaire. Latent profile analysis was used to describe unobserved heterogeneity in measures of carbohydrate, protein, and fat density. Mobility limitation counts were based on responses to 11 items indicating physical limitations. Poisson regression models with autoregressive controls were used to identify associations between macronutrient density profile membership and mobility limitations. Sociodemographic and health-related covariates were included in all Poisson regression models. Four latent subgroups of macronutrient density were identified: "High Carbohydrate", "Moderate with Fat", "Moderate", and "Low Carbohydrate/High Fat". Older adults with the lowest percentage of daily calories coming from carbohydrate and the greatest percentage coming from fat ("Low Carbohydrate/High Fat") were found to have greater reported mobility limitations in 2014 than those identified as having moderate macronutrient density, and more rapid two-year increases in mobility limitations than those identified as "Moderate with Fat" or "Moderate". Older adults identified as having the lowest carbohydrate and highest fat energy density were more likely to report a greater number

Low Bone Mineral Density Risk Factors and Testing Patterns in Institutionalized Adults with Intellectual and Developmental Disabilities

ERIC Educational Resources Information Center

Hess, Mailee; Campagna, Elizabeth J.; Jensen, Kristin M.

2018-01-01

Background: Adults with intellectual or developmental disability (ID/DD) have multiple risks for low bone mineral density (BMD) without formal guidelines to guide testing. We sought to identify risk factors and patterns of BMD testing among institutionalized adults with ID/DD. Methods: We evaluated risk factors for low BMD (Z-/T-score < -1) and…

Social Inclusion Predicts Lower Blood Glucose and Low-Density Lipoproteins in Healthy Adults.

PubMed

Floyd, Kory; Veksler, Alice E; McEwan, Bree; Hesse, Colin; Boren, Justin P; Dinsmore, Dana R; Pavlich, Corey A

2017-08-01

Loneliness has been shown to have direct effects on one's personal well-being. Specifically, a greater feeling of loneliness is associated with negative mental health outcomes, negative health behaviors, and an increased likelihood of premature mortality. Using the neuroendocrine hypothesis, we expected social inclusion to predict decreases in both blood glucose levels and low-density lipoproteins (LDLs) and increases in high-density lipoproteins (HDLs). Fifty-two healthy adults provided self-report data for social inclusion and blood samples for hematological tests. Results indicated that higher social inclusion predicted lower levels of blood glucose and LDL, but had no effect on HDL. Implications for theory and practice are discussed.

A spatial analysis of the association between restaurant density and body mass index in Canadian adults.

PubMed

Hollands, Simon; Campbell, M Karen; Gilliland, Jason; Sarma, Sisira

2013-10-01

To investigate the association between fast-food restaurant density and adult body mass index (BMI) in Canada. Individual-level BMI and confounding variables were obtained from the 2007-2008 Canadian Community Health Survey master file. Locations of the fast-food and full-service chain restaurants and other non-chain restaurants were obtained from the 2008 Infogroup Canada business database. Food outlet density (fast-food, full-service and other) per 10,000 population was calculated for each Forward Sortation Area (FSA). Global (Moran's I) and local indicators of spatial autocorrelation of BMI were assessed. Ordinary least squares (OLS) and spatial auto-regressive error (SARE) methods were used to assess the association between local food environment and adult BMI in Canada. Global and local spatial autocorrelation of BMI were found in our univariate analysis. We found that OLS and SARE estimates were very similar in our multivariate models. An additional fast-food restaurant per 10,000 people at the FSA-level is associated with a 0.022kg/m(2) increase in BMI. On the other hand, other restaurant density is negatively related to BMI. Fast-food restaurant density is positively associated with BMI in Canada. Results suggest that restricting availability of fast-food in local neighborhoods may play a role in obesity prevention. © 2013.

Effects of anesthesia and surgery on serial blood gas values and lactate concentrations in yellow perch (Perca flavescens), walleye pike (Sander vitreus), and koi (Cyprinus carpio).

PubMed

Hanley, Christopher S; Clyde, Victoria L; Wallace, Roberta S; Paul-Murphy, Joanne; Patterson, Tamatha A; Keuler, Nicholas S; Sladky, Kurt K

2010-05-15

OBJECTIVE-To evaluate serial blood gas values and lactate concentrations in 3 fish species undergoing surgery and to compare blood lactate concentrations between fish that survived and those that died during the short-term postoperative period. DESIGN-Prospective cohort study. Animals-10 yellow perch, 5 walleye pike, and 8 koi. PROCEDURES-Blood samples were collected from each fish at 3 time points: before anesthesia, during anesthesia, and immediately after surgery. Blood gas values and blood lactate concentrations were measured. Fish were monitored for 2 weeks postoperatively. RESULTS-All walleye and koi survived, but 2 perch died. Blood pH significantly decreased in perch from before to during anesthesia, but increased back to preanesthesia baseline values after surgery. Blood Pco(2) decreased significantly in perch from before anesthesia to immediately after surgery, and also from during anesthesia to immediately after surgery, whereas blood Pco(2) decreased significantly in koi from before to during anesthesia. Blood Po(2) increased significantly in both perch and koi from before to during anesthesia, and also in koi from before anesthesia to immediately after surgery. For all 3 species, blood lactate concentrations increased significantly from before anesthesia to immediately after surgery. Blood lactate concentration (mean +/- SD) immediately after surgery for the 8 surviving perch was 6.06 +/- 1.47 mmol/L, which was significantly lower than blood lactate concentrations in the 2 nonsurviving perch (10.58 and 10.72 mmol/L). CONCLUSIONS AND CLINICAL RELEVANCE-High blood lactate concentrations following surgery in fish may be predictive of a poor short-term postoperative survival rate.

Summer diet composition of walleye pollock and predator-prey relationships with copepods and euphausiids in the eastern Bering Sea, 1987-2011

NASA Astrophysics Data System (ADS)

Buckley, Troy W.; Ortiz, Ivonne; Kotwicki, Stan; Aydin, Kerim

2016-12-01

The composition of walleye pollock diets from the eastern Bering Sea continental shelf was determined from 25 years of sampling during summer surveys from 1987 through 2011. Substantial differences in the stomach contents of walleye pollock were found among the sizes and geographic strata that correspond to geographic distribution of the prey. With increasing pollock size, copepods decreased in importance in middle and outer shelf areas while mysids decreased in importance in the inner shelf. Euphausiids increased in importance with increasing pollock size in southeastern areas of the shelf, and fishes and shrimp increased in importance with increasing pollock size in northeastern areas of the middle and outer shelf. The biomass-weighted average diet composition of eastern Bering Sea pollock in each year's survey indicated perennial but variable importance of euphausiids and copepods as prey. An index of partial fullness indicated an interannual pattern of below-average consumption of copepods by the surveyed pollock from 1993 to 2004, but during this period the amount of euphausiids consumed continued to fluctuate about a mean that was similar to years surveyed before and after that period. The summer feeding success, as indicated by average stomach fullness, of intermediate sizes of pollock appears to be closely related to the consumption of copepods (especially for pollock 30-39 cm fork length (FL)) and prey other than euphausiids (especially for pollock 40-49 cm FL). Length-specific predator-prey relationships with copepods and euphausiids correspond to patterns in pollock feeding migrations. Interannual trends in the biomass of copepods in the EBS are reflected most closely in the diet of 20-29 cm FL pollock, and trends in the biomass of euphausiids in the EBS are reflected most closely in the diet of the largest pollock (60+ cm FL). Climate-mediated changes in the zooplankton community will likely have differential impacts across the demographic spectrum of

Prevalence of Low High-density Lipoprotein Cholesterol Among Adults, by Physical Activity: United States, 2011-2014.

PubMed

Zwald, Marissa L; Akinbami, Lara J; Fakhouri, Tala H I; Fryar, Chryl D

2017-03-01

Data from the National Health and Nutrition Examination Survey •The prevalence of low high-density lipoprotein (HDL) cholesterol was significantly higher among adults who did not meet recommended physical activity guidelines (21.0%) than adults who met the guidelines (17.7%). •Low HDL cholesterol prevalence differed significantly for both men and women by adherence to physical activity guidelines. •Prevalence of low HDL cholesterol declined as age increased for both those who did and did not meet the physical activity guidelines. •Non-Hispanic white and non-Hispanic black adults who did not meet the physical activity guidelines had a higher prevalence than those who met the guidelines. •Low HDL cholesterol prevalence declined with increasing education level regardless of adherence to physical activity guidelines. Regular physical activity can improve cholesterol levels among adults, including increasing high-density lipoprotein (HDL) cholesterol (1). HDL cholesterol is known as "good" cholesterol because high levels can reduce cardiovascular disease risk (2). The 2008 Physical Activity Guidelines for Americans recommend that adults engage in 150 minutes or more of moderate-intensity aerobic activity per week, 75 minutes of vigorous-intensity aerobic activity per week, or an equivalent combination (3). Adherence to these guidelines is expected to decrease the prevalence of low HDL cholesterol levels (4-8). This report presents national data for 2011-2014 on low HDL cholesterol prevalence among U.S. adults aged 20 and over, by whether they met these guidelines. All material appearing in this report is in the public domain and may be reproduced or copied without permission; citation as to source, however, is appreciated.

Factors related to commercial production of the walleye in Red Lakes, Minnesota

USGS Publications Warehouse

Smith, Lloyd L.; Pycha, Richard L.

1961-01-01

Growth of the walleye (Stizostedion vitreum vitreum) in Red Lakes, Minnesota, over a 17-year period was slower than in other waters of the Great Lakes region and fluctuated annually from 30.7 percent above to 42.2 percent below mean growth. Individual year classes varied considerably in growth rate. Age distribution in 3 1/2-inch stretch-measure commercial nets varied extremely in 9 years' collections and was related to year-class strength and fishing intensity during periods when classes were available for catch. Abundance of different classes varied 23-fold. Annulus formation and resumption of growth occurred from mid-June to late July. Effective growing season did not exceed 4 months and for some individuals in some years was 2 months or less. The catch contained age-groups II-XII but consisted principally of groups IV-VIII. Seasonal changes in age distribution were dependent on growth rate and fishing effort. Total catch was strongly influenced by growth and seasonal distribution of fishing effort. Maximum availability to commercial nets was at a total length of 15.1 inches, but a large percentage of the catch was smaller fish. Total annual mortality rate after fish attained 15.1 inches total length was 0.66, but continued recruitment through group VIII caused apparent change in mortality rate with increasing age up to IX. Maximum harvest could be attained by concentrating fishing effort in the latter part of the growing season. Abundance indices derived from commercial catch will be strongly influenced by the seasonal pattern of fishing.

Development of a walleye spleen stromal cell line sensitive to viral hemorrhagic septicemia virus (VHSV IVb) and to protection by synthetic dsRNA.

PubMed

Vo, Nguyen T K; Bender, Aaron W; Ammendolia, Dustin A; Lumsden, John S; Dixon, Brian; Bols, Niels C

2015-07-01

A cell line, WE-spleen6, has been developed from the stromal layer of primary spleen cell cultures. On conventional plastic, WE-spleen6 cells had a spindle-shaped morphology at low cell density but grew to become epithelial-like at confluency. On the commercial extracellular matrix (ECM), Matrigel, the cells remained spindle-shaped and formed lumen-like structures. WE-spleen6 cells had intermediate filament protein, vimentin and the ECM protein, collagen I, but not smooth muscle α-actin (SMA) and von Willebrand factor (vWF) and lacked alkaline phosphatase and phagocytic activities. WE-spleen6 was more susceptible to infection with VHSV IVb than a fibroblast and epithelial cell lines from the walleye caudal fin, WE-cfin11f and WE-cfin11e, respectively. Viral transcripts and proteins appeared earlier in WE-spleen6 cultures as did cytopathic effect (CPE) and significant virus production. The synthetic double-stranded RNA (dsRNA), polyinosinic: polycytidylic acid (pIC), induced the antiviral protein Mx in both cell lines. Treating WE-spleen6 cultures with pIC prior to infection with VHSV IVb inhibited the early accumulation of viral transcripts and proteins and delayed the appearance of CPE and significant viral production. Of particular note, pIC caused the disappearance of viral P protein 2 days post infection. WE-spleen6 should be useful for investigating the impact of VHSV IVb on hematopoietic organs and the actions of pIC on the rhabdovirus life cycle. Copyright © 2015 Elsevier Ltd. All rights reserved.

Pneumococcal colonisation density: a new marker for disease severity in HIV-infected adults with pneumonia

PubMed Central

Albrich, Werner C; Madhi, Shabir A; Adrian, Peter V; van Niekerk, Nadia; Telles, Jean-Noel; Ebrahim, N; Messaoudi, Melina; Paranhos-Baccalà, Glaucia; Giersdorf, Sven; Vernet, Guy; Mueller, Beat; Klugman, Keith P

2014-01-01

Objective A high genomic load of Pneumococcus from blood or cerebrospinal fluid has been associated with increased mortality. We aimed to analyse whether nasopharyngeal colonisation density in HIV-infected patients with community-acquired pneumonia (CAP) is associated with markers of disease severity or poor outcome. Methods Quantitative lytA real-time PCR was performed on nasopharyngeal swabs in HIV-infected South African adults hospitalised for acute CAP at Chris Hani Baragwanath Hospital, Soweto, South Africa. Pneumonia aetiology was considered pneumococcal if any sputum culture or Gram stain, urinary pneumococcal C-polysaccharide-based antigen, blood culture or whole blood lytA real-time PCR revealed pneumococci. Results There was a moderate correlation between the mean nasopharyngeal colonisation densities and increasing CURB65 scores among all-cause patients with pneumonia (Spearman correlation coefficient r=0.15, p=0.06) or with the Pitt bacteraemia score among patients with pneumococcal bacteraemia (p=0.63). In patients with pneumococcal pneumonia, nasopharyngeal pneumococcal colonisation density was higher among non-survivors than survivors (7.7 vs 6.1 log10 copies/mL, respectively, p=0.02) and among those who had pneumococci identified from blood cultures and/or by whole blood lytA real-time PCR than those with non-bacteraemic pneumococcal pneumonia (6.6 vs 5.6 log10 copies/mL, p=0.03). Nasopharyngeal colonisation density correlated positively with the biomarkers procalcitonin (Spearman correlation coefficient r=0.37, p<0.0001), proadrenomedullin (r=0.39, p=0.008) and copeptin (r=0.30, p=0.01). Conclusions In addition to its previously reported role as a diagnostic tool for pneumococcal pneumonia, quantitative nasopharyngeal colonisation density also correlates with mortality and prognostic biomarkers. It may also be useful as a severity marker for pneumococcal pneumonia in HIV-infected adults. PMID:25113557

Red cell density is sex and race dependent in the adult.

PubMed

Blumenfeld, N; Fabry, M E; Thysen, B; Nagel, R L

1988-09-01

Using a highly sensitive method for the determination of red cell densities (Percoll-Stractan continuous isopyknic gradients), we find that, in adults, this parameter varies with sex and race. Whites have red cell densities (expressed as mean corpuscular hemoglobin concentration [MCHC]) that are, on the average, 0.7 gm/dl higher than those in blacks (the difference of the means has p less than 2 x 10(-7]. White men have, on the average, 0.6 gm/dl higher MCHC than white women (the difference of the means has p less than 6 x 10(-5]. We find a strong correlation between all red cell densities and intracellular K+ and a slightly weaker correlation between red cell density and intracellular Na+ + K+. Men have an average intraerythrocytic K+ that is approximately 4.5 mmol/L of red cells less than that of women among whites as well as blacks (p less than 10(-5) and p less than 9 x 10(-4), respectively). Blacks have significantly higher plasma ferritin levels than do whites (in addition to the sex difference). Future work will have to dissect the possible causes of these differences, which include the high incidence of deletional alpha-thalassemia (-a/aa) among blacks, menstruation, hormonal effects, and the red cell transport and volume regulation differences between sexes and races. Whatever the cause of the sex and racial differences reported here, they are bound to affect the pathophysiologic expression of genetic red cell diseases that are particularly sensitive to the MCHC, such as the sickle cell syndromes.

The scavenging of free radical and oxygen species activities and hydration capacity of collagen hydrolysates from walleye pollock ( Theragra chalcogramma) skin

NASA Astrophysics Data System (ADS)

Zhuang, Yongliang; Li, Bafang; Zhao, Xue

2009-06-01

Fish skin collagen hydrolysates (FSCH) were prepared from walleye pollock ( Theragra chalcogramma) using a mixture of enzymes, namely trypsin and flavourzyme. The degree of hydrolysis of the skin collagen was 27.3%. FSCH was mainly composed of low-molecular-weight peptides and the relative proportion of <1000Da fraction was 70.6%. Free radical and oxygen species scavenging activities of FSCH were investigated in four model systems, including diphenylpicrylhy-drazyl radical (DPPH), superoxide anion radical, hydroxyl radical and hydrogen peroxide model, and compared with that of a native antioxidant, reduced glutathione (GSH). FSCH was also evaluated by water-absorbing and water-holding capacity. The results showed that FSCH was able to scavenge free radical and oxygen species significantly and to enhance water-absorbing and water-holding capacity remarkably. Therefore, FSCH may have potential applications in the medicine and food industries.

Online Learning from Input versus Offline Memory Evolution in Adult Word Learning: Effects of Neighborhood Density and Phonologically Related Practice

ERIC Educational Resources Information Center

Storkel, Holly L.; Bontempo, Daniel E.; Pak, Natalie S.

2014-01-01

Purpose: In this study, the authors investigated adult word learning to determine how neighborhood density and practice across phonologically related training sets influence online learning from input during training versus offline memory evolution during no-training gaps. Method: Sixty-one adults were randomly assigned to learn low- or…

Evaluation of bone density in the mandibles of young Australian adults of Mongoloid and Caucasoid descent.

PubMed

Ong, R G; Stevenson, M R

1999-01-01

To evaluate the bone density in the mandibles of young Australian adults of Mongoloid and Caucasoid descent. A panoramic radiograph (Orthophos C, Siemens AG, Bensheim, Germany) was obtained of 79 dental students from the School of Oral Health Sciences, The University of Western Australia. Exposure factors were varied for males and females. The films were automatically processed in a single batch and the optical density measured blindly at two locations by two examiners. The optical density was compared by race and sex to detect bone density differences. Individual lifestyle habits (exercise, alcohol consumption, smoking and diet) was recorded in a self-administered questionnaire. Multiple regression analysis was used to analyse the effects of physical, environmental and medical characteristics. The Mongoloid subjects were found to have approximately 20% higher bone density at the angle of mandible than Caucasoid subjects (P = 0.0094 for males, P = 0.0004 for females). Race is the most important variable associated with bone density. Mongoloid subjects should be given a higher exposure for panoramic radiography than that normally used for Caucasoid subjects.

Online learning from input versus offline memory evolution in adult word learning: effects of neighborhood density and phonologically related practice.

PubMed

Storkel, Holly L; Bontempo, Daniel E; Pak, Natalie S

2014-10-01

In this study, the authors investigated adult word learning to determine how neighborhood density and practice across phonologically related training sets influence online learning from input during training versus offline memory evolution during no-training gaps. Sixty-one adults were randomly assigned to learn low- or high-density nonwords. Within each density condition, participants were trained on one set of words and then were trained on a second set of words, consisting of phonological neighbors of the first set. Learning was measured in a picture-naming test. Data were analyzed using multilevel modeling and spline regression. Steep learning during input was observed, with new words from dense neighborhoods and new words that were neighbors of recently learned words (i.e., second-set words) being learned better than other words. In terms of memory evolution, large and significant forgetting was observed during 1-week gaps in training. Effects of density and practice during memory evolution were opposite of those during input. Specifically, forgetting was greater for high-density and second-set words than for low-density and first-set words. High phonological similarity, regardless of source (i.e., known words or recent training), appears to facilitate online learning from input but seems to impede offline memory evolution.

Associations between body composition and bone density and structure in men and women across the adult age spectrum.

PubMed

Baker, Joshua F; Davis, Matthew; Alexander, Ruben; Zemel, Babette S; Mostoufi-Moab, Sogol; Shults, Justine; Sulik, Michael; Schiferl, Daniel J; Leonard, Mary B

2013-03-01

The objective of this study was to identify independent associations between body composition and bone outcomes, including cortical structure and cortical and trabecular volumetric bone mineral density (vBMD) across the adult age spectrum. This cross-sectional study evaluated over 400 healthy adults (48% male, 44% black race), ages 21-78years. Multivariable linear regression models evaluated associations between whole-body DXA measures of lean body mass index (LBMI) and fat mass index (FMI) and tibia peripheral quantitative CT (pQCT) measures of cortical section modulus, cortical and trabecular vBMD and muscle density (as a measure of intramuscular fat), adjusted for age, sex, and race. All associations reported below were statistically significant (p<0.05). Older age and female sex were associated with lower LBMI and muscle strength. Black race was associated with greater LBMI but lower muscle density. Greater FMI was associated with lower muscle density. Cortical section modulus was positively associated with LBMI and muscle strength and negatively associated with FMI. Adjustment for body composition eliminated the greater section modulus observed in black participants and attenuated the lower section modulus in females. Greater LBMI was associated with lower cortical BMD and greater trabecular BMD. FMI was not associated with either BMD outcome. Greater muscle density was associated with greater trabecular and cortical BMD. Associations between body composition and bone outcomes did not vary by sex (no significant tests for interaction). These data highlight age-, sex- and race-specific differences in body composition, muscle strength and muscle density, and demonstrate discrete associations with bone density and structure. These data also show that age-, sex- and race-related patterns of bone density and strength are independent of differences in body composition. Longitudinal studies are needed to examine the temporal relations between changes in bone and body

Associations between Body Composition and Bone Density and Structure in Men and Women across the Adult Age Spectrum

PubMed Central

Baker, Joshua F.; Davis, Matthew; Alexander, Ruben; Zemel, Babette S.; Mostoufi-Moab, Sogol; Shults, Justine; Sulik, Michael; Schiferl, Daniel J.; Leonard, Mary B.

2012-01-01

Background/Purpose The objective of this study was identify independent associations between body composition and bone outcomes, including cortical structure and cortical and trabecular volumetric bone mineral density (vBMD) across the adult age spectrum. Methods This cross-sectional study evaluated over 400 healthy adults (48% male, 44% black race), ages 21–78 years. Multivariable linear regression models evaluated associations between whole-body DXA measures of lean body mass index (LBMI) and fat mass index (FMI) and tibia peripheral quantitative CT (pQCT) measures of cortical section modulus, cortical and trabecular vBMD and muscle density (as a measure of intramuscular fat), adjusted for age, sex, and race. All associations reported below were statistically significant (p < 0.05). Results Older age and female sex were associated with lower LBMI and muscle strength. Black race was associated with greater LBMI but lower muscle density. Greater FMI was associated with lower muscle density. Cortical section modulus was positively associated with LBMI and muscle strength and negatively associated with FMI. Adjustment for body composition eliminated the greater section modulus observed in black participants and attenuated the lower section modulus in females. Greater LBMI was associated with lower cortical BMD and greater trabecular BMD. FMI was not associated with either BMD outcome. Greater muscle density was associated with greater trabecular and cortical BMD. Associations between body composition and bone outcomes did not vary by sex (no significant tests for interaction). Conclusions These data highlight age, sex- and race-specific differences in body composition, muscle strength and muscle density, and demonstrate discrete associations with bone density and structure. These data also show that age, sex- and race- related patterns of bone density and strength are independent of differences in body composition. Longitudinal studies are needed to examine the

Treadmill running frequency on anxiety and hippocampal adenosine receptors density in adult and middle-aged rats.

PubMed

Costa, Marcelo S; Ardais, Ana Paula; Fioreze, Gabriela T; Mioranzza, Sabrina; Botton, Paulo Henrique S; Portela, Luis Valmor; Souza, Diogo O; Porciúncula, Lisiane O

2012-01-10

Physical exercise protocols have varied widely across studies raising the question of whether there is an optimal intensity, duration and frequency that would produce maximal benefits in attenuating symptoms related to anxiety disorders. Although physical exercise causes modifications in neurotransmission systems, the involvement of neuromodulators such as adenosine has not been investigated after chronic exercise training. Anxiety-related behavior was assessed in the elevated plus-maze in adult and middle-aged rats submitted to 8 weeks of treadmill running 1, 3 or 7 days/week. The speed of running was weekly adjusted to maintain moderate intensity. The hippocampal adenosine A1 and A2A receptors densities were also assessed. Treadmill running protocol was efficient in increasing physical exercise capacity in adult and middle-aged rats. All frequencies of treadmill running equally decreased the time spent in the open arms in adult animals. Middle-aged treadmill control rats presented lower time spent in the open arms than adult treadmill control rats. However, treadmill running one day/week reversed this age effect. Adenosine A1 receptor was not changed between groups, but treadmill running counteracted the age-related increase in adenosine A2A receptors. Although treadmill running, independent from frequency, triggered anxiety in adult rats and treadmill running one day/week reversed the age-related anxiety, no consistent relationship was found with hippocampal adenosine receptors densities. Thus, our data suggest that as a complementary therapy in the management of mental disturbances, the frequency and intensity of physical exercise should be taken into account according to age. Besides, this is the first study reporting the modulation of adenosine receptors after chronic physical exercise, which could be important to prevent neurological disorders associated to increase in adenosine A2A receptors. Copyright © 2011. Published by Elsevier Inc.

BMI, hypertension and low bone mineral density in adult men and women.

PubMed

Szklarska, Alicja; Lipowicz, Anna

2012-08-01

The aim of this work was to estimate the body mass index (BMI) at which risk of hypertension is lowest in men and women, while concurrently considering the protective role of adipose tissue in osteoporosis. Healthy, occupationally active inhabitants of the city of Wrocław, Poland, 1218 women and 434 men were studied. BMI, systolic and diastolic blood pressures, bone mineral density (BMD) of the trabecular compartment and distal radius of the non-dominant hand were recorded. Overweight in young women (≤45 years) was associated with increased risk of hypertension, whereas the risk of low bone mineral was decreased for the same BMI. In older women (>45 years), a BMI>27 was the threshold for increased risk of hypertension. In this age group, extremely slim women (BMI<21) had the highest risk of low bone mineral density. In younger males (≤45 years), risk of hypertension was lowest among the thinnest subjects (BMI<21). Increase in BMI over 21 kg/m(2) increased the risk of hypertension. The probability of low bone mineral density was the same in all BMI categories of men. In older men (>45 years), the thinnest (BMI<21) had higher risk of hypertension. To begin from BMI=25 kg/m(2), there was a monotonous increase in risk of hypertension in men. Higher risk for low bone mineral density was observed in older men with the BMI<23. Among younger adults, risk of hypertension and low bone mineral density increase at BMI≥21 kg/m(2) in men and BMI≥23 kg/m(2) in women. Among older men and women, the BMI threshold was 27 kg/m(2). Copyright © 2012 Elsevier GmbH. All rights reserved.

Higher sika deer density is associated with higher local abundance of Haemaphysalis longicornis nymphs and adults but not larvae in central Japan.

PubMed

Tsukada, Hideharu; Nakamura, Yoshio; Kamio, Tsugihiko; Inokuma, Hisashi; Hanafusa, Yasuko; Matsuda, Naoko; Maruyama, Tetsuya; Ohba, Takahiro; Nagata, Koji

2014-02-01

Haemaphysalis longicornis (Acari: Ixodidae) is one of the most common and important arthropod disease vectors in Japan, carrying Japanese spotted fever and bovine theileriosis. The recent expansion of sika deer (Cervus nippon, Artiodactyla: Cervidae) populations, the most common wild host of H. longicornis, has also caused concern about increasing the risk of vector-borne diseases in Japan. We used generalized linear mixed model analysis to determine the relative contribution of deer density and other biological and abiotic factors on the abundance of H. longicornis ticks questing at each developmental stage. A total of 6223 H. longicornis adults, nymphs, and larvae were collected from 70 sites in three regions of central Japan. The abundance of questing adult and nymphal ticks was associated with deer density and other biotic and abiotic factors. However, the abundance of questing larvae showed no association with deer density but did show an association with other biotic and abiotic factors. These findings show that a high density of deer along with other biotic and abiotic factors is associated with increased risk of vector-borne diseases through amplified local abundance of questing nymphal and adult H. longicornis. Further, questing larvae abundance is likely regulated by environmental conditions and is likely correlated with survival potential or the distribution of other host species.

Body composition, adipokines, bone mineral density and bone remodeling markers in relation to IGF-1 levels in adults with Prader-Willi syndrome.

PubMed

van Nieuwpoort, I Caroline; Twisk, Jos W R; Curfs, Leopold M G; Lips, Paul; Drent, Madeleine L

2018-01-01

In patients with Prader-Willi syndrome (PWS) body composition is abnormal and alterations in appetite regulating factors, bone mineral density and insulin-like growth factor-1 (IGF-1) levels have been described. Studies in PWS adults are limited. In this study, we investigated body composition, appetite regulating peptides, bone mineral density and markers of bone remodeling in an adult PWS population. Furthermore, we investigated the association between these different parameters and IGF-1 levels because of the described similarities with growth hormone deficient patients. In this cross-sectional observational cohort study in a university hospital setting we studied fifteen adult PWS patients. Anthropometric and metabolic parameters, IGF-1 levels, bone mineral density and bone metabolism were evaluated. The homeostasis model assessment of insulin resistance (HOMA2-IR) was calculated. Fourteen healthy siblings served as a control group for part of the measurements. In the adult PWS patients, height, fat free mass, IGF-1 and bone mineral content were significantly lower when compared to controls; body mass index (BMI), waist, waist-to-hip ratio and fat mass were higher. There was a high prevalence of osteopenia and osteoporosis in the PWS patients. Also, appetite regulating peptides and bone remodelling markers were aberrant when compared to reference values. Measurements of body composition were significantly correlated to appetite regulating peptides and high-sensitive C-reactive protein (hs-CRP), furthermore HOMA was correlated to BMI and adipokines. In adults with Prader-Willi syndrome alterations in body composition, adipokines, hs-CRP and bone mineral density were demonstrated but these were not associated with IGF-1 levels. Further investigations are warranted to gain more insight into the exact pathophysiology and the role of these alterations in the metabolic and cardiovascular complications seen in PWS, so these complications can be prevented or treated as

Oral contraceptive use and bone density in adolescent and young adult women

PubMed Central

Scholes, Delia; Ichikawa, Laura; LaCroix, Andrea Z.; Spangler, Leslie; Beasley, Jeannette M.; Reed, Susan; Ott, Susan M.

2009-01-01

Background Most of the millions of oral contraceptive (OC) users are under age 30 years and in the critical period for bone mass accrual. Study Design This cross-sectional study of 606 women aged 14–30 years examined both OC duration and estrogen dose and their association with bone mineral density (BMD) at the hip, spine, and whole-body (DEXA). Results Of 389 OC users and 217 nonusers enrolled, 50% were adolescents (14–18 years). Of OC users, 38% used “low-dose” OCs [<30 mcg ethinyl estradiol (EE)]. In adolescents, mean BMD differed by neither OC duration nor EE dose. However, 19–30 year-old women’s mean BMD was lower with longer OC use for spine and whole-body (p=0.004, p=0.02, respectively) and lowest for >12 months of low-dose OCs for the hip, spine and whole-body (p=0.02, 0.003 and 0.002, respectively). Conclusions Prolonged use of today’s OCs, particularly <30 mcg EE, may adversely impact young adult women’s bone density while ingesting these agents. PMID:20004271

Altered gene expression and spine density in nucleus accumbens of adolescent and adult male mice exposed to emotional and physical stress

PubMed Central

Warren, Brandon L; Sial, Omar K.; Alcantara, Lyonna F.; Greenwood, Maria A.; Brewer, Jacob S.; Rozofsky, John P.; Parise, Eric M.; Bolaños-Guzmán, Carlos A.

2014-01-01

Stressful early life experiences are implicated in lifelong health. However, little is known about the consequences of emotional or physical stress on neurobiology. Therefore, the following set of experiments was designed to assess changes in transcription and translation of key proteins within the nucleus accumbens (NAc). Male adolescent (postnatal day [PD] 35) or adult (eight-week old) mice were exposed to emotional (ES) or physical stress (PS) using a vicarious social defeat paradigm. Twenty-four hours after the last stress session, we measured levels of specific mRNAs and proteins within the NAc. Spine density was also assessed in separate groups of mice. Exposure to ES or PS disrupted ERK2, reduced transcription of ΔFosB, and had no effect on CREB mRNA. Western blots revealed that exposure to ES or PS decreased ERK2 phosphorylation in adolescents, whereas the same stress regimen increased ERK2 phosphorylation in adults. Exposure to ES or PS had no effect on ΔFosB or CREB phosphorylation. ES and PS increased spine density in the NAc of adolescent-exposed mice, but only exposure to PS increased spine density in adults. Together, these findings demonstrate that exposure to ES or PS is a potent stressor in adolescent and adult mice, and can disturb the integrity of the NAc by altering transcription and translation of important signaling molecules in an age-dependent manner. Furthermore, exposure to ES and PS induces substantial synaptic plasticity of the NAc. PMID:24943326

Trends of chlorinated organic contaminants in Great Lakes trout and walleye from 1970-1998

USGS Publications Warehouse

Hickey, J.P.; Batterman, S.A.; Chernyak, S.M.

2006-01-01

Levels of chlorinated organic contaminants in predator fish have been monitored annually in each of the Great Lakes since the 1970s. This article updates earlier reports with data from 1991 to 1998 for lake trout (Salvelinus namaycush) and (Lake Erie only) walleye (Sander vitreus) to provide a record that now extends nearly 30 years. Whole fish were analyzed for a number of industrial contaminants and pesticides, including polychlorinated biphenyls (PCBs), dichloro-diphenyl-trichloroethane (DDT), dieldrin, toxaphene, and mirex, and contaminant trends were quantified using multicompartment models. As in the past, fish from Lakes Michigan, Ontario, and Huron have the highest levels of PCBs, DDT, and dieldrin; Superior has the highest levels of toxaphene; and Ontario has the highest levels of mirex. In the period after curtailment of chemical use, concentrations rapidly decreased, represented by relatively short half-lives from approximately 1 to 9 years. Although trends depend on both the contaminant and the lake, in many cases the rate of decline has been decreasing, and concentrations are gradually approaching an irreducible concentration. For dioxin-like PCBs, levels have not been decreasing during the most recent 5-year period (1994 to 1998). In some cases, the year-to-year variation in contaminant levels is large, mainly because of food-web dynamics. Although this variation sometimes obscures long-term trends, the general pattern of a rapid decrease followed by slowing or leveling-off of the downward trend seems consistent across the Great Lakes, and future improvements of the magnitude seen in the 1970s and early 1980s likely will take much longer.

Exercise and Bone Density: Meta-Analysis.

DTIC Science & Technology

1999-09-01

1998, (4) changes in bone mineral density (regional, total) reported in adults ages 18 years and older . Disagreements between the Principal...individual patient data. C. So What? Our work to date suggests that exercise helps to increase and maintain bone mineral density in older (>31 years of age ...between January 1962 and December 1998, (4) changes in bone mineral density (regional, total) reported in adults ages 18 years and older . If you have any

Estimation of adult and neonatal RBC lifespans in anemic neonates using RBCs labeled at several discrete biotin densities.

PubMed

Kuruvilla, Denison J; Widness, John A; Nalbant, Demet; Schmidt, Robert L; Mock, Donald M; An, Guohua; Veng-Pedersen, Peter

2017-06-01

Prior conclusions that autologous neonatal red blood cells (RBC) have substantially shorter lifespans than allogeneic adult RBCs were not based on direct comparison of autologous neonatal vs. allogeneic adult RBCs performed concurrently in the same infant. Biotin labeling of autologous neonatal RBCs and allogeneic adult donor RBCs permits concurrent direct comparison of autologous vs. allogeneic RBC lifespan. RBCs from 15 allogeneic adult donors and from 15 very-low-birth-weight (VLBW) neonates were labeled at separate biotin densities and transfused simultaneously into the 15 neonates. Two mathematical models that account for the RBC differences were employed to estimate lifespans for the two RBC populations. Mean ± SD lifespan for adult allogeneic RBC was 70.1 ± 19.1 d, which is substantially shorter than the 120 d lifespan of both autologous and adult allogeneic RBC in healthy adults. Mean ± SD lifespan for neonatal RBC was 54.2 ± 11.3 d, which is only about 30% shorter than that of the adult allogeneic RBCs. This study provides evidence that extrinsic environmental factors primarily determine RBC survival (e.g., small bore of the capillaries of neonates, rate of oxygenation/deoxygenation cycles) rather than factors intrinsic to RBC.

Heterogeneity in Spinal Bone Mineral Density Among Young Adults From Three Eastern Provincial Capital Cities in Mainland China.

PubMed

Cheng, Xiao-Guang; Li, Kai; Ou, Shan-Xing; Tang, Guang-Yu; Wang, Qian-Qian; Wang, Chao; Wang, Ling; Tian, Wei

This study compares spinal volumetric bone mineral density (vBMD) with spinal areal bone mineral density (aBMD) among young adults from 3 eastern provincial capital cities in Mainland China. A total of 416 young adults (age range: 20-40 yr) from 3 eastern provincial capital cities (Beijing, Shanghai, and Guangzhou) in Mainland China were recruited in this study. From each subject, the vBMD of the lumbar spine was measured by the Mindways quantitative computed tomography system. Moreover, the aBMD of the lumbar spine, measured by the dual-energy X-ray absorptiometry, was extracted from a previous multicenter large-scale study, and the 420 participants were matched by age, gender, height, weight, as well as geographic territory. The vBMD and the aBMD values were further compared and analyzed. Generally, the bone mineral density (BMD) results were significantly different among participants from the 3 cities (p <0.05). Specifically, both vBMD and aBMD values of participants from Beijing were significantly different from those from Guangzhou (p <0.05). Additionally, a statistically significant difference in aBMD values was also found between participants from Beijing and Shanghai (p <0.05). However, no significant differences were found between participants from Shanghai and Guangzhou in terms of the aBMD and vBMD values (p 1  > 0.05 and p 2  > 0.05). Interestingly, the overall mean vBMD value was 5.9% greater in women than those in men for all the 3 cities (p <0.001). This study demonstrated an overall heterogeneity in spinal BMD among young adults from 3 eastern provincial capital cities in Mainland China. Specifically, the taller and heavier young adults from the northern part of China have smaller spinal vBMD but higher spinal aBMD values than those who were shorter and lighter from the southern part of China. Copyright © 2016 International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Prevalence and strength of density-dependent tree recruitment

Treesearch

Kai Zhu; Christopher W. Woodall; Joao V.D. Monteiro; James S. Clark

2015-01-01

Density dependence could maintain diversity in forests, but studies continue to disagree on its role. Part of the disagreement results from the fact that different studies have evaluated different responses (survival, recruitment, or growth) of different stages (seeds, seedlings, or adults) to different inputs (density of seedlings, density or distance to adults). Most...

The Macular Carotenoids Lutein and Zeaxanthin Are Related to Increased Bone Density in Young Healthy Adults

PubMed Central

Bovier, Emily R.; Hammond, Billy R.

2017-01-01

Lutein (L) and zeaxanthin (Z) status can be quantified by measuring their concentrations both in serum and, non-invasively, in retinal tissue. This has resulted in a unique ability to assess their role in a number of tissues ranging from cardiovascular to central nervous system tissue. Recent reports using animal models have suggested yet another role, a developmental increase in bone mass. To test this, we assessed L and Z status in 63 young healthy adults. LZ status was determined by measuring LZ in serum (using HPLC) and retina tissue (measuring macular pigment optical density, MPOD, using customized heterochromatic flicker photometry). Bone density was measured using dual-energy X-ray absorptiometry (DXA). Although serum LZ was generally not related to bone mass, MPOD was significantly related to bone density in the proximal femur and lumbar spine. In general, our results are consistent with carotenoids, specifically LZ, playing a role in optimal bone health. PMID:28880221

Genetic predisposition for adult lactose intolerance and relation to diet, bone density, and bone fractures.

PubMed

Obermayer-Pietsch, Barbara M; Bonelli, Christine M; Walter, Daniela E; Kuhn, Regina J; Fahrleitner-Pammer, Astrid; Berghold, Andrea; Goessler, Walter; Stepan, Vinzenz; Dobnig, Harald; Leb, Georg; Renner, Wilfried

2004-01-01

Evidence that genetic disposition for adult lactose intolerance significantly affects calcium intake, bone density, and fractures in postmenopausal women is presented. PCR-based genotyping of lactase gene polymorphisms may complement diagnostic procedures to identify persons at risk for both lactose malabsorption and osteoporosis. Lactase deficiency is a common autosomal recessive condition resulting in decreased intestinal lactose degradation. A -13910 T/C dimorphism (LCT) near the lactase phlorizin hydrolase gene, reported to be strongly associated with adult lactase nonpersistence, may have an impact on calcium supply, bone density, and osteoporotic fractures in the elderly. We determined LCT genotypes TT, TC, and CC in 258 postmenopausal women using a polymerase chain reaction-based assay. Genotypes were related to milk intolerance, nutritional calcium intake, intestinal calcium absorption, bone mineral density (BMD), and nonvertebral fractures. Twenty-four percent of all women were found to have CC genotypes and genetic lactase deficiency. Age-adjusted BMD at the hip in CC genotypes and at the spine in CC and TC genotypes was reduced by -7% to -11% depending on the site measured (p = 0.04). LCT(T/C-13910) polymorphisms alone accounted for 2-4% of BMD in a multiple regression model. Bone fracture incidence was significantly associated with CC genotypes (p = 0.001). Milk calcium intake was significantly lower (-55%, p = 0.004) and aversion to milk consumption was significantly higher (+166%, p = 0.01) in women with the CC genotype, but there were no differences in overall dietary calcium intake or in intestinal calcium absorption test values. The LCT(T/C-13910) polymorphism is associated with subjective milk intolerance, reduced milk calcium intake, and reduced BMD at the hip and the lumbar spine and may predispose to bone fractures. Genetic testing for lactase deficiency may complement indirect methods in the detection of individuals at risk for both lactose

Birthweight, early life body size and adult mammographic density: a review of epidemiologic studies.

PubMed

Yochum, Laura; Tamimi, Rulla M; Hankinson, Susan E

2014-10-01

To evaluate the association between birth weight and early life body size with adult mammographic density in the peer-reviewed literature. A comprehensive literature search was conducted through January, 2014. English language articles that assessed adult mammographic density (MD) in relation to early life body size (≤18 years old), or birthweight were included. Nine studies reported results for early life body size and %MD. Both exposure and outcome were assessed at different ages using multiple methods. In premenopausal women, findings were inconsistent; two studies reported significant, inverse associations, one reported a non-significant, inverse association, and two observed no association. Reasons for these inconsistencies were not obvious. In postmenopausal women, four of five studies supported an inverse association. Two of three studies that adjusted for menopausal status found significant, inverse associations. Birthweight and %MD was evaluated in nine studies. No association was seen in premenopausal women and two of three studies reported positive associations in postmenopausal women. Three of four studies that adjusted for menopausal status found no association. Early life body size and birthweight appear unrelated to %MD in premenopausal women while an inverse association in postmenopausal women is more likely. Although based on limited data, birthweight and %MD appear positively associated in postmenopausal women. Given the small number of studies, the multiple methods of data collection and analysis, other methodologic issues, and lack of consistency in results, additional research is needed to clarify this complex association and develop a better understanding of the underlying biologic mechanisms.

Diet breadth and variability in Sander spp. inferred from stable isotopes

USGS Publications Warehouse

Fincel, M.J.; Chipps, Steven R.; Graeb, B.D.S.; Brown, M.L.

2016-01-01

We used stable isotopes of carbon and nitrogen to evaluate trophic similarity between sauger Sander canadensis and walleye S. vitreus in three Missouri River impoundments characterized by unique differences in riverine habitat. Mean δ15N was similar for sauger and walleye in each reservoir ranging from 15.7 to 17.8‰ for sauger and 15.2 to 17.7‰ for walleye. However, mean δ13C was greater for sauger (−24‰) than for walleye (−25‰) in Lake Oahe (lacustrine habitat), where rainbow smelt Osmerus mordax is an important prey species for walleye. Variation in δ15N and δ13C values was similar between walleye and sauger in Lewis and Clark Lake (riverine habitat), but was greater for sauger than for walleye in Lake Oahe, implying that in pelagic environments, sauger exhibit a larger diet breadth and lower diet consistency compared with walleyes. Isotope analyses support observations from traditional gut content studies that diet overlap between sauger and walleye varies with environmental conditions and is more similar in riverine food webs than in large lakes and impoundments.

Comparison of potential fecundity models for walleye pollock Gadus chalcogrammus in the Pacific waters off Hokkaido, Japan.

PubMed

Tanaka, H; Hamatsu, T; Mori, K

2017-01-01

Potential fecundity models of walleye or Alaska pollock Gadus chalcogrammus in the Pacific waters off Hokkaido, Japan, were developed. They were compared using a generalized linear model with using either standard body length (L S ) or total body mass (M T ) as a main covariate along with Fulton's condition factor (K) and mean diameter of oocytes (D O ) as additional potential covariates to account for maternal conditions and maturity stage. The results of model selection showed that M T was a better single predictor of potential fecundity (F P ) than L S . The biological importance of K on F P was obscure, because it was statistically significant when used in the predictor with L S (i.e. length-based model), but not significant when used with M T (i.e. mass-based model). Meanwhile, D O was statistically significant in both length and mass-based models, suggesting the importance of downregulation on the number of oocytes with advancing maturation. Among all candidate models, the model with M T and D O in the predictor had the lowest Akaike's information criterion value, suggesting its better predictive power. These newly developed models will improve future comparisons of the potential fecundity within and among stocks by excluding potential biases other than body size. © 2016 The Fisheries Society of the British Isles.

Rodent neurotoxicity bioassays for screening contaminated Great Lakes fish

DOE Office of Scientific and Technical Information (OSTI.GOV)

Beattie, M.K.; Hoffman, R.; Gerstenberger, S.

1996-03-01

Standard laboratory rat neurotoxicity protocols were used to study the consequences resulting from the consumption of walleye (Stizostedion vitreum), whitefish (Coregonus clupeaformis), and lake trout (Salvelinus namaycush) from Lake Superior (LS) and the consumption of carp (Cyprinus carpio) from Little Lake Butte des Morte (LLBM) near Oshkosh, Wisconsin, USA. Two 90-d subchronic studies are described, including a 45-d exposure to fish diets using male Sprague-Dawley hooded rats, and a 90-d exposure to fish diets using female rats of the same species. Behavioral alterations were tested using a battery of behavioral tests. In addition, pharmacologic challenges using apomorphine and D-amphetamine weremore » administered to the rats to reveal latent neurotoxic effects. Cumulative fish consumption data were recorded daily, weight gain recorded weekly, and behavior data collected prior to exposure, and on days 7, 14, 55 {+-} 2, 85 {+-} 2. Motor activity data were collected on days 30 {+-} 2, 60 {+-} 2, and 90 {+-} 2 of the feeding protocols. Brain tissue from rodents fed these fish were subsequently analyzed for either mercury (Hg) or polychlorinated biphenyls (PCB). Mercury concentrations were increased in the brains of the walleye-fed rats, and PCB concentrations ranged from 0.5 nl/L to 10 nl/L in the brains of rats fed carp from LLBM, a Lake Michigan tributary. Adult male rats fed LLBM carp for 45 d exhibited the greatest behavior responses to the dopaminergic agonist apomorphine on the accelerating rotarod, although these differences were not significant. The 90-d exposure of LS walleye or Hg-spiked LS walleye resulted in behavior alterations on tactile startle response and second footsplay. D-Amphetamine challenge caused changes in tactile startle response, second footsplay, and accelerating rotarod performance after consuming walleye diets. Rats fed LLBM carp had altered behavioral responses to apomorphine on the accelerating rotarod.« less

Comparison of the relationship between bone marrow adipose tissue and volumetric bone mineral density in children and adults.

PubMed

Shen, Wei; Velasquez, Gilbert; Chen, Jun; Jin, Ye; Heymsfield, Steven B; Gallagher, Dympna; Pi-Sunyer, F Xavier

2014-01-01

Several large-scale studies have reported the presence of an inverse relationship between bone mineral density (BMD) and bone marrow adipose tissue (BMAT) in adults. We aim to determine if there is an inverse relationship between pelvic volumetric BMD (vBMD) and pelvic BMAT in children and to compare this relationship in children and adults. Pelvic BMAT and bone volume (BV) was evaluated in 181 healthy children (5-17yr) and 495 healthy adults (≥18yr) with whole-body magnetic resonance imaging (MRI). Pelvic vBMD was calculated using whole-body dual-energy X-ray absorptiometry to measure pelvic bone mineral content and MRI-measured BV. An inverse correlation was found between pelvic BMAT and pelvic vBMD in both children (r=-0.374, p<0.001) and adults (r=-0.650, p<0.001). In regression analysis with pelvic vBMD as the dependent variable and BMAT as the independent variable, being a child or adult neither significantly contribute to the pelvic BMD (p=0.995) nor did its interaction with pelvic BMAT (p=0.415). The inverse relationship observed between pelvic vBMD and pelvic BMAT in children extends previous findings that found the inverse relationship to exist in adults and provides further support for a reciprocal relationship between adipocytes and osteoblasts. Copyright © 2014 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Understanding the influence of predation on introduced fishes on juvenile salmonids in the Columbia River Basin: Closing some knowledge gaps. Late summer and fall diet and condition of smallmouth bass, walleye, and channel catfish in the middle Columbia River, USA. Interim Report of Research 2011.

USGS Publications Warehouse

Rose, Brien P.; Hansen, Gabriel S.; Weaver,; Ayers, David; Van Dyke, Erick S.; Mesa, Matthew G.

2012-01-01

American shad Alosa sapidissima in the middle Columbia River (MCR)—a high energy food available in the summer and fall—may be contributing to the increased growth and enhanced condition of nonnative piscivores. To test this hypothesis we quantified the late summer and autumn diets of smallmouth bass Micropterus dolomieu, walleye Sander vitreus, and channel catfish Ictalurus punctatus in the three lowermost reservoirs on the Columbia River (Bonneville [BON], The Dalles [TDA], and John Day [JDA]). The diet of smallmouth bass (SMB) was fairly similar among reservoirs, with crustaceans (52–82%) and fish (13–38%) being the dominant prey groups by percent mass. Cottidae were usually the dominant fish prey in the diet of SMB at all areas and the contribution of juvenile shad ranged from 0–8.2%. Fish (mostly Cyprinidae and Cottidae) were always the dominant prey item for walleye (WAL) at all areas and at all times, ranging from 70–100% of their diet by mass. Juvenile American shad composed from 10–27% (by mass) of the diet of walleye, depending on area and month. For channel catfish (CHC), the most common prey items consumed were crustaceans (20%–80% by mass) and unidentified items (30%–80%). Fish represented a relatively small component (< 4%) of their diet. We also evaluated the condition of SMB and WAL by determining relative weights (Wr) and hepatosomatic indices (HSI). Mean Wr for SMB greater than 300 mm ranged from 0.89 to 0.94 depending on area and month and showed a significant increase from August to September for fish in BON only. Overall, mean Wr of WAL was similar at all areas, ranging from 0.89–0.91, and increased significantly from September to mid-October and November for fish in TDA only. Overall, mean HSI of SMB ranged from 1.18 to 1.48, did not differ between fish in different reservoirs, and increased significantly from September to mid-October and November for fish from the lower JDA only. Mean HSI of WAL was significantly higher in

Does endothelial cell density correlate with corneal diameter in a group of young adults?

PubMed

Giasson, Claude J; Gosselin, Lucie; Masella, Aviva; Forcier, Pierre

2008-07-01

In children, but not in the elderly, an association exists between corneal diameter and endothelial cell density (ECD). We tested whether such an association also held true in young adults. The eyes of 35 healthy subjects (mean age, 23.1 +/- 3.1 years) were photographed by using a video camera and a noncontact endothelial microscope. Both sets of images were analyzed with image software and the contour method to measure corneal diameter, ECD, and endothelial coefficients. Axial lengths, refractive errors, and corneal curvatures were measured by using an A-scan ultrasonic biometer and kerato-refractometer. Measurements, averaged for the right and left eyes, were analyzed depending on (1) use of contact lenses, (2) ametropia, and on whether (3) axial length or (4) corneal diameter was above or below group means. Differences were tested for statistical significance with independent t tests and association with the Pearson correlation coefficient. ECD, corneal diameter, and spherical equivalent refraction were 3022 +/- 262 cells/mm2, 12.0 +/- 0.5 mm, and -3.1 +/- 2.5 D, respectively. The only significant differences between wearers and nonwearers of contact lenses were the spherical refractive equivalent and axial length. There was no correlation between ECD and corneal diameter or axial length. As opposed to previously reported results in children, but as found in the elderly, there is no correlation between ECD and corneal diameter in young adults. Therefore, corneal size cannot be considered a determinant of ECD in young adults.

DENSITY-DEPENDENT EVOLUTION OF LIFE-HISTORY TRAITS IN DROSOPHILA MELANOGASTER.

PubMed

Bierbaum, Todd J; Mueller, Laurence D; Ayala, Francisco J

1989-03-01

Populations of Drosophila melanogaster were maintained for 36 generations in r- and K-selected environments in order to test the life-history predictions of theories on density-dependent selection. In the r-selection environment, populations were reduced to low densities by density-independent adult mortality, whereas populations in the K-selection environment were maintained at their carrying capacity. Some of the experimental results support the predictions or r- and K-selection theory; relative to the r-selected populations, the K-selected populations evolved an increased larval-to-adult viability, larger body size, and longer development time at high larval densities. Mueller and Ayala (1981) found that K-selected populations also have a higher rate of population growth at high densities. Other predictions of the thoery are contradicted by the lack of differences between the r and K populations in adult longevity and fecundity and a slower rate of development for r-selected individuals at low densities. The differences between selected populations in larval survivorship, larval-to-adult development time, and adult body size are strongly dependent on larval density, and there is a significant interaction between populations and larval density for each trait. This manifests an inadequacy of the theory on r- and K-selection, which does not take into account such interactions between genotypes and environments. We describe mechanisms that may explain the evolution of preadult life-history traits in our experiment and discuss the need for changes in theories of density-dependent selection. © 1989 The Society for the Study of Evolution.

Inferred fish behavior its implications for hydroacoustic surveys in nearshore habitats

USGS Publications Warehouse

DuFour, Mark R.; Mayer, Christine M.; Qian, Song S.; Vandergoot, Christopher; Kraus, Richard T.; Kocovsky, Patrick; Warner, David M.

2018-01-01

Population availability and vessel avoidance effects on hydroacoustic abundance estimates may be scale dependent; therefore, it is important to evaluate these biases across systems. We performed an inter-ship comparison survey to determine the effect of vessel size, day-night period, depth, and environmental gradients on walleye (Sander vitreus) density estimates in Lake Erie, an intermediate-scaled system. Consistent near-bottom depth distributions coupled with horizontal fish movements relative to vessel paths indicated avoidance behavior contributed to higher walleye densities from smaller vessels in shallow water (i.e., <15 m), although the difference decreased with increasing depth. Diel bank migrations in response to seasonally varying onshore-to-offshore environmental gradients likely contributed to day-night differences in densities between sampling locations and seasons. Spatial and unexplained variation accounted for a high proportion of total variation; however, increasing sampling intensity can mitigate effects on precision. Therefore, researchers should minimize systematic avoidance and availability related biases (i.e., vessel and day-night period) to improve population abundance estimates. Quantifying availability and avoidance behavior effects and partitioning sources of variation provides informed flexibility for designing future hydroacoustic surveys in shallow-water nearshore environments.

Decreased Bone Mineral Density in Adults Born with Very Low Birth Weight: A Cohort Study

PubMed Central

Hovi, Petteri; Andersson, Sture; Järvenpää, Anna-Liisa; Eriksson, Johan G.; Strang-Karlsson, Sonja; Kajantie, Eero; Mäkitie, Outi

2009-01-01

Background Very-low-birth-weight (VLBW, <1,500 g) infants have compromised bone mass accrual during childhood, but it is unclear whether this results in subnormal peak bone mass and increased risk of impaired skeletal health in adulthood. We hypothesized that VLBW is associated with reduced bone mineral density (BMD) in adulthood. Methods and Findings The Helsinki Study of Very Low Birth Weight Adults is a multidisciplinary cohort study representative of all VLBW births within the larger Helsinki area from 1978 to 1985. This study evaluated skeletal health in 144 such participants (all born preterm, mean gestational age 29.3 wk, birth weight 1,127 g, birth weight Z score 1.3), and in 139 comparison participants born at term, matched for sex, age, and birth hospital. BMD was measured by dual energy X-ray absorptiometry at age 18.5 to 27.1 y. Adults born with VLBW had, in comparison to participants born at term, a 0.51-unit (95% confidence interval [CI] 0.28–0.75) lower lumbar spine Z score and a 0.56-unit (95% CI 0.34–0.78) lower femoral neck Z score for areal BMD. These differences remained statistically significant after adjustment for the VLBW adults' shorter height and lower self-reported exercise intensity. Conclusions Young adults born with VLBW, when studied close to the age of peak bone mass, have significantly lower BMD than do their term-born peers. This suggests that compromised childhood bone mass accrual in preterm VLBW children translates into increased risk for osteoporosis in adulthood, warranting vigilance in osteoporosis prevention. Please see later in the article for the Editors' Summary PMID:19707270

Population-Level Density Dependence Influences the Origin and Maintenance of Parental Care

PubMed Central

Reyes, Elijah; Thrasher, Patsy; Bonsall, Michael B.; Klug, Hope

2016-01-01

Parental care is a defining feature of animal breeding systems. We now know that both basic life-history characteristics and ecological factors influence the evolution of care. However, relatively little is known about how these factors interact to influence the origin and maintenance of care. Here, we expand upon previous work and explore the relationship between basic life-history characteristics (stage-specific rates of mortality and maturation) and the fitness benefits associated with the origin and the maintenance of parental care for two broad ecological scenarios: the scenario in which egg survival is density dependent and the case in which adult survival is density dependent. Our findings suggest that high offspring need is likely critical in driving the origin, but not the maintenance, of parental care regardless of whether density dependence acts on egg or adult survival. In general, parental care is more likely to result in greater fitness benefits when baseline adult mortality is low if 1) egg survival is density dependent or 2) adult mortality is density dependent and mutant density is relatively high. When density dependence acts on egg mortality, low rates of egg maturation and high egg densities are less likely to lead to strong fitness benefits of care. However, when density dependence acts on adult mortality, high levels of egg maturation and increasing adult densities are less likely to maintain care. Juvenile survival has relatively little, if any, effect on the origin and maintenance of egg-only care. More generally, our results suggest that the evolution of parental care will be influenced by an organism’s entire life history characteristics, the stage at which density dependence acts, and whether care is originating or being maintained. PMID:27093056

Does targeting key-containers effectively reduce Aedes aegypti population density?

PubMed

Maciel-de-Freitas, Rafael; Lourenço-de-Oliveira, Ricardo

2011-08-01

The elimination of Aedes aegypti breeding sites has been broadly adopted worldwide to keep vector population density below a critical threshold. We observed the effectiveness of targeting the most productive containers on adult A. aegypti females density, which was evaluated weekly. Adult mosquitoes were collected weekly over 55 weeks and pupal surveys were done in intervals of 4 months to determine container productivity and guidelines for interventions. Pupal surveys indicated that water tanks (72% of pupae in first survey) and metal drums (30.7% of pupae in second survey) were the most productive container types. We observed a dramatic but short-term decrease in weekly adult female A. aegypti density after covering 733 water tanks with nylon net. A long-term decrease in female adult population density was achieved only when we covered both water tanks and metal drums. Overall, pupae abundance and pupae standing crop diminished after netting water tanks and metal drums. Pupae per person, per hectare and per house decreased gradually between the first and the third pupal surveys, suggesting that targeting the most productive container types (water tanks and metal drums) produced a reduction in adult population density and infestation levels. Overall, targeting the most productive container types caused the adult mosquito density to decrease over time, supporting the assumption that this intervention is an effective tool for dengue control. However, this effect was observed only when both water tanks and metal drums were covered, possibly due to the functional similarity between these container types, which are large, often shaded, perennial water storage containers. © 2011 Blackwell Publishing Ltd.

Impact of experimental human pneumococcal carriage on nasopharyngeal bacterial densities in healthy adults.

PubMed

Shak, Joshua R; Cremers, Amelieke J H; Gritzfeld, Jenna F; de Jonge, Marien I; Hermans, Peter W M; Vidal, Jorge E; Klugman, Keith P; Gordon, Stephen B

2014-01-01

Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary precursor to pneumococcal diseases that result in morbidity and mortality worldwide. The nasopharynx is also host to other bacterial species, including the common pathogens Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis. To better understand how these bacteria change in relation to pneumococcal colonization, we used species-specific quantitative PCR to examine bacterial densities in 52 subjects 7 days before, and 2, 7, and 14 days after controlled inoculation of healthy human adults with S. pneumoniae serotype 6B. Overall, 33 (63%) of subjects carried S. pneumoniae post-inoculation. The baseline presence and density of S. aureus, H. influenzae, and M. catarrhalis were not statistically associated with likelihood of successful pneumococcal colonization at this study's sample size, although a lower rate of pneumococcal colonization in the presence of S. aureus (7/14) was seen compared to that in the presence of H. influenzae (12/16). Among subjects colonized with pneumococci, the number also carrying either H. influenzae or S. aureus fell during the study and at 14 days post-inoculation, the proportion carrying S. aureus was significantly lower among those who were colonized with S. pneumoniae (p = 0.008) compared to non-colonized subjects. These data on bacterial associations are the first to be reported surrounding experimental human pneumococcal colonization and show that co-colonizing effects are likely subtle rather than absolute.

Effect of chromium chloride supplementation on glucose tolerance and serum lipids including high-density lipoprotein of adult men.

PubMed

Riales, R; Albrink, M J

1981-12-01

Chromium deficiency may cause insulin resistance, hyperinsulinemia, impaired glucose tolerance, and hyperlipidemia, recovered by chromium supplementation. The effect of chromium supplementation on serum lipids and glucose tolerance was tested in a double-blind 12-wk study of 23 healthy adult men aged 31 to 60 yr. Either 200 micrograms trivalent chromium in 5 ml water (Cr) or 5 ml plain water (W) was ingested daily 5 days each week. Half the subjects volunteered for glucose tolerance tests with insulin levels. At 12 wk high-density lipoprotein cholesterol increased in the Cr group from 35 to 39 mg/dl (p less than 0.05) but did not change in the water group (34 mg/dl). The largest increase in high-density lipoprotein cholesterol and decreases in insulin and glucose were found in those subjects having normal glucose levels together with elevated insulin levels at base-line. The data are thus consistent with the hypothesis that Cr supplementation raises high-density lipoprotein cholesterol and improves insulin sensitivity in those with evidence of insulin resistance but normal glucose tolerance.

Reduction in recruitment of white bass in Lake Erie after invasion of white perch

USGS Publications Warehouse

Madenjian, Charles P.; Knight, Roger L.; Bur, Michael; Forney, John L.

2000-01-01

Recruitment to the adult population of white bass Morone chrysops in Lake Erie sharply declined during the early 1980s. To explain this phenomenon, we formulated the following four hypotheses: (1) the biological characteristics of adult spawners changed during the early 1980s, so that the ability to produce eggs decreased; (2) the decrease in phosphorus loadings to Lake Erie during the 1970s resulted in a lower abundance of crustacean zooplankton and thus in reduced survival of age-0 white bass; (3) the increase in the population of adult walleyes Stizostedion vitreum in Lake Erie during the 1970s and 1980s led to reduced survival of age-0 white bass; and (4) establishment of the white perch Morone americana population in Lake Erie during the early 1980s led to reduced survival of the early life stages of white bass. The growth, maturity, and fecundity of adults during the period 1981-1997 were compared with the same characteristics found by earlier studies. The mean length, weight, and condition factors that we calculated were higher than those reported for Lake Erie in 1927-1929 for all age groups examined, and white bass in Lake Erie matured at an earlier age during 1981-1997 than during 1927-1929. Fecundity estimates ranged from 128,897 to 1,049,207 eggs/female and were similar to estimates from other populations. Therefore, the first hypothesis was rejected. With respect to the second hypothesis, zooplankton surveys conducted during 1970 and 1983-1987 indicated that the abundance of crustacean zooplankton in Lake Erie did not change between the two time periods. However, these results were not conclusive because only a single-year survey was conducted before 1980. Based on walleye diet studies and estimates of walleye population size, walleye predation pressure on age-0 white bass in Lake Erie during 1986-1988 was just slightly higher than that during 1979-1981. Thus, such pressure can explain only a minor portion of the reduction in white bass recruitment. To

Tumor frequencies in walleye (Stizostedion vitreum) and brown bullhead (Ictalurus nebulosus) and sediment contaminants in tributaries of the Laurentian Great Lakes

USGS Publications Warehouse

Baumann, Paul C.; Mac, Michael J.; Smith, Stephen B.; Harshbarger, John C.

1991-01-01

To better characterize neoplasm epizootics in the Great Lakes basin and their association with families of contaminants, we sampled five locations: the Fox and Menominee rivers, Lake Michigan; Munuscong Lake, St. Mary's River; and the Black and Cuyahoga rivers, Lake Erie. Frequencies of external and liver tumors were determined for brown bullhead (Ictalurus nebulosus) from all locations except the Black River and for walleye (Stizostedion vitreum) from the Lake Michigan and St. Mary's River sites. Sediment samples were analyzed for metals, polychlorinated aromatics, and polynuclear aromatic hydrocarbons (PAH). Liver neoplasms occurred in brown bullhead from the Cuyahoga River and Munuscong Lake; brown bullhead captured from Munuscong Lake were older than those collected from the other locations. Brown bullhead from these same two rivers had elevated hepatosomatic indexes. No liver neoplasms were found in brown bullhead from the Fox and Menominee rivers, although polychlorinated aromatics were highest in both Fox River sediment and Fox and Menominee brown bullhead, and arsenic was highest in Menominee River sediment and fish. Liver neoplasms in brown bullhead from the Cuyahoga River fit the prevailing hypothesis that elevated PAH in sediment can induce cancer in wild fish. The cause of the liver neoplasms in Munuscong Lake brown bullhead is undetermined.

Associations between bone-alkaline phosphatase and bone mineral density in adults with and without diabetes

PubMed Central

Chen, Hailing; Li, Jufen; Wang, Qian

2018-01-01

Abstract Insufficient evidence is available to reliably compare the roles of bone alkaline phosphatase (BAP) and bone mineral density (BMD) in diabetes. This study aimed to compare associations between BAP and BMD in adults with and without diabetes to elucidate fracture risk in diabetes. Data were extracted from the National Health and Nutrition Examination Survey (NHANES), 2001–2004, including 4197 adults aged 20 to 49 years, 143 with diabetes (DM group), and 4054 without (non-DM group). Main outcome measure was BMD and regression analyses were performed to identify serum BAP and other covariates associated with total BMD. BMD decreased significantly in DM patients when BAP was increased. In the non-DM group, all BMD results were significantly decreased when BAP was increased. Factors associated with total BMD varied with DM status. Lifestyle measures such as smoking and physical activity were also associated with BMD in the non-DM group. BAP and BMD are inversely associated in DM and non-DM patients. BAP is significantly associated with BMD after controlling for other variables, suggesting that BAP may interact with other factors altering bone metabolism in DM patients. PMID:29702995

Effects of dietary creatine supplementation on systemic microvascular density and reactivity in healthy young adults.

PubMed

Moraes, Roger de; Van Bavel, Diogo; Moraes, Beatriz Serpa de; Tibiriçá, Eduardo

2014-12-15

Dietary creatine supplementation (CrS) is a practice commonly adopted by physically active individuals. However, the effects of CrS on systemic microvascular reactivity and density have never been reported. Additionally, CrS is able to influence blood levels of homocysteine, resulting in presumed effects on vascular endothelial function. Thus, we investigated the effects of CrS on the systemic microcirculation and on homocysteine levels in healthy young individuals. This open-label study was performed on a group of 40 healthy male, moderately physically active subjects aged 27.7 ± 13.4 years who received one week of CrS at a dose of 20 g/day of commercially available micronized creatine monohydrate. Laser speckle contrast imaging was used in the evaluation of cutaneous microvascular reactivity, and intra-vital video microscopy was used to evaluate skin capillary density and reactivity, before and after CrS. CrS did not alter plasma levels of homocysteine, although CrS increased creatinine (p = 0.0001) and decreased uric acid (p = 0.0004) plasma levels. Significant changes in total cholesterol (p = 0.0486) and LDL-cholesterol (p = 0.0027) were also observed along with a reduction in plasma levels of T3 (p = 0.0074) and an increase in T4 levels (p = 0.0003). Skin functional capillary density (p = 0.0496) and capillary recruitment during post-occlusive reactive hyperemia (p = 0.0043) increased after CrS. Increases in cutaneous microvascular vasodilation induced by post-occlusive reactive hyperemia (p = 0.0078) were also observed. Oral supplementation with creatine in healthy, moderately physically active young adults improves systemic endothelial-dependent microvascular reactivity and increases skin capillary density and recruitment. These effects are not concurrent with changes in plasma homocysteine levels.

Zinc deficiency reduces bone mineral density in the spine of young adult rats: a pilot study.

PubMed

Ryz, Natasha R; Weiler, Hope A; Taylor, Carla G

2009-01-01

The objective of this study was to investigate the effects of zinc deficiency initiated during adolescence on skeletal densitometry, serum markers of bone metabolism, femur minerals and morphometry in young adult rats. Ten-week-old male rats were fed a <1-mg Zn/kg diet (9ZD), a 5-mg Zn/kg diet (9MZD) or a 30-mg Zn/kg diet (9CTL) for up to 9 weeks. Analyses included bone mineral density, serum osteocalcin and C-terminal peptides of type I collagen, serum zinc, femur zinc, calcium and phosphorus, and femur morphometry. Bone mineral density was 14% lower in the spine of 9ZD, but was not altered in the whole body, tibia or femur, or in any of the aforementioned sites in 9MZD, compared to 9CTL. When adjusted for size, spine bone mineral apparent density was still 8% lower in 9ZD than 9CTL. Serum osteocalcin, a marker for bone formation, was approximately 33% lower in 9ZD compared to both 9MZD and 9CTL. The 9ZD and 9MZD had 57% lower femur zinc and 56-88% lower serum zinc concentrations compared to 9CTL. These findings indicate that severe zinc deficiency initiated during adolescence may have important implications for future bone health, especially with regards to bone consolidation in the spine. 2009 S. Karger AG, Basel.

Impact of Experimental Human Pneumococcal Carriage on Nasopharyngeal Bacterial Densities in Healthy Adults

PubMed Central

Shak, Joshua R.; Cremers, Amelieke J. H.; Gritzfeld, Jenna F.; de Jonge, Marien I.; Hermans, Peter W. M.; Vidal, Jorge E.; Klugman, Keith P.; Gordon, Stephen B.

2014-01-01

Colonization of the nasopharynx by Streptococcus pneumoniae is a necessary precursor to pneumococcal diseases that result in morbidity and mortality worldwide. The nasopharynx is also host to other bacterial species, including the common pathogens Staphylococcus aureus, Haemophilus influenzae, and Moraxella catarrhalis. To better understand how these bacteria change in relation to pneumococcal colonization, we used species-specific quantitative PCR to examine bacterial densities in 52 subjects 7 days before, and 2, 7, and 14 days after controlled inoculation of healthy human adults with S. pneumoniae serotype 6B. Overall, 33 (63%) of subjects carried S. pneumoniae post-inoculation. The baseline presence and density of S. aureus, H. influenzae, and M. catarrhalis were not statistically associated with likelihood of successful pneumococcal colonization at this study’s sample size, although a lower rate of pneumococcal colonization in the presence of S. aureus (7/14) was seen compared to that in the presence of H. influenzae (12/16). Among subjects colonized with pneumococci, the number also carrying either H. influenzae or S. aureus fell during the study and at 14 days post-inoculation, the proportion carrying S. aureus was significantly lower among those who were colonized with S. pneumoniae (p = 0.008) compared to non-colonized subjects. These data on bacterial associations are the first to be reported surrounding experimental human pneumococcal colonization and show that co-colonizing effects are likely subtle rather than absolute. PMID:24915552

Evolution of complex density-dependent dispersal strategies.

PubMed

Parvinen, Kalle; Seppänen, Anne; Nagy, John D

2012-11-01

The question of how dispersal behavior is adaptive and how it responds to changes in selection pressure is more relevant than ever, as anthropogenic habitat alteration and climate change accelerate around the world. In metapopulation models where local populations are large, and thus local population size is measured in densities, density-dependent dispersal is expected to evolve to a single-threshold strategy, in which individuals stay in patches with local population density smaller than a threshold value and move immediately away from patches with local population density larger than the threshold. Fragmentation tends to convert continuous populations into metapopulations and also to decrease local population sizes. Therefore we analyze a metapopulation model, where each patch can support only a relatively small local population and thus experience demographic stochasticity. We investigated the evolution of density-dependent dispersal, emigration and immigration, in two scenarios: adult and natal dispersal. We show that density-dependent emigration can also evolve to a nonmonotone, "triple-threshold" strategy. This interesting phenomenon results from an interplay between the direct and indirect benefits of dispersal and the costs of dispersal. We also found that, compared to juveniles, dispersing adults may benefit more from density-dependent vs. density-independent dispersal strategies.

Comparison of SAR and induced current densities in adults and children exposed to electromagnetic fields from electronic article surveillance devices

NASA Astrophysics Data System (ADS)

Martínez-Búrdalo, M.; Sanchis, A.; Martín, A.; Villar, R.

2010-02-01

Electronic article surveillance (EAS) devices are widely used in most stores as anti-theft systems. In this work, the compliance with international guidelines in the human exposure to these devices is analysed by using the finite-difference time-domain (FDTD) method. Two sets of high resolution numerical phantoms of different size (REMCOM/Hershey and Virtual Family), simulating adult and child bodies, are exposed to a 10 MHz pass-by panel-type EAS consisting of two overlapping current-carrying coils. Two different relative positions between the EAS and the body (frontal and lateral exposures), which imply the exposure of different parts of the body at different distances, have been considered. In all cases, induced current densities in tissues of the central nervous system and specific absorption rates (SARs) are calculated to be compared with the limits from the guidelines. Results show that induced current densities are lower in the case of adult models as compared with those of children in both lateral and frontal exposures. Maximum SAR values calculated in lateral exposure are significantly lower than those calculated in frontal exposure, where the EAS-body distance is shorter. Nevertheless, in all studied cases, with an EAS driving current of 4 A rms, maximum induced current and SAR values are below basic restrictions.

Comparison of SAR and induced current densities in adults and children exposed to electromagnetic fields from electronic article surveillance devices.

PubMed

Martínez-Búrdalo, M; Sanchis, A; Martín, A; Villar, R

2010-02-21

Electronic article surveillance (EAS) devices are widely used in most stores as anti-theft systems. In this work, the compliance with international guidelines in the human exposure to these devices is analysed by using the finite-difference time-domain (FDTD) method. Two sets of high resolution numerical phantoms of different size (REMCOM/Hershey and Virtual Family), simulating adult and child bodies, are exposed to a 10 MHz pass-by panel-type EAS consisting of two overlapping current-carrying coils. Two different relative positions between the EAS and the body (frontal and lateral exposures), which imply the exposure of different parts of the body at different distances, have been considered. In all cases, induced current densities in tissues of the central nervous system and specific absorption rates (SARs) are calculated to be compared with the limits from the guidelines. Results show that induced current densities are lower in the case of adult models as compared with those of children in both lateral and frontal exposures. Maximum SAR values calculated in lateral exposure are significantly lower than those calculated in frontal exposure, where the EAS-body distance is shorter. Nevertheless, in all studied cases, with an EAS driving current of 4 A rms, maximum induced current and SAR values are below basic restrictions.

Association of Adenylate Cyclase 10 (ADCY10) Polymorphisms and Bone Mineral Density in Healthy Adults

PubMed Central

Ichikawa, Shoji; Koller, Daniel L.; Curry, Leah R.; Lai, Dongbing; Xuei, Xiaoling; Edenberg, Howard J.; Hui, Siu L.; Peacock, Munro; Foroud, Tatiana; Econs, Michael J.

2010-01-01

Phenotypic variation in bone mineral density (BMD) among healthy adults is influenced by both genetic and environmental factors. Genetic sequence variations in the adenylate cyclase 10 (ADCY10) gene, which is also called soluble adenylate cyclase, have previously been reported to be associated with low spinal BMD in hypercalciuric patients. Since ADCY10 is located in the region linked to spinal BMD in our previous linkage analysis, we tested whether polymorphisms in this gene are also associated with normal BMD variation in healthy adults. Sixteen single nucleotide polymorphisms (SNPs) distributed throughout ADCY10 were genotyped in two healthy groups of American whites: 1,692 premenopausal women and 715 men. Statistical analyses were performed in the two groups to test for association between these SNPs and femoral neck and lumbar spine areal BMD. We observed significant evidence of association (p<0.01) with one SNP each in men and women. Genotypes at these SNPs accounted for less than 1% of hip BMD variation in men, but 1.5% of spinal BMD in women. However, adjacent SNPs did not corroborate the association in either males or females. In conclusion, we found a modest association between an ADCY10 polymorphism and spinal areal BMD in premenopausal white women. PMID:19093065

Density-dependent intraspecific aggression regulates survival in northern Yellowstone wolves (Canis lupus).

PubMed

Cubaynes, Sarah; MacNulty, Daniel R; Stahler, Daniel R; Quimby, Kira A; Smith, Douglas W; Coulson, Tim

2014-11-01

Understanding the population dynamics of top-predators is essential to assess their impact on ecosystems and to guide their management. Key to this understanding is identifying the mechanisms regulating vital rates. Determining the influence of density on survival is necessary to understand the extent to which human-caused mortality is compensatory or additive. In wolves (Canis lupus), empirical evidence for density-dependent survival is lacking. Dispersal is considered the principal way in which wolves adjust their numbers to prey supply or compensate for human exploitation. However, studies to date have primarily focused on exploited wolf populations, in which density-dependent mechanisms are likely weak due to artificially low wolf densities. Using 13 years of data on 280 collared wolves in Yellowstone National Park, we assessed the effect of wolf density, prey abundance and population structure, as well as winter severity, on age-specific survival in two areas (prey-rich vs. prey-poor) of the national park. We further analysed cause-specific mortality and explored the factors driving intraspecific aggression in the prey-rich northern area of the park. Overall, survival rates decreased during the study. In northern Yellowstone, density dependence regulated adult survival through an increase in intraspecific aggression, independent of prey availability. In the interior of the park, adult survival was less variable and density-independent, despite reduced prey availability. There was no effect of prey population structure in northern Yellowstone, or of winter severity in either area. Survival was similar among yearlings and adults, but lower for adults older than 6 years. Our results indicate that density-dependent intraspecific aggression is a major driver of adult wolf survival in northern Yellowstone, suggesting intrinsic density-dependent mechanisms have the potential to regulate wolf populations at high ungulate densities. When low prey availability or high

Energy Density, Energy Intake, and Body Weight Regulation in Adults12345

PubMed Central

Karl, J. Philip; Roberts, Susan B.

2014-01-01

The role of dietary energy density (ED) in the regulation of energy intake (EI) is controversial. Methodologically, there is also debate about whether beverages should be included in dietary ED calculations. To address these issues, studies examining the effects of ED on EI or body weight in nonelderly adults were reviewed. Different approaches to calculating dietary ED do not appear to alter the direction of reported relations between ED and body weight. Evidence that lowering dietary ED reduces EI in short-term studies is convincing, but there are currently insufficient data to determine long-term effectiveness for weight loss. The review also identified key barriers to progress in understanding the role of ED in energy regulation, in particular the absence of a standard definition of ED, and the lack of data from multiple long-term clinical trials examining the effectiveness of low-ED diet recommendations for preventing both primary weight gain and weight regain in nonobese individuals. Long-term clinical trials designed to examine the impact of dietary ED on energy regulation, and including multiple ED calculation methods within the same study, are still needed to determine the importance of ED in the regulation of EI and body weight. PMID:25398750

Effects of Nativity, Length of Residence, and County-Level Foreign-Born Density on Mental Health Among Older Adults in the U.S.

PubMed

Choi, Sunha; Kim, Giyeon; Lee, Sungkyu

2016-12-01

Using the 2004-2007 Medical Expenditure Panel Survey data that are linked to county-level data from the Area Health Resources Files, this study examined whether the healthy immigrant effect applies to mental health of foreign-born older adults. Additionally, testing a protective ethnic density effect on older foreign-born individuals' mental health, this study examined how the percentage of foreign-born population in the county affected the relationship between older adults' immigration status (U.S.-nativity and length of residence in the U.S.) and their mental health status. The sample included 29,011 individuals (level-1) from 920 counties (level-2) across 50 states and D.C. Using the Mental Component Summary of the Short-Form 12, the Kessler Index (K-6), and the Patient Health Questionnaire (PHQ-2), U.S.-born individuals (n = 24,225), earlier immigrants (≥15 years in the U.S.; n = 3866), and recent immigrants (<15 years in the U.S.; n = 920) were compared. The results indicate that recent immigrants showed worse mental health on all three measures compared with U.S.-born individuals and on the K-6 and PHQ-2 compared with earlier immigrants. Higher county-level foreign-born densities were associated with worse mental health status of individuals. However, the significant interactions found in the full conditional multilevel models indicated that the high foreign-born density functioned as a risk factor for worse mental health only among recent immigrants but not among the U.S.-born. In conclusion, the results revealed the vulnerability of older recent immigrants, especially those living in the counties with high foreign-born densities.

Density of Emerald Ash Borer (Coleoptera: Buprestidae) Adults and Larvae at Three Stages of the Invasion Wave.

PubMed

Burr, Stephen J; McCullough, Deborah G; Poland, Therese M

2018-02-08

Emerald ash borer (EAB) (Agrilus planipennis Fairmaire) (Coleoptera: Buprestidae), an invasive phloem-feeding buprestid, has killed hundreds of millions of ash (Fraxinus spp.) trees in the United States and two Canadian provinces. We evaluated EAB persistence in post-invasion sites and compared EAB adult captures and larval densities in 24 forested sites across an east-west gradient in southern Michigan representing the Core (post-invasion), Crest (high EAB populations), and Cusp (recently infested areas) of the EAB invasion wave. Condition of green ash (Fraxinus pennsylvanica Marsh) trees were recorded in fixed radius plots and linear transects in each site. Ash mortality was highest in Core sites in the southeast, moderate in Crest sites in central southern Michigan, and low in Cusp sites in the southwest. Traps and trap trees in Crest sites accounted for 75 and 60% of all EAB beetles captured in 2010 and 2011, respectively. Populations of EAB were present in all Core sites and traps in these sites captured 13% of all beetles each year. Beetle captures and larval densities at Cusp sites roughly doubled between 2010 and 2011, reflecting the increasing EAB populations. Sticky bands on girdled trees captured the highest density of EAB beetles per m2 of area, while baited double-decker traps had the highest detection rates and captured the most beetles. Larval densities were higher on girdled ash than on similar ungirdled trees and small planted trees. Woodpecker predation and a native larval parasitoid were present in all three invasion regions but had minor effects on ash survival and EAB densities. © The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Correlation of quantitative computed tomographic subchondral bone density and ash density in horses.

PubMed

Drum, M G; Les, C M; Park, R D; Norrdin, R W; McIlwraith, C W; Kawcak, C E

2009-02-01

The purpose of this study was to compare subchondral bone density obtained using quantitative computed tomography with ash density values from intact equine joints, and to determine if there are measurable anatomic variations in mean subchondral bone density. Five adult equine metacarpophalangeal joints were scanned with computed tomography (CT), disarticulated, and four 1-cm(3) regions of interest (ROI) cut from the distal third metacarpal bone. Bone cubes were ashed, and percent mineralization and ash density were recorded. Three-dimensional models were created of the distal third metacarpal bone from CT images. Four ROIs were measured on the distal aspect of the third metacarpal bone at axial and abaxial sites of the medial and lateral condyles for correlation with ash samples. Overall correlations of mean quantitative CT (QCT) density with ash density (r=0.82) and percent mineralization (r=0.93) were strong. There were significant differences between abaxial and axial ROIs for mean QCT density, percent bone mineralization and ash density (p<0.05). QCT appears to be a good measure of bone density in equine subchondral bone. Additionally, differences existed between axial and abaxial subchondral bone density in the equine distal third metacarpal bone.

Group Independent Component Analysis (gICA) and Current Source Density (CSD) in the study of EEG in ADHD adults.

PubMed

Ponomarev, Valery A; Mueller, Andreas; Candrian, Gian; Grin-Yatsenko, Vera A; Kropotov, Juri D

2014-01-01

To investigate the performance of the spectral analysis of resting EEG, Current Source Density (CSD) and group independent components (gIC) in diagnosing ADHD adults. Power spectra of resting EEG, CSD and gIC (19 channels, linked ears reference, eyes open/closed) from 96 ADHD and 376 healthy adults were compared between eyes open and eyes closed conditions, and between groups of subjects. Pattern of differences in gIC and CSD spectral power between conditions was approximately similar, whereas it was more widely spatially distributed for EEG. Size effect (Cohen's d) of differences in gIC and CSD spectral power between groups of subjects was considerably greater than in the case of EEG. Significant reduction of gIC and CSD spectral power depending on conditions was found in ADHD patients. Reducing power in a wide frequency range in the fronto-central areas is a common phenomenon regardless of whether the eyes were open or closed. Spectral power of local EEG activity isolated by gICA or CSD in the fronto-central areas may be a suitable marker for discrimination of ADHD and healthy adults. Spectral analysis of gIC and CSD provides better sensitivity to discriminate ADHD and healthy adults. Copyright © 2013 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

Density-dependence in the establishment of juvenile Allium ursinum individuals in a monodominant stand of conspecific adults

NASA Astrophysics Data System (ADS)

Morschhauser, Tamás; Rudolf, Kinga; Botta-Dukát, Zoltán; Oborny, Beáta

2009-09-01

We studied the establishment of new genets in a wild garlic population ( Allium ursinum L.) in the herb layer of an oak-hornbeam forest. We tested whether establishment could be successful in relatively small gaps (25 cm) surrounded by adult individuals. Furthermore, we asked whether more empty space in the neighborhood would increase the success. Newly germinated individuals were selected, and observed throughout the growth season. The success of establishment was characterized by the biomass of the bulb at the end of the season. The surrounding vegetation cover was recorded in a 25 cm resolution. We found that the success of establishment had a peak at intermediate neighborhood density. At higher densities, a significant, linear decline was found, indicating competition with the neighbors. At lower values, this trend did not continue, but a plateau was observed, indicating the effect of inverse density-dependence (an Allee effect). The results suggest that a rather broad radius (>25 cm) should be considered when predicting the establishment of new genets in A. ursinum, and beside competition, facilitative interactions should also be taken into consideration. This may explain the tendency of the species for maintaining high, often monodominant cover in the herb layer. Due to the observed efficiency of gap-filling and lateral spreading by sexual reproduction, we predict considerable genetic diversity even in high-cover A. ursinum patches.

Circulating levels of dickkopf-1, osteoprotegerin and sclerostin are higher in old compared with young men and women and positively associated with whole-body bone mineral density in older adults.

PubMed

Coulson, J; Bagley, L; Barnouin, Y; Bradburn, S; Butler-Browne, G; Gapeyeva, H; Hogrel, J-Y; Maden-Wilkinson, T; Maier, A B; Meskers, C; Murgatroyd, C; Narici, M; Pääsuke, M; Sassano, L; Sipilä, S; Al-Shanti, N; Stenroth, L; Jones, D A; McPhee, J S

2017-09-01

Bone mineral density declines with increasing older age. We examined the levels of circulating factors known to regulate bone metabolism in healthy young and older adults. The circulating levels of dickkopf-1, osteocalcin, osteoprotegerin and sclerostin were positively associated with whole-body bone mineral density (WBMD) in older adults, despite the average WBMD being lower and circulating dickkopf-1, osteoprotegerin and sclerostin being higher in old than young. This study aims to investigate the relationship between whole-body bone mineral density (WBMD) and levels of circulating factors with known roles in bone remodelling during 'healthy' ageing. WBMD and fasting plasma concentrations of dickkopf-1, fibroblast growth factor-23, osteocalcin, osteoprotegerin, osteopontin and sclerostin were measured in 272 older subjects (69 to 81 years; 52% female) and 171 younger subjects (18-30 years; 53% female). WBMD was lower in old than young. Circulating osteocalcin was lower in old compared with young, while dickkopf-1, osteoprotegerin and sclerostin were higher in old compared with young. These circulating factors were each positively associated with WBMD in the older adults and the relationships remained after adjustment for covariates (r values ranging from 0.174 to 0.254, all p < 0.01). In multivariate regression, the body mass index, circulating sclerostin and whole-body lean mass together accounted for 13.8% of the variation with WBMD in the older adults. In young adults, dickkopf-1 and body mass index together accounted for 7.7% of variation in WBMD. Circulating levels of dickkopf-1, osteocalcin, osteoprotegerin and sclerostin are positively associated with WBMD in community-dwelling older adults, despite the average WBMD being lower and circulating dickkopf-1, osteoprotegerin and sclerostin being higher in old than young.

Low bone mineral density and risk of incident fracture in HIV-infected adults.

PubMed

Battalora, Linda; Buchacz, Kate; Armon, Carl; Overton, Edgar T; Hammer, John; Patel, Pragna; Chmiel, Joan S; Wood, Kathy; Bush, Timothy J; Spear, John R; Brooks, John T; Young, Benjamin

2016-01-01

Prevalence rates of low bone mineral density (BMD) and bone fractures are higher among HIV-infected adults compared with the general United States (US) population, but the relationship between BMD and incident fractures in HIV-infected persons has not been well described. Dual energy X-ray absorptiometry (DXA) results of the femoral neck of the hip and clinical data were obtained prospectively during 2004-2012 from participants in two HIV cohort studies. Low BMD was defined by a T-score in the interval >-2.5 to <-1.0 (osteopenia) or ≤-2.5 (osteoporosis). We analysed the association of low BMD with risk of subsequent incident fractures, adjusted for sociodemographics, other risk factors and covariables, using multivariable proportional hazards regression. Among 1,006 participants analysed (median age 43 years [IQR 36-49], 83% male, 67% non-Hispanic white, median CD4(+) T-cell count 461 cells/mm(3) [IQR 311-658]), 36% (n=358) had osteopenia and 4% (n=37) osteoporosis; 67 had a prior fracture documented. During 4,068 person-years of observation after DXA scanning, 85 incident fractures occurred, predominantly rib/sternum (n=18), hand (n=14), foot (n=13) and wrist (n=11). In multivariable analyses, osteoporosis (adjusted hazard ratio [aHR] 4.02, 95% CI 2.02, 8.01) and current/prior tobacco use (aHR 1.59, 95% CI 1.02, 2.50) were associated with incident fracture. In this large sample of HIV-infected adults in the US, low baseline BMD was significantly associated with elevated risk of incident fracture. There is potential value of DXA screening in this population.

Projected shifts in fish species dominance in Wisconsin lakes under climate change.

PubMed

Hansen, Gretchen J A; Read, Jordan S; Hansen, Jonathan F; Winslow, Luke A

2017-04-01

Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989-2014) and future (2040-2064 and 2065-2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33-75% of lakes where recruitment is currently supported and a 27-60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up to 85

Projected shifts in fish species dominance in Wisconsin lakes under climate change

USGS Publications Warehouse

Hansen, Gretchen JA; Read, Jordan S.; Hansen, Jonathan F.; Winslow, Luke

2016-01-01

Temperate lakes may contain both coolwater fish species such as walleye (Sander vitreus) and warmwater fish species such as largemouth bass (Micropterus salmoides). Recent declining walleye and increasing largemouth bass populations have raised questions regarding the future trajectories and management actions for these species. We developed a thermodynamic model of water temperatures driven by downscaled climate data and lake-specific characteristics to estimate daily water temperature profiles for 2148 lakes in Wisconsin, US, under contemporary (1989–2014) and future (2040–2064 and 2065–2089) conditions. We correlated contemporary walleye recruitment and largemouth bass relative abundance to modeled water temperature, lake morphometry, and lake productivity, and projected lake-specific changes in each species under future climate conditions. Walleye recruitment success was negatively related and largemouth bass abundance was positively related to water temperature degree days. Both species exhibited a threshold response at the same degree day value, albeit in opposite directions. Degree days were predicted to increase in the future, although the magnitude of increase varied among lakes, time periods, and global circulation models (GCMs). Under future conditions, we predicted a loss of walleye recruitment in 33–75% of lakes where recruitment is currently supported and a 27–60% increase in the number of lakes suitable for high largemouth bass abundance. The percentage of lakes capable of supporting abundant largemouth bass but failed walleye recruitment was predicted to increase from 58% in contemporary conditions to 86% by mid-century and to 91% of lakes by late century, based on median projections across GCMs. Conversely, the percentage of lakes with successful walleye recruitment and low largemouth bass abundance was predicted to decline from 9% of lakes in contemporary conditions to only 1% of lakes in both future periods. Importantly, we identify up

Do muscle mass, muscle density, strength, and physical function similarly influence risk of hospitalization in older adults?

PubMed

Cawthon, Peggy Mannen; Fox, Kathleen M; Gandra, Shravanthi R; Delmonico, Matthew J; Chiou, Chiun-Fang; Anthony, Mary S; Sewall, Ase; Goodpaster, Bret; Satterfield, Suzanne; Cummings, Steven R; Harris, Tamara B

2009-08-01

To examine the association between strength, function, lean mass, muscle density, and risk of hospitalization. Prospective cohort study. Two U.S. clinical centers. Adults aged 70 to 80 (N=3,011) from the Health, Aging and Body Composition Study. Measurements were of grip strength, knee extension strength, lean mass, walking speed, and chair stand pace. Thigh computed tomography scans assessed muscle area and density (a proxy for muscle fat infiltration). Hospitalizations were confirmed by local review of medical records. Negative binomial regression models estimated incident rate ratios (IRRs) of hospitalization for race- and sex-specific quartiles of each muscle and function parameter separately. Multivariate models adjusted for age, body mass index, health status, and coexisting medical conditions. During an average 4.7 years of follow-up, 1,678 (55.7%) participants experienced one or more hospitalizations. Participants in the lowest quartile of muscle density were more likely to be subsequently hospitalized (multivariate IRR=1.47, 95% confidence interval (CI)=1.24-1.73) than those in the highest quartile. Similarly, participants with the weakest grip strength were at greater risk of hospitalization (multivariate IRR=1.52, 95% CI=1.30-1.78, Q1 vs. Q4). Comparable results were seen for knee strength, walking pace, and chair stands pace. Lean mass and muscle area were not associated with risk of hospitalization. Weak strength, poor function, and low muscle density, but not muscle size or lean mass, were associated with greater risk of hospitalization. Interventions to reduce the disease burden associated with sarcopenia should focus on increasing muscle strength and improving physical function rather than simply increasing lean mass.

Obesity and Regional Immigrant Density.

PubMed

Emerson, Scott D; Carbert, Nicole S

2017-11-24

Canada has an increasingly large immigrant population. Areas of higher immigrant density, may relate to immigrants' health through reduced acculturation to Western foods, greater access to cultural foods, and/or promotion of salubrious values/practices. It is unclear, however, whether an association exists between Canada-wide regional immigrant density and obesity among immigrants. Thus, we examined whether regional immigrant density was related to obesity, among immigrants. Adult immigrant respondents (n = 15,595) to a national population-level health survey were merged with region-level immigrant density data. Multi-level logistic regression was used to model the odds of obesity associated with increased immigrant density. The prevalence of obesity among the analytic sample was 16%. Increasing regional immigrant density was associated with lower odds of obesity among minority immigrants and long-term white immigrants. Immigrant density at the region-level in Canada may be an important contextual factor to consider when examining obesity among immigrants.

Constitutive melanin density is associated with higher 25-hydroxyvitamin D and potentially total body BMD in older Caucasian adults via increased sun tolerance and exposure.

PubMed

Thompson, M J W; Jones, G; Aitken, D A

2018-06-01

Greater skin pigmentation reduces dose equivalent cutaneous vitamin D3 production, potentially impacting lifetime vitamin D status and fracture risk. We show that melanin density was positively associated with 25-hydroxyvitamin D and total body bone mineral density. These relationships were partially explained by greater sun exposure due to more permissive skin phenotype. Higher cutaneous melanin reduces vitamin D3 production. This may impact lifetime vitamin D status and increase fracture risk. This study aimed to describe the relationship between spectrophotometrically determined constitutive melanin density, osteoporotic risk factors and potential intermediaries in a cohort of exclusively older Caucasian adults. One thousand seventy-two community-dwelling adults aged 50-80 years had constitutive melanin density quantified using spectrophotometry. Sun exposure, skin phenotype, non-melanoma skin cancer (NMSC) prevalence and smoking status were assessed by questionnaire. Bone mineral density (BMD), falls risk, physical activity and 25-hydroxyvitamin D were measured using DXA, the short form Physiological Profile Assessment, pedometer and radioimmunoassay, respectively. Higher melanin density was independently associated with greater ability to tan (RR = 1.27, p < 0.001), less propensity to sunburn (RR = 0.92, p < 0.001), fewer lifetime sunburns (RR = 0.94, p = 0.01), current smoking (RR = 1.41, p < 0.001), female sex (RR = 1.24, p < 0.001) and less photodamage (RR = 0.98, p = 0.01). The associations between melanin density and sun exposure (RR = 1.05-1.11, p < 0.001-0.01), sun protection behaviours (RR = 0.89, p < 0.001) and NMSC prevalence (RR = 0.75, p = 0.001) were no longer significant after taking into account skin phenotype and sun exposure, respectively. 25-Hydroxyvitamin D was strongly associated with higher melanin density (β = 1.71-2.05, p = 0.001). The association between

Emergence flux declines disproportionately to larval density along a stream metals gradient

USGS Publications Warehouse

Schmidt, Travis S.; Kraus, Johanna M.; Walters, David M.; Wanty, Richard B.

2013-01-01

Effects of contaminants on adult aquatic insect emergence are less well understood than effects on insect larvae. We compared responses of larval density and adult emergence along a metal contamination gradient. Nonlinear threshold responses were generally observed for larvae and emergers. Larval densities decreased significantly at low metal concentrations but precipitously at concentrations of metal mixtures above aquatic life criteria (Cumulative Criterion Accumulation Ratio (CCAR) ≥ 1). In contrast, adult emergence declined precipitously at low metal concentrations (CCAR ≤ 1), followed by a modest decline above this threshold. Adult emergence was a more sensitive indicator of the effect of low metals concentrations on aquatic insect communities compared to larvae, presumably because emergence is limited by a combination of larval survival and other factors limiting successful emergence. Thus effects of exposure to larvae are not manifest until later in life (during metamorphosis and emergence). This loss in emergence reduces prey subsidies to riparian communities at concentrations considered safe for aquatic life. Our results also challenge the widely held assumption that adult emergence is a constant proportion of larval densities in all streams.

Influence of neighbourhood ethnic density, diet and physical activity on ethnic differences in weight status: a study of 214,807 adults in Australia.

PubMed

Astell-Burt, Thomas; Feng, Xiaoqi; Croteau, Karen; Kolt, Gregory S

2013-09-01

We investigated whether ethnic and country of birth differences in adult Body Mass Index (BMI) were associated with differences in diet, physical activity and ethnic density (the percentage of an ethnic group within the neighbourhood environment). A sample of 214,807 adults living in Australia was extracted from the 45 and Up Study. Analyses comprised multilevel modelling of BMI for 38 ethnic and country of birth groups. Physical activity was ascertained using the Active Australia Survey. Dietary measures included self-reported consumption of fruit, vegetables, meat and cheese. Ethnic density was objectively measured using 2006 Australian Census data. Possible confounders included age, gender, household income, educational qualifications, economic status, couple status, language, duration of residence, neighbourhood affluence and remoteness. Compared to Australian-born Australians (age-gender adjusted mean BMI = 27.1, 95%CI 27.1, 27.2), overseas-born groups often had lower mean BMI, especially the Chinese born in China (23.2, 23.0, 23.4). Exceptions included the Italians (BMI = 28.1), Greeks (28.5), Maltese (27.6), Lebanese (28.4) and Croatians (27.8) born in their ethnic-country of origin. Regardless of birthplace, BMI was lower for the English, Scottish, and Chinese, but higher for Italians and Greeks. Some ethnic differences reflected the 'healthy migrant' hypothesis, whereas others did not. These differences were only partially attenuated by controls for portions of fruit and vegetables, meat and cheese, frequency of participation in physical activity, and other explanatory variables. Ethnic density was associated with lower BMI for the English and Irish (p < 0.05), regardless of whether they were born in the UK, Ireland, or Australia. Ethnic differences in adult weight status in Australia do not appear to be fully explained by conventional risk factors. For some groups, but not all, living among others of the same ethnic group may proxy unmeasured health

Differences in regional adiposity, bone mineral density, and physical exercise participation based on exercise self-efficacy among senior adults.

PubMed

Glenn, J M; Gray, M; Vincenzo, J L

2015-10-01

The impact of exercise self-efficacy levels (ESE) on exercise participation, levels of body fat (BF), and bone mineral density (BMD) are unclear in senior-aged adults. The purpose of this study was to investigate effects of ESE on exercise participation, regional distribution of BF, and BMD among seniors. Senior adults (N.=76; 36 males, 40 females) were separated into tertiles (T1, age=60.4±1.4; T2, age=61.3±1.4; T3, age=60.4±1.5) based on self-reported levels of ESE. BMD and regional BF were measured using dual-energy x-ray absorptiometry and exercise participation levels were measured using the Rapid Physical-Activity Questionnaire. MANOVA revealed a significant Wilks Lambda (p < 0.001) and univariate analysis was completed for exercise participation levels, android BF, gynoid BF, and spinal BMD. ANOVA revealed T3 was significantly lower for android BF (p=0.002) than T1 and T2 (30% and 26%, respectively) while gynoid BF was significantly lower (p=0.012) for T3 (24%) compared to T1. When evaluating exercise participation levels, T3 was significantly higher (p < 0.001) than T1 or T2. Spinal BMD was significantly higher (p=0.030) between T2 (10%) and T1. ESE is an important factor in senior adults ability to maintain longitudinal health.

Population-regulating processes during the adult phase in flatfish

NASA Astrophysics Data System (ADS)

Rijnsdorp, A. D.

Flatfish support major fisheries and the study of regulatory processes are of paramount importance for evaluating the resilience of the resource to exploitation. This paper reviews the evidence for processes operating during the adult phase that may 1. generate interannual variability in recruitment; 2. contribute to population regulation through density-dependent growth, density-dependent ripening of adults and density-dependent egg production. With regard to (1), there is evidence that in the adult phase processes do occur that may generate recruitment variability through variation in size-specific fecundity, contraction of spawning season, reduction in egg quality, change in sex ratio and size composition of the adult population. However, time series of recruitment do not provide support for this hypothesis. With regard to (2), there is ample evidence that exploitation of flatfish coincides with an increase in growth, although the mechanisms involved are not always clear. The presence of density-dependent growth in the adult phase of unexploited populations appears to be the most likely explanation in some cases. From the early years of exploitation of flatfish stocks inhabiting cold waters, evidence exists that adult fish do not spawn each year. Fecundity schedules show annual variations, but the available information suggests that size-specific fecundity is stable over a broad range of population abundance and may only decrease at high population abundance. The analysis is complicated by the possibility of a trade-off between egg numbers and egg size. Nevertheless, a density-dependent decrease in growth will automatically result in a decrease in absolute fecundity because of the reduced body size. The potential contribution of these regulatory effects on population regulation is explored. Results indicate that density-dependent ripening and absolute fecundity, mediated through density-dependent growth, may control recruitment at high levels of population

Stem cell motility enables a density-dependent rate of fate commitment during scaled resizing of adult organs

NASA Astrophysics Data System (ADS)

Du, Xinxin; O'Brien, Lucy; Riedel-Kruse, Ingmar

Many adult organs grow or shrink to accommodate fluctuating levels of physiological demand. Specifically, the intestine of the fruit fly (the midgut) expands four-fold in the number of mature cells and, proportionally, the number of stem cells when the fly eats. However, the cellular behaviors that give rise to this stem scaling are not well-understood. Here we present a biophysical model of the adult fly midgut. A set of differential equations can recapitulate the physiological kinetics of cells during midgut growth and shrinkage as long as the rate of stem cell fate commitment depends on the stem cell number density in the tissue. To elucidate the source of this dependence, we model the tissue in a 2D simulation with soft spheres, where stem cells choose fate commitment through Delta-Notch pathway interactions with other stem cells, a known process in fly midguts. We find that as long as stem cells exhibit a large enough amplitude of random motion through the tissue (`stem cell motility'), and explore a large enough `territory' in their lifetime, stem cell scaling can occur. These model observations are confirmed through in vivo live-imaging, where we indeed see that stem cells are motile in the fly midgut.

Detection of density dependence requires density manipulations and calculation of lambda.

PubMed

Fowler, N L; Overath, R Deborah; Pease, Craig M

2006-03-01

To investigate density-dependent population regulation in the perennial bunchgrass Bouteloua rigidiseta, we experimentally manipulated density by removing adults or adding seeds to replicate quadrats in a natural population for three annual intervals. We monitored the adjacent control quadrats for 14 annual intervals. We constructed a population projection matrix for each quadrat in each interval, calculated lambda, and did a life table response experiment (LTRE) analysis. We tested the effects of density upon lambda by comparing experimental and control quadrats, and by an analysis of the 15-year observational data set. As measured by effects on lambda and on N(t+1/Nt in the experimental treatments, negative density dependence was strong: the population was being effectively regulated. The relative contributions of different matrix elements to treatment effect on lambda differed among years and treatments; overall the pattern was one of small contributions by many different life cycle stages. In contrast, density dependence could not be detected using only the observational (control quadrats) data, even though this data set covered a much longer time span. Nor did experimental effects on separate matrix elements reach statistical significance. These results suggest that ecologists may fail to detect density dependence when it is present if they have only descriptive, not experimental, data, do not have data for the entire life cycle, or analyze life cycle components separately.

Influence of deer abundance on the abundance of questing adult Ixodes scapularis (Acari: Ixodidae)

USGS Publications Warehouse

Ginsberg, H.S.; Zhioua, E.

1999-01-01

Nymphal and adult Ixodes scapularis Say were sampled by flagging at 2 sites on a barrier island, Fire Island, NY, and at 2 sites on the nearby mainland. Nymphal densities did not differ consistently between island and mainland sites, but adult densities were consistently lower on the island. We tested whether lower adult densities on the island resulted from greater nymphal mortality on the island than the mainland, or whether adult ticks on the island were poorly sampled by flagging because they had attached abundantly to deer, which were common on Fire Island. Differential nymphal mortality on islands vs. mainland did not explain this difference in adult densities because survival of flat and engorged nymphs in enclosures was the same at island and mainland sites. Ticks were infected by parasitic wasps on the island and not the mainland, but the infection rate (4.3%) was too low to explain the difference in adult tick densities. In contrast, exclusion of deer by game fencing on Fire Island resulted in markedly increased numbers of adult ticks in flagging samples inside compared to samples taken outside the exclosures. Therefore, the scarcity of adult ticks in flagging samples on Fire Island resulted, at least in part, from the ticks being unavailable to flagging samples because they were on deer hosts. Differences in the densities of flagged ticks inside and outside the exclosures were used to estimate the percentage of questing adults on Fire Island that found deer hosts, excluding those that attached to other host species. Approximately 56% of these questing adult ticks found deer hosts in 1995 and 50% found deer hosts in 1996. Therefore, in areas where vertebrate hosts are highly abundant, large proportions of the questing tick population can find hosts. Moreover, comparisons of tick densities at different sites by flagging can potentially be biased by differences in host densities among sites.

Association between adiposity outcomes and residential density: a full-data, cross-sectional analysis of 419 562 UK Biobank adult participants.

PubMed

Sarkar, Chinmoy; Webster, Chris; Gallacher, John

2017-10-01

Obesity is a major health issue and an important public health target for urban design. However, the evidence for identifying the optimum residential density in relation to obesity has been far from compelling. We examined the association of obesity with residential density in a large and diverse population sample drawn from the UK Biobank to identify healthy-weight-sustaining density environments. For this full-data, cross-sectional analysis, we used UK Biobank data for adult men and women aged 37-73 years from 22 cities across the UK. Baseline examinations were done between 2006 and 2010. Residential unit density was objectively assessed within a 1 km street catchment of a participant's residence. Other activity-influencing built environment factors were measured in terms of density of retail, public transport, and street-level movement density, which were modelled from network analyses of through movement of street links within the defined catchment. We regressed adiposity indicators of body-mass index (BMI; kg/m 2 ), waist circumference (cm), whole body fat (kg), and obesity (WHO criteria of BMI ≥30 kg/m 2 ) on residential density (units per km 2 ), adjusting for activity-influencing built environment factors and individual covariates. We also investigated effect modification by age, sex, employment status, and physical activity. We used a series of linear continuous and logistic regression models and non-linear restricted cubic spline models as appropriate. Of 502 649 adults in the prospective cohort, 419 562 (83·5%) participants across 22 UK Biobank assessment centres met baseline data requirements and were included in the analytic sample. The fitted restricted cubic spline adiposity-residential density dose-response curve identified a turning point at a residential density of 1800 residential units per km 2 . Below a residential density of 1800 units per km 2 , an increment of 1000 units per km 2 was positively related with adiposity, being associated

Bone Mineral Density and Fat-Soluble Vitamin Status in Adults with Cystic Fibrosis Undergoing Lung Transplantation: A Pilot Study.

PubMed

Hubert, Grace; Chung, Theresa Tam; Prosser, Connie; Lien, Dale; Weinkauf, Justin; Brown, Neil; Goodvin, Marianne; Jackson, Kathy; Tabak, Joan; Salgado, Josette; Alzaben, Abeer Salman; Mager, Diana R

2016-12-01

Patients with cystic fibrosis (CF) often experience low bone mineral density (BMD) pre- and post-lung transplantation (LTX). The study purpose was to describe BMD and micronutrient status in adults with CF pre- and post-LTX. Twelve patients with CF (29 ± 8 years) were recruited from the CF clinic at the University of Alberta Lung Transplant Program. BMD and vitamins A, D, E, K status, and parathyroid hormone were measured pre- and post-LTX. No significant differences pre- and post-LTX were observed at the different bone sites measured (lumber-spine, femoral-neck (FN), hip, and femoral-trochlea) (P > 0.05). BMD T-scores (<-2) was present in lumbar-spine, FN, hip, and femoral-trochlea in 33%, 17%, 17%, and 25% of individuals pre-LTX and 58%, 33%, 58%, and 33% of individuals post-LTX, respectively. More than 50% of patients had suboptimal vitamin K levels (PIVKA-II values >3 ng/mL) pre- and post-LTX. Adults with CF pre- and post-LTX had reduced BMD and suboptimal vitamin K status.

Functional consequences of neurite orientation dispersion and density in humans across the adult lifespan.

PubMed

Nazeri, Arash; Chakravarty, M Mallar; Rotenberg, David J; Rajji, Tarek K; Rathi, Yogesh; Michailovich, Oleg V; Voineskos, Aristotle N

2015-01-28

As humans age, a characteristic pattern of widespread neocortical dendritic disruption coupled with compensatory effects in hippocampus and other subcortical structures is shown in postmortem investigations. It is now possible to address age-related effects on gray matter (GM) neuritic organization and density in humans using multishell diffusion-weighted MRI and the neurite-orientation dispersion and density imaging (NODDI) model. In 45 healthy individuals across the adult lifespan (21-84 years), we used a multishell diffusion imaging and the NODDI model to assess the intraneurite volume fraction and neurite orientation-dispersion index (ODI) in GM tissues. We also determined the functional correlates of variations in GM microstructure by obtaining resting-state fMRI and behavioral data. We found a significant age-related deficit in neocortical ODI (most prominently in frontoparietal regions), whereas increased ODI was observed in hippocampus and cerebellum with advancing age. Neocortical ODI outperformed cortical thickness and white matter fractional anisotropy for the prediction of chronological age in the same individuals. Higher GM ODI sampled from resting-state networks with known age-related susceptibility (default mode and visual association networks) was associated with increased functional connectivity of these networks, whereas the task-positive networks tended to show no association or even decreased connectivity. Frontal pole ODI mediated the negative relationship of age with executive function, whereas hippocampal ODI mediated the positive relationship of age with executive function. Our in vivo findings align very closely with the postmortem data and provide evidence for vulnerability and compensatory neural mechanisms of aging in GM microstructure that have functional and cognitive impact in vivo. Copyright © 2015 the authors 0270-6474/15/351753-10$15.00/0.

Change in Bone Mineral Density During Weight Loss with Resistance Versus Aerobic Exercise Training in Older Adults.

PubMed

Beavers, Kristen M; Beavers, Daniel P; Martin, Sarah B; Marsh, Anthony P; Lyles, Mary F; Lenchik, Leon; Shapses, Sue A; Nicklas, Barbara J

2017-10-12

To examine the effect of exercise modality during weight loss on hip and spine bone mineral density (BMD) in overweight and obese, older adults. This analysis compared data from two 5-month, randomized controlled trials of caloric restriction (CR; inducing 5-10% weight loss) with either resistance training (RT) or aerobic training (AT) in overweight and obese, older adults. Participants in the RT + CR study underwent 3 days/week of 8 upper/lower body exercises (3 sets, 10 repetitions at 70% 1 RM) and participants in the AT+CR study underwent 4 days/week of treadmill walking (30 min at 65-70% heart rate reserve). BMD at the total hip, femoral neck, and lumbar spine was assessed via dual-energy X-ray absorptiometry at baseline and 5 months. A total of 123 adults (69.4 ± 3.5 years, 67% female, 81% Caucasian) participated in the RT+CR (n = 60) and AT+CR (n = 63) interventions. Average weight loss was 5.7% (95% CI: 4.6-6.7%) and 8.2% (95% CI: 7.2-9.3%) in RT+CR and AT+CR groups, respectively. After adjustment for age, gender, race, baseline BMI and BMD, and weight change, differential treatment effects were observed for total hip and femoral neck (both p < .05), but not lumbar spine. Total hip (1.83 [-3.90, 7.55] mg/cm2) and femoral neck (9.14 [-0.70, 18.98] mg/cm2) BMD was unchanged in RT+CR participants, and modestly decreased in AT+CR participants (total hip: -7.01 [-12.73, -1.29] mg/cm2; femoral neck: -5.36 [-14.92, 4.20] mg/cm2). Results suggest performing resistance, rather than aerobic, training during CR may attenuate loss of hip and femoral neck BMD in overweight and obese older adults. Findings warrant replication from a long-term, adequately powered, RCT. © The Author 2017. Published by Oxford University Press on behalf of The Gerontological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Drosophila Regulate Yeast Density and Increase Yeast Community Similarity in a Natural Substrate

PubMed Central

Stamps, Judy A.; Yang, Louie H.; Morales, Vanessa M.; Boundy-Mills, Kyria L.

2012-01-01

Drosophila melanogaster adults and larvae, but especially larvae, had profound effects on the densities and community structure of yeasts that developed in banana fruits. Pieces of fruit exposed to adult female flies previously fed fly-conditioned bananas developed higher yeast densities than pieces of the same fruits that were not exposed to flies, supporting previous suggestions that adult Drosophila vector yeasts to new substrates. However, larvae alone had dramatic effects on yeast density and species composition. When yeast densities were compared in pieces of the same fruits assigned to different treatments, fruits that developed low yeast densities in the absence of flies developed significantly higher yeast densities when exposed to larvae. Across all of the fruits, larvae regulated yeast densities within narrow limits, as compared to a much wider range of yeast densities that developed in pieces of the same fruits not exposed to flies. Larvae also affected yeast species composition, dramatically reducing species diversity across fruits, reducing variation in yeast communities from one fruit to the next (beta diversity), and encouraging the consistent development of a yeast community composed of three species of yeast (Candida californica, C. zemplinina, and Pichia kluvyeri), all of which were palatable to larvae. Larvae excreted viable cells of these three yeast species in their fecal pools, and discouraged the growth of filamentous fungi, processes which may have contributed to their effects on the yeast communities in banana fruits. These and other findings suggest that D. melanogaster adults and their larval offspring together engage in ‘niche construction’, facilitating a predictable microbial environment in the fruit substrates in which the larvae live and develop. PMID:22860093

Sparse targets in hydroacoustic surveys: Balancing quantity and quality of in situ target strength data

USGS Publications Warehouse

DuFour, Mark R.; Mayer, Christine M.; Kocovsky, Patrick; Qian, Song; Warner, David M.; Kraus, Richard T.; Vandergoot, Christopher

2017-01-01

Hydroacoustic sampling of low-density fish in shallow water can lead to low sample sizes of naturally variable target strength (TS) estimates, resulting in both sparse and variable data. Increasing maximum beam compensation (BC) beyond conventional values (i.e., 3 dB beam width) can recover more targets during data analysis; however, data quality decreases near the acoustic beam edges. We identified the optimal balance between data quantity and quality with increasing BC using a standard sphere calibration, and we quantified the effect of BC on fish track variability, size structure, and density estimates of Lake Erie walleye (Sander vitreus). Standard sphere mean TS estimates were consistent with theoretical values (−39.6 dB) up to 18-dB BC, while estimates decreased at greater BC values. Natural sources (i.e., residual and mean TS) dominated total fish track variation, while contributions from measurement related error (i.e., number of single echo detections (SEDs) and BC) were proportionally low. Increasing BC led to more fish encounters and SEDs per fish, while stability in size structure and density were observed at intermediate values (e.g., 18 dB). Detection of medium to large fish (i.e., age-2+ walleye) benefited most from increasing BC, as proportional changes in size structure and density were greatest in these size categories. Therefore, when TS data are sparse and variable, increasing BC to an optimal value (here 18 dB) will maximize the TS data quantity while limiting lower-quality data near the beam edges.

Effect of high density on the short term Calomys musculinus spacing behaviour: A fencing experiment

NASA Astrophysics Data System (ADS)

Sommaro, Lucía V.; Steinmann, Andrea R.; Chiappero, Marina B.; Priotto, José W.

2010-05-01

We studied the short term spacing behavioural responses of corn mice ( Calomys musculinus) with regard to population density in four 0.25 ha enclosures (two control and two experimental) in the 2007 breeding season. The goal of this research was to test the hypothesis that spacing behaviour only operates among C. musculinus adult females. We estimated 207 home ranges to study: 1) the home range size and the overlap degree of adult males and females in relation to population density; 2) the settlement distances of juveniles to the centre of activity of their mothers and the home range overlap proportion between them and their mothers in relation to population density. We found that home range size and overlap degree in C. musculinus adults were determined by sex and density. At high population density males had significant smaller and more exclusive home ranges, and this might reflect induced territoriality derived from social restrictions. Female home range sizes remained similar irrespective of population density, and they kept exclusive home ranges in both control and experimental enclosures. Thus, females maintained their territories independent of the population density values. The settlement distances of juveniles from their mothers and the overlap proportion between them and their mothers were independent of population density. We conclude that spacing behaviour only operates among C. musculinus adult females and it could have a role in regulating population abundances limiting the number of females that acquire breeding spaces.

Macular pigment optical density in young adults of South Asian origin.

PubMed

Howells, Olivia; Eperjesi, Frank; Bartlett, Hannah

2013-04-17

To assess the range of macular pigment optical density (MPOD) in a healthy group of young adults of South Asian origin; to investigate whether any dietary factors or personal characteristics were related to intersubject variations in MPOD; and to compare the mean MPOD of the South Asian group with the mean MPOD of a white group. Heterochromatic flicker photometry was used to measure the macular pigment (MP) levels of 169 healthy volunteers, of which 117 were Asian and 52 were white. In addition, the Asian participants completed a questionnaire pertaining to the various physical, ocular, lifestyle, dietary, and environmental factors that may be associated with MPOD or AMD. The mean MPOD of the Asian subjects was 0.43 ± 0.14. The male participants had a higher mean MPOD than the females (0.47 ± 0.13 vs. 0.41 ± 0.14, P < 0.01). Possible associations also emerged between MPOD and form of refractive correction, and iris color. No MPOD associations were found for the other variables examined in the questionnaire. The mean MPOD of the white subject group was 0.33 ± 0.13, which was significantly lower than the Asian group (P < 0.0005). This study adds to the currently limited information on MPOD in South Asians, and while a comparison between Asians and Whites was not the main focus here, highly significant differences between these two ethnicities were revealed. This provokes the possibility that South Asian individuals could have a lower risk for AMD, and it warrants further study.

Vitamin D3 supplementation increases spine bone mineral density in adolescents and young adults with HIV infection being treated with tenofovir disoproxil fumarate: a randomized, placebo controlled trial

USDA-ARS?s Scientific Manuscript database

Background: Tenofovir disoproxil fumarate (TDF) decreases bone mineral density (BMD). We hypothesized vitamin D3 (VITD3) would increase BMD in adolescents/young adults receiving TDF. Methods: Randomized double-blind placebo-controlled trial of directly observed VITD3 50,000 IU vs. placebo every 4 ...

Oligodendrocyte- and Neuron-Specific Nogo-A Restrict Dendritic Branching and Spine Density in the Adult Mouse Motor Cortex.

PubMed

Zemmar, Ajmal; Chen, Chia-Chien; Weinmann, Oliver; Kast, Brigitt; Vajda, Flora; Bozeman, James; Isaad, Noel; Zuo, Yi; Schwab, Martin E

2018-06-01

Nogo-A has been well described as a myelin-associated inhibitor of neurite outgrowth and functional neuroregeneration after central nervous system (CNS) injury. Recently, a new role of Nogo-A has been identified as a negative regulator of synaptic plasticity in the uninjured adult CNS. Nogo-A is present in neurons and oligodendrocytes. However, it is yet unclear which of these two pools regulate synaptic plasticity. To address this question we used newly generated mouse lines in which Nogo-A is specifically knocked out in (1) oligodendrocytes (oligoNogo-A KO) or (2) neurons (neuroNogo-A KO). We show that both oligodendrocyte- and neuron-specific Nogo-A KO mice have enhanced dendritic branching and spine densities in layer 2/3 cortical pyramidal neurons. These effects are compartmentalized: neuronal Nogo-A affects proximal dendrites whereas oligodendrocytic Nogo-A affects distal regions. Finally, we used two-photon laser scanning microscopy to measure the spine turnover rate of adult mouse motor cortex layer 5 cells and find that both Nogo-A KO mouse lines show enhanced spine remodeling after 4 days. Our results suggest relevant control functions of glial as well as neuronal Nogo-A for synaptic plasticity and open new possibilities for more selective and targeted plasticity enhancing strategies.

Bone Mineral Density in Adults With Down Syndrome, Intellectual Disability, and Nondisabled Adults

ERIC Educational Resources Information Center

Geijer, Justin R.; Stanish, Heidi I.; Draheim, Christopher C.; Dengel, Donald R.

2014-01-01

Individuals with intellectual disability (ID) or Down syndrome (DS) may be at greater risk of osteoporosis. The purpose of this study was to compare bone mineral density (BMD) of DS, ID, and non-intellectually disabled (NID) populations. In each group, 33 participants between the ages of 28 and 60 years were compared. BMD was measured with…

Synchronic inverse seasonal rhythmus of energy density of food intake and sleep quality: a contribution to chrono-nutrition from a Polish adult population.

PubMed

Stelmach-Mardas, M; Iqbal, K; Mardas, M; Schwingshackl, L; Walkowiak, J; Tower, R J; Boeing, H

2017-06-01

There is evidence which suggests that sleep behavior and dietary intake are interlinked. Thus, we investigated whether a seasonal rhythm in food-energy density exists, and how this relates to quality of sleep. Two hundred and thirty adult volunteers were investigated across the four seasons. Anthropometrical measurements were obtained and The Pittsburgh Sleep Quality Index was used for an assessment of sleep quality and disturbances. The dietary intake was evaluated using a 24 h dietary recall. Generalized estimating equations were used to estimate seasonal changes in energy density and sleep quality, as well as the association of energy density with sleep quality. All analyses were adjusted for age, sex, education, occupation and shift-work. Mean food energy density was significantly higher in winter as compared with other seasons (P<0.05), although no seasonal variations were observed in macronutrient intake (fat and protein). Overall, the sleep quality was low (score value >5) in all seasons, with the lowest quality occurring in winter and the highest in spring (P<0.05). The components of sleep quality score showed that winter had statistically (P<0.05) poorer subjective sleep quality, sleep latency and sleep disturbances, but lower daytime dysfunction compared with spring and summer. After adjusting for seasonal effects (correlated outcome data) and shift-work, energy density was found to be inversely associated (P<0.0001) with sleep quality. An inverse association between seasonal fluctuation of food energy density and sleep quality was found with winter time, associated with the intake of higher energy dense food products and the lowest sleep quality.

Population density-dependent hair cortisol concentrations in rhesus monkeys (Macaca mulatta)

PubMed Central

Dettmer, A.M.; Novak, M.A.; Meyer, J.S.; Suomi, S.J.

2014-01-01

Summary Population density is known to influence acute measures of hypothalamic-pituitary-adrenal (HPA) axis activity in a variety of species, including fish, deer, birds, and humans. However, the effects of population density on levels of chronic stress are unknown. Given the fact that exposure to chronically elevated levels of circulating glucocorticoids results in a host of health disparities in animals and humans alike, it is important to understand how population density may impact chronic stress. We assessed hair cortisol concentrations (HCCs), which are reliable indicators of chronic HPA axis activity, in rhesus monkeys (Macaca mulatta) to determine the influence of population density on these values. In Experiment 1, we compared HCCs of monkeys living in high-density (HD; 1 monkey/0.87m2) and low-density (LD; 1 monkey/63.37m2) environments (N=236 hair samples) and found that HD monkeys exhibited higher hair cortisol across all age categories (infant, juvenile, young adult, adult, and aged) except infancy and aged (F(5)=4.240, p=0.001), for which differences were nearly significant. HD monkeys also received more severe fight wounds than LD monkeys (χ2=26.053, p<0.001), though no effects of dominance status emerged. In Experiment 2, we examined how HCCs change with fluctuating population levels across five years in the adult LD monkeys (N=155 hair samples) and found that increased population density was significantly positively correlated with HCCs in this semi-naturalistic population (r(s)=0.975, p=0.005). These are the first findings to demonstrate that increased population density is associated with increased chronic, endogenous glucocorticoid exposure in a nonhuman primate species. We discuss the implications of these findings with respect to laboratory research, population ecology, and human epidemiology. PMID:24636502

Population density-dependent hair cortisol concentrations in rhesus monkeys (Macaca mulatta).

PubMed

Dettmer, A M; Novak, M A; Meyer, J S; Suomi, S J

2014-04-01

Population density is known to influence acute measures of hypothalamic-pituitary-adrenal (HPA) axis activity in a variety of species, including fish, deer, birds, and humans. However, the effects of population density on levels of chronic stress are unknown. Given the fact that exposure to chronically elevated levels of circulating glucocorticoids results in a host of health disparities in animals and humans alike, it is important to understand how population density may impact chronic stress. We assessed hair cortisol concentrations (HCCs), which are reliable indicators of chronic HPA axis activity, in rhesus monkeys (Macaca mulatta) to determine the influence of population density on these values. In Experiment 1, we compared HCCs of monkeys living in high-density (HD; 1 monkey/0.87m(2)) and low-density (LD; 1 monkey/63.37m(2)) environments (N=236 hair samples) and found that HD monkeys exhibited higher hair cortisol across all age categories (infant, juvenile, young adult, adult, and aged) except infancy and aged (F(5)=4.240, p=0.001), for which differences were nearly significant. HD monkeys also received more severe fight wounds than LD monkeys (χ(2)=26.053, p<0.001), though no effects of dominance status emerged. In Experiment 2, we examined how HCCs change with fluctuating population levels across 5 years in the adult LD monkeys (N=155 hair samples) and found that increased population density was significantly positively correlated with HCCs in this semi-naturalistic population (r(s)=0.975, p=0.005). These are the first findings to demonstrate that increased population density is associated with increased chronic, endogenous glucocorticoid exposure in a nonhuman primate species. We discuss the implications of these findings with respect to laboratory research, population ecology, and human epidemiology. Published by Elsevier Ltd.

Sport fishery potential of power plant cooling ponds: Final report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Heidinger, R.C.; Lewis, W.M.

1986-10-01

This research was undertaken to determine if cooling ponds could serve as habitat for several coolwater fish species and also to evaluate the potential use of cooling ponds as nursery areas for receiving waters. The work was conducted on two cooling ponds in northern Illinois. Walleye (Stizostedion vitreum), muskellunge (Esox masquinongy), striped bass (Morone saxatilis) fingerlings, and adult threadfin shad (Dorosoma petenense) were stocked into both cooling ponds. The hybrids between the striped bass and white bass (M. chrysops) had been previously stocked into Collins Pond. Smallmouth bass (Micropterus dolomieui) fingerlings and larval striped bass and walleye were stocked inmore » Dresden Pond. Several sampling techniques including seining, electrofishing, and rotenoning were used to monitor growth and survival of stocked species. In addition, escapement of stocked and indigenous species was monitored at the Dresden Pond spillway. Walleye, muskellunge, striped bass and hybrid striped bass exhibited excellent growth in Collins Pond as did smallmouth bass in Dresden Pond. One of the primary differences between an open system (such as Dresden Pond) and a closed system (such as Collins Pond) is the potential that the open system has to serve as a fish nursery area for receiving waters. The stocking of ''coolwater'' species in a closed type system such as Collins Pond is an effective way to control and maintain selected sport species. Dresden Pond was not open to public fishing during this study, but Collins Pond developed an excellent sport fishery as a result of these stockings.« less

Evaluation of Bone Thickness and Density in the Lower Incisors' Region in Adults with Different Types of Skeletal Malocclusion using Cone-beam Computed Tomography.

PubMed

Al-Masri, Maram M N; Ajaj, Mowaffak A; Hajeer, Mohammad Y; Al-Eed, Muataz S

2015-08-01

To evaluate the bone thickness and density in the lower incisors' region in orthodontically untreated adults, and to examine any possible relationship between thickness and density in different skeletal patterns using cone-beam computed tomography (CBCT). The CBCT records of 48 patients were obtained from the archive of orthodontic department comprising three groups of malocclusion (class I, II and III) with 16 patients in each group. Using OnDemand 3D software, sagittal sections were made for each lower incisor. Thicknesses and densities were measured at three levels of the root (cervical, middle and apical regions) from the labial and lingual sides. Accuracy and reliability tests were undertaken to assess the intraobserver reliability and to detect systematic error. Pearson correlation coefficients were calculated and one-way analysis of variance (ANOVA) was employed to detect significant differences among the three groups of skeletal malocclusion. Apical buccal thickness (ABT) in the four incisors was higher in class II and I patients than in class III patients (p < 0.05). There were significant differences between buccal and lingual surfaces at the apical and middle regions only in class II and III patients. Statistical differences were found between class I and II patients for the cervical buccal density (CBD) and between class II and III patients for apical buccal density (ABD). Relationship between bone thickness and density values ranged from strong at the cervical regions to weak at the apical regions. Sagittal skeletal patterns affect apical bone thickness and density at buccal surfaces of the four lower incisors' roots. Alveolar bone thickness and density increased from the cervical to the apical regions.

Impact of Weight Loss With Intragastric Balloon on Bone Density and Microstructure in Obese Adults.

PubMed

Madeira, Eduardo; Madeira, Miguel; Guedes, Erika Paniago; Mafort, Thiago Thomaz; Moreira, Rodrigo Oliveira; de Mendonça, Laura Maria Carvalho; Lima, Inayá Correa Barbosa; Neto, Leonardo Vieira; de Pinho, Paulo Roberto Alves; Lopes, Agnaldo José; Farias, Maria Lucia Fleiuss

2018-03-21

The historical concept that obesity protects against bone fractures has been questioned. Weight loss appears to reduce bone mineral density (BMD); however, the results in young adults are inconsistent, and data on the effects of weight loss on bone microstructure are limited. This study aimed to evaluate the impact of weight loss using an intragastric balloon (IGB) on bone density and microstructure. Forty obese patients with metabolic syndrome (mean age 35.1 ± 7.3 yr) used an IGB continuously for 6 mo. Laboratory tests, areal BMD, and body composition measurements via dual-energy X-ray absorptiometry, and volumetric BMD and bone microstructure measurements via high-resolution peripheral quantitative computed tomography were conducted before IGB placement and after IGB removal. The mean weight loss was 11.5%. After 6 mo, there were significant increases in vitamin D and carboxyterminal telopeptide of type 1 collagen levels. After IGB use, areal BMD increased in the spine but decreased in the total femur and the 33% radius. Cortical BMD increased in the distal radius but tended to decrease in the distal tibia. The observed trabecular bone loss in the distal tibia contributed to the decline in the total volumetric BMD at this site. There was a negative correlation between the changes in leptin levels and the measures of trabecular quality in the tibia on high-resolution peripheral quantitative computed tomography. Weight loss may negatively impact bone microstructure in young patients, especially for weight-bearing bones, in which obesity has a more prominent effect. Copyright © 2018 The International Society for Clinical Densitometry. Published by Elsevier Inc. All rights reserved.

Butterflies Do Not Alter Conspecific Avoidance in Response to Variation in Density.

PubMed

Jaumann, Sarah; Snell-Rood, Emilie C

2017-08-01

High conspecific densities are associated with increased levels of intraspecific competition and a variety of negative effects on performance. However, changes in life history strategy could compensate for some of these effects. For instance, females in crowded conditions often have fewer total offspring, but they may invest more in each one. Such investment could include the production of larger offspring, more time spent engaging in parental care, or more choosy decisions about where offspring are placed. For animals that have a relatively immobile juvenile stage, the costs of competition can be particularly high. Females may be able to avoid such costs by investing more in individual reproductive decisions, rearing young or laying eggs in locations away from other females. We tested the hypothesis that conspecific density cues during juvenile and adult life stages lead to changes in life history strategy, including both reproduction and oviposition choices. We predicted that high-density cues during the larval and adult stages of female Pieris rapae butterflies lead to lower fecundity but higher conspecific avoidance during oviposition, compared to similar low-density cues. We used a 2×2 factorial design to examine the effects of low and high conspecific density during the larval and adult stages of butterflies on avoidance behavior and fecundity. We found that past information about conspecific density did not matter; all butterflies exhibited similar levels of fecundity and a low level of conspecific avoidance during oviposition regardless of their previous experience as larvae and adults. These results suggest that P. rapae females use a fixed, rather than flexible, conspecific avoidance strategy when making oviposition decisions, and past information about conspecific density has no effect on life history and current reproductive investment. We speculate that this may be partially because past conspecific density per se is not a reliable cue for predicting

Land Use, Residential Density, and Walking

PubMed Central

Rodríguez, Daniel A.; Evenson, Kelly R.; Diez Roux, Ana V.; Brines, Shannon J.

2009-01-01

Background The neighborhood environment may play a role in encouraging sedentary patterns, especially for middle-aged and older adults. Purpose Associations between walking and neighborhood population density, retail availability, and land use distribution were examined using data from a cohort of adults aged 45 to 84 years old. Methods Data from a multi-ethnic sample of 5529 adult residents of Baltimore MD, Chicago IL, Forsyth County NC, Los Angeles CA, New York NY, and St. Paul MN, enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000–2002 were linked to secondary land use and population data. Participant reports of access to destinations and stores and objective measures of the percentage of land area in parcels devoted to retail land uses, the population divided by land area in parcels, and the mixture of uses for areas within 200m of each participant's residence were examined. Multinomial logistic regression was used to investigate associations of self-reported and objective neighborhood characteristics with walking. All analyses were conducted in 2008 and 2009. Results After adjustment for individual-level characteristics and neighborhood connectivity, higher density, greater land area devoted to retail uses, and self-reported measures of proximity of destinations and ease of walking to places were each related to walking. In models including all land use measures, population density was positively associated with walking to places and with walking for exercise for more than 90 min/wk both relative to no walking. Availability of retail was associated with walking to places relative to not walking, having a more proportional mix of land uses was associated with walking for exercise for more than 90 min/wk, while self-reported ease of access to places was related to higher levels of exercise walking both relative to not walking. Conclusions Residential density and the presence of retail uses are related to various walking behaviors. Efforts to

Ecological Associations of Alcohol Outlets with Underage and Young Adult Injuries

PubMed Central

Gruenewald, Paul J.; Freisthler, Bridget; Remer, Lillian; LaScala, Elizabeth A.; Treno, Andrew J.; Ponicki, William R.

2010-01-01

Objective This paper argues that associations between rates of three specific problems related to alcohol (i.e., accidents, traffic crashes, and assaults) should be differentially related to densities of off-premise outlets among underage youth and young adults based upon age related-patterns of alcohol outlet use. Methods Zip code-level population models assessed local and distal effects of alcohol outlets upon rates of hospital discharges for these outcomes. Results Densities of off-premise alcohol outlets were significantly related to injuries from accidents, assaults, and traffic crashes for both underage youth and young adults. Densities of bars were associated with more assaults and densities of restaurants were associated with more traffic crash injuries for young adults. Conclusions The distribution of alcohol-related injuries relative to alcohol outlets reflect patterns of alcohol outlet use. PMID:20028361

Bioimpedence to Assess Breast Density as a Risk Factor for Breast Cancer in Adult Women and Adolescent Girls.

PubMed

Maskarinec, Gertraud; Morimoto, Yukiko; Laguana, Michelle B; Novotny, Rachel; Leon Guerrero, Rachael T

2016-01-01

Although high mammographic density is one of the strongest predictors of breast cancer risk, X-ray based mammography cannot be performed before the recommended screening age, especially not in adolescents and young women. Therefore, new techniques for breast density measurement are of interest. In this pilot study in Guam and Hawaii, we evaluated a radiation-free, bioimpedance device called Electrical Breast DensitometerTM (EBD; senoSENSE Medical Systems, Inc., Ontario, Canada) for measuring breast density in 95 women aged 31-82 years and 41 girls aged 8-18 years. Percent density (PD) was estimated in the women's most recent mammogram using a computer-assisted method. Correlation coefficients and linear regression were applied for statistical analysis. In adult women, mean EBD and PD values of the left and right breasts were 230±52 and 226±50 Ω and 23.7±15.1 and 24.2±15.2%, respectively. The EBD measurements were inversely correlated with PD (rSpearman=-0.52, p<0.0001); the correlation was stronger in Caucasians (rSpearman=-0.70, p<0.0001) than Asians (rSpearman=-0.54, p<0.01) and Native Hawaiian/Chamorro/Pacific Islanders (rSpearman=-0.34, p=0.06). Using 4 categories of PD (<10, 10-25, 26-50, 51-75%), the respective mean EBD values were 256±32, 249±41, 202±46, and 178±43 Ω (p<0.0001). In girls, the mean EBD values in the left and right breast were 148±40 and 155±54 Ω; EBD values decreased from Tanner stages 1 to 4 (204±14, 154±79, 136±43, and 119±16 Ω for stages 1-4, respectively) but were higher at Tanner stage 5 (165±30 Ω). With further development, this bioimpedance method may allow for investigations of breast development among adolescent, as well as assessment of breast cancer risk early in life and in populations without access to mammography.

Measurement of landing mosquito density on humans

USDA-ARS?s Scientific Manuscript database

In conventional vector surveillance systems, adult mosquito density and the rate of human-mosquito contact is estimated from the mosquito numbers captured in mechanical traps. However, the design of the traps, their placement in the habitat and operating time, microclimate, and other environmental ...

Winter movements of four fish species near a thermal plume in northern Minnesota

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ross, M.J.; Winter, J.D.

1981-01-01

During winter 1975, 17 yellow perch (Perca flavescens), 6 northern pike (Esox lucius), 3 walleyes (Stizostedion vitreum), and 2 largemouth bass (Micropterus salmoides) were equipped with radio frequency transmitters to compare their winter movements near the thermal plume of a power plant. The mean home range sizes, in hectares, were northern pike 19.0; yellow perch 13.4; largemouth bass 3.7; walleye 2.2. Northern pike and yellow perch had mean home range sizes larger than the discharge area. Mean water depths at fish locations were as follows: largemouth bass 0.8 m; northern pike 1.2 m; yellow perch 1.6 m; walleye 3.5 m.more » Largemouth bass preferred the warmest locations near the discharge point. Yellow perch were most often located in the peripheral areas of the discharge bay while walleyes were most often located in the deeper center area. Northern pike moved over the entire discharge area. All species except largemouth bass moved freely between discharge-affected and unaltered waters. The average numbers of movements per individual per week between heated and unheated areas were the following: northern pike 0.8; yellow perch 1.2; walleye 1.1; largemouth bass, 0.« less

Possible mechanism linking ocean conditions to low body weight and poor recruitment of age-0 walleye pollock (Gadus chalcogrammus) in the southeast Bering Sea during 2007

NASA Astrophysics Data System (ADS)

Gann, Jeanette C.; Eisner, Lisa B.; Porter, Steve; Watson, Jordan T.; Cieciel, Kristin D.; Mordy, Calvin W.; Yasumiishi, Ellen M.; Stabeno, Phyllis J.; Ladd, Carol; Heintz, Ron A.; Farley, Edward V.

2016-12-01

Changes to physical and chemical oceanographic structure can lead to changes in phytoplankton biomass and growth, which, in-turn, lead to variability in the amount of energy available for transfer to higher trophic levels (e.g., forage fish). In general, age-0 (juvenile) walleye pollock (Gadus chalcogrammus) have been shown to have low fitness (determined by energy density and size), in warm years compared to average or cold years in the southeastern Bering Sea. Contrary to these findings, the year 2007 was a cold year with low fitness of age-0 pollock compared to the transition year of 2006 (transitioning from warm to cold conditions) and cold years, 2008-2011. In late summer/early fall (mid-August through September), significantly lower surface silicic acid concentrations coupled with low phytoplankton production and chlorophyll a (Chl a) biomass were observed in 2007 among 2006-2012 (P<0.05). We postulate that the low silicic acid concentrations may be an indication of reduced surface nutrient flux during summer, leading to low primary productivity (PP). The nutrient replenishing shelf/slope water exchange that occurred during late October-February (2006-2007) indicates that deep-water nutrient/salinity reserves for the start of the 2007 growing season were plentiful and had similar concentrations to other years (2006-2012). The spring bloom magnitude appeared to be slightly below average, and surface silicic acid concentrations at the end of the spring bloom period in 2007 appeared similar to other years in the middle domain of the southeastern Bering Sea. However, during summer (June-August) 2007, high stratification and the low number of storm events resulted in low flux of nutrients to surface waters, indicated by the low surface silicic acid concentrations at the end of summer (mid-August through September). Surface silicic acid may be useful as an indicator of surface nutrient enrichment (and subsequent PP) during summer since other macronutrients (e

Hypothyroidism in the adult rat causes incremental changes in brain-derived neurotrophic factor, neuronal and astrocyte apoptosis, gliosis, and deterioration of postsynaptic density.

PubMed

Cortés, Claudia; Eugenin, Eliseo; Aliaga, Esteban; Carreño, Leandro J; Bueno, Susan M; Gonzalez, Pablo A; Gayol, Silvina; Naranjo, David; Noches, Verónica; Marassi, Michelle P; Rosenthal, Doris; Jadue, Cindy; Ibarra, Paula; Keitel, Cecilia; Wohllk, Nelson; Court, Felipe; Kalergis, Alexis M; Riedel, Claudia A

2012-09-01

Adult hypothyroidism is a highly prevalent condition that impairs processes, such as learning and memory. Even though tetra-iodothyronine (T(4)) treatment can overcome the hypothyroidism in the majority of cases, it cannot fully recover the patient's learning capacity and memory. In this work, we analyzed the cellular and molecular changes in the adult brain occurring with the development of experimental hypothyroidism. Adult male Sprague-Dawley rats were treated with 6-propyl-2-thiouracil (PTU) for 20 days to induce hypothyroidism. Neuronal and astrocyte apoptosis were analyzed in the hippocampus of control and hypothyroid adult rats by confocal microscopy. The content of brain-derived neurotrophic factor (BDNF) was analyzed using enzyme-linked immunosorbent assay (ELISA) and in situ hybridization. The glutamatergic synapse and the postsynaptic density (PSD) were analyzed by electron microscopy. The content of PSD proteins like tyrosine receptor kinase B (TrkB), p75, and N-methyl-D-aspartate receptor (NMDAr) were analyzed by immunoblot. We observed that the hippocampus of hypothyroid adult rats displayed increased apoptosis levels in neurons and astrocyte and reactive gliosis compared with controls. Moreover, we found that the amount of BDNF mRNA was higher in the hippocampus of hypothyroid rats and the content of TrkB, the receptor for BDNF, was reduced at the PSD of the CA3 region of hypothyroid rats, compared with controls. We also observed that the glutamatergic synapses from the stratum radiatum of CA3 from hypothyroid rats, contained thinner PSDs than control rats. This observation was in agreement with a reduced content of NMDAr subunits at the PSD in hypothyroid animals. Our data suggest that adult hypothyroidism affects the hippocampus by a mechanism that alters the composition of PSD, reduces neuronal and astrocyte survival, and alters the content of the signaling neurotrophic factors, such as BDNF.

Incidence of malignant lymphoma in adolescents and young adults in the 58 counties of California with varying synthetic turf field density.

PubMed

Bleyer, Archie; Keegan, Theresa

2018-04-01

Case reports of cancer among soccer players raised concerns that the crumb rubber infill in synthetic turf fields may cause malignant lymphoma. One prior epidemiologic study on the topic found no association. An ecologic evaluation of county-level incidence of lymphomas by race/ethnicity and socioeconomic status for the state of California with data obtained from the National Cancer Institute Surveillance, Epidemiology, and End Results Program. Synthetic turf field density by county was obtained from the Synthetic Turf Council. During 2000-2013, 7214 14- to 30-year-old Californians were diagnosed with malignant lymphoma. Annual lymphoma county incidence trends were not associated with the county-level synthetic turf field density. None of 20 sub-analyses by race/ethnicity, sex and county median household income indicated a correlation of lymphoma incidence with synthetic turf field density. In California, there was no evidence at the county-level that synthetic turf fields are associated with an increased incidence of lymphoma in adolescents and young adults. Our findings in the state with the greatest number of such fields and a large, diverse patient population are consistent with those of a prior study observing no association between individual-level exposures to turf fields and cancer incidence. Avoidance of synthetic turf fields for fear of increased cancer risk is not warranted. Copyright © 2018 Elsevier Ltd. All rights reserved.

Spinal Implant Density and Postoperative Lumbar Lordosis as Predictors for the Development of Proximal Junctional Kyphosis in Adult Spinal Deformity.

PubMed

McClendon, Jamal; Smith, Timothy R; Sugrue, Patrick A; Thompson, Sara E; O'Shaughnessy, Brian A; Koski, Tyler R

2016-11-01

To evaluate spinal implant density and proximal junctional kyphosis (PJK) in adult spinal deformity (ASD). Consecutive patients with ASD receiving ≥5 level fusions were retrospectively analyzed between 2007 and 2010. ASD, elective fusions, minimum 2-year follow-up. age <18 years, neuromuscular or congenital scoliosis, cervical or cervicothoracic fusions, nonelective conditions (infection, tumor, trauma). Instrumented fusions were classified by the Scoliosis Research Society-Schwab ASD classification. Statistical analysis consisted of descriptives (measures of central tendency, dispersion, frequencies), independent Student t tests, χ 2 , analysis of variance, and logistic regression to determine association of implant density [(number of screws + number of hooks)/surgical levels of fusion] and PJK. Mean and median follow-up was 2.8 and 2.7 years, respectively. Eighty-three patients (17 male, 66 female) with a mean age of 59.7 years (standard deviation, 10.3) were analyzed. Mean body mass index (BMI) was 29.5 kg/m 2 (range, 18-56 kg/m 2 ) with mean preoperative Oswestry Disability Index of 48.67 (range, 6-86) and mean preoperative sagittal vertical axis of 8.42. The mean levels fused were 9.95 where 54 surgeries had interbody fusion. PJK prevalence was 21.7%, and pseudoarthrosis was 19.3%. Mean postoperative Oswestry Disability Index was 27.4 (range, 0-74). Independent Student t tests showed that PJK was not significant for age, gender, BMI, rod type, mean postoperative sagittal vertical axis, or Scoliosis Research Society-Schwab ASD classification; but iliac fixation approached significance (P = 0.077). Implant density and postoperative lumbar lordosis (LL) were predictors for PJK (P = 0.018 and 0.045, respectively). Controlling for age, BMI, and gender, postoperative LL (not implant density) continued to show significance in multivariate logistic regression model. PJK, although influenced by a multitude of factors, may be statistically related to implant

Reduction of I(Ca,L) and I(to1) density in hypertrophied right ventricular cells by simulated high altitude in adult rats.

PubMed

Chouabe, C; Espinosa, L; Megas, P; Chakir, A; Rougier, O; Freminet, A; Bonvallet, R

1997-01-01

The present paper describes the effect of a simulated hypobaric condition (at the altitude of 4500 m) on morphological characteristics and on some ionic currents in ventricular cells of adult rats. According to current data, chronic high-altitude exposure led to mild right ventricular hypertrophy. Increase in right ventricular weight appeared to be due wholly or partly to an enlargement of myocytes. The whole-cell patch-clamp technique was used and this confirmed, by cell capacitance measurement, that chronic high-altitude exposure induced an increase in the size of the right ventricular cells. Hypertrophied cells showed prolongation of action potential (AP). Four ionic currents, playing a role along with many others in the precise balance of inward and outward currents that control the duration of cardiac AP, were investigated. We report a significant decrease in the transient outward (I(to1)) and in the L-type calcium current (I(Ca,L)) densities while there was no significant difference in the delayed rectifier current (I(K)) or in the inward rectifier current (I(K1)) densities in hypertrophied right ventricular cells compared to control cells. At a given potential the decrease in I(to 1) density was relatively more important than the decrease in I(Ca,L) density. In both cell types, all the currents displayed the same voltage dependence. The inactivation kinetics of I(to 1) and I(Ca,L) or the steady-state activation and inactivation relationships were not significantly modified by chronic high-altitude exposure. We conclude that chronic high-altitude exposure induced true right ventricular myocyte hypertrophy and that the decrease in I(to 1) density might account for the lengthened action potential, or have a partial effect.

Aging adult skull remains through radiological density estimates: A comparison of different computed tomography systems and the use of computer simulations to judge the accuracy of results.

PubMed

Obert, Martin; Kubelt, Carolin; Schaaf, Thomas; Dassinger, Benjamin; Grams, Astrid; Gizewski, Elke R; Krombach, Gabriele A; Verhoff, Marcel A

2013-05-10

The objective of this article was to explore age-at-death estimates in forensic medicine, which were methodically based on age-dependent, radiologically defined bone-density (HC) decay and which were investigated with a standard clinical computed tomography (CT) system. Such density decay was formerly discovered with a high-resolution flat-panel CT in the skulls of adult females. The development of a standard CT methodology for age estimations--with thousands of installations--would have the advantage of being applicable everywhere, whereas only few flat-panel prototype CT systems are in use worldwide. A Multi-Slice CT scanner (MSCT) was used to obtain 22,773 images from 173 European human skulls (89 male, 84 female), taken from a population of patients from the Department of Neuroradiology at the University Hospital Giessen and Marburg during 2010 and 2011. An automated image analysis was carried out to evaluate HC of all images. The age dependence of HC was studied by correlation analysis. The prediction accuracy of age-at-death estimates was calculated. Computer simulations were carried out to explore the influence of noise on the accuracy of age predictions. Human skull HC values strongly scatter as a function of age for both sexes. Adult male skull bone-density remains constant during lifetime. Adult female HC decays during lifetime, as indicated by a correlation coefficient (CC) of -0.53. Prediction errors for age-at-death estimates for both of the used scanners are in the range of ±18 years at a 75% confidence interval (CI). Computer simulations indicate that this is the best that can be expected for such noisy data. Our results indicate that HC-decay is indeed present in adult females and that it can be demonstrated both by standard and by high-resolution CT methods, applied to different subject groups of an identical population. The weak correlation between HC and age found by both CT methods only enables a method to estimate age-at-death with limited

Association between fibroblast growth factor 21 and bone mineral density in adults.

PubMed

Hao, Ruo-Han; Gao, Jun-Ling; Li, Meng; Huang, Wei; Zhu, Dong-Li; Thynn, Hlaing Nwe; Dong, Shan-Shan; Guo, Yan

2018-02-01

Animal-based studies have reported a decrease in bone mass resulting from high level of fibroblast growth factor 21 (FGF21). However, the correlation between plasma FGF21 levels and bone mineral density (BMD) is paradoxical in previous human-based studies, and the associations between FGF21 gene polymorphisms and BMD haven't been reported yet. Therefore, here, we evaluated plasma FGF21 levels with sufficient study samples, and performed genetic association test to reveal the physiological and genetic role of FGF21 on BMD in adults. Plasma and genetic samples containing 168 and 569 Han Chinese subjects, respectively, were employed in this study. Fasting plasma FGF21 levels were determined using enzyme-linked immunosorbent assay (ELISA). Regional BMD values were measured by dual energy X-ray absorptiometry (DXA). Five variants of FGF21 gene were successfully genotyped. Physiological association suggested that plasma FGF21 levels were inversely correlated with BMD in femoral neck (Neck-BMD: P = 0.039) and Ward's triangle (Ward's-BMD: P = 0.002) of hip region. A FGF21 gene variant, rs490942, was significantly associated with the increase of Ward's-BMD in total (P = 0.027) and female (P = 0.016) cohorts, as well as Neck-BMD in female cohort (P = 7.45 × 10 -3 ). Meanwhile, eQTL results indicated that this SNP was related to the decreased level of FGF21 gene expression. Taking together from both physiological and genetic levels, we suggest that FGF21 is inversely associated with regional BMD. And we haven't observed sex-specific effect in this study.

Regulation of Aedes aegypti Population Dynamics in Field Systems: Quantifying Direct and Delayed Density Dependence

PubMed Central

Walsh, Rachael K.; Aguilar, Cristobal L.; Facchinelli, Luca; Valerio, Laura; Ramsey, Janine M.; Scott, Thomas W.; Lloyd, Alun L.; Gould, Fred

2013-01-01

Transgenic strains of Aedes aegypti have been engineered to help control transmission of dengue virus. Although resources have been invested in developing the strains, we lack data on the ecology of mosquitoes that could impact the success of this approach. Although studies of intra-specific competition have been conducted using Ae. aegypti larvae, none of these studies examine mixed age cohorts at densities that occur in the field, with natural nutrient levels. Experiments were conducted in Mexico to determine the impact of direct and delayed density dependence on Ae. aegypti populations. Natural water, food, and larval densities were used to estimate the impacts of density dependence on larval survival, development, and adult body size. Direct and delayed density-dependent factors had a significant impact on larval survival, larval development, and adult body size. These results indicate that control methods attempting to reduce mosquito populations may be counteracted by density-dependent population regulation. PMID:23669230

Adult mortality in a low-density tree population using high-resolution remote sensing.

PubMed

Kellner, James R; Hubbell, Stephen P

2017-06-01

We developed a statistical framework to quantify mortality rates in canopy trees observed using time series from high-resolution remote sensing. By timing the acquisition of remote sensing data with synchronous annual flowering in the canopy tree species Handroanthus guayacan, we made 2,596 unique detections of 1,006 individual adult trees within 18,883 observation attempts on Barro Colorado Island, Panama (BCI) during an 11-yr period. There were 1,057 observation attempts that resulted in missing data due to cloud cover or incomplete spatial coverage. Using the fraction of 123 individuals from an independent field sample that were detected by satellite data (109 individuals, 88.6%), we estimate that the adult population for this species on BCI was 1,135 individuals. We used a Bayesian state-space model that explicitly accounted for the probability of tree detection and missing observations to compute an annual adult mortality rate of 0.2%·yr -1 (SE = 0.1, 95% CI = 0.06-0.45). An independent estimate of the adult mortality rate from 260 field-checked trees closely matched the landscape-scale estimate (0.33%·yr -1 , SE = 0.16, 95% CI = 0.12-0.74). Our proof-of-concept study shows that one can remotely estimate adult mortality rates for canopy tree species precisely in the presence of variable detection and missing observations. © 2017 by the Ecological Society of America.

Population density predicts outcome from out-of-hospital cardiac arrest in Victoria, Australia.

PubMed

Nehme, Ziad; Andrew, Emily; Cameron, Peter A; Bray, Janet E; Bernard, Stephen A; Meredith, Ian T; Smith, Karen

2014-05-05

To examine the impact of population density on incidence and outcome of out-of-hospital cardiac arrest (OHCA). Data were extracted from the Victorian Ambulance Cardiac Arrest Registry for all adult OHCA cases of presumed cardiac aetiology attended by the emergency medical service (EMS) between 1 January 2003 and 31 December 2011. Cases were allocated into one of five population density groups according to their statistical local area: very low density (≤ 10 people/km(2)), low density (11-200 people/km(2)), medium density (201-1000 people/km(2)), high density (1001-3000 people/km(2)), and very high density (> 3000 people/km(2)). Survival to hospital and survival to hospital discharge. The EMS attended 27 705 adult presumed cardiac OHCA cases across 204 Victorian regions. In 12 007 of these (43.3%), resuscitation was attempted by the EMS. Incidence was lower and arrest characteristics were consistently less favourable for lower population density groups. Survival outcomes, including return of spontaneous circulation, survival to hospital and survival to hospital discharge, were significantly poorer in less densely populated groups (P < 0.001 for all comparisons). When compared with very low density populations, the risk-adjusted odds ratios of surviving to hospital discharge were: low density, 1.88 (95% CI, 1.15-3.07); medium density, 2.49 (95% CI, 1.55-4.02); high density, 3.47 (95% CI, 2.20-5.48) and very high density, 4.32 (95% CI, 2.67-6.99). Population density is independently associated with survival after OHCA, and significant variation in the incidence and characteristics of these events are observed across the state.

Effects of Nativity, Length of Residence, and County-Level Foreign-Born Density on Mental Health Among Older Adults in the U.S

PubMed Central

Choi, Sunha; Kim, Giyeon

2016-01-01

Using the 2004–2007 Medical Expenditure Panel Survey data that are linked to county-level data from the Area Health Resources Files, this study examined whether the healthy immigrant effect applies to mental health of foreign-born older adults. Additionally, testing a protective ethnic density effect on older foreign-born individuals’ mental health, this study examined how the percentage of foreign-born population in the county affected the relationship between older adults’ immigration status (U.S.-nativity and length of residence in the U.S.) and their mental health status. The sample included 29,011 individuals (level-1) from 920 counties (level-2) across 50 states and D.C. Using the Mental Component Summary of the Short-Form 12, the Kessler Index (K-6), and the Patient Health Questionnaire (PHQ-2), U.S.-born individuals (n = 24,225), earlier immigrants (≥15 years in the U.S.; n = 3866), and recent immigrants (<15 years in the U.S.; n = 920) were compared. The results indicate that recent immigrants showed worse mental health on all three measures compared with U.S.-born individuals and on the K-6 and PHQ-2 compared with earlier immigrants. Higher county-level foreign-born densities were associated with worse mental health status of individuals. However, the significant interactions found in the full conditional multilevel models indicated that the high foreign-born density functioned as a risk factor for worse mental health only among recent immigrants but not among the U.S.-born. In conclusion, the results revealed the vulnerability of older recent immigrants, especially those living in the counties with high foreign-born densities. PMID:26910461

Ghrelin plasma levels, gastric ghrelin cell density and bone mineral density in women with rheumatoid arthritis

PubMed Central

Maksud, F.A.N.; Kakehasi, A.M.; Guimarães, M.F.B.R.; Machado, C.J.; Barbosa, A.J.A.

2017-01-01

Generalized bone loss can be considered an extra-articular manifestation of rheumatoid arthritis (RA) that may lead to the occurrence of fractures, resulting in decreased quality of life and increased healthcare costs. The peptide ghrelin has demonstrated to positively affect osteoblasts in vitro and has anti-inflammatory actions, but the studies that correlate ghrelin plasma levels and RA have contradictory results. We aimed to evaluate the correlation between total ghrelin plasma levels, density of ghrelin-immunoreactive cells in the gastric mucosa, and bone mineral density (BMD) in twenty adult women with established RA with 6 months or more of symptoms (mean age of 52.70±11.40 years). Patients with RA presented higher ghrelin-immunoreactive cells density in gastric mucosa (P=0.008) compared with healthy females. There was a positive relationship between femoral neck BMD and gastric ghrelin cell density (P=0.007). However, these same patients presented a negative correlation between plasma ghrelin levels and total femoral BMD (P=0.03). The present results indicate that ghrelin may be involved in bone metabolism of patients with RA. However, the higher density of ghrelin-producing cells in the gastric mucosa of these patients does not seem to induce a corresponding elevation in the plasma levels of this peptide. PMID:28538835

Ghrelin plasma levels, gastric ghrelin cell density and bone mineral density in women with rheumatoid arthritis.

PubMed

Maksud, F A N; Kakehasi, A M; Guimarães, M F B R; Machado, C J; Barbosa, A J A

2017-05-18

Generalized bone loss can be considered an extra-articular manifestation of rheumatoid arthritis (RA) that may lead to the occurrence of fractures, resulting in decreased quality of life and increased healthcare costs. The peptide ghrelin has demonstrated to positively affect osteoblasts in vitro and has anti-inflammatory actions, but the studies that correlate ghrelin plasma levels and RA have contradictory results. We aimed to evaluate the correlation between total ghrelin plasma levels, density of ghrelin-immunoreactive cells in the gastric mucosa, and bone mineral density (BMD) in twenty adult women with established RA with 6 months or more of symptoms (mean age of 52.70±11.40 years). Patients with RA presented higher ghrelin-immunoreactive cells density in gastric mucosa (P=0.008) compared with healthy females. There was a positive relationship between femoral neck BMD and gastric ghrelin cell density (P=0.007). However, these same patients presented a negative correlation between plasma ghrelin levels and total femoral BMD (P=0.03). The present results indicate that ghrelin may be involved in bone metabolism of patients with RA. However, the higher density of ghrelin-producing cells in the gastric mucosa of these patients does not seem to induce a corresponding elevation in the plasma levels of this peptide.

High-Density Lipoprotein Cholesterol Level Relates to Working Memory, Immediate and Delayed Cued Recall in Brazilian Older Adults: The Role of Cognitive Reserve.

PubMed

Ihle, Andreas; Gouveia, Élvio R; Gouveia, Bruna R; Freitas, Duarte L; Jurema, Jefferson; Tinôco, Maria A; Kliegel, Matthias

2017-01-01

The present study set out to investigate the relation of the high-density lipoprotein cholesterol (HDL-C) level to cognitive performance and its interplay with key markers of cognitive reserve in a large sample of older adults. We assessed tests of working memory, immediate and delayed cued recall in 701 older adults from Amazonas, Brazil. The HDL-C level was derived from fasting blood samples. In addition, we interviewed individuals on their education, past occupation, and cognitive leisure activity. A critically low HDL-C level (<40 mg/dL) was significantly related to lower performance in working memory, immediate and delayed cued recall. Moderation analyses suggested that the relations of the HDL-C level to working memory and delayed cued recall were negligible in individuals with longer education, a higher cognitive level of the job, and greater engagement in cognitive leisure activity. Cognitive reserve accumulated during the life course may reduce the detrimental influences of a critically low HDL-C level on cognitive functioning in old age. © 2017 S. Karger AG, Basel.

Density-dependence interacts with extrinsic mortality in shaping life histories

PubMed Central

Burger, Oskar; Kozłowski, Jan

2017-01-01

The role of extrinsic mortality in shaping life histories is poorly understood. However, substantial evidence suggests that extrinsic mortality interacts with density-dependence in crucial ways. We develop a model combining Evolutionarily Stable Strategies with a projection matrix that allows resource allocation to growth, tissue repairs, and reproduction. Our model examines three cases, with density-dependence acting on: (i) mortality, (ii) fecundity, and (iii) production rate. We demonstrate that density-independent extrinsic mortality influences the rate of aging, age at maturity, growth rate, and adult size provided that density-dependence acts on fertility or juvenile mortality. However, density-independent extrinsic mortality has no effect on these life history traits when density-dependence acts on survival. We show that extrinsic mortality interacts with density-dependence via a compensation mechanism: the higher the extrinsic mortality the lower the strength of density-dependence. However, this compensation fully offsets the effect of extrinsic mortality only if density-dependence acts on survival independently of age. Both the age-pattern and the type of density-dependence are crucial for shaping life history traits. PMID:29049399

Breast Density Assessment by Dual Energy X-ray Absorptiometry in Women and Girls

DTIC Science & Technology

2009-07-01

of this project among adult women and adolescent girls, who will be recruited as mothers and daughters, will be to 1. Correlate breast density...scans to their association with mammographic density; 3. Assess DXA breast density by Tanner stage of breast maturation among adolescent girls; 4...cancer risk, adolescents 16. SECURITY CLASSIFICATION OF: 17. LIMITATION OF ABSTRACT 18. NUMBER OF PAGES 19a. NAME OF RESPONSIBLE PERSON USAMRMC

Age, gender, and race/ethnic differences in total body and subregional bone density.

PubMed

Looker, A C; Melton, L J; Harris, T; Borrud, L; Shepherd, J; McGowan, J

2009-07-01

Total body bone density of adults from National Health and Nutrition Examination Survey (NHANES) 1999-2004 differed as expected for some groups (men>women and blacks>whites) but not others (whites>Mexican Americans). Cross-sectional age patterns in bone mineral density (BMD) of older adults differed at skeletal sites that varied by degree of weight-bearing. Total body dual-energy X-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton. The present study uses total body DXA data (Hologic QDR 4500A, Hologic, Bedford MA, USA) from the NHANES 1999-2004 to examine BMD of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults aged 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight-bearing. Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg, and arm. This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population.

Evolution of increased adult longevity in Drosophila melanogaster populations selected for adaptation to larval crowding.

PubMed

Shenoi, V N; Ali, S Z; Prasad, N G

2016-02-01

In holometabolous animals such as Drosophila melanogaster, larval crowding can affect a wide range of larval and adult traits. Adults emerging from high larval density cultures have smaller body size and increased mean life span compared to flies emerging from low larval density cultures. Therefore, adaptation to larval crowding could potentially affect adult longevity as a correlated response. We addressed this issue by studying a set of large, outbred populations of D. melanogaster, experimentally evolved for adaptation to larval crowding for 83 generations. We assayed longevity of adult flies from both selected (MCUs) and control populations (MBs) after growing them at different larval densities. We found that MCUs have evolved increased mean longevity compared to MBs at all larval densities. The interaction between selection regime and larval density was not significant, indicating that the density dependence of mean longevity had not evolved in the MCU populations. The increase in longevity in MCUs can be partially attributed to their lower rates of ageing. It is also noteworthy that reaction norm of dry body weight, a trait probably under direct selection in our populations, has indeed evolved in MCU populations. To the best of our knowledge, this is the first report of the evolution of adult longevity as a correlated response of adaptation to larval crowding. © 2015 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2015 European Society For Evolutionary Biology.

Is the time course of lexical activation and competition in spoken word recognition affected by adult aging? An event-related potential (ERP) study.

PubMed

Hunter, Cynthia R

2016-10-01

Adult aging is associated with decreased accuracy for recognizing speech, particularly in noisy backgrounds and for high neighborhood density words, which sound similar to many other words. In the current study, the time course of neighborhood density effects in young and older adults was compared using event-related potentials (ERP) and behavioral responses in a lexical decision task for spoken words and nonwords presented either in quiet or in noise. Target items sounded similar either to many or to few other words (neighborhood density) but were balanced for the frequency of their component sounds (phonotactic probability). Behavioral effects of density were similar across age groups, but the event-related potential effects of density differed as a function of age group. For young adults, density modulated the amplitude of both the N400 and the later P300 or late positive complex (LPC). For older adults, density modulated only the amplitude of the P300/LPC. Thus, spreading activation to the semantics of lexical neighbors, indexed by the N400 density effect, appears to be reduced or delayed in adult aging. In contrast, effects of density on P300/LPC amplitude were present in both age groups, perhaps reflecting attentional allocation to items that resemble few words in the mental lexicon. The results constitute the first evidence that ERP effects of neighborhood density are affected by adult aging. The age difference may reflect either a unitary density effect that is delayed by approximately 150ms in older adults, or multiple processes that are differentially affected by aging. Copyright © 2016 Elsevier Ltd. All rights reserved.

Correlation between Tick Density and Pathogen Endemicity, New Hampshire

PubMed Central

Walk, Seth T.; Xu, Guang; Stull, Jason W.

2009-01-01

To assess the endemicity of tick-borne pathogens in New Hampshire, we surveyed adult tick vectors. Pathogens were more prevalent in areas of high tick density, suggesting a correlation between tick establishment and pathogen endemicity. Infection rates in ticks correlated with disease frequency in humans. PMID:19331738

Climate and Physiography Predict Mercury Concentrations in Game Fish Species in Quebec Lakes Better than Anthropogenic Disturbances.

PubMed

Lucotte, Marc; Paquet, Serge; Moingt, Matthieu

2016-05-01

The fluctuations of mercury levels (Hg) in fish consumed by sport fishers in North-Eastern America depend upon a plethora of interrelated biological and abiological factors. To identify the dominant factors ultimately controlling fish Hg concentrations, we compiled mercury levels (Hg) during the 1976-2010 period in 90 large natural lakes in Quebec (Canada) for two major game species: northern pike (Esox lucius) and walleye (Sander vitreus). Our statistical analysis included 28 geographic information system variables and 15 climatic variables, including sulfate deposition. Higher winter temperatures explained 36% of the variability in higher walleye growth rates, in turn accounting for 54% of the variability in lower Hg concentrations. For northern pike, the dominance of a flat topography in the watershed explained 31% of the variability in lower Hg concentrations. Higher mean annual temperatures explained 27% of the variability in higher pike Hg concentrations. Pelagic versus littoral preferred habitats for walleye and pike respectively could explain the contrasted effect of temperature between the two species. Heavy logging could only explain 2% of the increase in walleye Hg concentrations. The influence of mining on fish Hg concentrations appeared to be masked by climatic effects.

Association between full service and fast food restaurant density, dietary intake and overweight/obesity among adults in Delhi, India.

PubMed

Patel, Opal; Shahulhameed, Safraj; Shivashankar, Roopa; Tayyab, Mohammad; Rahman, Atiqur; Prabhakaran, Dorairaj; Tandon, Nikhil; Jaacks, Lindsay M

2017-07-19

attenuated: 1.08 (0.92, 1.26). Results were consistent with further adjustment for tobacco and alcohol use, moderate physical activity, and owning a bicycle or motorized vehicle. Most full service and fast food restaurants were Indian, suggesting that the nutrition transition in this megacity may be better characterized by the large number of unhealthy Indian food outlets rather than the Western food outlets. Full service and fast food restaurant density in the residence area of adults in Delhi, India, was associated with poor dietary intake. It was also positively associated with overweight/obesity, but this was largely explained by socioeconomic status. Further research is needed exploring these associations prospectively and in other LMICs.

Socioeconomic status and bone mineral density in adults by race/ethnicity and gender: the Louisiana osteoporosis study.

PubMed

Du, Y; Zhao, L-J; Xu, Q; Wu, K-H; Deng, H-W

2017-05-01

Low bone mineral density (BMD) and osteoporosis have become a public health problem. We found that non-Hispanic white, black, and Asian adults with extremely low education and personal income are more likely to have lower BMD. This relationship is gender-specific. These findings are valuable to guide bone health interventions. The evidence is limited regarding the relationship between socioeconomic status (SES) and bone mineral density (BMD) for minority populations in the USA, as well as the relationship between SES and BMD for men. This study explored and examined the relationship between SES and BMD by race/ethnicity and gender. Data (n = 6568) from the Louisiana Osteoporosis Study (LOS) was examined, including data for non-Hispanic whites (n = 4153), non-Hispanic blacks (n = 1907), and non-Hispanic Asians (n = 508). General linear models were used to estimate the relationship of SES and BMD (total hip and lumbar spine) stratified by race/ethnicity and gender. Adjustments were made for physiological and behavioral factors. After adjusting for covariates, men with education levels below high school graduate experienced relatively low hip BMD than their counterparts with college or graduate education (p < 0.05). In addition, women reporting a personal annual income under $20,000 had relatively low hip and spine BMD than their counterparts with higher income level(s) (p < 0.05). Establishing a conclusive positive or negative association between BMD and SES proved to be difficult. However, individuals who are at an extreme SES disadvantage are the most vulnerable to have relatively low BMD in the study population. Efforts to promote bone health may benefit from focusing on men with low education levels and women with low individual income.

Trends in Bone Mineral Density in Young Adults with Cystic Fibrosis over a 15 Year Period

PubMed Central

Putman, Melissa S.; Baker, Joshua F.; Uluer, Ahmet; Herlyn, Karen; Lapey, Allen; Sicilian, Leonard; Tillotson, Angela Pizzo; Gordon, Catherine M.; Merkel, Peter A.; Finkelstein, Joel S.

2015-01-01

Background Improvements in clinical care have led to increased life expectancy in patients with cystic fibrosis (CF) over the past several decades. Whether these improvements have had significant effects on bone health in patients with CF is unclear. Methods This is a cross-sectional study comparing clinical characteristics and bone mineral density (BMD) measured by dual energy X-ray absorptiometry (DXA) in adults with CF evaluated in 1995–1999 to age-, race-, and gender matched patients with CF evaluated in 2011–2013 at the same center on calibrated DXA machines. Results The cohorts were similar in terms of age, BMI, pancreatic insufficiency, presence of F508del mutation, and reproductive history. In the most recent cohort, pulmonary function was superior, and fewer patients had vitamin D deficiency or secondary hyperparathyroidism. Areal BMD measures of the PA spine, lateral spine, and distal radius were similarly low in the two cohorts. Conclusions Although pulmonary function and vitamin D status were better in patients in the present-day cohort, areal BMD of the spine was reduced in a significant number of patients and was no different in patients with CF today than in the late 1990s. Further attention to optimizing bone health may be necessary to prevent CF-related bone disease. PMID:25698451

Low load, high repetition resistance training program increases bone mineral density in untrained adults.

PubMed

Petersen, Bailey A; Hastings, Bryce; Gottschall, Jinger S

2017-01-01

High load, low repetition resistance training increases BMD in untrained adults; however, many older and untrained adults cannot maintain this type of strenuous program. Our goal was to evaluate whether a low load, high repetition resistance training program would increase BMD in untrained adults. Twenty sedentary, but otherwise healthy, adults (6 men and 14 women, age 28-63 yrs) completed a 27-week group exercise program. The participants were randomly assigned to one of two strength groups: one group completed full body, low load, high repetition weight training classes (S-WEIGHT), while the other group completed core focused fusion classes (S-CORE). Both groups also completed indoor cycling classes for cardiovascular conditioning. After a 3-week familiarization period, all participants completed a 12-week block of 5 fitness classes per week (3 cycling + 2 strength) and concluded with another 12-week block of 6 classes per week (3 cycling + 3 strength). We completed iDXA scans at baseline (week 3) and final (week 28). Compared to baseline, BMD significantly increased for S-WEIGHT in the arms (+4%, P<0.001), legs (+8%, P<0.01), pelvis (+6%, P<0.01) and lumbar spine (+4%, P<0.05), whereas BMD did not significantly change for S-CORE at any site. These results suggest that a low load, high repetition resistance training program may be an effective method to improve bone mass in adults.

Anticipatory flexibility: larval population density in moths determines male investment in antennae, wings and testes.

PubMed

Johnson, Tamara L; Symonds, Matthew R E; Elgar, Mark A

2017-11-15

Developmental plasticity provides individuals with a distinct advantage when the reproductive environment changes dramatically. Variation in population density, in particular, can have profound effects on male reproductive success. Females may be easier to locate in dense populations, but there may be a greater risk of sperm competition. Thus, males should invest in traits that enhance fertilization success over traits that enhance mate location. Conversely, males in less dense populations should invest more in structures that will facilitate mate location. In Lepidoptera, this may result in the development of larger antennae to increase the likelihood of detecting female sex pheromones, and larger wings to fly more efficiently. We explored the effects of larval density on adult morphology in the gum-leaf skeletonizer moth, Uraba lugens , by manipulating both the number of larvae and the size of the rearing container. This experimental arrangement allowed us to reveal the cues used by larvae to assess whether absolute number or density influences adult responses. Male investment in testes size depended on the number of individuals, while male investment in wings and antennae depended upon larval density. By contrast, the size of female antennae and wings were influenced by an interaction of larval number and container size. This study demonstrates that male larvae are sensitive to cues that may reveal adult population density, and adjust investment in traits associated with fertilization success and mate detection accordingly. © 2017 The Author(s).

Hair product use, age at menarche and mammographic breast density in multiethnic urban women.

PubMed

McDonald, Jasmine A; Tehranifar, Parisa; Flom, Julie D; Terry, Mary Beth; James-Todd, Tamarra

2018-01-04

Select hair products contain endocrine disrupting chemicals (EDCs) that may affect breast cancer risk. We hypothesize that, if EDCs are related to breast cancer risk, then they may also affect two important breast cancer risk factors: age at menarche and mammographic breast density. In two urban female cohorts (N = 248): 1) the New York site of the National Collaborative Perinatal Project and 2) the New York City Multiethnic Breast Cancer Project, we measured childhood and adult use of hair oils, lotions, leave-in conditioners, root stimulators, perms/relaxers, and hair dyes using the same validated questionnaire. We used multivariable relative risk regression models to examine the association between childhood hair product use and early age at menarche (defined as <11 years of age) and multivariable linear regression models to examine the association between childhood and adult hair product use and adult mammographic breast density. Early menarche was associated with ever use of childhood hair products (RR 2.3, 95% CI 1.1, 4.8) and hair oil use (RR 2.5, 95% CI 1.2, 5.2); however, additional adjustment for race/ethnicity, attenuated associations (hair products RR 1.8, 95% CI 0.8, 4.1; hair oil use RR 2.3, 95% CI 1.0, 5.5). Breast density was not associated with adult or childhood hair product or hair oil use. If confirmed in larger prospective studies, these data suggest that exposure to EDCs through hair products in early life may affect breast cancer risk by altering timing of menarche, and may operate through a mechanism distinct from breast density.

Social Determinants and Poor Diet Quality of Energy-Dense Diets of Australian Young Adults.

PubMed

Grech, Amanda; Rangan, Anna; Allman-Farinelli, Margaret

2017-10-01

This research aimed to determine the diet quality and socio-demographic determinants by level of energy-density of diets of Australian young adults. Secondary analysis of the Australian National Nutrition and Physical Activity Survey-2011/2012 for adults aged 18-34 years ( n = 2397) was conducted. Diet was assessed by 24-h recalls. Dietary energy-density was calculated as dietary energy/grams of food (kJ/g) and the Healthy-Eating-Index-for-Australians (HEIFA-2013) was used to assess diet quality (highest score = 100). Dietary energy-density was examined with respect to diet quality and sociodemographic determinants including gender, highest tertiary-education attainment, country-of-birth, age, income, and socio-economic-index-for-area (SEIFA). Higher dietary energy-density was associated with lower diet quality scores (β = -3.71, t (2394) = -29.29, p < 0.0001) and included fewer fruits and vegetables, and more discretionary foods. The mean dietary energy-density was 7.7 kJ/g and 7.2 kJ/g for men and women, respectively. Subpopulations most at risk of consuming high energy-dense diets included those with lower education, Australian and English-speaking countries of birth, and men with low income and women from areas of lower socio-economic status. Young adults reporting low energy-dense diets had higher quality diets. Intensive efforts are needed to reduce the high energy-density of young adults' diets, and should ensure they include populations of lower socio-economic status.

A fruit, milk and whole grain dietary pattern is positively associated with bone mineral density in Korean healthy adults.

PubMed

Shin, S; Sung, J; Joung, H

2015-04-01

Osteoporosis is a major health problem that will grow in burden with ageing of the global population. Modifiable risk factors for osteoporosis, including diet, have significant implications for disease prevention. We examined associations between dietary patterns and bone mineral density (BMD) in a Korean adult population. In total, 1828 individuals from the Healthy Twin Cohort were included as subjects. Information on general characteristics, lifestyles and health status was obtained through a health examination, and BMD was assessed using DEXA. Dietary intake was assessed using a 3-day food record, and dietary patterns were examined by factor analysis. Associations between dietary patterns and BMD were examined using mixed linear regression, adjusting for family and twin structure as well as other potential risk factors for bone health. Four dietary patterns were identified (Rice and kimchi; eggs, meat and flour; Fruit, milk and whole grains; and Fast food and soda). The 'Fruit, milk and whole grains' pattern was associated with a reduced risk of having low BMD in men (odds ratio (OR)=0.38; 95% confidence interval (CI)=0.22-0.67) and women (OR=0.45; 95% CI=0.28-0.72) and was positively associated with BMD at multiple sites. The 'rice and kimchi' pattern had a positive association with only whole-arm BMD in men and women. Our results suggest that a dietary pattern with high intake of dairy products, fruits and whole grains may contribute positively to bone health in a Korean adult population, and dietary pattern-based strategies could have potential in promoting bone health.

Dietary energy density: Applying behavioural science to weight management.

PubMed

Rolls, B J

2017-09-01

Studies conducted by behavioural scientists show that energy density (kcal/g) provides effective guidance for healthy food choices to control intake and promote satiety. Energy density depends upon a number of dietary components, especially water (0 kcal/g) and fat (9 kcal/g). Increasing the proportion of water or water-rich ingredients, such as vegetables or fruit, lowers a food's energy density. A number of studies show that when the energy density of the diet is reduced, both adults and children spontaneously decrease their ad libitum energy intake. Other studies show that consuming a large volume of a low-energy-dense food such as soup, salad, or fruit as a first course preload can enhance satiety and reduce overall energy intake at a meal. Current evidence suggests that energy density influences intake through a complex interplay of cognitive, sensory, gastrointestinal, hormonal and neural influences. Other studies that focus on practical applications show how the strategic incorporation of foods lower in energy density into the diet allows people to eat satisfying portions while improving dietary patterns. This review discusses studies that have led to greater understanding of the importance of energy density for food intake regulation and weight management.

Effects of seedling size, El Niño drought, seedling density, and distance to nearest conspecific adult on 6-year survival of Ocotea whitei seedlings in Panamá.

PubMed

Gilbert, Gregory S; Harms, Kyle E; Hamill, David N; Hubbell, Stephen P

2001-05-01

We present an analysis of the long-term survival of two cohorts of seedlings of the tropical canopy tree Ocotea whitei (Lauraceae) on a 1-ha plot of mature, lowland moist forest on Barro Colorado Island, Panamá. In 1980, we counted an even-aged cohort of seedlings that germinated in 1979, then measured and tagged survivors in 1981. We also measured and tagged a second, smaller cohort of seedlings that germinated in 1981. We followed the subsequent survival of all seedlings through 1985. Seedling mortality was phenotypically, temporally, and spatially non-random. Important correlates of non-random mortality included: (1) seedling size and age, (2) an El Niño drought, and (3) biotic neighborhood. Larger and older seedlings survived better than smaller and younger seedlings, respectively, and the El Niño-related drought of 1982-1983 was associated with elevated mortality rates. Seedling density, which was strongly correlated with the proximity to the nearest conspecific adult, increased mortality. The observed mortality patterns suggest that processes consistent with the Janzen-Connell hypothesis operate during the recruitment phase of O. whitei population dynamics. However, the processes causing the observed density- and distance-dependent mortality may vary with factors such as total seed number, seedling size, and climatic variation, making it difficult to determine whether time-integrated seedling-to-adult spacing mechanisms other than self-thinning operate on a given plant population. After 6 years in the hectare studied, survivors remained densest and most numerous underneath the adult trees. We conclude that only long-term demographic data, collected at a variety of scales on a variety of species, will ultimately answer the question: do Janzen-Connell effects contribute substantially to structuring tropical forests?

Bone mineral density, growth, pubertal development and other parameters in Brazilian children and young adults with sickle cell anaemia.

PubMed

Meeuwes, M; Souza de Carvalho, T F; Cipolotti, R; Gurgel, R Q; Ferrão, T O; Peters, M; Agyemang, C

2013-12-01

To evaluate the occurrence of low bone mineral density (BMD) and its relationship with clinical and laboratorial characteristics in children and young adults with sickle cell anaemia living in Northeast-Brazil, and to assess the role of radiography in diagnosing low BMD. Bone mineral density of lumbar spine was measured by dual energy X-ray absorptiometry (DXA) in 27 patients with Sickle cell anaemia (SCA) aged 7-28 years. Clinical history, calcium and calorie intake, laboratory measurements, anthropometrics and pubertal development were assessed, and X-rays were obtained. Z-scores and T-scores for weight, height, Body Mass Index (BMI) and BMD were calculated using age and gender matched reference data. Mean lumbar spine BMD Z-scores and T-scores were -1.81 SD in boys and -0.80 SD in girls. BMD Z-scores were below -2 SD in 33.3% of girls and in 46.7% of boys. Low BMD (<-2 SD) occurred significantly more in patients with low height-for-age (P = 0.02), low weight-for-age (P = 0.001) and low BMI-for-age (P = 0.006). No significant relationships were found between BMD and other clinical and laboratory parameters. Radiography had a sensitivity of 75% and a specificity of 36% to detect low BMD, and was considered not useful in this context. Patients with low height and/or low weight-for-age seem to be at high risk for developing low BMD. © 2013 John Wiley & Sons Ltd.

Low bone mineral density in ambulatory persons with cerebral palsy? A systematic review.

PubMed

Mus-Peters, Cindy T R; Huisstede, Bionka M A; Noten, Suzie; Hitters, Minou W M G C; van der Slot, Wilma M A; van den Berg-Emons, Rita J G

2018-05-22

Non-ambulatory persons with cerebral palsy are prone to low bone mineral density. In ambulatory persons with cerebral palsy, bone mineral density deficits are expected to be small or absent, but a consensus conclusion is lacking. In this systematic review bone mineral density in ambulatory persons with cerebral palsy (Gross Motor Function Classification Scales I-III) was studied. Medline, Embase, and Web of Science were searched. According to international guidelines, low bone mineral density was defined as Z-score ≤ -2.0. In addition, we focused on Z-score ≤ -1.0 because this may indicate a tendency towards low bone mineral density. We included 16 studies, comprising 465 patients aged 1-65 years. Moderate and conflicting evidence for low bone mineral density (Z-score ≤ -2.0) was found for several body parts (total proximal femur, total body, distal femur, lumbar spine) in children with Gross Motor Function Classification Scales II and III. We found no evidence for low bone mineral density in children with Gross Motor Function Classification Scale I or adults, although there was a tendency towards low bone mineral density (Z-score ≤ -1.0) for several body parts. Although more high-quality research is needed, results indicate that deficits in bone mineral density are not restricted to non-ambulatory people with cerebral palsy. Implications for Rehabilitation Although more high-quality research is needed, including adults and fracture risk assessment, the current study indicates that deficits in bone mineral density are not restricted to non-ambulatory people with CP. Health care professionals should be aware that optimal nutrition, supplements on indication, and an active lifestyle, preferably with weight-bearing activities, are important in ambulatory people with CP, also from a bone quality point-of-view. If indicated, medication and fall prevention training should be prescribed.

Auditory short-term memory capacity correlates with gray matter density in the left posterior STS in cognitively normal and dyslexic adults.

PubMed

Richardson, Fiona M; Ramsden, Sue; Ellis, Caroline; Burnett, Stephanie; Megnin, Odette; Catmur, Caroline; Schofield, Tom M; Leff, Alex P; Price, Cathy J

2011-12-01

A central feature of auditory STM is its item-limited processing capacity. We investigated whether auditory STM capacity correlated with regional gray and white matter in the structural MRI images from 74 healthy adults, 40 of whom had a prior diagnosis of developmental dyslexia whereas 34 had no history of any cognitive impairment. Using whole-brain statistics, we identified a region in the left posterior STS where gray matter density was positively correlated with forward digit span, backward digit span, and performance on a "spoonerisms" task that required both auditory STM and phoneme manipulation. Across tasks and participant groups, the correlation was highly significant even when variance related to reading and auditory nonword repetition was factored out. Although the dyslexics had poorer phonological skills, the effect of auditory STM capacity in the left STS was the same as in the cognitively normal group. We also illustrate that the anatomical location of this effect is in proximity to a lesion site recently associated with reduced auditory STM capacity in patients with stroke damage. This result, therefore, indicates that gray matter density in the posterior STS predicts auditory STM capacity in the healthy and damaged brain. In conclusion, we suggest that our present findings are consistent with the view that there is an overlap between the mechanisms that support language processing and auditory STM.

Mountain lions: preliminary findings on home-range use and density, central Sierra Nevada

Treesearch

Donald L. Neal; George N. Steger; Ronald C. Bertram

1987-01-01

Between August 1983 and December 1985, 19 mountain lions were captured, radio equipped, and monitored daily within a portion of the North Kings deer herd range on the west slope of the central Sierra Nevada in California. The density of adult mountain lions was estimated to be one per 33.3 km²; that of adults and kittens together was estimated to be one per 20...

Effects of forest management on density, survival, and population growth of wood thrushes

USGS Publications Warehouse

Powell, L.A.; Lang, J.D.; Conroy, M.J.; Krementz, D.G.

2000-01-01

Loss and alteration of breeding habitat have been proposed as causes of declines in several Neotropical migrant bird populations. We conducted a 4-year study to determine the effects of winter prescribed burning and forest thinning on breeding wood thrush (Hylocichla mustelina) populations at the Piedmont National Wildlife Refuge (PNWR) in Georgia. We estimated density, adult and juvenile survival rates, and apparent annual survival using transect surveys, radiotelemetry, and mist netting. Burning and thinning did not cause lower densities (P = 0.25); wood thrush density ranged from 0.15 to 1.30 pairs/10 ha. No radiomarked male wood thrushes (n = 68) died during the 4 years, but female (n = 63) weekly survival was 0.981 ? 0.014 (SE) for females (n = 63) and 0.976 ? 0.010 for juveniles (n = 38). Apparent annual adult survival was 0.579 (SE = 0.173). Thinning and prescribed burning did not reduce adult or juvenile survival during the breeding season or apparent annual adult survival. Annual population growth (lambda) at PNWR was 1.00 (95% confidence interval = 0.32--1.63), and the considerable uncertainty in this prediction underscores the need for long term monitoring to effectively manage Neotropical migrants. Population growth increased on experimental compartments after the burn and thin (95% CI before = 0.91--0.97, after = 0.98--1.05), while control compartment declined (before = 0.98--1.05, after = 0.87--0.92). We found no evidence that the current management regime at PNWR, designed to improve red-cockaded woodpecker (Picoides borealis) habitat, negatively affected wood thrushes.

Clinical Assessment of Functional Movement in Adults with Visual Impairments

ERIC Educational Resources Information Center

Ray, Christopher T.; Horvat, Michael; Williams, Michael; Blasch, Bruce B.

2007-01-01

Adults with visual impairments have significantly more health risks than do sighted adults because of a number of factors, including the lower mineral density of their femoral neck bones, which is indicative of reduced weight-bearing exercise; their lesser maximal strength; and their higher rates of stroke, osteoporosis, depression, hypertension,…

Human self-control and the density of reinforcement

PubMed Central

Flora, Stephen R.; Pavlik, William B.

1992-01-01

Choice responding in adult humans on a discrete-trial button-pressing task was examined as a function of amount, delay, and overall density (points per unit time) of reinforcement. Reinforcement consisted of points that were exchangeable for money. In T 0 conditions, an impulsive response produced 4 points immediately and a self-control response produced 10 points after a delay of 15 s. In T 15 conditions, a constant delay of 15 s was added to both prereinforcer delays. Postreinforcer delays, which consisted of 15 s added to the end of each impulsive trial, equated trial durations regardless of choice, and was manipulated in both T 0 and T 15 conditions. In all conditions, choice was predicted directly from the relative reinforcement densities of the alternatives. Self-control was observed in all conditions except T 0 without postreinforcer delays, where the impulsive choices produced the higher reinforcement density. These results support previous studies showing that choice is a direct function of the relative reinforcement densities when conditioned (point) reinforcers are used. In contrast, where responding produces intrinsic (immediately consumable) reinforcers, immediacy of reinforcement appears to account for preference when density does not. PMID:16812652

Outcomes of bone density measurements in coeliac disease.

PubMed

Bolland, Mark J; Grey, Andrew; Rowbotham, David S

2016-01-29

Some guidelines recommend that patients with newly diagnosed coeliac disease undergo bone density scanning. We assessed the bone density results in a cohort of patients with coeliac disease. We searched bone density reports over two 5-year periods in all patients from Auckland District Health Board (2008-12) and in patients under 65 years from Counties Manukau District Health Board (2009-13) for the term 'coeliac.' Reports for 137 adults listed coeliac disease as an indication for bone densitometry. The average age was 47 years, body mass index (BMI) 25 kg/m(2), and 77% were female. The median time between coeliac disease diagnosis and bone densitometry was 261 days. The average bone density Z-score was slightly lower than expected (Z-score -0.3 to 0.4) at the lumbar spine, total hip and femoral neck, but 88-93% of Z-scores at each site lay within the normal range. Low bone density was strongly related to BMI: the proportions with Z-score <-2 for BMI <20, 20-25, 25-30, and >30 kg/m(2) were 28%, 15%, 6% and 0% respectively. Average bone density was normal, suggesting that bone density measurement is not indicated routinely in coeliac disease, but could be considered on a case-by-case basis for individuals with strong risk factors for fracture.

Comparison of individual-based model output to data using a model of walleye pollock early life history in the Gulf of Alaska

NASA Astrophysics Data System (ADS)

Hinckley, Sarah; Parada, Carolina; Horne, John K.; Mazur, Michael; Woillez, Mathieu

2016-10-01

Biophysical individual-based models (IBMs) have been used to study aspects of early life history of marine fishes such as recruitment, connectivity of spawning and nursery areas, and marine reserve design. However, there is no consistent approach to validating the spatial outputs of these models. In this study, we hope to rectify this gap. We document additions to an existing individual-based biophysical model for Alaska walleye pollock (Gadus chalcogrammus), some simulations made with this model and methods that were used to describe and compare spatial output of the model versus field data derived from ichthyoplankton surveys in the Gulf of Alaska. We used visual methods (e.g. distributional centroids with directional ellipses), several indices (such as a Normalized Difference Index (NDI), and an Overlap Coefficient (OC), and several statistical methods: the Syrjala method, the Getis-Ord Gi* statistic, and a geostatistical method for comparing spatial indices. We assess the utility of these different methods in analyzing spatial output and comparing model output to data, and give recommendations for their appropriate use. Visual methods are useful for initial comparisons of model and data distributions. Metrics such as the NDI and OC give useful measures of co-location and overlap, but care must be taken in discretizing the fields into bins. The Getis-Ord Gi* statistic is useful to determine the patchiness of the fields. The Syrjala method is an easily implemented statistical measure of the difference between the fields, but does not give information on the details of the distributions. Finally, the geostatistical comparison of spatial indices gives good information of details of the distributions and whether they differ significantly between the model and the data. We conclude that each technique gives quite different information about the model-data distribution comparison, and that some are easy to apply and some more complex. We also give recommendations for

[Density, size structure and reproductive activity of the pink conch Eustrombus gigas (Mesogastropoda: Strombidae) in Banco Chinchorro, Mexico].

PubMed

Cala, Yuself R; Navarrete, Alberto de Jesús; Ocaña, Frank A; Rivera, José Oliva

2013-12-01

The pink conch Eustrombus gigas is an important fisheries resource. At the regional level in the Caribbean, over-exploitation and habitat destruction have caused a decrease in the abundance of this resource. In order to provide necessary information for the species management in Mexico, this work aimed to analyze the total density, adult density, size structure and reproductive behavior of pink conch population at Banco Chinchorro during 2009-2010. Data from three seasons were obtained (rainy, dry and cold fronts periods) in three areas: Norte (North), Centro (Center) and Sur (South). The organisms were separated into two groups: (a) the criteria based upon legal harvest in Mexico: legal size conchs (siphonal length > 200 mm) and illegal size conchs (siphonal length < 200 mm), and (b) the criteria based upon sexual maturity using the 15 mm lip thickness standard: lip < 15 mm as juvenile conch and lip > or = 15 mm as adult conch. Copulation, spawning, egg masses and aggregations were evaluated as reproductive evidences. The highest total density was observed during the dry season with 384ind./ha, and the lowest during the rainy season with 127ind./ha. The highest density was reported at Sur (385ind./ha) and the lowest at Norte (198ind./ ha). The highest adult density was observed during the rainy season (8.33ind./ha), and the lowest occurred in the dry season (6.1 ind./ha). Adult density values were 5.55, 7.05 and 8.33ind./ha for Centro, Sur and Norte areas, respectively. Adult densities were lower than the threshold needed for reproduction, and 42% of the population may be vulnerable to fishing, as they had the minimum size for catch (Lsi 200 mm). Furthermore, only 2.2% of the population reached a Gl > 15 mm as sexual maturity indicator. During the study period, only six evidences of reproductive activity were observed. The smaller densities reported at Banco Chinchorro may cause reproduction events to be almost absent which in turn is sufficient evidence to show

Indirect measurement of lung density and air volume from electrical impedance tomography (EIT) data.

PubMed

Nebuya, Satoru; Mills, Gary H; Milnes, Peter; Brown, Brian H

2011-12-01

This paper describes a method for estimating lung density, air volume and changes in fluid content from a non-invasive measurement of the electrical resistivity of the lungs. Resistivity in Ω m was found by fitting measured electrical impedance tomography (EIT) data to a finite difference model of the thorax. Lung density was determined by comparing the resistivity of the lungs, measured at a relatively high frequency, with values predicted from a published model of lung structure. Lung air volume can then be calculated if total lung weight is also known. Temporal changes in lung fluid content will produce proportional changes in lung density. The method was implemented on EIT data, collected using eight electrodes placed in a single plane around the thorax, from 46 adult male subjects and 36 adult female subjects. Mean lung densities (±SD) of 246 ± 67 and 239 ± 64 kg m(-3), respectively, were obtained. In seven adult male subjects estimates of 1.68 ± 0.30, 3.42 ± 0.49 and 4.40 ± 0.53 l in residual volume, functional residual capacity and vital capacity, respectively, were obtained. Sources of error are discussed. It is concluded that absolute differences in lung density of about 30% and changes over time of less than 30% should be detected using the current technology in normal subjects. These changes would result from approximately 300 ml increase in lung fluid. The method proposed could be used for non-invasive monitoring of total lung air and fluid content in normal subjects but needs to be assessed in patients with lung disease.

Diet dynamics of the juvenile piscivorous fish community in Spirit Lake, Iowa, USA, 1997-1998

USGS Publications Warehouse

Pelham, M.E.; Pierce, C.L.; Larscheid, J.G.

2001-01-01

We assessed temporal dynamics and variation among species and age-classes in the diets of age 0 and age 1 piscivorous fish species in Spirit Lake, Iowa, USA during 1997 and 1998. Species included walleye Stizostedion vitreum, yellow perch Perca flavescens, smallmouth bass Micropterus dolomieui, largemouth bass Micropterus salmoides, black crappie Pomoxis nigromaculatus and white bass Morone chrysops. Thirty taxa were identified in diets, including 12 species of fish. We found dramatic differences in diets among species, among age-classes within species and over time. Walleye, largemouth bass, smallmouth bass and white bass were piscivorous at age 0. Black crappie began piscivory at age 1. Yellow perch also began piscivory at age 1, but fish were a very small fraction of age-1 diets. The primary temporal pattern, seen in several species and age- classes, was an increase in piscivory from spring to fall. This pattern was due to the lack of small, age-0 prey fish in spring. Although some patterns were evident, the taxonomic composition of the diets of all species was highly variable over time, making generalizations difficult. A surprising result was the absence of yellow perch in the diet of age-0 walleye, despite their abundance in Spirit Lake and prominence in diets of age-1 walleye and other age 1-piscivores. Age-0 yellow perch were consistently too large to be eaten by age-0 piscivores, which preyed primarily on invertebrates and smaller fish such as johnny darters Etheostoma nigrum and age 0 bluegill Lepomis macrochirus. This finding suggests that predator-prey interactions and resulting population dynamics may be quite different in Spirit Lake than in other systems dominated by walleye and yellow perch.

Population density and phenotypic attributes influence the level of nematode parasitism in roe deer.

PubMed

Body, Guillaume; Ferté, Hubert; Gaillard, Jean-Michel; Delorme, Daniel; Klein, François; Gilot-Fromont, Emmanuelle

2011-11-01

The impact of parasites on population dynamics is well documented, but less is known on how host population density affects parasite spread. This relationship is difficult to assess because of confounding effects of social structure, population density, and environmental conditions that lead to biased among-population comparisons. Here, we analyzed the infestation by two groups of nematodes (gastro-intestinal (GI) strongyles and Trichuris) in the roe deer (Capreolus capreolus) population of Trois Fontaines (France) between 1997 and 2007. During this period, we experimentally manipulated population density through changes in removals. Using measures collected on 297 individuals, we quantified the impact of density on parasite spread after taking into account possible influences of date, age, sex, body mass, and weather conditions. The prevalence and abundance of eggs of both parasites in females were positively related to roe deer density, except Trichuris in adult females. We also found a negative relationship between parasitism and body mass, and strong age and sex-dependent patterns of parasitism. Prime-age adults were less often parasitized and had lower fecal egg counts than fawns or old individuals, and males were more heavily and more often infected than females. Trichuris parasites were not affected by weather, whereas GI strongyles were less present after dry and hot summers. In the range of observed densities, the observed effect of density likely involves a variation of the exposure rate, as opposed to variation in host susceptibility.

Journal of Naval Science. Volume 1, Number 3, July 1975

DTIC Science & Technology

1975-07-01

includes the Maverick, Walleye, and HOBOS, homes on the video contrast of a target. Both Maverick, which is rocket powered, and Walleye, a glide...television system could give a clear-night capability. The sensor output must be transmitted to the control station, and a one-way video com...systems are already available or under development in the U.S.A. which would serve these pur- poses, including a video transmitter weighing only 3 lb𔃻

Human Responding on Random-Interval Schedules of Response-Cost Punishment: The Role of Reduced Reinforcement Density

ERIC Educational Resources Information Center

Pietras, Cynthia J.; Brandt, Andrew E.; Searcy, Gabriel D.

2010-01-01

An experiment with adult humans investigated the effects of response-contingent money loss (response-cost punishment) on monetary-reinforced responding. A yoked-control procedure was used to separate the effects on responding of the response-cost contingency from the effects of reduced reinforcement density. Eight adults pressed buttons for money…

Reducing energy intake and energy density for a sustainable diet: a study based on self-selected diets in French adults.

PubMed

Masset, Gabriel; Vieux, Florent; Verger, Eric Olivier; Soler, Louis-Georges; Touazi, Djilali; Darmon, Nicole

2014-06-01

Studies on theoretical diets are not sufficient to implement sustainable diets in practice because of unknown cultural acceptability. In contrast, self-selected diets can be considered culturally acceptable. The objective was to identify the most sustainable diets consumed by people in everyday life. The diet-related greenhouse gas emissions (GHGE) for self-selected diets of 1918 adults participating in the cross-sectional French national dietary survey Individual and National Survey on Food Consumption (INCA2) were estimated. "Lower-Carbon," "Higher-Quality," and "More Sustainable" diets were defined as having GHGE lower than the overall median value, a probability of adequate nutrition intake (PANDiet) score (a measure of the overall nutritional adequacy of a diet) higher than the overall median value, and a combination of both criteria, respectively. Diet cost, as a proxy for affordability, and energy density were also assessed. More Sustainable diets were consumed by 23% of men and 20% of women, and their GHGE values were 19% and 17% lower than the population average (mean) value, respectively. In comparison with the average value, Lower-Carbon diets achieved a 20% GHGE reduction and lower cost, but they were not sustainable because they had a lower PANDiet score. Higher-Quality diets were not sustainable because of their above-average GHGE and cost. More Sustainable diets had an above-average PANDiet score and a below-average energy density, cost, GHGE, and energy content; the energy share of plant-based products was increased by 20% and 15% compared with the average for men and women, respectively. A strength of this study was that most of the dimensions for "sustainable diets" were considered, ie, not only nutritional quality and GHGE but also affordability and cultural acceptability. A reduction in diet-related GHGE by 20% while maintaining high nutritional quality seems realistic. This goal could be achieved at no extra cost by reducing energy intake and

Application of the stage-projection model with density-dependent fecundity to the population dynamics of Spanish ibex

USGS Publications Warehouse

Escos, J.; Alados, C.L.; Emlen, John M.

1994-01-01

A stage-class population model with density-feedback term included was used to identify the most critical parameters determining the population dynamics of female Spanish ibex (Capra pyrenaica) in southern Spain. A population in the Cazorla and Segura mountains is rapidly declining, but the eastern Sierra Nevada population is growing. The stable population density obtained using estimated values of kid and adult survival (0.49 and 0.87, respectively) and with fecundity equal to 0.367 in the absence of density feedback is 12.7 or 16.82 individuals/km2, based on a non-time-lagged and a time-lagged model, respectively. Given the maximum estimate of fecundity and an adult survival rate of 0.87, a kid survival rate of at least 0.41 is required to avoid extinction. At the minimum fecundity estimate, kid survival would have to exceed 0.52. Elasticities were used to estimate the influence of variation in life-cycle parameters on the intrinsic rate of increase. Adult survival is the most critical parameter, while fecundity and juvenile survival are less important. An increase in adult survival from 0.87 to 0.91 in the Cazorla and Segura mountains population would almost stabilize the population in the absence of stochastic variation, while the same increase in the Sierra Nevada population would yield population growth of 4–5% per annum. A reduction in adult survival to 0.83 results in population decline in both cases.

Effect of oxidative insult on young and adult cardiac muscle cells in vitro.

PubMed

Nag, A C; Sreepathi, P; Lee, M L; Reddan, J R

1996-01-01

The effect of hydrogen peroxide on cultured neonatal and adult cardiac myocytes was investigated. On neonatal cardiac myocytes the effect was very pronounced at a low concentration (0.03 mM), whereas the adult cardiac myocytes were resistant to the same concentration of H2O2. Dividing neonatal cardiac myocytes were more susceptible to H2O2 insult than the non-dividing adult cardiac myocytes. At a concentration of 0.1 mM H2O2, the neonatal cardiac myocytes were significantly damaged compared with the adult cardiac myocytes. Cardiac muscle cells from neonatal and adult hearts at high density culture were more tolerant to the oxidative insult by H2O2 than cells in low density culture. The damaging effect of H2O2 was very selective on F-actin in neonatal and adult cardiac muscle cells. The effect of H2O2 on myosin, titin, alpha-actinin, desmin or tubulin was not pronounced. Microscopical studies suggested a more marked protection by catalase than by glutathione reductase in the neonatal cells.

History of Red Lakes fishery, 1917-38, with observations on population status

USGS Publications Warehouse

Van Oosten, John; Deason, Hilary J.

1957-01-01

A historical account traces the development of the commercial fisheries of the Red Lakes, Minnesota, from its inception in 1917 as a war measure through 1938. The trends of production and catch per unit of effort were followed for the principal species with notes on statistics of the minor fishes. Life history data were recorded for the walleye and yellow perch. A historical account was presented of the artificial propagation of the walleye and whitefish from 1918 through 1938.

Appendicular Fractures: A Significant Problem among Institutionalized Adults with Developmental Disabilities.

ERIC Educational Resources Information Center

Ryder, K. M.; Williams, J.; Womack, C.; Nayak, N. G.; Nasef, S.; Bush, A.; Tylavsky, F. A.; Carbone, L.

2003-01-01

This study found a high incidence of nontraumatic fractures in adults with developmental disabilities living in a state-run facility, a 7.3% incidence among 391 adults. Factors associated with fractures included use of antiepileptic medication. Although bone mineral density (BMD) by heel ultrasound did not predict fracture, values were much lower…

Fibroblast growth factor 23, bone mineral density, and risk of hip fracture among older adults: the cardiovascular health study.

PubMed

Jovanovich, Anna; Bùzková, Petra; Chonchol, Michel; Robbins, John; Fink, Howard A; de Boer, Ian H; Kestenbaum, Bryan; Katz, Ronit; Carbone, Laura; Lee, Jennifer; Laughlin, Gail A; Mukamal, Kenneth J; Fried, Linda F; Shlipak, Michael G; Ix, Joachim H

2013-08-01

Fibroblast growth factor 23 (FGF23) is a phosphaturic hormone that also inhibits calcitriol synthesis. Our objective was to evaluate the relationships of plasma FGF23 concentrations with bone mineral density (BMD) and hip fracture in community-dwelling older adults. Linear regression and Cox proportional hazard models were used to examine the associations of plasma FGF23 concentrations with BMD and incident hip fracture, respectively. Analyses were also stratified by chronic kidney disease. Participants included 2008 women and 1329 men ≥65 years from the 1996 to 1997 Cardiovascular Health Study visit. Dual x-ray absorptiometry measured total hip (TH) and lumbar spine (LS) BMD in 1291 participants. Hip fracture incidence was assessed prospectively through June 30, 2008 by hospitalization records in all participants. Women had higher plasma FGF23 concentrations than men (75 [56-107] vs 66 [interquartile range = 52-92] relative units/mL; P < .001). After adjustment, higher FGF23 concentrations were associated with greater total hip and lumbar spine BMD in men only (β per doubling of FGF23 = 0.02, with 95% confidence interval [CI] = 0.001-0.04 g/cm(2), and 0.03 with 95% CI = 0.01-0.06 g/cm(2)). During 9.6 ± 5.1-11.0 years of follow-up, 328 hip fractures occurred. Higher FGF23 concentrations were not associated with hip fracture risk in women or men (adjusted hazard ratio = 0.95, with 95% CI = 0.78-1.15, and 1.09 with 95% CI = 0.82-1.46 per doubling of FGF23). Results did not differ by chronic kidney disease status (P > .4 for interactions). In this large prospective cohort of community-dwelling older adults, higher FGF23 concentrations were weakly associated with greater lumbar spine and total hip BMD but not with hip fracture risk.

Distribution of cone density, spacing and arrangement in adult healthy retinas with adaptive optics flood illumination

PubMed Central

Gaudric, Alain; Woog, Kelly

2018-01-01

The aim of this article is to analyse cone density, spacing and arrangement using an adaptive optics flood illumination retina camera (rtx1™) on a healthy population. Cone density, cone spacing and packing arrangements were measured on the right retinas of 109 subjects at 2°, 3°, 4°, 5° and 6° of eccentricity along 4 meridians. The effects of eccentricity, meridian, axial length, spherical equivalent, gender and age were evaluated. Cone density decreased on average from 28 884 ± 3 692 cones/mm2, at 2° of eccentricity, to 15 843 ± 1 598 cones/mm2 at 6°. A strong inter-individual variation, especially at 2°, was observed. No important difference of cone density was observed between the nasal and temporal meridians or between the superior and inferior meridians. However, the horizontal and vertical meridians differed by around 14% (T-test, p<0.0001). Cone density, expressed in units of area, decreased as a function of axial length (r2 = 0.60), but remained constant (r2 = 0.05) when cone density is expressed in terms of visual angle supporting the hypothesis that the retina is stretched during the elongation of the eyeball. Gender did not modify the cone distribution. Cone density was slightly modified by age but only at 2°. The older group showed a smaller density (7%). Cone spacing increased from 6,49 ± 0,42 μm to 8,72 ± 0,45 μm respectively between 2° and 6° of eccentricity. The mosaic of the retina is mainly triangularly arranged (i.e. cells with 5 to 7 neighbors) from 2° to 6°. Around half of the cells had 6 neighbors. PMID:29338027

Habitat characteristics of adult frosted elfins (Callophrys irus) in sandplain communities of southeastern Massachusetts, USA

USGS Publications Warehouse

Albanese, G.; Vickery, P.D.; Sievert, P.R.

2007-01-01

Changes to land use and disturbance frequency threaten disturbance-dependent Lepidoptera within sandplain habitats of the northeastern United States. The frosted elfin (Callophrys irus) is a rare and declining monophagous butterfly that is found in xeric open habitats maintained by disturbance. We surveyed potential habitat for adult frosted elfins at four sites containing frosted elfin populations in southeastern Massachusetts, United States. Based on the survey data, we used kernel density estimation to establish separate adult frosted elfin density classes, and then used regression tree analysis to describe the relationship between density and habitat features. Adult frosted elfin density was greatest when the host plant, wild indigo (Baptisia tinctoria), density was >2.6 plants/m2 and tree canopy cover was <29%. Frosted elfin density was inversely related to tree cover and declined when the density of wild indigo was <2.6 plants/m2 and shrub cover was ???16%. Even small quantities of non-native shrub cover negatively affected elfin densities. This effect was more pronounced when native herbaceous cover was <36%. Our results indicate that management for frosted elfins should aim to increase both wild indigo density and native herbaceous cover and limit native tree and shrub cover in open sandplain habitats. Elimination of non-native shrub cover is also recommended because of the negative effects of even low non-native shrub cover on frosted elfin densities. The maintenance of patches of early successional sandplain habitat with the combination of low tree and shrub cover, high host plant densities, and the absence of non-native shrubs appears essential for frosted elfin persistence, but may also be beneficial for a number of other rare sandplain insects and plant species. ?? 2006 Elsevier Ltd. All rights reserved.

Global and local processing in adult humans (Homo sapiens), 5-year-old children (Homo sapiens), and adult cotton-top tamarins (Saguinus oedipus).

PubMed

Neiworth, Julie J; Gleichman, Amy J; Olinick, Anne S; Lamp, Kristen E

2006-11-01

This study compared adults (Homo sapiens), young children (Homo sapiens), and adult tamarins (Saguinus oedipus) while they discriminated global and local properties of stimuli. Subjects were trained to discriminate a circle made of circle elements from a square made of square elements and were tested with circles made of squares and squares made of circles. Adult humans showed a global bias in testing that was unaffected by the density of the elements in the stimuli. Children showed a global bias with dense displays but discriminated by both local and global properties with sparse displays. Adult tamarins' biases matched those of the children. The striking similarity between the perceptual processing of adult monkeys and humans diagnosed with autism and the difference between this and normatively developing human perception is discussed.

Managing the Cayo Santiago rhesus macaque population: The role of density.

PubMed

Hernandez-Pacheco, Raisa; Delgado, Diana L; Rawlins, Richard G; Kessler, Matthew J; Ruiz-Lambides, Angelina V; Maldonado, Elizabeth; Sabat, Alberto M

2016-01-01

Cayo Santiago is the oldest continuously operating free-ranging rhesus monkey colony in the world. Population control of this colony has historically been carried out by periodic live capture and removal of animals. However, the effect of such a strategy on the size, growth rate, age structure, and sex ratio of the population has not been analyzed. This study reviews past removal data and uses a population projection model to simulate the effects of different removal schemes based on Cayo Santiago demographic data from 2000-2012. The model incorporates negative density-dependence in female fertility, as well as male and female survival rates, to determine the population-level effects of selective removal by age and sex. Modeling revealed that removal of sexually immature individuals has negligible effects on the population dynamics explaining why with an initial population of 1309 in 2000 and annual removals of immature monkeys a mean annual population growth rate of 12% and a final population size of ∼1,435 individuals by 2012 (∼0.009 animal/m(2) ) was observed. With no removals, the population is expected to exhibit dampened oscillations until reaching equilibrium at ∼1,690 individuals (∼0.0111 animal/m(2) ) in 2,100. In contrast, removal of adult females (≥4 yrs) would significantly reduce the population size, but would also promote an increase in population growth rate due to density feedback. A maximum annual production of 275 births is expected when 550 adult females are present in the population. Sensitivity analyses showed that removing females, in contrast to controlling their fertility through invasive treatments would contribute the most to changes in population growth rate. Given the density compensation on fertility, stabilizing the population would require removing ∼80% of the current population of adult females. This study highlights the importance of addressing the population-level density effects, as well as sensitivity analyses, to

Optimization of mosquito egg production under mass rearing setting: effects of cage volume, blood meal source and adult population density for the malaria vector, Anopheles arabiensis.

PubMed

Mamai, Wadaka; Bimbile-Somda, Nanwintoum S; Maiga, Hamidou; Juarez, José Guillermo; Muosa, Zaynab A I; Ali, Adel Barakat; Lees, Rosemary Susan; Gilles, Jeremie R L

2017-01-24

Anopheles arabiensis is one of the major malaria vectors that put millions of people in endemic countries at risk. Mass-rearing of this mosquito is crucial for strategies that use sterile insect technique to suppress vector populations. The sterile insect technique (SIT) package for this mosquito species is being developed by the Insect Pest Control Subprogramme of the Joint FAO/IAEA Division of Nuclear Techniques in Food and Agriculture. To improve mass-rearing outcomes for An. arabiensis, the question of whether the egg production by females would be affected by the size of the adult holding cages, the source of the blood meal and the total number of pupae that could be loaded into the cages was addressed and finally the impact of adding additional pupae to the cage daily to maintain adult numbers on egg productivity assessed. Mass production cages of two different volumes, two different sources of blood meal (bovine and porcine) and two different population densities (cages originally loaded with either 15,000 or 20,000 pupae) were tested and evaluated on the basis of eggs produced/cage or per female. Males and females pupae with a ratio of 1:1 were added to the cages at day 1 and 2 of pupation. The emerging adults had constant access to 5% sugar solution and blood fed via the Hemotek membrane feeding system. Eggs were collected either twice a week or daily. A generalized linear model was used to identify factors which gave significantly higher egg production. Neither cage volume nor blood meal source affected egg production per cage or per female. However, increasing population density to 20,000 pupae had a negative effect on eggs produced per cage and per female. Although high density negatively impacted egg production, adding 1000 daily additional pupae compensating for daily mortality resulted in a substantial increase in egg production. Moreover, in all tests the first and the third egg batches collected were significantly higher than others eggs batches

Reconciling catch differences from multiple fishery independent gill net surveys

USGS Publications Warehouse

Kraus, Richard T.; Vandergoot, Christopher; Kocovsky, Patrick M.; Rogers, Mark W.; Cook, H. Andrew; Brenden, Travis O.

2017-01-01

Fishery independent gill net surveys provide valuable demographic information for population assessment and resource management, but relative to net construction, the effects of ancillary species, and environmental variables on focal species catch rates are poorly understood. In response, we conducted comparative deployments with three unique, inter-agency, survey gill nets used to assess walleye Sander vitreus in Lake Erie. We used an information-theoretic approach with Akaike’s second-order information criterion (AICc) to evaluate linear mixed models of walleye catch as a function of net type (multifilament and two types of monofilament netting), mesh size (categorical), Secchi depth, temperature, water depth, catch of ancillary species, and interactions among selected variables. The model with the greatest weight of evidence showed that walleye catches were positively associated with potential prey and intra-guild predators and negatively associated with water depth and temperature. In addition, the multifilament net had higher average walleye catches than either of the two monofilament nets. Results from this study both help inform decisions about proposed gear changes to stock assessment surveys in Lake Erie, and advance our understanding of how multispecies associations explain variation in gill net catches. Of broader interest to fishery-independent gill net studies, effects of abiotic variables and ancillary species on focal specie’s catch rates were small in comparison with net characteristics of mesh size or twine type.

Dispersal, mortality, and predation on recently-stocked rainbow trout in Dale Hollow Lake, Tennessee

USGS Publications Warehouse

Ivasauskas, Tomas J.; Bettoli, Phillip William

2011-01-01

Forty-four hatchery-raised rainbow trout (Oncorhynchus mykiss) were implanted with ultrasonic tags and stocked into Dale Hollow Lake, Tennessee, and tracked at least once per week for eight weeks to describe post-stocking dispersal rates, movements, and habitat use. Dispersal followed a three-stage pattern characterized by rapid movement away from each stocking site during the first week, relatively little dispersal during the next three weeks, and further dispersion during the final four weeks that fish were tracked. Rainbow trout exhibited a strong affinity for coves and were rarely encountered in the main channel. Tagged fish stocked in March exhibited lower mortality (Zweekly = 0.027) than those stocked in January (Zweekly = 0.062) during the first eight weeks post-stocking. Diets of potential predators in Dale Hollow Lake were examined. Walleye (Sander vitreus), smallmouth bass (Micropterus dolomieu), largemouth bass (M. salmoides), and holdover rainbow trout all preyed on recently stocked trout. Larger walleye were more likely to prey on stocked rainbow trout, and walleye of all sizes tended to prey on the smaller trout in each stocked cohort. Walleye were more likely to feed on rainbow trout during January than March. Effective stocking strategies should focus on reducing predation by stocking larger rainbow trout or by stocking when predation risk is minimized (i.e., March).

Using Fish Population Metrics to Compare the Effects of Artificial Reef Density.

PubMed

Froehlich, Catheline Y M; Kline, Richard J

2015-01-01

Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1-190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71-120 culverts in a 30-m radius to yield the highest fish abundances.

Osteoporosis and Prevalent Fractures among Adult Filipino Men Screened for Bone Mineral Density in a Tertiary Hospital.

PubMed

Mendoza, Erick S; Lopez, Amy A; Valdez, Valerie Ann U; Mercado-Asis, Leilani B

2016-09-01

Osteoporosis in men is markedly underdiagnosed and undertreated despite higher morbidity and mortality associated with fractures. This study aimed to characterize adult Filipino men with osteopenia, osteoporosis and prevalent fractures. A cross-sectional study of 184 Filipino men ≥50 years screened for bone mineral density was performed. Age, weight, body mass index (BMI), Osteoporosis Self-Assessment Tool for Asians (OSTA) score, smoking status, family history of fracture, diabetes mellitus, physical inactivity, and T-score were considered. Of the 184 patients, 40.2% and 29.9% have osteopenia and osteoporosis. Sixteen (21.6%) and 18 (32.1%) osteopenic and osteoporotic men have fragility hip, spine, or forearm fractures. Men aged 50 to 69 years have the same risk of osteoporosis and fractures as those ≥70 years. While hip fractures are higher in osteoporotic men, vertebral fractures are increased in both osteopenic and osteoporotic men. Mere osteopenia predicts the presence of prevalent fractures. A high risk OSTA score can predict fracture. A BMI <21 kg/m² (P<0.05) and current smoking are associated with osteoporosis. A significant fraction of Filipino men with osteopenia and osteoporosis have prevalent fractures. Our data suggest that fractures occur in men <70 years even before osteoporosis sets in. Low BMI, high OSTA score, and smoking are significant risk factors of osteoporosis.

Social Determinants and Poor Diet Quality of Energy-Dense Diets of Australian Young Adults

PubMed Central

Allman-Farinelli, Margaret

2017-01-01

This research aimed to determine the diet quality and socio-demographic determinants by level of energy-density of diets of Australian young adults. Secondary analysis of the Australian National Nutrition and Physical Activity Survey-2011/2012 for adults aged 18–34 years (n = 2397) was conducted. Diet was assessed by 24-h recalls. Dietary energy-density was calculated as dietary energy/grams of food (kJ/g) and the Healthy-Eating-Index-for-Australians (HEIFA-2013) was used to assess diet quality (highest score = 100). Dietary energy-density was examined with respect to diet quality and sociodemographic determinants including gender, highest tertiary-education attainment, country-of-birth, age, income, and socio-economic-index-for-area (SEIFA). Higher dietary energy-density was associated with lower diet quality scores (β = −3.71, t (2394) = −29.29, p < 0.0001) and included fewer fruits and vegetables, and more discretionary foods. The mean dietary energy-density was 7.7 kJ/g and 7.2 kJ/g for men and women, respectively. Subpopulations most at risk of consuming high energy-dense diets included those with lower education, Australian and English-speaking countries of birth, and men with low income and women from areas of lower socio-economic status. Young adults reporting low energy-dense diets had higher quality diets. Intensive efforts are needed to reduce the high energy-density of young adults’ diets, and should ensure they include populations of lower socio-economic status. PMID:28974029

Glycaemic, Blood Pressure and Low Density Lipoprotein Cholesterol Control in Adult Patients with Diabetes in Singapore: A Review of Singapore Literature Over Two Decades.

PubMed

Poh, Zhongxian; Venkataraman, Kavita; Toh, Sue-Anne Es; Low, Lian Leng

2017-10-01

Diabetes mellitus is a burgeoning global health epidemic, with an estimated 422 million people living with diabetes in 2014. The number of adult diabetic patients in Singapore is expected to rise to 1 million in 2050. Despite advances made in the management of diabetes and improvements in healthcare accessibility and delivery, the rate and complications of diabetes (myocardial infarction, stroke, kidney failure and lower limb amputation) in Singapore have not decreased. Gaps between guidelines and practice have been reported in several parts of the world. In this narrative review, we aimed to describe the control of diabetes in Singapore over the past 20 years. We reviewed studies describing, or trials intervening in, the glycaemic, blood pressure (BP) and low density lipoprotein cholesterol (LDL-C) control of adult diabetic patients in Singapore published over the past 20 years (1997-2016). Studies selected from comprehensive electronic databases searches were reviewed by 4 reviewers (2 primary care physicians, 1 diabetologist and 1 public health epidemiologist). The GRADE approach was used to evaluate the quality of evidence. We included 23 articles involving 257,097 subjects. There were 9 longitudinal, 12 cross-sectional and 2 case-control studies. All studies reported mean/median HbA1c between 7.2%-8.6%. BP ranged between 126.5-144 mmHg (systolic) and 70-84 mmHg (diastolic) in 9 studies. Nine studies reported LDL-C between 2.4-3.3 mmol/L. Mirroring global patterns, the glycaemic, BP and LDL-C control in adult diabetic patients in Singapore do not appear to be treated to target in the majority of patients.

Mercury accumulation in yellow perch in Wisconsin seepage lakes: Relation to lake characteristics

USGS Publications Warehouse

Cope, W.G.; Wiener, J.G.; Rada, R.G.

1990-01-01

We studied relations between lacustrine characteristics and the total mercury (Hg) content of calendar age-2 yellow perch (Perca flavescens) in 10 seepage lakes in north-central Wisconsin. Mean concentrations and burdens (masses) of Hg in whole perch varied widely among lakes, were negatively correlated with lake pH and were positively correlated with total Hg concentration in surficial profundal sediment. Approximately 80 to 90% of the variation in Hg concentration and burden in whole perch was explained with multiple regressions containing two independent variables: either lake pH or alkalinity, and Hg concentration in surficial sediment. Variation among lakes in the Hg concentration in yellow perch was unrelated to their relative rates of growth. The mean concentration of Hg in axial muscle tissue of age-5 walleyes (Stizostedion vitreum vitreum) from five of the study lakes was highly correlated with the mean concentration in whole age-2 perch in the same lakes. We hypothesized that the high Hg concentrations often seen in piscivorous fish in low-alkalinity lakes (relative to high-alkalinity lakes) is at least partly due to a greater dietary intake of Hg in such waters. Furthermore, the analysis of small yellow perch—the preferred prey of adult walleyes and an important forage species for many predatory fishes in the north-central United States—may be an effective approach to assessing Hg bioavailability in the region's lakes.

Intercohort density dependence drives brown trout habitat selection

NASA Astrophysics Data System (ADS)

Ayllón, Daniel; Nicola, Graciela G.; Parra, Irene; Elvira, Benigno; Almodóvar, Ana

2013-01-01

Habitat selection can be viewed as an emergent property of the quality and availability of habitat but also of the number of individuals and the way they compete for its use. Consequently, habitat selection can change across years due to fluctuating resources or to changes in population numbers. However, habitat selection predictive models often do not account for ecological dynamics, especially density dependent processes. In stage-structured population, the strength of density dependent interactions between individuals of different age classes can exert a profound influence on population trajectories and evolutionary processes. In this study, we aimed to assess the effects of fluctuating densities of both older and younger competing life stages on the habitat selection patterns (described as univariate and multivariate resource selection functions) of young-of-the-year, juvenile and adult brown trout Salmo trutta. We observed all age classes were selective in habitat choice but changed their selection patterns across years consistently with variations in the densities of older but not of younger age classes. Trout of an age increased selectivity for positions highly selected by older individuals when their density decreased, but this pattern did not hold when the density of younger age classes varied. It suggests that younger individuals are dominated by older ones but can expand their range of selected habitats when density of competitors decreases, while older trout do not seem to consider the density of younger individuals when distributing themselves even though they can negatively affect their final performance. Since these results may entail critical implications for conservation and management practices based on habitat selection models, further research should involve a wider range of river typologies and/or longer time frames to fully understand the patterns of and the mechanisms underlying the operation of density dependence on brown trout habitat

Density-associated recruitment mediates coral population dynamics on a coral reef

NASA Astrophysics Data System (ADS)

Bramanti, Lorenzo; Edmunds, Peter J.

2016-06-01

Theory suggests that density-associated processes can modulate community resilience following declines in population size. Here, we demonstrate density-associated processes in two scleractinian populations on the outer reef of Moorea, French Polynesia, that are rapidly increasing in size following the effects of two catastrophic disturbances. Between 2006 and 2010, predation by the corallivorous crown-of-thorns sea star reduced coral cover by 93 %; in 2010, the dead coral skeletons were removed by a cyclone, and in 2011 and 2012, high coral recruitment initiated population recovery. Coral recruitment was associated with coral cover, but the relationship differed between two coral genera that are almost exclusively broadcast spawners in Moorea. Acroporids recruited at low densities, and the density of recruits was positively associated with cover of Acropora, whereas pocilloporids recruited at high densities, and densities of their recruits were negatively associated with cover of Pocillopora. Together, our results suggest that associations between adult cover and density of both juveniles and recruits can mediate rapid coral community recovery after large disturbances. The difference between taxa in sign of the relationships between recruit density and coral cover indicate that they reflect contrasting mechanisms with the potential to mediate temporal shifts in taxonomic composition of coral communities.

Situated Naïve Physics: Task Constraints Decide what Children Know about Density

PubMed Central

Kloos, Heidi; Fisher, Anna; Van Orden, Guy C.

2013-01-01

Children’s understanding of density is riddled with misconceptions – or so it seems. Yet even preschoolers at times appear to understand density. This article seeks to reconcile these conflicting outcomes by investigating the nature of constraints available in different experimental protocols. Protocols that report misconceptions about density used stimulus arrangements that make differences in mass and volume more salient than differences in density. In contrast, protocols that report successful performance used stimulus arrangements that might have increased the salience of density. To test this hypothesis, the present experiments manipulate the salience of object density. Children between 2 and 9 years of age and adults responded whether an object would sink or float when placed in water. Results indicated that children’s performance on exactly the same objects differed as a function of the saliency of the dimension of density, relative to the dimensions of mass and volume. These results support the idea that constraints – rather than stable knowledge – drive performance, with implications for teaching children about non-obvious concepts such as density. PMID:20853994

Challenges of Fracture Management for Adults With Osteogenesis Imperfecta.

PubMed

Gil, Joseph A; DeFroda, Steven F; Sindhu, Kunal; Cruz, Aristides I; Daniels, Alan H

2017-01-01

Osteogenesis imperfecta is caused by qualitative or quantitative defects in type I collagen. Although often considered a disease with primarily pediatric manifestations, more than 25% of lifetime fractures are reported to occur in adulthood. General care of adults with osteogenesis imperfecta involves measures to preserve bone density, regular monitoring of hearing and dentition, and maintenance of muscle strength through physical therapy. Surgical stabilization of fractures in these patients can be challenging because of low bone mineral density, preexisting skeletal deformities, or obstruction by instrumentation from previous surgeries. Additionally, unique perioperative considerations exist when operatively managing fractures in patients with osteogenesis imperfecta. To date, there is little high-quality literature to help guide the optimal treatment of fractures in adult patients with osteogenesis imperfecta. [Orthopedics. 2017; 40(1):e17-e22.]. Copyright 2016, SLACK Incorporated.

Effects of Long-Term Low-Molecular-Weight Heparin on Fractures and Bone Density in Non-Pregnant Adults: A Systematic Review With Meta-Analysis.

PubMed

Gajic-Veljanoski, Olga; Phua, Chai W; Shah, Prakesh S; Cheung, Angela M

2016-08-01

Adults who require long-term anticoagulation with low-molecular-weight heparin (LMWH) such as cancer patients or the elderly may be at increased risk of fractures. To determine the effects of LMWH therapy of at least 3 months' duration on fractures and bone mineral density (BMD) in non-pregnant adult populations. We systematically reviewed electronic databases (e.g., MEDLINE, EMBASE), conferences and bibliographies until June 2015 and included comparative studies in non-pregnant adult populations that examined the effects of LMWH (≥3 months) on fractures and BMD. We synthesized evidence qualitatively and used random-effects meta-analysis to quantify the effect of LMWH on fractures. Sixteen articles reporting 14 studies were included: 10 clinical trials (n = 4865 participants) and four observational cohort studies (3 prospective, n = 221; 1 retrospective, n = 30). BMD and fractures were secondary outcomes in the majority of trials, while they were primary outcomes in the majority of observational studies. In participants with venous thromboembolism and underlying cardiovascular disease or cancer (5 RCTs, n = 2280), LMWH for 3-6 months did not increase the relative risk of all fractures at 6-12 months compared to unfractionated heparin, oral vitamin K antagonists or placebo [pooled risk ratio (RR) = 0.58, 95 % CI: 0.23-1.43; I(2) = 12.5 %]. No statistically significant increase in the risk of fractures at 6-12 months was found for cancer patients (RR = 1.08, 95 % CI: 0.31-3.75; I(2) = 4.4 %). Based on the data from two prospective cohort studies (n = 166), LMWH for 3-24 months decreased mean BMD by 2.8-4.8 % (depending on the BMD site) compared to mean BMD decreases of 1.2-2.5 % with oral vitamin K antagonists. LMWH for 3-6 months may not increase the risk of fractures, but longer exposure for up to 24 months may adversely affect BMD. Clinicians should consider monitoring BMD in adults on long-term LMWH who are at

Serengeti real estate: density vs. fitness-based indicators of lion habitat quality.

PubMed

Mosser, Anna; Fryxell, John M; Eberly, Lynn; Packer, Craig

2009-10-01

Habitat quality is typically inferred by assuming a direct relationship between consumer density and resource abundance, although it has been suggested that consumer fitness may be a more accurate measure of habitat quality. We examined density vs. fitness-based measures of habitat quality for lions in the Serengeti National Park, Tanzania. A 40-year average of female reproductive success (yearling cubs per female) was best explained by proximity to river confluences, whereas patterns of productivity (yearling cubs per km(2)) and adult female density (individuals per km(2)) were associated with more general measures of habitat quality and areas of shelter in poor habitat. This suggests that density may not accurately distinguish between high-quality 'source' areas and low-quality sites that merely provide refuges for effectively non-reproductive individuals. Our results indicate that density may be a misleading indicator of real estate value, particularly for populations that do not conform to an ideal free distribution.

Predictions of adult Anopheles albimanus densities in villages based on distances to remotely sensed larval habitats

NASA Technical Reports Server (NTRS)

Rejmankova, E.; Roberts, D. R.; Pawley, A.; Manguin, S.; Polanco, J.

1995-01-01

Remote sensing is particularly helpful for assessing the location and extent of vegetation formations, such as herbaceous wetlands, that are difficult to examine on the ground. Marshes that are sparsely populated with emergent macrophytes and dense cyanobacterial mats have previously been identified as very productive Anopheles albimanus larval habitats. This type of habitat was detectable on a classified multispectral System Probatoire d'Observation de la Terre image of northern Belize as a mixture of two isoclasses. A similar spectral signature is characteristic for vegetation of river margins consisting of aquatic grasses and water hyacinth, which constitutes another productive larval habitat. Based on the distance between human settlements (sites) of various sizes and the nearest marsh/river exhibiting this particular class combination, we selected two groups of sites: those located closer than 500 m and those located more than 1,500 m from such habitats. Based on previous adult collections near larval habitats, we defined a landing rate of 0.5 mosquitoes/human/min from 6:30 PM to 8:00 PM as the threshold for high (> or = 0.5 mosquitoes/human/min) versus low (< 0.5 mosquitoes/human/min) densities of An. albimanus. Sites located less than 500 m from the habitat were predicted as having values higher than this threshold, while lower values were predicted for sites located greater than 1,500 m from the habitat. Predictions were verified by collections of mosquitoes landing on humans. The predictions were 100% accurate for sites in the > 1,500-m category and 89% accurate for sites in the < 500-m category.

Impact of soft and hard insole density on postural stability in older adults.

PubMed

Losa Iglesias, Marta Elena; Becerro de Bengoa Vallejo, Ricardo; Palacios Peña, Domingo

2012-01-01

A significant predictor of falls in the elderly population is attributed to postural instability. Thus, it is important to identify and implement practical clinical interventions to enhance postural stability in older adults. Shoe insoles have been identified as a mechanism to enhance postural control, and our study aimed to evaluate the impact of 2 shoe insoles on static standing balance in healthy, older adults compared with standing posture while barefoot. We hypothesized that both hard and soft shoe insoles would decrease postural sway compared with the barefoot condition. Indeed, excursion distances and sway areas were reduced, and sway velocity was decreased when wearing insoles. The hard insole was also effective when visual feedback was removed, suggesting that the more rigid an insole, the greater potential reduction in fall risk. Thus, shoe insoles may be a cost-effective, clinical intervention that is easy to implement to reduce the risk of falling in the elderly population. Copyright © 2012 Mosby, Inc. All rights reserved.

Predation on ruffe by native fishes of the St. Louis River Estuary, Lake Superior, 1989-1991

USGS Publications Warehouse

Ogle, Derek H.; Selgeby, James H.; Savino, Jacqueline F.; Newman, Raymond M.; Henry, Mary G.

1996-01-01

The ruffe Gymnocephalus cernuus, an exotic Eurasian percid, recently became established in the St. Louis River estuary, Lake Superior, after accidental introduction. Management actions (catch regulations and stockings) were enacted in 1989 to increase the density of top-level predators in the estuary, and thus to increase predation on ruffe. We conducted a field and laboratory study to determine if, and to what extent, native piscivores consume ruffe. Stomachs of 3,669 predators were examined in 1989–1991. Ruffe occurred in 6.7% of burbot Lota lota, 5.8% of bullheads Ictalurus spp., 4.7% of smallmouth bass Micropterus dolomieu, 2.6% of northern pike Esox lucius, 2.6% of black crappiesPomoxis nigromaculatus, and 1.3% of yellow perch Perca flavescens (4.5% after 1989) captured during the 3-year study. No ruffe were found in 967 stomachs of walleyesStizostedion vitreum examined. Ruffe were 22.7%, of the diet (by weight) of bullheads (during the only year bullheads were captured) and 0.1–17.9% of the diet of northern pike. Ruffe were 0.9–24.5% of the diet of smallmouth bass that contained fish, 1.5–6.9% of yellow perch that contained fish, and 0.0–10.9% of black crappies that contained fish. Most ruffe eaten were age-0 or small age- 1 fish. In the laboratory, walleyes that were first fed soft-rayed prey or that were also offered soft-rayed prey consumed very few ruffe, whereas walleyes that were first fed spiny-rayed yellow perch or were also offered yellow perch consumed about equal numbers of ruffe and yellow perch. Northern pike and burbot consumed about equal numbers of ruffe and yellow perch in the laboratory. It is unlikely that predation will effectively control the initial expansion of ruffe in other areas of the Great Lakes because native predators initially consume few ruffe, especially if more preferred soft-rayed prey are available.

Density of indoor tanning facilities in 116 large U.S. cities.

PubMed

Hoerster, Katherine D; Garrow, Rebecca L; Mayer, Joni A; Clapp, Elizabeth J; Weeks, John R; Woodruff, Susan I; Sallis, James F; Slymen, Donald J; Patel, Minal R; Sybert, Stephanie A

2009-03-01

U.S. adolescents and young adults are using indoor tanning at high rates, even though it has been linked to both melanoma and squamous cell cancer. Because the availability of commercial indoor tanning facilities may influence use, data are needed on the number and density of such facilities. In March 2006, commercial indoor tanning facilities in 116 large U.S. cities were identified, and the number and density (per 100,000 population) were computed for each city. Bivariate and multivariate analyses conducted in 2008 tested the association between tanning-facility density and selected geographic, climatologic, demographic, and legislative variables. Mean facility number and density across cities were 41.8 (SD=30.8) and 11.8 (SD=6.0), respectively. In multivariate analysis, cities with higher percentages of whites and lower ultraviolet (UV)index scores had significantly higher facility densities than those with lower percentages of whites and higher UV index scores. These data indicate that commercial indoor tanning is widely available in the urban U.S., and this availability may help explain the high usage of indoor tanning.

Comparison of Intrinsic Rate of Different House Fly Densities in a Simulated Condition: A Prediction for House Fly Population and Control Threshold.

PubMed

Ong, Song-Quan; Ahmad, Hamdan; Jaal, Zairi; Rus, Adanan; Fadzlah, Fadhlina Hazwani Mohd

2017-01-01

Determining the control threshold for a pest is common prior to initiating a pest control program; however, previous studies related to the house fly control threshold for a poultry farm are insufficient for determining such a threshold. This study aimed to predict the population changes of house fly population by comparing the intrinsic rate of increase (r m ) for different house fly densities in a simulated system. This study first defined the knee points of a known population growth curve as a control threshold by comparing the r m of five densities of house flies in a simulated condition. Later, to understand the interactions between the larval and adult populations, the correlation between larval and adult capacity rate (r c ) was studied. The r m values of 300- and 500-fly densities were significantly higher compared with the r m values at densities of 50 and 100 flies. This result indicated their representative indices as candidates for a control threshold. The r c of larval and adult populations were negatively correlated with densities of fewer than 300 flies; this implicated adult populations with fewer than 300 flies as declining while the larval population was growing; therefore, control approaches should focus on the immature stages. The results in the present study suggest a control threshold for house fly populations. Future works should focus on calibrating the threshold indices in field conditions. © The Authors 2016. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Land use, residential density, and walking. The multi-ethnic study of atherosclerosis.

PubMed

Rodríguez, Daniel A; Evenson, Kelly R; Diez Roux, Ana V; Brines, Shannon J

2009-11-01

The neighborhood environment may play a role in encouraging sedentary patterns, especially for middle-aged and older adults. The aim of this study was to examine the associations between walking and neighborhood population density, retail availability, and land-use distribution using data from a cohort of adults aged 45 to 84 years. Data from a multi-ethnic sample of 5529 adult residents of Baltimore MD, Chicago IL, Forsyth County NC, Los Angeles CA, New York NY, and St. Paul MN enrolled in the Multi-Ethnic Study of Atherosclerosis in 2000-2002 were linked to secondary land-use and population data. Participant reports of access to destinations and stores and objective measures of the percentage of land area in parcels devoted to retail land uses, the population divided by land area in parcels, and the mixture of uses for areas within 200 m of each participant's residence were examined. Multinomial logistic regression was used to investigate associations of self-reported and objective neighborhood characteristics with walking. All analyses were conducted in 2008 and 2009. After adjustment for individual-level characteristics and neighborhood connectivity, it was found that higher density, greater land area devoted to retail uses, and self-reported proximity of destinations and ease of walking to places were each related to walking. In models including all land-use measures, population density was positively associated with walking to places and with walking for exercise for more than 90 minutes/week, both relative to no walking. Availability of retail was associated with walking to places relative to not walking, and having a more proportional mix of land uses was associated with walking for exercise for more than 90 minutes/week, while self-reported ease of access to places was related to higher levels of exercise walking, both relative to not walking. Residential density and the presence of retail uses are related to various walking behaviors. Efforts to increase

12-h abstinence-induced functional connectivity density changes and craving in young smokers: a resting-state study.

PubMed

Zhao, Shuzhi; Li, Yangding; Li, Min; Wang, Ruonan; Bi, Yanzhi; Zhang, Yajuan; Lu, Xiaoqi; Yu, Dahua; Yang, Likun; Yuan, Kai

2018-06-20

Studying the neural correlates of craving to smoke is of great importance to improve treatment outcomes in smoking addiction. According to previous studies, the critical roles of striatum and frontal brain regions had been revealed in addiction. However, few studies focused on the hub of brain regions in the 12 h abstinence induced craving in young smokers. Thirty-one young male smokers were enrolled in the present study. A within-subject experiment design was carried out to compare functional connectivity density between 12-h smoking abstinence and smoking satiety conditions during resting state in young adult smokers by using functional connectivity density mapping (FCDM). Then, the functional connectivity density changes during smoking abstinence versus satiety were further used to examine correlations with abstinence-induced changes in subjective craving. We found young adult smokers in abstinence state (vs satiety) had higher local functional connectivity density (lFCD) and global functional connectivity density (gFCD) in brain regions including striatal subregions (i.e., bilateral caudate and putamen), frontal regions (i.e., anterior cingulate cortex (ACC) and orbital frontal cortex (OFC)) and bilateral insula. We also found higher lFCD during smoking abstinence (vs satiety) in bilateral thalamus. Additionally, the lFCD changes of the left ACC, bilateral caudate and right OFC were positively correlated with the changes in craving induced by abstinence (i.e., abstinence minus satiety) in young adult smokers. The present findings improve the understanding of the effects of acute smoking abstinence on the hubs of brain gray matter in the abstinence-induces craving and may contribute new insights into the neural mechanism of abstinence-induced craving in young smokers in smoking addiction.

Optimal Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae) density and time of introduction for suppression of bruchid progeny in stored legumes

Treesearch

Sharlene E. Sing; Richard T. Arbogast

2008-01-01

The influences of both predator density and elapsed time between initial infestation and introduction of predators were determined for suppression of bruchids infesting stored grain legumes by Xylocoris flavipes (Reuter) (Hemiptera: Anthocoridae). Predator density treatments consisted of zero, one, two, three, or five male:female pairs of adult

Using Fish Population Metrics to Compare the Effects of Artificial Reef Density

PubMed Central

2015-01-01

Artificial reefs continue to be added as habitat throughout the world, yet questions remain about how reef design affects fish diversity and abundance. In the present study, the effects of reef density were assessed for fish communities and sizes of economically valuable Lutjanus campechanus 13 km off Port Mansfield, Texas, at a reef composed of more than 4000 concrete culverts. The study spanned from May to June in 2013 and 2014, and sites sampled included natural reefs, bare areas, and varying culvert patch density categories, ranging from 1–190 culverts. Abundances of adults and species evenness of juvenile populations differed between the years. Fish communities did not significantly differ among density categories; however, highest species richness and total abundances were observed at intermediate culvert densities and at natural reefs. Whereas the abundance of L. campechanus did not differ among density categories, mean total lengths of L. campechanus were greatest at the lower density. Our findings suggest that reefs should be deployed with intermediate patch density of 71–120 culverts in a 30-m radius to yield the highest fish abundances. PMID:26422472

The independent and combined effects of intensive weight loss and exercise training on bone mineral density in overweight and obese, older adults with osteoarthritis

PubMed Central

Beavers, Daniel P.; Beavers, Kristen M.; Loeser, Richard F.; Walton, Nicole R.; Lyles, Mary F.; Nicklas, Barbara J.; Shapses, Sue A.; Newman, Jovita J.; Messier, Stephen P.

2014-01-01

Objective To determine the effects of dietary-induced weight loss (D) and weight loss plus exercise (D+E) compared to exercise alone (E) on bone mineral density (BMD) in older adults with knee osteoarthritis (OA). Design Data come from 284 older (66.0±6.2 years), overweight/obese (BMI 33.4±3.7 kg/m2), adults with knee OA enrolled in the Intensive Diet and Exercise for Arthritis (IDEA) study. Participants were randomized to 18 months of walking and strength training (E; n=95), dietary-induced weight loss targeting 10% of baseline weight (D; n=88) or a combination of the two (D+E; n=101). Body weight and composition (DXA), regional BMD, were obtained at baseline and 18 months. Results E, D, and D+E groups lost 1.3±4.5 kg, 9.1±8.6 kg and 10.4±8.0 kg, respectively (p<0.01). Significant treatment effects were observed for BMD in both hip and femoral neck regions, with the D and D+E groups showing similar relative losses compared to E (both p<0.01). Despite reduced BMD, fewer overall participants had T-scores indicative of osteoporosis after intervention (9 at 18 months vs. 10 at baseline). Within the D and D+E groups, changes in hip and femoral neck, but not spine, BMD correlated positively with changes in body weight (r=0.21 and 0.54 respectively, both p=<0.01). Conclusions Weight loss via an intensive dietary intervention, with or without exercise, results in bone loss at the hip and femoral neck in overweight and obese, older adults with OA. Although the exercise intervention did not attenuate weight loss associated reductions in BMD, classification of osteoporosis and osteopenia remained unchanged. PMID:24742955

Effect of alendronate on bone mineral density in adult patients with Laron syndrome (primary growth hormone insensitivity).

PubMed

Eshed, Varda; Benbassat, Carlos A; Laron, Zvi

2006-04-01

Severe short stature resulting from a deficiency in insulin-like growth factor-I (IGF-I) is a prominent feature of Laron syndrome (LS). Whether patients with LS are osteopenic or not, and whether they need treatment with bisphosphonates, remains uncertain. The aim of this study was to investigate the action of alendronate on the IGF-I-deficient bones of adult patients with LS and osteoporosis, as determined by dual X-ray absorptiometry . Seven patients (5 women and 2 men) of mean age 40.8+/-7.6 years and mean bone mass density (BMD) 0.843+/-0.06 g/cm2 (T score -2.9+/-0.5) at the lumbar spine and 0.734+/-0.11 g/cm2 (T score -2.2+/-0.9) at the femoral neck were treated with alendronate 70 mg once/weekly over a 12-month period. Treatment led to an increase of 5.3% in BMD (p=0.038) at the femoral neck. There was a similar trend at the lumbar spine, but the difference was not statistically significant (2.3%, p=0.34). Mean total alkaline phosphatase decreased by 14% from normal range at baseline (p=0.007). Urinary deoxypyridinoline levels, which were elevated at baseline (10+/-2.3 nM/mMcre), showed a nonsignificant change during treatment. Our study suggests that treatment with alendronate may have positive effects in patients with LS and low BMD on dual X-ray absorptiometry.

Feeding of predaceous fishes on out-migrating juvenile-salmonids in John Day Reservoir, Columbia River

USGS Publications Warehouse

Poe, Thomas P.; Hansel, Hal C.; Vigg, S.; Palmer, D.E.; Prendergast, L.A.

1991-01-01

Diets of northern squawfish Ptychocheilus oregonensis, smallmouth bass Micropterus dolomieu, walleye Stizostedion vitreum, and channel catfish Ictalurus punctatus from John Day Reservoir were examined to determine the extent of predation on juvenile salmonids during seaward migrations of the salmonids during April–August 1983–1986. Juvenile Pacific salmon Oncorhynchus spp. and steelhead O. mykiss were the most important food group (by weight) of northern squawfish – about 67% – but made up smaller proportions of the food of the other predators: channel catfish, 33%; walleyes, 14%; smallmouth bass, 4%. Seasonal changes in diets indicated that northern squawfish preferred juvenile salmonids in May and August (generally the peak period of salmonid out-migration), and switched to prickly sculpin Cottus asper when numbers of juvenile salmonids declined; walleyes and smallmouth bass showed a preference only for prickly sculpin among the prey fishes analyzed. As judged by dietary composition and prey selectivity, the northern squawfish was the major fish predator on juvenile salmonids in the reservoir; channel catfish also were important predators in the upper reservoir in spring. Walleyes and smallmouth bass were much less important predators on salmonids, and appeared to select subyearling chinook salmon only in August when the distribution of this prey overlapped with that of the predators. Size-selective predation by northern squawfish may also play an important role in reducing survival of the smaller individuals within each run of out-migrating juvenile salmonids.

Computed tomography of adult colonic intussusception: clinical and experimental studies

DOE Office of Scientific and Technical Information (OSTI.GOV)

Iko, B.O.; Teal, J.S.; Siram, S.M.

1984-10-01

The CT features of a case of adult ileocolic intussusception and of experimentally induced ileocolic, cecocolic, and colocolic intussusceptions are presented. Both the clinical and experimental cases demonstrated (1) target masses with enveloped, eccentrically located areas of low density and (2) interspersed low- and high-density stripes within the intussusception producing a layered or stratified pattern. This layered pattern of abdominal masses may be characteristic of intussusceptions regardless of location.

Deer presence rather than abundance determines the population density of the sheep tick, Ixodes ricinus, in Dutch forests.

PubMed

Hofmeester, Tim R; Sprong, Hein; Jansen, Patrick A; Prins, Herbert H T; van Wieren, Sipke E

2017-09-19

Understanding which factors drive population densities of disease vectors is an important step in assessing disease risk. We tested the hypothesis that the density of ticks from the Ixodes ricinus complex, which are important vectors for tick-borne diseases, is determined by the density of deer, as adults of these ticks mainly feed on deer. We performed a cross-sectional study to investigate I. ricinus density across 20 forest plots in the Netherlands that ranged widely in deer availability to ticks, and performed a deer-exclosure experiment in four pairs of 1 ha forest plots in a separate site. Ixodes ricinus from all stages were more abundant in plots with deer (n = 17) than in plots without deer (n = 3). Where deer were present, the density of ticks did not increase with the abundance of deer. Experimental exclosure of deer reduced nymph density by 66% and adult density by 32% within a timeframe of two years. In this study, deer presence rather than abundance explained the density of I. ricinus. This is in contrast to previous studies and might be related to the relatively high host-species richness in Dutch forests. This means that reduction of the risk of acquiring a tick bite would require the complete elimination of deer in species rich forests. The fact that small exclosures (< 1 ha) substantially reduced I. ricinus densities suggests that fencing can be used to reduce tick-borne disease risk in areas with high recreational pressure.

Density-dependent effects on growth, body size, and clutch size in Black Brant

USGS Publications Warehouse

Sedinger, James S.; Lindberg, Mark S.; Person, Brian T.; Eichholz, Michael W.; Herzog, Mark P.; Flint, Paul L.

1998-01-01

We documented gosling size in late summer, adult body size, and clutch size of known-age Black Brant (Branta bernicla nigricans) females nesting on the Tutakoke River colony between 1986 and 1995. During this period, the colony increased from 1,100 to >5,000 nesting pairs. Gosling mass at 30 days of age declined from 764 ± SE of 13 g and 723 ± 15 g for males and females, respectively, in the 1986 cohort, to 665 ± 18 g and 579 ± 18 g in the 1994 cohort. Gosling size was directly negatively correlated with number of Black Brant broods. We detected no trend in adult body size for individuals from these cohorts; in fact, adults from the 1992 and 1994 cohorts had the largest overall masses. Clutch size increased with age from 3.4 eggs for 2-year-old females to 4.4 eggs for 5-year-old females. Clutch size declined during the study by 0.20 (3-year-old females) to 0.45 (2-year-old females) eggs. Clutch size did not decline between the 1986 and 1990 cohorts for females that were >5 years old. Our results for clutch size and gosling size are similar to those recorded for Lesser Snow Geese (Chen caerulescens caerulescens). Our failure to detect a trend in adult body size, however, differs from the response of other geese to increasing population density. We interpret this difference in effects of density on adult size between Black Brant and other geese as an indication of stronger selection against the smallest individuals in Black Brant relative to other species of geese.

Tobacco outlet density and tobacco knowledge, beliefs, purchasing behaviours and price among adolescents in Scotland.

PubMed

Tunstall, Helena; Shortt, Niamh K; Niedzwiedz, Claire L; Richardson, Elizabeth A; Mitchell, Richard J; Pearce, Jamie R

2018-06-01

Despite long-term falls in global adult smoking prevalence and over 50 years of tobacco control policies, adolescent smoking persists. Research suggests greater densities of tobacco retail outlets in residential neighbourhoods are associated with higher adolescent smoking rates. Policies to reduce retail outlets have therefore been identified by public health researchers as a potential 'new frontier' in tobacco control. Better understanding of the pathways linking density of tobacco retailers and smoking behaviour could support these policies. In this study we use path analysis to assess how outlet density in the home environment is related to adolescent tobacco knowledge, beliefs, retail purchases and price in Scotland. We assessed 22,049 13 and 15 year old respondents to the nationally representative cross-sectional 2010 Scottish School Adolescent Lifestyle and Substance Use Survey. Outlet density was based on Scottish Tobacco Retailers Register, 2012, data. A spatially-weighted Kernel Density Estimation measure of outlet density within 400 m of respondents' home postcode was grouped into tertiles. The analysis considered whether outlet density was associated with the number of cigarette brands adolescents could name, positive beliefs about smoking, whether smokers purchased cigarettes from shops themselves or through adult proxies and perceived cost of cigarettes. Models were stratified by adolescent smoking status. The path analyses indicated that outlet density was not associated with most outcomes, but small, significant direct effects on knowledge of cigarette brands among those who had never smoked were observed. With each increase in outlet density tertile the mean number of brands adolescents could name rose by 0.07 (mean = 1.60; SD = 1.18; range = 4). This suggests greater outlet densities may have affected adolescents' knowledge of cigarette brands but did not encourage positive attitudes to smoking, purchases from shops or lower cigarette

Decreased bone mineral density in young adults treated with SCT in childhood: the role of 25-hydroxyvitamin D.

PubMed

Frisk, P; Arvidson, J; Ljunggren, O; Gustafsson, J

2012-05-01

We measured bone mineral density (BMD) with dual-energy X-ray absorptiometry in the total body, at the lumbar spine, at the femoral neck and in the total hip, in 18 young adults with a median of 18.2 years after SCT. Fifteen patients had undergone auto-SCT and all patients had received TBI. The patients had significantly lower BMD in the total body, at the femoral neck, and in the total hip compared with age- and sex-matched controls. Six of 18 patients (33%) had low bone mass (z-score <-1) at one or more measurement sites, as opposed to two of the controls (11%, P=0.29). We found no significant influence of growth hormone levels or of untreated hypogonadism on BMD variables. Levels of 25-hydroxy (25(OH)) vitamin D were lower among the patients (35.2 vs 48.8 nmol/L, P=0.044) and were significantly correlated with total body BMD in the patient group (r=0.55, P=0.021). All six patients with low bone mass had hypovitaminosis D (≤37 nmol/L as opposed to 4 of the 11 (36%) patients without low bone mass (P=0.035). In conclusion, we found decreased BMD in SCT survivors, which may in part be caused by 25(OH) vitamin D deficiency.

Effects of bioDensity Training and Power Plate Whole-Body Vibration on Strength, Balance, and Functional Independence in Older Adults.

PubMed

Smith, Derek T; Judge, Stacey; Malone, Ashley; Moynes, Rebecca C; Conviser, Jason; Skinner, James S

2016-01-01

Reduced strength, balance, and functional independence diminish quality of life and increase health care costs. Sixty adults (82.2 ± 4.9 years) were randomized to a control or three 12-week intervention groups: bioDensity (bD); Power Plate (PP) whole-body vibration (WBV); or bD+PP. bD involved one weekly 5-s maximal contraction of four muscle groups. PP involved two 5-min WBV sessions. Primary outcomes were strength, balance, and Functional Independence Measure (FIM). No groups differed initially. Strength significantly increased 22-51% for three muscle groups in bD and bD+PP (P < .001), with no changes in control and PP. Balance significantly improved in PP and bD+PP but not in control or bD. bD, PP, and bD+PP differentially improved FIM self-care and mobility. Strength improvements from weekly 5-min sessions of bD may impart health/clinical benefits. Balance and leg strength improvements suggest WBV beneficially impacts fall risk and incidence. Improved FIM scores are encouraging and justify larger controlled trials on bD and bD+PP efficacy.

Body Density Estimates from Upper-Body Skinfold Thicknesses Compared to Air-Displacement Plethysmography

USDA-ARS?s Scientific Manuscript database

Technical Summary Objectives: Determine the effect of body mass index (BMI) on the accuracy of body density (Db) estimated with skinfold thickness (SFT) measurements compared to air displacement plethysmography (ADP) in adults. Subjects/Methods: We estimated Db with SFT and ADP in 131 healthy men an...

Milk-cereal and whole-grain dietary patterns protect against low bone mineral density among male adolescents and young adults.

PubMed

Shin, S; Kim, S-H; Joung, H; Park, M J

2017-09-01

Evidence supporting the possible effect of dietary factors on adult bone health has emerged in recent decades. The purpose of this study was to ascertain the influence of different dietary patterns on bone mineral density (BMD) among Korean male youth. Data were extracted from the Korean National Health and Nutrition Examination Survey (KNHANES) during 2008-2011. The subjects included 1351 male aged 10-25 years. We defined 'low BMD group' as subjects with a BMD Z-score of -2.0 or less. Dietary patterns were derived from 20 food groups via factor analysis. Three dietary patterns-meat and vegetable, white rice and kimchi, milk-cereal and whole grain-were derived. The 'milk-cereal and whole-grain' dietary pattern score showed positive association with energy, protein, fat, calcium, phosphorus, potassium, riboflavin and vitamin C intakes. Participants in the top tertile of the milk-cereal and whole-grain pattern were less likely to have low BMD, compared with subjects in the bottom tertile (odds ratio=0.36, 95% confidence interval=0.16-0.81, P=0.018). Our findings suggest that the milk-cereal and whole-grain dietary pattern may have a benign influence on bone health in the Korean male youth.

Variation in foraging behavior and body mass in broods of Emperor Geese (Chen canagica): Evidence for interspecific density dependence

USGS Publications Warehouse

Schmutz, J.A.; Laing, K.K.

2002-01-01

Broods of geese spend time feeding according to availability and quality of food plants, subject to inherent foraging and digestive constraints. We studied behavioral patterns of broods of Emperor Geese (Chen canagica) on the Yukon–Kuskokwim Delta, Alaska, and examined how feeding and alert behavior varied in relation to habitat and goose density. During 1994–1996, time spent feeding by Emperor Goose goslings and adult females was positively related to multispecies goose densities near observation blinds, and not to just Emperor Goose density. Similarly, body mass of Emperor Goose goslings was more strongly related (negatively) to multispecies goose densities than intraspecific densities. A grazing experiment in 1995 indicated that most above ground primary production by Carex subspathacea, a preferred food plant, was consumed by grazing geese. Those results demonstrate that interspecific competition for food occurred, with greatest support for goslings whose behavioral repertoire is limited primarily to feeding, digesting, and resting. Although the more abundant Cackling Canada Geese (Branta canadensis minima) differed from Emperor Geese in their preferred use of habitats during brooding rearing (Schmutz 2001), the two species occurred in equal abundance in habitats preferred by Emperor Goose broods. Thus, Cackling Canada Geese were a numerically significant competitor with Emperor Geese. Comparing these results to an earlier study, time spent feeding by goslings, adult females, and adult males were greater during 1993–1996 than during 1985–1986. During the interval between those studies, densities of Cackling Canada Geese increased two to three times whereas Emperor Goose numbers remained approximately stable, which implies that interspecific competition affected foraging behavior over a long time period. These density-dependent changes in foraging behavior and body mass indicate that interspecific competition affects nutrient acquisition and gosling

An example of fisheries oceanography: Walleye pollock in Alaskan waters

NASA Astrophysics Data System (ADS)

Schumacher, Jim; Kendall, Arthur W.

1995-07-01

A major area of research in fisheries oceanography examines relationships between recruitment dynamics of fish populations and the marine environment. A primary goal is to understand the natural causes of variability in year-class strength of commercially valuable species and apply this knowledge to management [Perry, 1994]. The paradigm that the majority of mortality occurs during transport of early life history stages from spawning to nursery grounds [Rothschild, 1986; Houde, 1987] provides an initial temporal focus for most research. The spatial domain includes the region occupied by early life history stages. Since global climate variability impacts regional ecosystem dynamics, however, the spatial domain often must be expanded. The relative importance and manifestation of biological factors [starvation and predation] that limit survival varies each year. Marked interannual and longer period variations in temperature (an influence on metabolic rates and behavior), transport of planktonic stages, and turbulence can exert an influence on both survival of early life history stages, and distribution of juveniles and adults. To understand how these environmental factors influence reproductive success of fish stocks also requires knowledge of the impact of these factors on predators and prey throughout the food web.

First records of a European cladoceran, Bythotrephes cederstroemi, in Lakes Erie and Huron

USGS Publications Warehouse

Bur, Michael T.; Klarer, David M.; Krieger, Kenneth A.

1986-01-01

Adult forms of the cladoceran Bythotrephes cederstroemi Schoedler (Cercopagidae), a widespread European freshwater zooplankter, occurred in the stomachs of four common species of Lake Erie fish (yellow perch, Perca flavescens; white perch, Morone americana; white bass, M. chrysops; and walleye, Stizostedion vitreum vitreum) collected in early October 1985. The fish were collected at several stations in the nearshore open waters of the central basin between Ashtabula and Huron, Ohio. Other investigators have seen this species in other locations in Lake Erie and also in Lake Huron. The report of B. cederstroemi in Lake Huron in December 1984 appears to be the first record of this species in North America.

Survival of cool and warm freshwater fish following chloramine-T exposure

USGS Publications Warehouse

Gaikowski, M.P.; Larson, W.J.; Gingerich, W.H.

2008-01-01

Chloramine-T is presently available in the USA to control mortalities associated with bacterial gill disease or external columnaris only through an Investigational New Animal Drug Permit authorized by the US Food and Drug Administration (FDA). Its US approval hinges on FDA's acceptance of several key data, including those describing animal safety. Chloramine-T is presently applied in US aquaculture, by permit only, once daily on consecutive or alternate days for 1??h at 10 to 20??mg/L to control mortalities associated with bacterial gill disease or external columnaris. Our objective was to determine the safety of chloramine-T bath exposures at multiples of the proposed maximum treatment concentration (i.e., 0, 20, 60, 100, and 200??mg/L) administered on four consecutive days at 20????C to lake sturgeon Acipenser fulvescens, northern pike Esox lucius, and walleye Sander vitreum, or at 27????C to channel catfish Ictalurus punctatus, and largemouth bass Micropterus salmoides. All fish were tested as five to eight week old fry except for walleye and channel catfish which were tested as both fry and fingerling (fingerlings were at least four weeks older than the fry tested). Walleye and channel catfish were selected to evaluate the effects of life stage (fry vs. fingerling), temperature (walleye - 15, 20, or 25????C; channel catfish - 22, 27, or 32????C), exposure duration (60 vs. 180??min), and water chemistry (walleye only - reconstituted soft water vs. well water). Except for channel catfish fry, survival was significantly reduced only when fish were treated at 100 or 200??mg/L. Channel catfish fry survival was significantly reduced when exposed at 60??mg/L for 180??min at 27????C. Based on our mortality data, chloramine-T administered once daily for 60??min on four consecutive days at concentrations of up to 20??mg/L is not likely to adversely affect survival of cool or warmwater fish cultured in freshwater. Crown Copyright ?? 2007.

Obesity and the built environment: does the density of neighborhood fast-food outlets matter?

PubMed

Li, Fuzhong; Harmer, Peter; Cardinal, Bradley J; Bosworth, Mark; Johnson-Shelton, Deb

2009-01-01

Examine variation in obesity among older adults relative to the joint influences of density of neighborhood fast food outlets and residents' behavioral, psychosocial, and sociodemographic characteristics. Cross-sectional and multilevel design. Census block groups, used as a proxy for neighborhoods, within the metropolitan region's Urban Growth Boundary in Portland, Oregon. A total of 1221 residents (mean age, 65 years) recruited randomly from 120 neighborhoods (48% response rate). A geographic information system-based measure of fast food restaurant density across 120 neighborhoods was created. Residents within the sampled neighborhoods were assessed with respect to their body mass indices (BMI), frequency of visits to local fast food restaurants, fried food consumption, levels of physical activity, self-efficacy of eating fruits and vegetables, household income, and race/ethnicity. Multilevel logistic regression analyses. Significant associations were found between resident-level individual characteristics and the likelihood of being obese (BMI > or = 30) for neighborhoods with a high-density of fast food restaurants in comparison with those with a low density: odds ratios for obesity, 95% confidence intervals (CI), were 1.878 (CI, 1.006-3.496) for weekly visits to local fast food restaurants; 1.792 (CI, 1.006-3.190) for not meeting physical activity recommendations; 1.212 (CI, 1.057-1.391) for low confidence in eating healthy food; and 8.057 (CI, 1.705-38.086) for non-Hispanic black residents. Increased density of neighborhood fast food outlets was associated with unhealthy lifestyles, poorer psychosocial profiles, and increased risk of obesity among older adults.

Availability of Recreational Resources and Physical Activity in Adults

PubMed Central

Roux, Ana V. Diez; Evenson, Kelly R.; McGinn, Aileen P.; Brown, Daniel G.; Moore, Latetia; Brines, Shannon; Jacobs, David R.

2007-01-01

Objectives. Using data from a large cohort of adults aged 45 to 84 years-old, we investigated whether availability of recreational resources is related to physical activity levels. Methods. Data from a multiethnic sample of 2723 adult residents of New York City, NY; Baltimore, Md; and Forsyth County, NC, were linked to data on locations of recreational resources. We measured the availability (density) of resources within 0.5 (0.8 km), 1, 2, and 5 miles of each participant’s residence and used binomial regression to investigate associations of density with physical activity. Results. After adjustment for potential confounders, individuals in the tertile of participants residing in areas with the highest density of resources were more likely to report physical activity during a typical week than were individuals in the lowest tertile. Associations between availability of recreational resources and physical activity levels were not present for the smallest area assessed (0.5 miles) but were present for areas ranging from 1 to 5 miles. These associations were slightly stronger among minority and low-income residents. Conclusions. Availability of resources may be 1 of several environmental factors that influence individuals’ physical activity behaviors. PMID:17267710

Bones of contention: bone mineral density recovery in celiac disease--a systematic review.

PubMed

Grace-Farfaglia, Patricia

2015-05-07

Metabolic bone disease is a frequent co-morbidity in newly diagnosed adults with celiac disease (CD), an autoimmune disorder triggered by the ingestion of dietary gluten. This systematic review of studies looked at the efficacy of the gluten-free diet, physical activity, nutrient supplementation, and bisphosphonates for low bone density treatment. Case control and cohort designs were identified from PubMed and other academic databases (from 1996 to 2015) that observed newly diagnosed adults with CD for at least one year after diet treatment using the dual-energy x-ray absorptiometry (DXA) scan. Only 20 out of 207 studies met the inclusion criteria. Methodological quality was assessed using the Strengthening of the Reporting of Observational Studies in Epidemiology (STROBE) statement checklist. Gluten-free diet adherence resulted in partial recovery of bone density by one year in all studies, and full recovery by the fifth year. No treatment differences were observed between the gluten-free diet alone and diet plus bisphosphonates in one study. For malnourished patients, supplementation with vitamin D and calcium resulted in significant improvement. Evidence for the impact of physical activity on bone density was limited. Therapeutic strategies aimed at modifying lifestyle factors throughout the lifespan should be studied.

A common factor suppresses thickening in young women with malar area port wine stains and delays low density lipoprotein elevation: is it estrogen?

PubMed

Klapman, M H; Sosa, V B; Yao, J F

2014-06-01

Port wine stains in the malar area of the face can develop thickening in early adult life. We began a study with a hypothesis that this thickening can be associated with elevation of low density lipoprotein. In a retrospective review, we divided 53 subjects with malar port wine stains into 4 groups, adults 25-39 years of age with thickening, that age group without thickening, adults 40+ years of age with thickening, and that age group without thickening. Low density lipoprotein levels in the subjects were compared to age and sex matched controls randomly selected from the general Dermatology clinic. The younger subjects with thickening demonstrated significantly higher low density lipoprotein levels than their controls (p .0082) and without thickening lower low density lipoprotein levels than their controls with great significance (p .00058). The subjects without thickening also consisted mainly of women. The low density lipoprotein levels in the older age groups, whether thickened or not, demonstrated no significant difference in low density lipoprotein levels between subjects and controls. This led to a new hypothesis that there is a factor in a subgroup of young adult women with malar port wine stains that suppresses thickening and delays the elevation of low density lipoprotein and that this factor might be estrogen. The implications of this hypothesis are that it could define a marker for a subset of the population that might be protected from the diseases associated with early elevation of low density lipoprotein and provide a source of cutaneous tissue for studying the basic science of this protection (although limited by cosmetic considerations). Future laboratory research to test the new hypothesis might include testing blood of women with malar port wine stains with or without thickening for estrogen and other sex hormones. It might also include skin biopsies to study receptors for estrogen, other sex hormones, and angiogenic factors in malar port wine

The infant mirror neuron system studied with high density EEG.

PubMed

Nyström, Pär

2008-01-01

The mirror neuron system has been suggested to play a role in many social capabilities such as action understanding, imitation, language and empathy. These are all capabilities that develop during infancy and childhood, but the human mirror neuron system has been poorly studied using neurophysiological measures. This study measured the brain activity of 6-month-old infants and adults using a high-density EEG net with the aim of identifying mirror neuron activity. The subjects viewed both goal-directed movements and non-goal-directed movements. An independent component analysis was used to extract the sources of cognitive processes. The desynchronization of the mu rhythm in adults has been shown to be a marker for activation of the mirror neuron system and was used as a criterion to categorize independent components between subjects. The results showed significant mu desynchronization in the adult group and significantly higher ERP activation in both adults and 6-month-olds for the goal-directed action observation condition. This study demonstrate that infants as young as 6 months display mirror neuron activity and is the first to present a direct ERP measure of the mirror neuron system in infants.

Density of Indoor Tanning Facilities in 116 Large U.S. Cities

PubMed Central

Hoerster, Katherine D.; Garrow, Rebecca L.; Mayer, Joni A.; Clapp, Elizabeth J.; Weeks, John R.; Woodruff, Susan I.; Sallis, James F.; Slymen, Donald J.; Patel, Minal R.; Sybert, Stephanie A.

2009-01-01

Background U.S. adolescents and young adults are using indoor tanning at high rates, even though it has been linked to both melanoma and squamous cell cancer. Because the availability of commercial indoor tanning facilities may influence use, data are needed on the number and density of such facilities. Methods In March 2006, commercial indoor tanning facilities in 116 large U.S. cities were identified, and the number and density (per 100,000 population) were computed for each city. Bivariate and multivariate analyses conducted in 2008 tested the association between tanning-facility density and selected geographic, climatologic, demographic, and legislative variables. Results Mean facility number and density across cities were 41.8 (SD=30.8) and 11.8 (SD=6.0), respectively. In multivariate analysis, cities with higher percentages of whites and lower ultraviolet (UV)index scores had significantly higher facility densities than those with lower percentages of whites and higher UV index scores. Conclusions These data indicate that commercial indoor tanning is widely available in the urban U.S., and this availability may help explain the high usage of indoor tanning. PMID:19215849

Demographic response of black bears at Cold Lake, Alberta, to the removal of adult males

USGS Publications Warehouse

Sargeant, Glen A.; Ruff, Robert L.

2001-01-01

Previous reports described an increase in population density following the removal of 23 adult male black bears (Ursus americanus) from a 218-km2 study area near Cold Lake, Alberta (the CLSA). This finding plays a central role in continuing debates over population regulation in bears, but has recently been criticized because density estimates were based on assumptions that were not met. Moreover, subsequent discussion has been predicated on conjecture that human exploitation had minimal influence on population dynamics. Our reanalysis supports previous descriptions of trends in bear density at Cold Lake. However, survival records revealed heavier exploitation than previously suspected. An underlying assumption of previous interpretationsCthat the Cold Lake bear population was naturally regulated near carrying capacityCno longer seems reasonable. Adult males deterred bears in other sex-age groups from using the CLSA; however, we found no evidence that birth or death rates were affected. The observed increase in local density should not be construed as a density-dependent response. Abrupt changes in local density might not have occurred if males had been removed from a larger area encompassing the CLSA.

The influence of density on adults and juveniles of the estuarine fish, the sheepshead minnow (cyprinodon variegatus)

EPA Science Inventory

The relationship between population density and demographic rates (e.g. survival, reproduction, growth) is critical to understand population dynamics and has been widely studied in fishes. Estuarine species are regularly exposed to dramatic changes in density with daily, monthly,...

Avocado consumption increases macular pigment density in older adults: a randomized, controlled trial

USDA-ARS?s Scientific Manuscript database

Lutein is selectively incorporated into the macula and brain. Lutein levels in the macula (macular pigment; MP) and the brain are related to better cognition. MP density (MPD) is a biomarker of brain lutein. Avocados are a bioavailable source of lutein. This study tests the effects of the intake of ...

Abundance of adult saugers across the Wind River watershed, Wyoming

USGS Publications Warehouse

Amadio, C.J.; Hubert, W.A.; Johnson, K.; Oberlie, D.; Dufek, D.

2006-01-01

The abundance of adult saugers Sander canadensis was estimated over 179 km of continuous lotic habitat across a watershed on the western periphery of their natural distribution in Wyoming. Three-pass depletions with raft-mounted electrofishing gear were conducted in 283 pools and runs among 19 representative reaches totaling 51 km during the late summer and fall of 2002. From 2 to 239 saugers were estimated to occur among the 19 reaches of 1.6-3.8 km in length. The estimates were extrapolated to a total population estimate (mean ?? 95% confidence interval) of 4,115 ?? 308 adult saugers over 179 km of lotie habitat. Substantial variation in mean density (range = 1.0-32.5 fish/ha) and mean biomass (range = 0.5-16.8 kg/ha) of adult saugers in pools and runs was observed among the study reaches. Mean density and biomass were highest in river reaches with pools and runs that had maximum depths of more than 1 m, mean daily summer water temperatures exceeding 20??C, and alkalinity exceeding 130 mg/L. No saugers were captured in the 39 pools or runs with maximum water depths of 0.6 m or less. Multiple-regression analysis and the information-theoretic approach were used to identify watershed-scale and instream habitat features accounting for the variation in biomass among the 244 pools and runs across the watershed with maximum depths greater than 0.6 m. Sauger biomass was greater in pools than in runs and increased as mean daily summer water temperature, maximum depth, and mean summer alkalinity increased and as dominant substrate size decreased. This study provides an estimate of adult sauger abundance and identifies habitat features associated with variation in their density and biomass across a watershed, factors important to the management of both populations and habitat. ?? Copyright by the American Fisheries Society 2006.

Energy density of lake whitefish Coregonus clupeaformis in Lakes Huron and Michigan

USGS Publications Warehouse

Pothoven, S.A.; Nalepa, T.F.; Madenjian, C.P.; Rediske, R.R.; Schneeberger, P.J.; He, J.X.

2006-01-01

We collected lake whitefish Coregonus clupeaformis off Alpena and Tawas City, Michigan, USA in Lake Huron and off Muskegon, Michigan USA in Lake Michigan during 2002–2004. We determined energy density and percent dry weight for lake whitefish from both lakes and lipid content for Lake Michigan fish. Energy density increased with increasing fish weight up to 800 g, and then remained relatively constant with further increases in fish weight. Energy density, adjusted for weight, was lower in Lake Huron than in Lake Michigan for both small (≤800 g) and large fish (>800 g). Energy density did not differ seasonally for small or large lake whitefish or between adult male and female fish. Energy density was strongly correlated with percent dry weight and percent lipid content. Based on data from commercially caught lake whitefish, body condition was lower in Lake Huron than Lake Michigan during 1981–2003, indicating that the dissimilarity in body condition between the lakes could be long standing. Energy density and lipid content in 2002–2004 in Lake Michigan were lower than data for comparable sized fish collected in 1969–1971. Differences in energy density between lakes were attributed to variation in diet and prey energy content as well as factors that affect feeding rates such as lake whitefish density and prey abundance.

An evaluation of density-dependent and density-independent influences on population growth rates in Weddell seals

USGS Publications Warehouse

Rotella, J.J.; Link, W.A.; Nichols, J.D.; Hadley, G.L.; Garrott, R.A.; Proffitt, K.M.

2009-01-01

Much of the existing literature that evaluates the roles of density-dependent and density-independent factors on population dynamics has been called into question in recent years because measurement errors were not properly dealt with in analyses. Using state-space models to account for measurement errors, we evaluated a set of competing models for a 22-year time series of mark-resight estimates of abundance for a breeding population of female Weddell seals (Leptonychotes weddellii) studied in Erebus Bay, Antarctica. We tested for evidence of direct density dependence in growth rates and evaluated whether equilibrium population size was related to seasonal sea-ice extent and the Southern Oscillation Index (SOI). We found strong evidence of negative density dependence in annual growth rates for a population whose estimated size ranged from 438 to 623 females during the study. Based on Bayes factors, a density-dependence-only model was favored over models that also included en! vironmental covariates. According to the favored model, the population had a stationary distribution with a mean of 497 females (SD = 60.5), an expected growth rate of 1.10 (95% credible interval 1.08-1.15) when population size was 441 females, and a rate of 0.90 (95% credible interval 0.87-0.93) for a population of 553 females. A model including effects of SOI did receive some support and indicated a positive relationship between SOI and population size. However, effects of SOI were not large, and including the effect did not greatly reduce our estimate of process variation. We speculate that direct density dependence occurred because rates of adult survival, breeding, and temporary emigration were affected by limitations on per capita food resources and space for parturition and pup-rearing. To improve understanding of the relative roles of various demographic components and their associated vital rates to population growth rate, mark-recapture methods can be applied that incorporate both

A geostatistical state-space model of animal densities for stream networks.

PubMed

Hocking, Daniel J; Thorson, James T; O'Neil, Kyle; Letcher, Benjamin H

2018-06-21

Population dynamics are often correlated in space and time due to correlations in environmental drivers as well as synchrony induced by individual dispersal. Many statistical analyses of populations ignore potential autocorrelations and assume that survey methods (distance and time between samples) eliminate these correlations, allowing samples to be treated independently. If these assumptions are incorrect, results and therefore inference may be biased and uncertainty under-estimated. We developed a novel statistical method to account for spatio-temporal correlations within dendritic stream networks, while accounting for imperfect detection in the surveys. Through simulations, we found this model decreased predictive error relative to standard statistical methods when data were spatially correlated based on stream distance and performed similarly when data were not correlated. We found that increasing the number of years surveyed substantially improved the model accuracy when estimating spatial and temporal correlation coefficients, especially from 10 to 15 years. Increasing the number of survey sites within the network improved the performance of the non-spatial model but only marginally improved the density estimates in the spatio-temporal model. We applied this model to Brook Trout data from the West Susquehanna Watershed in Pennsylvania collected over 34 years from 1981 - 2014. We found the model including temporal and spatio-temporal autocorrelation best described young-of-the-year (YOY) and adult density patterns. YOY densities were positively related to forest cover and negatively related to spring temperatures with low temporal autocorrelation and moderately-high spatio-temporal correlation. Adult densities were less strongly affected by climatic conditions and less temporally variable than YOY but with similar spatio-temporal correlation and higher temporal autocorrelation. This article is protected by copyright. All rights reserved. This article is

Sibling cannibalism in a web-building spider: effects of density and shared environment.

PubMed

Modanu, Maria; Li, Lucy Dong Xuan; Said, Hosay; Rathitharan, Nizanthan; Andrade, Maydianne C B

2014-07-01

Sibling cannibalism occurs across diverse taxa and can affect population size and structure, as well as the fitness of parents and the cannibal, via density effects and variation in individual propensity to cannibalize. We examined these effects on sibling cannibalism in juveniles of a web-building spider (Latrodectus hasselti, Australian redbacks). Adult redbacks are solitary, but juveniles live in clusters of variable density for a week after hatching. We confined newly hatched siblings from a singly-mated female to a low or high density treatment in a split-clutch design, then left spiderlings unfed for a week. Our results showed no effect of density on overall cannibalism levels, but a strong correlation between cannibalism counts from the same maternal lines across densities. Unlike web-bound sit-and-wait predators, wandering spiders that are active hunters have been shown to experience density-dependent cannibalism. In contrast, we suggest sibling cannibalism in web-building spiders may be density independent because early cohabitation on the web selects for elevated tolerance of conspecifics. We conclude that, rather than being linked to density, cannibalism of siblings in these species may be controlled more strongly by variation in individual propensity to cannibalize. Copyright © 2014 Elsevier B.V. All rights reserved.

Before-after, control-impact analysis of evidence for the impacts of water level on Walleye, Northern Pike and Yellow Perch in lakes of the Rainy-Namakan complex (MN, USA and ON, CA).

PubMed

Larson, James H; Maki, Ryan P; Vondra, Benjamin A; Peterson, Kevin E

2018-01-01

Water level (WL) fluctuations in lakes influence many aspects of ecosystem processes. Concern about the potential impact of WL fluctuations on fisheries was one of the factors that motivated the decision in 2000 to alter the management of WL in the Rainy-Namakan reservoir complex (on the border between the U.S. state of Minnesota and the Canadian province of Ontario). We used a Before-After, Control-Impact (BACI) framework to identify potential impacts of the change in WL management to Walleye, Northern Pike and Yellow Perch catch per unit effort (CPUE). The CPUE of these species from 1990-1999 and from 2005-2014 were compared in four impact lakes (Lake Kabetogama, Namakan Lake, Rainy Lake and Sand Point Lake) and two control lakes (Lake of the Woods and Lake Vermilion) using a simple Bayesian model. Changes in fish CPUE in the impact lakes were often similar to changes that occurred in at least one control lake. The only change that was not similar to changes in control lakes was an increase of Yellow Perch in Lake Kabetogama. The two control lakes often differed substantially from each other, such that if only one had been available our conclusions about the role of WL management on fisheries would be very different. In general, identifying cause-and-effect relationships in observational field data is very difficult, and the BACI analysis used here does not specify a causative mechanism, so co-occurring environmental and management changes may obscure the effect of WL management.

Pre-sarcopenia and bone mineral density in adults submitted to hematopoietic stem cell transplantation.

PubMed

Pereira, Cristiane Pavan; Amaral, Denise Johnsson Campos; Funke, Vaneuza Araujo Moreira; Borba, Victória Zeghbi Cochenski

The aim of this study was to evaluate the prevalence of pre-sarcopenia and bone mineral density after hematopoietic stem cell transplantation. The study group consisted of over 18-year-old patients who had been submitted to allogeneic transplantation at least one year previously. Patients and healthy controls were matched by sex, ethnic background, age, and body mass index. Body composition and bone mineral density were measured by dual-energy X-ray absorptiometry. A 24-h food recall and food frequency survey were performed. The biochemical evaluation included calcium, parathormone and vitamin D. Eighty-seven patients (52 men; age: 37.2±12.7 years; body mass index: 25±4.5kg/m 2 ) were compared to 68 controls [31 men; age 35.4±15.5 years (p=0.467); body mass index 25.05±3.7kg/m 2 (p=0.927)]. There was no significant difference in the dietary intake between patients and controls. The mean levels of vitamin D were 23.5±10.3ng/mL; 29 patients (41.0%) had insufficient and 26 (37.14%) deficient levels. A higher prevalence of reduced bone mineral density was observed in 24 patients (25%) compared to 12 controls (19.1% - p<0.001). Pre-sarcopenia was diagnosed in 14 (14.4%) patients and none of the controls (p=0.05). There was a higher prevalence of pre-sarcopenia (66%) in patients with grades III and IV compared to those with grades 0-II graft-versus-host disease (10.9%) (p=0.004). patients submitted to transplantation had a higher prevalence of pre-sarcopenia and greater changes in bone mineral density compared to controls; the severity of graft-versus-host disease had an impact on the prevalence of pre-sarcopenia. Copyright © 2017 Associação Brasileira de Hematologia, Hemoterapia e Terapia Celular. Published by Elsevier Editora Ltda. All rights reserved.

Egg deposition by lithophilic-spawning fishes in the Detroit and Saint Clair Rivers, 2005–14

USGS Publications Warehouse

Prichard, Carson G.; Craig, Jaquelyn M.; Roseman, Edward F.; Fischer, Jason L.; Manny, Bruce A.; Kennedy, Gregory W.

2017-03-14

A long-term, multiseason, fish egg sampling program conducted annually on the Detroit (2005–14) and Saint Clair (2010–14) Rivers was summarized to identify where productive fish spawning habitat currently exists. Egg mats were placed on the river bottom during the spring and fall at historic spawning areas and candidate fish spawning habitat restoration sites throughout both rivers. Widespread evidence was found of lithophilic spawning by numerous native fish species, including walleye (Sander vitreus), lake whitefish (Coregonus clupeaformis), lake sturgeon (Acipenser fulvescens), suckers (Catostomidae spp.), and trout-perch (Percopsis omiscomaycus). Walleye, lake whitefish, and suckers spp. spawned in nearly every region of each river in all years on both reef and nonreef substrates. Lake sturgeon eggs were collected almost exclusively over constructed reefs. Catch-per-unit effort of walleye, lake whitefish, and sucker eggs was much greater in the Detroit River than in the Saint Clair River, while Saint Clair River sites supported the greatest collections of lake sturgeon eggs. Collections during this study of lake sturgeon eggs on man-made spawning reefs suggest that artificial reefs may be an effective tool for restoring fish populations in the Detroit and Saint Clair Rivers; however, the quick response of lake sturgeon to spawn on newly constructed reefs and the fact that walleye, lake whitefish, and sucker eggs were often collected over substrate with little interstitial space to protect eggs from siltation and predators suggests that lack of suitable spawning habitat may continue to limit reproduction of lithophilic-spawning fish species in the Saint Clair-Detroit River System.

Design of smart home sensor visualizations for older adults.

PubMed

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-01-01

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date. Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

Design of smart home sensor visualizations for older adults.

PubMed

Le, Thai; Reeder, Blaine; Chung, Jane; Thompson, Hilaire; Demiris, George

2014-07-24

Smart home sensor systems provide a valuable opportunity to continuously and unobtrusively monitor older adult wellness. However, the density of sensor data can be challenging to visualize, especially for an older adult consumer with distinct user needs. We describe the design of sensor visualizations informed by interviews with older adults. The goal of the visualizations is to present sensor activity data to an older adult consumer audience that supports both longitudinal detection of trends and on-demand display of activity details for any chosen day. The design process is grounded through participatory design with older adult interviews during a six-month pilot sensor study. Through a secondary analysis of interviews, we identified the visualization needs of older adults. We incorporated these needs with cognitive perceptual visualization guidelines and the emotional design principles of Norman to develop sensor visualizations. We present a design of sensor visualization that integrate both temporal and spatial components of information. The visualization supports longitudinal detection of trends while allowing the viewer to view activity within a specific date.CONCLUSIONS: Appropriately designed visualizations for older adults not only provide insight into health and wellness, but also are a valuable resource to promote engagement within care.

Flow management and fish density regulate salmonid recruitment and adult size in tailwaters across western North America

USGS Publications Warehouse

Dibble, Kimberly L.; Yackulic, Charles B.; Kennedy, Theodore A.; Budy, Phaedra E.

2015-01-01

The mean lengths of adult rainbow and brown trout were influenced by similar flow and catch metrics. Length in both species was positively correlated with high annual flow but declined in tailwaters with high daily fluctuations in flow, high catch rates of conspecifics, and when large cohorts recruited to adult size. Whereas brown trout did not respond to the proportion of water allocated between seasons, rainbow trout length increased in rivers that released more water during winter than in spring. Rainbow trout length was primarily related to high catch rates of conspecifics, whereas brown trout length was mainly related to large cohorts recruiting to the adult size class. Species-specific responses to flow management are likely attributable to differences in seasonal timing of key life history events such as spawning, egg hatching, and fry emergence.

Age, gender, and race/ethnic differences in total body and subregional bone density1

PubMed Central

Looker, Anne C; Melton, L. Joseph; Harris, Tamara; Borrud, Lori; Shepherd, John; McGowan, Joan

2011-01-01

Introduction Total body dual-energy x-ray absorptiometry (DXA) data offer the opportunity to compare bone density of demographic groups across the entire skeleton. Methods The present study uses total body DXA data (Hologic QDR 4500A, Hologic Inc, Bedford MA) from the National Health and Nutrition Examination Survey (NHANES) 1999–2004 to examine bone mineral density (BMD) of the total body and selected skeletal subregions in a wide age range of adult men and women from three race/ethnic groups. Total body, lumbar spine, pelvis, right leg, and left arm BMD and lean mass from 13,091 adults age 20 years and older were used. The subregions were chosen to represent sites with different degrees of weight bearing. Results Mean BMD varied in expected ways for some demographic characteristics (men>women and non-Hispanic blacks>non-Hispanic whites) but not others (non-Hispanic whites>Mexican Americans). Differences in age patterns in BMD also emerged for some characteristics (sex) but not others (race/ethnicity). Differences in cross-sectional age patterns in BMD and lean mass by degree of weight-bearing in older adults were observed for the pelvis, leg and arm. Conclusion This information may be useful for generating hypotheses about age, race, and sex differences in fracture risk in the population. PMID:19048179

Calculation of induced current densities for humans by magnetic fields from electronic article surveillance devices

NASA Astrophysics Data System (ADS)

Gandhi, Om P.; Kang, Gang

2001-11-01

This paper illustrates the use of the impedance method to calculate the electric fields and current densities induced in millimetre resolution anatomic models of the human body, namely an adult and 10- and 5-year-old children, for exposure to nonuniform magnetic fields typical of two assumed but representative electronic article surveillance (EAS) devices at 1 and 30 kHz, respectively. The devices assumed for the calculations are a solenoid type magnetic deactivator used at store checkouts and a pass-by panel-type EAS system consisting of two overlapping rectangular current-carrying coils used at entry and exit from a store. The impedance method code is modified to obtain induced current densities averaged over a cross section of 1 cm2 perpendicular to the direction of induced currents. This is done to compare the peak current densities with the limits or the basic restrictions given in the ICNIRP safety guidelines. Because of the stronger magnetic fields at lower heights for both the assumed devices, the peak 1 cm2 area-averaged current densities for the CNS tissues such as the brain and the spinal cord are increasingly larger for smaller models and are the highest for the model of the 5-year-old child. For both the EAS devices, the maximum 1 cm2 area-averaged current densities for the brain of the model of the adult are lower than the ICNIRP safety guideline, but may approach or exceed the ICNIRP basic restrictions for models of 10- and 5-year-old children if sufficiently strong magnetic fields are used.

Calculation of induced current densities for humans by magnetic fields from electronic article surveillance devices.

PubMed

Gandhi, O P; Kang, G

2001-11-01

This paper illustrates the use of the impedance method to calculate the electric fields and current densities induced in millimetre resolution anatomic models of the human body, namely an adult and 10- and 5-year-old children, for exposure to nonuniform magnetic fields typical of two assumed but representative electronic article surveillance (EAS) devices at 1 and 30 kHz, respectively. The devices assumed for the calculations are a solenoid type magnetic deactivator used at store checkouts and a pass-by panel-type EAS system consisting of two overlapping rectangular current-carrying coils used at entry and exit from a store. The impedance method code is modified to obtain induced current densities averaged over a cross section of 1 cm2 perpendicular to the direction of induced currents. This is done to compare the peak current densities with the limits or the basic restrictions given in the ICNIRP safety guidelines. Because of the stronger magnetic fields at lower heights for both the assumed devices, the peak 1 cm2 area-averaged current densities for the CNS tissues such as the brain and the spinal cord are increasingly larger for smaller models and are the highest for the model of the 5-year-old child. For both the EAS devices, the maximum 1 cm2 area-averaged current densities for the brain of the model of the adult are lower than the ICNIRP safety guideline, but may approach or exceed the ICNIRP basic restrictions for models of 10- and 5-year-old children if sufficiently strong magnetic fields are used.

Anomalous evolution of Ar metastable density with electron density in high density Ar discharge

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Min; Chang, Hong-Young; You, Shin-Jae

2011-10-15

Recently, an anomalous evolution of argon metastable density with plasma discharge power (electron density) was reported [A. M. Daltrini, S. A. Moshkalev, T. J. Morgan, R. B. Piejak, and W. G. Graham, Appl. Phys. Lett. 92, 061504 (2008)]. Although the importance of the metastable atom and its density has been reported in a lot of literature, however, a basic physics behind the anomalous evolution of metastable density has not been clearly understood yet. In this study, we investigated a simple global model to elucidate the underlying physics of the anomalous evolution of argon metastable density with the electron density. Onmore » the basis of the proposed simple model, we reproduced the anomalous evolution of the metastable density and disclosed the detailed physics for the anomalous result. Drastic changes of dominant mechanisms for the population and depopulation processes of Ar metastable atoms with electron density, which take place even in relatively low electron density regime, is the clue to understand the result.« less

Obesity and the Built Environment: Does the Density of Neighborhood Fast-Food Outlets Matter?

PubMed Central

Li, Fuzhong; Harmer, Peter; Cardinal, Bradley J.; Bosworth, Mark; Johnson-Shelton, Deb

2009-01-01

Purpose To examine variation in obesity among older adults relative to the joint influences of density of neighborhood fast-food outlets and residents' behavioral, psychosocial, and sociodemographic characteristics. Design Cross-sectional and multilevel design. Setting Census block groups, used as a proxy for neighborhoods, within the metropolitan region's Urban Growth Boundary in Portland, Oregon. Subjects A total of 1,221 residents (mean age=65 years old) recruited randomly from 120 neighborhoods (48% response rate). Measures A Geographic Information System-based measure of fast-food restaurant density across 120 neighborhoods was created. Residents within the sampled neighborhoods were assessed with respect to their body mass index (BMI), frequency of visits to local fast-food restaurants, fried food consumption, levels of physical activity, self-efficacy of eating fruits and vegetables, household income, and race/ethnicity. Analyses Multilevel logistic regression analyses. Results Significant associations were found between resident-level individual characteristics and the likelihood of being obese (BMI≥30) for neighborhoods with a high-density of fast-food restaurants in comparison to those with a low density: odds ratios [OR] for obesity, 95% confidence interval [CI] were: 1.878 (CI=1.006-3.496) for weekly visits to local fast-food restaurants; 1.792 (CI=1.006-3.190) for not meeting physical activity recommendations; 1.212 (CI=1.057-1.391) for low confidence in eating healthy food; and 8.057 (CI=1.705-38.086) for non-Hispanic black residents. Conclusion Increased density of neighborhood fast-food outlets was associated with unhealthy lifestyles, poorer psychosocial profiles, and increased risk of obesity among older adults. PMID:19149426

Lexical restructuring in the absence of literacy.

PubMed

Venturaa, Paulo; Kolinsky, Régine; Fernandesa, Sandra; Queridoa, Luís; Morais, José

2007-11-01

Vocabulary growth was suggested to prompt the implementation of increasingly finer-grained lexical representations of spoken words in children (e.g., [Metsala, J. L., & Walley, A. C. (1998). Spoken vocabulary growth and the segmental restructuring of lexical representations: precursors to phonemic awareness and early reading ability. In J. L. Metsala & L. C. Ehri (Eds.), Word recognition in beginning literacy (pp. 89-120). Hillsdale, NJ: Erlbaum.]). Although literacy was not explicitly mentioned in this lexical restructuring hypothesis, the process of learning to read and spell might also have a significant impact on the specification of lexical representations (e.g., [Carroll, J. M., & Snowling, M. J. (2001). The effects of global similarity between stimuli on children's judgments of rime and alliteration. Applied Psycholinguistics, 22, 327-342.]; [Goswami, U. (2000). Phonological representations, reading development and dyslexia: Towards a cross-linguistic theoretical framework. Dyslexia, 6, 133-151.]). This is what we checked in the present study. We manipulated word frequency and neighborhood density in a gating task (Experiment 1) and a word-identification-in-noise task (Experiment 2) presented to Portuguese literate and illiterate adults. Ex-illiterates were also tested in Experiment 2 in order to disentangle the effects of vocabulary size and literacy. There was an interaction between word frequency and neighborhood density, which was similar in the three groups. These did not differ even for the words that are supposed to undergo lexical restructuring the latest (low frequency words from sparse neighborhoods). Thus, segmental lexical representations seem to develop independently of literacy. While segmental restructuring is not affected by literacy, it constrains the development of phoneme awareness as shown by the fact that, in Experiment 3, neighborhood density modulated the phoneme deletion performance of both illiterates and ex-illiterates.

Triglyceride to high density lipoprotein cholesterol ratio and its association with periodontal disease in Korean adults: findings based on the 2012-2014 Korean national health and nutrition examination survey.

PubMed

Kwon, Yu-Jin; Park, Jeong-Won; Lim, Hyoung-Ji; Lee, Yong-Jae; Lee, Hye-Sun; Shim, Jae-Yong

2018-01-01

The aim of this study is to evaluate whether the triglyceride to high-density lipoprotein cholesterol (TG/HDL-C) ratio is associated with periodontal disease in Korean adults. This cross-sectional study included 12,249 individuals (4,941 men and 7,308 women) who took part in the 2012-2014 Korean National Health and Nutrition Examination Survey. We categorized the TG/HDL-C ratio into three groups. Periodontal disease was defined as a community pocket index score ≥3 with at least one affected site. Multiple logistic analyses were used to analyze the association between TG/HDL-C ratio and periodontal disease. In the study population, prevalence of periodontal disease was 31.6% in men and 21% in women. Compared to the lowest tertile group, OR (95% CI) of the highest tertile group for periodontal disease was 1.474 (1.220-1.780) in men and 1.259 (1.041-1.522) in women after adjusting for age, waist circumference, systolic blood pressure, fasting glucose, current smoking, alcohol drinking, physical activity, household income, oral health behavior, and use of anti-dyslipidemia medication. Our study suggests that the TG/HDL-C ratio is associated with periodontal disease in Korean adults. TG/HDL-C ratio is a simple and useful marker to reflect insulin resistance. And periodontal disease is also known to be related with insulin resistance. This study indicates that TG/HDL-C ratio was associated with periodontal disease in Korean adults.

Developmental Patterns of Doublecortin Expression and White Matter Neuron Density in the Postnatal Primate Prefrontal Cortex and Schizophrenia

PubMed Central

Fung, Samantha J.; Joshi, Dipesh; Allen, Katherine M.; Sivagnanasundaram, Sinthuja; Rothmond, Debora A.; Saunders, Richard; Noble, Pamela L.; Webster, Maree J.; Shannon Weickert, Cynthia

2011-01-01

Postnatal neurogenesis occurs in the subventricular zone and dentate gyrus, and evidence suggests that new neurons may be present in additional regions of the mature primate brain, including the prefrontal cortex (PFC). Addition of new neurons to the PFC implies local generation of neurons or migration from areas such as the subventricular zone. We examined the putative contribution of new, migrating neurons to postnatal cortical development by determining the density of neurons in white matter subjacent to the cortex and measuring expression of doublecortin (DCX), a microtubule-associated protein involved in neuronal migration, in humans and rhesus macaques. We found a striking decline in DCX expression (human and macaque) and density of white matter neurons (humans) during infancy, consistent with the arrival of new neurons in the early postnatal cortex. Considering the expansion of the brain during this time, the decline in white matter neuron density does not necessarily indicate reduced total numbers of white matter neurons in early postnatal life. Furthermore, numerous cells in the white matter and deep grey matter were positive for the migration-associated glycoprotein polysialiated-neuronal cell adhesion molecule and GAD65/67, suggesting that immature migrating neurons in the adult may be GABAergic. We also examined DCX mRNA in the PFC of adult schizophrenia patients (n = 37) and matched controls (n = 37) and did not find any difference in DCX mRNA expression. However, we report a negative correlation between DCX mRNA expression and white matter neuron density in adult schizophrenia patients, in contrast to a positive correlation in human development where DCX mRNA and white matter neuron density are higher earlier in life. Accumulation of neurons in the white matter in schizophrenia would be congruent with a negative correlation between DCX mRNA and white matter neuron density and support the hypothesis of a migration deficit in schizophrenia. PMID

Exploring the perceptual spaces of faces, cars and birds in children and adults

PubMed Central

Tanaka, James W.; Meixner, Tamara L.; Kantner, Justin

2011-01-01

While much developmental research has focused on the strategies that children employ to recognize faces, less is known about the principles governing the organization of face exemplars in perceptual memory. In this study, we tested a novel, child-friendly paradigm for investigating the organization of face, bird and car exemplars. Children ages 3–4, 5–6, 7–8, 9–10, 11–12 and adults were presented with 50/50 morphs of typical and atypical face, bird and car parent images. Participants were asked to judge whether the 50/50 morph more strongly resembled the typical or the atypical parent image. Young and older children and adults showed a systematic bias to the atypical faces and birds, but no bias toward the atypical cars. Collectively, these findings argue that by the age of 3, children encode and organize faces, birds and cars in a perceptual space that is strikingly similar to that of adults. Category organization for both children and adults follows Krumhansl’s (1978) distance-density principle in which the similarity between two exemplars is jointly determined by their physical appearance and the density of neighboring exemplars in the perceptual space. PMID:21676096

Banks Lake Fishery Evaluation Project Annual Report : Fiscal Year 2008 (March 1, 2008 to February 1, 2009).

DOE Office of Scientific and Technical Information (OSTI.GOV)

Polacek, Matt

2009-07-15

The Washington Department of Fish and Wildlife implemented the Banks Lake Fishery Evaluation Project (BLFEP) in September 2001 with funds from the Bonneville Power Administration, and continued project tasks in 2008. The objective was to evaluate factors that could limit kokanee in Banks Lake, including water quality, prey availability, harvest, and acute predation during hatchery releases. Water quality parameters were collected twice monthly from March through November. Banks Lake water temperatures began to increase in May and stratification was apparent by July. By late August, the thermocline had dropped to 15 meters deep, with temperatures of 21-23 C in themore » epilimnion and 16-19 C in the hypolimnion. Dissolved oxygen levels were generally above 8 mg/L until August when they dropped near or below 5 mg/L deeper than 20-meters. Secchi depths ranged from 3.2 to 6.2 meters and varied spatially and temporally. Daphnia and copepod densities were the highest in May and June, reaching densities of 26 copepods/liter and 9 Daphnia/liter. Fish surveys were conducted in July and October 2008 using boat electrofishing, gill netting, and hydroacoustic surveys. Lake whitefish (71%) and yellow perch (16%) dominated the limnetic fish assemblage in the summer, while lake whitefish (46%) and walleye (22%) were the most abundant in gill net catch during the fall survey. Piscivore diets switched from crayfish prior to the release of rainbow trout to crayfish and rainbow trout following the release. The highest angling pressure occurred in May, when anglers were primarily targeting walleye and smallmouth bass. Boat anglers utilized Steamboat State Park more frequently than any other boat ramp on Banks Lake. Shore anglers used the rock jetty at Coulee City Park 45% of the time, with highest use occurring from November through April. Ice fishing occurred in January and February at the south end of the lake. An estimated total of 4,397 smallmouth bass, 11,106 walleye, 371

Development of binomial sequential sampling plans for forecasting Listronotus maculicollis (Coleoptera: Curculionidae) larvae based on the relationship to adult counts and turfgrass damage.

PubMed

McGraw, Benjamin A; Koppenhöfer, Albrecht M

2009-06-01

Binomial sequential sampling plans were developed to forecast weevil Listronotus maculicollis Kirby (Coleoptera: Curculionidae), larval damage to golf course turfgrass and aid in the development of integrated pest management programs for the weevil. Populations of emerging overwintered adults were sampled over a 2-yr period to determine the relationship between adult counts, larval density, and turfgrass damage. Larval density and composition of preferred host plants (Poa annua L.) significantly affected the expression of turfgrass damage. Multiple regression indicates that damage may occur in moderately mixed P. annua stands with as few as 10 larvae per 0.09 m2. However, > 150 larvae were required before damage became apparent in pure Agrostis stolonifera L. plots. Adult counts during peaks in emergence as well as cumulative counts across the emergence period were significantly correlated to future densities of larvae. Eight binomial sequential sampling plans based on two tally thresholds for classifying infestation (T = 1 and two adults) and four adult density thresholds (0.5, 0.85, 1.15, and 1.35 per 3.34 m2) were developed to forecast the likelihood of turfgrass damage by using adult counts during peak emergence. Resampling for validation of sample plans software was used to validate sampling plans with field-collected data sets. All sampling plans were found to deliver accurate classifications (correct decisions were made between 84.4 and 96.8%) in a practical timeframe (average sampling cost < 22.7 min).

The epidemiology of malaria in adults in a rural area of southern Mozambique.

PubMed

Mayor, Alfredo; Aponte, John J; Fogg, Carole; Saúte, Francisco; Greenwood, Brian; Dgedge, Martinho; Menendez, Clara; Alonso, Pedro L

2007-01-17

Epidemiological studies of malaria in adults who live in malaria endemic areas are scarce. More attention to the natural history of malaria affecting adults is needed to understand the dynamics of malaria infection and its interaction with the immune system. The present study was undertaken to investigate the clinical, parasitological and haematological status of adults exposed to malaria, and to characterize parasites in these individuals who progressively acquire protective immunity. A cross-sectional survey of 249 adults was conducted in a malaria endemic area of Mozambique. Clinical, parasitological and haematological status of the study population was recorded. Sub-microscopic infections and multiplicity of infections were investigated using polymerase chain reaction (PCR) and restriction fragment length polymorphism of Plasmodium falciparum merozoite surface protein 2 (msp2). Prevalence of P. falciparum infection by microscopy (14%) and PCR (42%) decreased progressively during adulthood, in parallel with an increase in the prevalence of sub-microscopic infections. Anaemia was only related to parasitaemia as detected by PCR. Multiplicity of infection decreased with age and was higher in subjects with high P. falciparum densities, highlighting density-dependent constraints upon the PCR technique. Adults of Manhiça progressively develop non-sterile, protective immunity against P. falciparum malaria. The method of parasite detection has a significant effect on the observed natural history of malaria infections. A more sensitive definition of malaria in adults should be formulated, considering symptoms such as diarrhoea, shivering and headache, combined with the presence of parasitaemia.

The topology of the Coulomb potential density. A comparison with the electron density, the virial energy density, and the Ehrenfest force density.

PubMed

Ferreira, Lizé-Mari; Eaby, Alan; Dillen, Jan

2017-12-15

The topology of the Coulomb potential density has been studied within the context of the theory of Atoms in Molecules and has been compared with the topologies of the electron density, the virial energy density and the Ehrenfest force density. The Coulomb potential density is found to be mainly structurally homeomorphic with the electron density. The Coulomb potential density reproduces the non-nuclear attractor which is observed experimentally in the molecular graph of the electron density of a Mg dimer, thus, for the first time ever providing an alternative and energetic foundation for the existence of this critical point. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Gedanken densities and exact constraints in density functional theory.

PubMed

Perdew, John P; Ruzsinszky, Adrienn; Sun, Jianwei; Burke, Kieron

2014-05-14

Approximations to the exact density functional for the exchange-correlation energy of a many-electron ground state can be constructed by satisfying constraints that are universal, i.e., valid for all electron densities. Gedanken densities are designed for the purpose of this construction, but need not be realistic. The uniform electron gas is an old gedanken density. Here, we propose a spherical two-electron gedanken density in which the dimensionless density gradient can be an arbitrary positive constant wherever the density is non-zero. The Lieb-Oxford lower bound on the exchange energy can be satisfied within a generalized gradient approximation (GGA) by bounding its enhancement factor or simplest GGA exchange-energy density. This enhancement-factor bound is well known to be sufficient, but our gedanken density shows that it is also necessary. The conventional exact exchange-energy density satisfies no such local bound, but energy densities are not unique, and the simplest GGA exchange-energy density is not an approximation to it. We further derive a strongly and optimally tightened bound on the exchange enhancement factor of a two-electron density, which is satisfied by the local density approximation but is violated by all published GGA's or meta-GGA's. Finally, some consequences of the non-uniform density-scaling behavior for the asymptotics of the exchange enhancement factor of a GGA or meta-GGA are given.

Effective size of density-dependent two-sex populations: the effect of mating systems.

PubMed

Myhre, A M; Engen, S; SAEther, B-E

2017-08-01

Density dependence in vital rates is a key feature affecting temporal fluctuations of natural populations. This has important implications for the rate of random genetic drift. Mating systems also greatly affect effective population sizes, but knowledge of how mating system and density regulation interact to affect random genetic drift is poor. Using theoretical models and simulations, we compare N e in short-lived, density-dependent animal populations with different mating systems. We study the impact of a fluctuating, density-dependent sex ratio and consider both a stable and a fluctuating environment. We find a negative relationship between annual N e /N and adult population size N due to density dependence, suggesting that loss of genetic variation is reduced at small densities. The magnitude of this decrease was affected by mating system and life history. A male-biased, density-dependent sex ratio reduces the rate of genetic drift compared to an equal, density-independent sex ratio, but a stochastic change towards male bias reduces the N e /N ratio. Environmental stochasticity amplifies temporal fluctuations in population size and is thus vital to consider in estimation of effective population sizes over longer time periods. Our results on the reduced loss of genetic variation at small densities, particularly in polygamous populations, indicate that density regulation may facilitate adaptive evolution at small population sizes. © 2017 European Society For Evolutionary Biology. Journal of Evolutionary Biology © 2017 European Society For Evolutionary Biology.

Spatial variation in density and size structure indicate habitat selection throughout life stages of two Southwestern Atlantic snappers.

PubMed

Aschenbrenner, Alexandre; Hackradt, Carlos Werner; Ferreira, Beatrice Padovani

2016-02-01

The early life history of Lutjanus alexandrei and Lutjanus jocu in Southwestern Atlantic is still largely unknown. Habitat use of different life stages (i.e. size categories and densities) of the Brazilian snapper (L. alexandrei) and dog snapper (L. jocu) was examined in a tropical portion of NE coast of Brazil. Visual surveys were conducted in different shallow habitats (mangroves and reefs). Both snapper species showed higher densities in early life stages in mangrove habitat, with a clear increase in fish size from mangrove to adjacent reefs. Post-settler individuals were exclusively found in mangroves for both species. Juveniles of L. alexandrei were also registered only in mangroves, while sub-adult individuals were associated with both mangrove and reef habitats. Mature individuals of L. alexandrei were only observed in reef habitats. Juvenile and sub-adult individuals of the dog snapper were both associated with mangrove and reef habitats, with high densities registered in mangroves. Mature individuals of L. jocu were not registered in the study area. This pattern suggests preference for mangrove habitat in early life stages for both species. Ontogenetic movement between habitats was also recorded. This pattern denotes habitat selection across different life cycle of both species. Such information highlights the importance of directing management and conservation efforts to these habitats to secure the continuity of contribution to adult populations. Copyright © 2015 Elsevier Ltd. All rights reserved.

Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforests.

PubMed

Duminil, J; Daïnou, K; Kaviriri, D K; Gillet, P; Loo, J; Doucet, J-L; Hardy, O J

2016-03-01

Owing to the reduction of population density and/or the environmental changes it induces, selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression. Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging. Here, we analysed patterns of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha). The comparison of inbreeding levels among cohorts suggests that selfing is detrimental as inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (∼16%) and patterns of spatial genetic structure (Sp ∼0.006) were similar in all three populations. However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). Overall, our results suggest that the reproductive biology and genetic diversity of the species are not affected by current logging practices. However, further investigations need to be conducted in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species.

Relationships between population density, fine-scale genetic structure, mating system and pollen dispersal in a timber tree from African rainforests

PubMed Central

Duminil, J; Daïnou, K; Kaviriri, D K; Gillet, P; Loo, J; Doucet, J-L; Hardy, O J

2016-01-01

Owing to the reduction of population density and/or the environmental changes it induces, selective logging could affect the demography, reproductive biology and evolutionary potential of forest trees. This is particularly relevant in tropical forests where natural population densities can be low and isolated trees may be subject to outcross pollen limitation and/or produce low-quality selfed seeds that exhibit inbreeding depression. Comparing reproductive biology processes and genetic diversity of populations at different densities can provide indirect evidence of the potential impacts of logging. Here, we analysed patterns of genetic diversity, mating system and gene flow in three Central African populations of the self-compatible legume timber species Erythrophleum suaveolens with contrasting densities (0.11, 0.68 and 1.72 adults per ha). The comparison of inbreeding levels among cohorts suggests that selfing is detrimental as inbred individuals are eliminated between seedling and adult stages. Levels of genetic diversity, selfing rates (∼16%) and patterns of spatial genetic structure (Sp ∼0.006) were similar in all three populations. However, the extent of gene dispersal differed markedly among populations: the average distance of pollen dispersal increased with decreasing density (from 200 m in the high-density population to 1000 m in the low-density one). Overall, our results suggest that the reproductive biology and genetic diversity of the species are not affected by current logging practices. However, further investigations need to be conducted in low-density populations to evaluate (1) whether pollen limitation may reduce seed production and (2) the regeneration potential of the species. PMID:26696137

Does food vendor density mediate the association between neighborhood deprivation and BMI?: a G-computation mediation analysis.

PubMed

Zhang, Y Tara; Laraia, Barbara A; Mujahid, Mahasin S; Tamayo, Aracely; Blanchard, Samuel D; Warton, E Margaret; Kelly, N Maggi; Moffet, Howard H; Schillinger, Dean; Adler, Nancy; Karter, Andrew J

2015-05-01

In previous research, neighborhood deprivation was positively associated with body mass index (BMI) among adults with diabetes. We assessed whether the association between neighborhood deprivation and BMI is attributable, in part, to geographic variation in the availability of healthful and unhealthful food vendors. Subjects were 16,634 participants of the Diabetes Study of Northern California, a multiethnic cohort of adults living with diabetes. Neighborhood deprivation and healthful (supermarket and produce) and unhealthful (fast food outlets and convenience stores) food vendor kernel density were calculated at each participant's residential block centroid. We estimated the total effect, controlled direct effect, natural direct effect, and natural indirect effect of neighborhood deprivation on BMI. Mediation effects were estimated using G-computation, a maximum likelihood substitution estimator of the G-formula that allows for complex data relations such as multiple mediators and sequential causal pathways. We estimated that if neighborhood deprivation was reduced from the most deprived to the least deprived quartile, average BMI would change by -0.73 units (95% confidence interval: -1.05, -0.32); however, we did not detect evidence of mediation by food vendor density. In contrast to previous findings, a simulated reduction in neighborhood deprivation from the most deprived to the least deprived quartile was associated with dramatic declines in both healthful and unhealthful food vendor density. Availability of food vendors, both healthful and unhealthful, did not appear to explain the association between neighborhood deprivation and BMI in this population of adults with diabetes.

Microglial K+ Channel Expression in Young Adult and Aged Mice

PubMed Central

Schilling, Tom; Eder, Claudia

2015-01-01

The K+ channel expression pattern of microglia strongly depends on the cells' microenvironment and has been recognized as a sensitive marker of the cells' functional state. While numerous studies have been performed on microglia in vitro, our knowledge about microglial K+ channels and their regulation in vivo is limited. Here, we have investigated K+ currents of microglia in striatum, neocortex and entorhinal cortex of young adult and aged mice. Although almost all microglial cells exhibited inward rectifier K+ currents upon membrane hyperpolarization, their mean current density was significantly enhanced in aged mice compared with that determined in young adult mice. Some microglial cells additionally exhibited outward rectifier K+ currents in response to depolarizing voltage pulses. In aged mice, microglial outward rectifier K+ current density was significantly larger than in young adult mice due to the increased number of aged microglial cells expressing these channels. Aged dystrophic microglia exhibited outward rectifier K+ currents more frequently than aged ramified microglia. The majority of microglial cells expressed functional BK-type, but not IK- or SK-type, Ca2+-activated K+ channels, while no differences were found in their expression levels between microglia of young adult and aged mice. Neither microglial K+ channel pattern nor K+ channel expression levels differed markedly between the three brain regions investigated. It is concluded that age-related changes in microglial phenotype are accompanied by changes in the expression of microglial voltage-activated, but not Ca2+-activated, K+ channels. PMID:25472417

Adult vector control, mosquito ecology and malaria transmission

PubMed Central

Brady, Oliver J.; Godfray, H. Charles J.; Tatem, Andrew J.; Gething, Peter W.; Cohen, Justin M.; McKenzie, F. Ellis; Alex Perkins, T.; Reiner, Robert C.; Tusting, Lucy S.; Scott, Thomas W.; Lindsay, Steven W.; Hay, Simon I.; Smith, David L.

2015-01-01

Background Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of ‘vectorial capacity’, a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model. Methods In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity. Results We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density. Conclusions These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission. PMID:25733562

Adult vector control, mosquito ecology and malaria transmission.

PubMed

Brady, Oliver J; Godfray, H Charles J; Tatem, Andrew J; Gething, Peter W; Cohen, Justin M; McKenzie, F Ellis; Alex Perkins, T; Reiner, Robert C; Tusting, Lucy S; Scott, Thomas W; Lindsay, Steven W; Hay, Simon I; Smith, David L

2015-03-01

Standard advice regarding vector control is to prefer interventions that reduce the lifespan of adult mosquitoes. The basis for this advice is a decades-old sensitivity analysis of 'vectorial capacity', a concept relevant for most malaria transmission models and based solely on adult mosquito population dynamics. Recent advances in micro-simulation models offer an opportunity to expand the theory of vectorial capacity to include both adult and juvenile mosquito stages in the model. In this study we revisit arguments about transmission and its sensitivity to mosquito bionomic parameters using an elasticity analysis of developed formulations of vectorial capacity. We show that reducing adult survival has effects on both adult and juvenile population size, which are significant for transmission and not accounted for in traditional formulations of vectorial capacity. The elasticity of these effects is dependent on various mosquito population parameters, which we explore. Overall, control is most sensitive to methods that affect adult mosquito mortality rates, followed by blood feeding frequency, human blood feeding habit, and lastly, to adult mosquito population density. These results emphasise more strongly than ever the sensitivity of transmission to adult mosquito mortality, but also suggest the high potential of combinations of interventions including larval source management. This must be done with caution, however, as policy requires a more careful consideration of costs, operational difficulties and policy goals in relation to baseline transmission. © The Author 2015. Published by Oxford University Press on behalf of Royal Society of Tropical Medicine and Hygiene.

Evaluating the power to detect temporal trends in fishery independent surveys: A case study based on Gillnets Set in the Ohio waters of Lake Erie for walleye

USGS Publications Warehouse

Wagner, Tyler; Vandergoot, Christopher S.; Tyson, Jeff

2009-01-01

Fishery-independent (FI) surveys provide critical information used for the sustainable management and conservation of fish populations. Because fisheries management often requires the effects of management actions to be evaluated and detected within a relatively short time frame, it is important that research be directed toward FI survey evaluation, especially with respect to the ability to detect temporal trends. Using annual FI gill-net survey data for Lake Erie walleyes Sander vitreus collected from 1978 to 2006 as a case study, our goals were to (1) highlight the usefulness of hierarchical models for estimating spatial and temporal sources of variation in catch per effort (CPE); (2) demonstrate how the resulting variance estimates can be used to examine the statistical power to detect temporal trends in CPE in relation to sample size, duration of sampling, and decisions regarding what data are most appropriate for analysis; and (3) discuss recommendations for evaluating FI surveys and analyzing the resulting data to support fisheries management. This case study illustrated that the statistical power to detect temporal trends was low over relatively short sampling periods (e.g., 5–10 years) unless the annual decline in CPE reached 10–20%. For example, if 50 sites were sampled each year, a 10% annual decline in CPE would not be detected with more than 0.80 power until 15 years of sampling, and a 5% annual decline would not be detected with more than 0.8 power for approximately 22 years. Because the evaluation of FI surveys is essential for ensuring that trends in fish populations can be detected over management-relevant time periods, we suggest using a meta-analysis–type approach across systems to quantify sources of spatial and temporal variation. This approach can be used to evaluate and identify sampling designs that increase the ability of managers to make inferences about trends in fish stocks.

Is density of neighbourhood restaurants associated with BMI in rural Chinese adults? A longitudinal study from the China Health and Nutrition Survey.

PubMed

Du, Wenwen; Su, Chang; Wang, Huijun; Wang, Zhihong; Wang, Youfa; Zhang, Bing

2014-04-22

The neighbourhood availability of restaurants has been linked to the weight status. However, little is known regarding the relation between access to restaurant and obesity among the Chinese population. This study aims to explore the relationship between neighbourhood restaurant density and body mass index (BMI) in rural China. A longitudinal study using data from the China Health and Nutrition Survey (CHNS) was conducted. Participants aged 18 and older from the 2004, 2006, 2009 and 2011 CHNS were recruited Separate sex-stratified random intercept-slope growth models of repeated BMI observations were estimated in the study. The data were derived from rural communities in nine provinces in China. There were 11 835 male and 12 561 female person-years assessed in this study. The primary outcome of this study was weight status. It is defined as a BMI value, a continuous variable which is calculated by dividing weight (kg) by the square of height (m(2)). The study indicated that among men an increase of one indoor restaurant in the neighbourhood was associated with a 0.01 kg/m(2) increase in BMI, and an increase of one fixed outdoor food stall was associated with a 0.01 kg/m(2) decrease in BMI, whereas among women, an increase of one indoor restaurant in the neighbourhood was associated with a 0.005 kg/m(2) increase in BMI, and an increase of one fast-food restaurant and one fixed outdoor food stall was associated with a 0.02 and 0.004 kg/m(2) decline in BMI, respectively. The density of neighbourhood restaurants was found to be significantly related to BMI in rural China. The results indicated that providing healthy food choices and developing related public health policies are necessary to tackle obesity among rural Chinese adults.

Is density of neighbourhood restaurants associated with BMI in rural Chinese adults? A longitudinal study from the China Health and Nutrition Survey

PubMed Central

Du, Wenwen; Su, Chang; Wang, Huijun; Wang, Zhihong; Wang, Youfa; Zhang, Bing

2014-01-01

Objectives The neighbourhood availability of restaurants has been linked to the weight status. However, little is known regarding the relation between access to restaurant and obesity among the Chinese population. This study aims to explore the relationship between neighbourhood restaurant density and body mass index (BMI) in rural China. Design A longitudinal study using data from the China Health and Nutrition Survey (CHNS) was conducted. Participants aged 18 and older from the 2004, 2006, 2009 and 2011 CHNS were recruited Separate sex-stratified random intercept-slope growth models of repeated BMI observations were estimated in the study. Setting The data were derived from rural communities in nine provinces in China. Participants There were 11 835 male and 12 561 female person-years assessed in this study. Outcomes The primary outcome of this study was weight status. It is defined as a BMI value, a continuous variable which is calculated by dividing weight (kg) by the square of height (m2). Results The study indicated that among men an increase of one indoor restaurant in the neighbourhood was associated with a 0.01 kg/m2 increase in BMI, and an increase of one fixed outdoor food stall was associated with a 0.01 kg/m2 decrease in BMI, whereas among women, an increase of one indoor restaurant in the neighbourhood was associated with a 0.005 kg/m2 increase in BMI, and an increase of one fast-food restaurant and one fixed outdoor food stall was associated with a 0.02 and 0.004 kg/m2 decline in BMI, respectively. Conclusions The density of neighbourhood restaurants was found to be significantly related to BMI in rural China. The results indicated that providing healthy food choices and developing related public health policies are necessary to tackle obesity among rural Chinese adults. PMID:24755211

Neighborhood alcohol outlet density and genetic influences on alcohol use: evidence for gene-environment interaction.

PubMed

Slutske, Wendy S; Deutsch, Arielle R; Piasecki, Thomas M

2018-05-07

Genetic influences on alcohol involvement are likely to vary as a function of the 'alcohol environment,' given that exposure to alcohol is a necessary precondition for genetic risk to be expressed. However, few gene-environment interaction studies of alcohol involvement have focused on characteristics of the community-level alcohol environment. The goal of this study was to examine whether living in a community with more alcohol outlets would facilitate the expression of the genetic propensity to drink in a genetically-informed national survey of United States young adults. The participants were 2434 18-26-year-old twin, full-, and half-sibling pairs from Wave III of the National Longitudinal Study of Adolescent to Adult Health. Participants completed in-home interviews in which alcohol use was assessed. Alcohol outlet densities were extracted from state-level liquor license databases aggregated at the census tract level to derive the density of outlets. There was evidence that the estimates of genetic and environmental influences on alcohol use varied as a function of the density of alcohol outlets in the community. For example, the heritability of the frequency of alcohol use for those residing in a neighborhood with ten or more outlets was 74% (95% confidence limits = 55-94%), compared with 16% (95% confidence limits = 0-34%) for those in a neighborhood with zero outlets. This moderating effect of alcohol outlet density was not explained by the state of residence, population density, or neighborhood sociodemographic characteristics. The results suggest that living in a neighborhood with many alcohol outlets may be especially high-risk for those individuals who are genetically predisposed to frequently drink.

The relationship between adenovirus-36 seropositivity, obesity and metabolic profile in Turkish children and adults.

PubMed

Karamese, M; Altoparlak, U; Turgut, A; Aydogdu, S; Karamese, S Aksak

2015-12-01

Obesity potentially arising from viral infection is known as 'infectobesity'. The latest reports suggest that adenovirus-36 (Adv36) is related to obesity in adults and children. Our aim was not only to determine the Adv36 seropositivity in both obese and non-obese children and adults, but also to investigate correlations between antibody positivity and serum lipid profiles. Both Adv36 positivity and tumour-necrosis-factor-alpha, leptin and interleukin-6 levels were detected in blood samples collected from 146 children and 130 adults by ELISA. Fasting plasma triglycerides, total cholesterol and low-density lipoprotein levels were also measured. Adv36 positivity was determined to be 27·1% and 6% in obese and non-obese children and 17·5% and 4% in obese and non-obese adults, respectively. There was no difference with regard to total cholesterol, low-density lipoprotein, triglyceride, tumour-necrosis-factor-alpha and interleukin-6 levels (P > 0·05). However, there was a significant difference between groups in terms of leptin levels (P < 0·05). We determined the prevalence of Adv36 positivity in obese children and adults. Our results showed that Adv36 may be an obesity agent for both adults and children, parallel with current literature data. However, the available data on a possible relationship between Adv36 infection and obesity both in children and adults do not completely solve the problem.

Neighborhood built environment and cognition in non-demented older adults: The Multi-Ethnic Study of Atherosclerosis.

PubMed

Besser, Lilah M; Rodriguez, Daniel A; McDonald, Noreen; Kukull, Walter A; Fitzpatrick, Annette L; Rapp, Stephen R; Seeman, Teresa

2018-03-01

Preliminary studies suggest that neighborhood social and built environment (BE) characteristics may affect cognition in older adults. Older adults are particularly vulnerable to the neighborhood environment due to a decreasing range of routine travel with increasing age. We examined if multiple neighborhood BE characteristics are cross-sectionally associated with cognition in a diverse sample of older adults, and if the BE-cognition associations vary by individual-level demographics. The sample included 4539 participants from the Multi-Ethnic Study of Atherosclerosis. Multivariable linear regression was used to examine the associations between five BE measures and four cognitive measures, and effect modification by individual-level education and race/ethnicity. In the overall sample, increasing social destination density, walking destination density, and intersection density were associated with worse overall cognition, whereas increasing proportion of land dedicated to retail was associated with better processing speed. Effect modification results suggest that the association between urban density and worse cognition may be limited to or strongest in those of non-white race/ethnicity. Although an increase in neighborhood retail destinations was associated with better cognition in the overall sample, these results suggest that certain BE characteristics in dense urban environments may have a disproportionately negative association with cognition in vulnerable populations. However, our findings must be replicated in longitudinal studies and other regional samples. Copyright © 2018 Elsevier Ltd. All rights reserved.

Increases in bone density during treatment of men with idiopathic hypogonadotropic hypogonadism

DOE Office of Scientific and Technical Information (OSTI.GOV)

Finkelstein, J.S.; Klibanski, A.; Neer, R.M.

To assess the effects of gonadal steroid replacement on bone density in men with osteoporosis due to severe hypogonadism, we measured cortical bone density in the distal radius by 125I photon absorptiometry and trabecular bone density in the lumbar spine by quantitative computed tomography in 21 men with isolated GnRH deficiency while serum testosterone levels were maintained in the normal adult male range for 12-31 months (mean +/- SE, 23.7 +/- 1.1). In men who initially had fused epiphyses (n = 15), cortical bone density increased from 0.71 +/- 0.02 to 0.74 +/- 0.01 g/cm2 (P less than 0.01), whilemore » trabecular bone density did not change (116 +/- 9 compared with 119 +/- 7 mg/cm3). In men who initially had open epiphyses (n = 6), cortical bone density increased from 0.62 +/- 0.01 to 0.70 +/- 0.03 g/cm2 (P less than 0.01), while trabecular bone density increased from 96 +/- 13 to 109 +/- 12 mg/cm3 (P less than 0.01). Cortical bone density increased 0.03 +/- 0.01 g/cm2 in men with fused epiphyses and 0.08 +/- 0.02 g/cm2 in men with open epiphyses (P less than 0.05). Despite these increases, neither cortical nor trabecular bone density returned to normal levels. Histomorphometric analyses of iliac crest bone biopsies demonstrated that most of the men had low turnover osteoporosis, although some men had normal to high turnover osteoporosis. We conclude that bone density increases during gonadal steroid replacement of GnRH-deficient men, particularly in men who are skeletally immature.« less

The effect of retained intramedullary nails on tibial bone mineral density.

PubMed

Allen, J C; Lindsey, R W; Hipp, J A; Gugala, Z; Rianon, N; LeBlanc, A

2008-07-01

Intramedullary nailing has become a standard treatment for adult tibial shaft fractures. Retained intramedullary nails have been associated with stress shielding, although their long-term effect on decreasing tibial bone mineral density is currently unclear. The purpose of this study was to determine if retained tibial intramedullary nails decrease tibial mineral density in patients with successfully treated fractures. Patients treated with statically locked intramedullary nails for isolated, unilateral tibia shaft fractures were studied. Inclusion required that fracture had healed radiographically and that the patient returned to the pre-injury activity level. Data on patient demographic, fracture type, surgical technique, implant, and post-operative functional status were tabulated. Dual energy X-ray absorptiometry was used to measure bone mineral density in selected regions of the affected tibia and the contralateral intact tibia. Image reconstruction software was employed to ensure symmetry of the studied regions. Twenty patients (mean age 43; range 22-77 years) were studied at a mean of 29 months (range 5-60 months) following intramedullary nailing. There was statistically significant reduction of mean bone mineral density in tibiae with retained intramedullary nails (1.02 g/cm(2) versus 1.06 g/cm(2); P=0.04). A significantly greater decrease in bone mineral density was detected in the reamed versus non-reamed tibiae (-7% versus +6%, respectively; P<0.05). The present study demonstrates a small, but statistically significant overall bone mineral density decrease in healed tibiae with retained nails. Intramedullary reaming appears to be a factor potentiating the reduction of tibia bone mineral density in long-term nail retention.

Increased density and periosteal expansion of the tibia in young adult men following short-term arduous training.

PubMed

Izard, Rachel M; Fraser, William D; Negus, Charles; Sale, Craig; Greeves, Julie P

2016-07-01

Few human studies have reported early structural adaptations of bone to weight-bearing exercise, which provide a greater contribution to improved bone strength than increased density. This prospective study examined site- and regional-specific adaptations of the tibia during arduous training in a cohort of male military (infantry) recruits to better understand how bone responds in vivo to mechanical loading. Tibial bone density and geometry were measured in 90 British Army male recruits (ages 21±3years, height: 1.78±0.06m, body mass: 73.9±9.8kg) in weeks 1 (Baseline) and 10 of initial military training. Scans were performed at the 4%, 14%, 38% and 66% sites, measured from the distal end plate, using pQCT (XCT2000L, Stratec Pforzheim, Germany). Customised software (BAMPack, L-3 ATI) was used to examine whole bone cross-section and regional sectors. T-tests determined significant differences between time points (P<0.05). Bone density of trabecular and cortical compartments increased significantly at all measured sites. Bone geometry (cortical area and thickness) and bone strength (i, MMi and BSI) at the diaphyseal sites (38 and 66%) were also significantly higher in week 10. Regional changes in density and geometry were largely observed in the anterior, medial-anterior and anterior-posterior sectors. Calf muscle density and area (66% site) increased significantly at week 10 (P<0.01). In vivo mechanical loading improves bone strength of the human tibia by increased density and periosteal expansion, which varies by site and region of the bone. These changes may occur in response to the nature and distribution of forces originating from bending, torsional and shear stresses of military training. These improvements are observed early in training when the osteogenic stimulus is sufficient, which may be close to the fracture threshold in some individuals. Crown Copyright © 2016. Published by Elsevier Inc. All rights reserved.

Fish community dynamics in northeastern Lake Ontario with emphasis on the growth and reproductive success of yellow perch (Perca flavescens) and white perch (Morone americana), 1978 to1997

USGS Publications Warehouse

O'Gorman, Robert; Burnett, John A.D.

2001-01-01

Fishes were assessed in Guffin, Chaumount, and Black River bays in northeastern Lake Ontario with a 7.9-m (headrope) bottom trawl during late September and early October, 1978 to 1997. Fish density declined in the early 1990s with sharp declines in abundance of spottail shiner (Notropis hudsonius), trout-perch (Percopsis omiscomaycus), and johnny darter (Etheostoma nigrum) occurring in 1993 to 1995. Rising numbers of piscivores, walleye (Stizostedion vitreum) and double-crested cormorant (Phalacrocorax auritus), increased predation pressure, presumably acting in concert with oligotrophication to lower fish density, particularly after 1991 when large numbers of adult alewife (Alosa pseudoharengus) no longer migrated to the northeast basin in spring. Annual mortality of yellow perch (Perca flavescens) from age 2 to 5 rose from 33% in 1980–83 to 65% in 1992–95 and was positively related to piscivore numbers (P = 0.01, r = 0.96, n = 5). Annual mortality of yellow perch from age 0 to 2 also peaked in 1992–95. Abundance of yellow perch YOY in fall varied 40 fold and was not related to water warming in spring (P = 0.45, r = −0.19, n = 18) but was negatively related to the abundance of adult alewives in spring (P = 0.04, r = −0.49, n = 18). Although yellow perch produced moderate to strong year classes each year during 1991–95, stock size failed to increase because of rapidly accelerating mortality. Fully 85% of the variation in mean length of yellow perch YOY was explained by a multiple regression model which included YOY abundance, mean total phosphorus, and cumulative degree days > 13.5°C (P < 0.01, n = 15). Abundance of white perch (Morone americana) YOY varied nearly 200 fold and was not related to water warming or spring alewife abundance (P > 0.15). Variation in mean length of white perch YOY was related to cumulative degree days > 15°C (P < 0.01, r = 0.69).

Blinded by the light? Nearshore energy pathway coupling and relative predator biomass increase with reduced water transparency across lakes.

PubMed

Tunney, Tyler D; McCann, Kevin S; Jarvis, Lauren; Lester, Nigel P; Shuter, Brian J

2018-04-01

Habitat coupling is a concept that refers to consumer integration of resources derived from different habitats. This coupling unites fundamental food web pathways (e.g., cross-habitat trophic linkages) that mediate key ecological processes such as biomass flows, nutrient cycling, and stability. We consider the influence of water transparency, an important environmental driver in aquatic ecosystems, on habitat coupling by a light-sensitive predator, walleye (Sander vitreus), and its prey in 33 Canadian lakes. Our large-scale, across-lake study shows that the contribution of nearshore carbon (δ 13 C) relative to offshore carbon (δ 13 C) to walleye is higher in less transparent lakes. To a lesser degree, the contribution of nearshore carbon increased with a greater proportion of prey in nearshore compared to offshore habitats. Interestingly, water transparency and habitat coupling predict among-lake variation in walleye relative biomass. These findings support the idea that predator responses to changing conditions (e.g., water transparency) can fundamentally alter carbon pathways, and predator biomass, in aquatic ecosystems. Identifying environmental factors that influence habitat coupling is an important step toward understanding spatial food web structure in a changing world.

The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories.

PubMed

Lepak, Jesse M; Hooten, Mevin B; Johnson, Brett M

2012-10-01

Mercury (Hg) contamination in sport fish is a global problem. In freshwater systems, food web structure, sport fish sex, size, diet and growth rates influence Hg bioaccumulation. Fish stocking is a common management practice worldwide that can introduce external energy and contaminants into freshwater systems. Thus, stocking can alter many of the factors that influence Hg concentrations in sport fish. Here we evaluated the influence of external subsidies, in the form of hatchery-raised rainbow trout Oncorhynchus mykiss on walleye Sander vitreus diet, growth and Hg concentrations in two freshwater systems. Stocking differentially influenced male and female walleye diets and growth, producing a counterintuitive size-contamination relationship. Modeling indicated that walleye growth rate and diet were important explanatory variables when predicting Hg concentrations. Thus, hatchery contributions to freshwater systems in the form of energy and contaminants can influence diet, growth and Hg concentrations in sport fish. Given the extensive scale of fish stocking, and the known health risks associated with Hg contamination, this represents a significant issue for managers monitoring and manipulating freshwater food web structures, and policy makers attempting to develop fish consumption advisories to protect human health in stocked systems.

The influence of external subsidies on diet, growth and Hg concentrations of freshwater sport fish: implications for management and fish consumption advisories

USGS Publications Warehouse

Lepak, J.M.; Hooten, M.B.; Johnson, B.M.

2012-01-01

Mercury (Hg) contamination in sport fish is a global problem. In freshwater systems, food web structure, sport fish sex, size, diet and growth rates influence Hg bioaccumulation. Fish stocking is a common management practice worldwide that can introduce external energy and contaminants into freshwater systems. Thus, stocking can alter many of the factors that influence Hg concentrations in sport fish. Here we evaluated the influence of external subsidies, in the form of hatchery-raised rainbow trout Oncorhynchus mykiss on walleye Sander vitreus diet, growth and Hg concentrations in two freshwater systems. Stocking differentially influenced male and female walleye diets and growth, producing a counterintuitive size-contamination relationship. Modeling indicated that walleye growth rate and diet were important explanatory variables when predicting Hg concentrations. Thus, hatchery contributions to freshwater systems in the form of energy and contaminants can influence diet, growth and Hg concentrations in sport fish. Given the extensive scale of fish stocking, and the known health risks associated with Hg contamination, this represents a significant issue for managers monitoring and manipulating freshwater food web structures, and policy makers attempting to develop fish consumption advisories to protect human health in stocked systems.

Effects of an evidence-based computerized virtual clinician on low-density lipoprotein and non-high-density lipoprotein cholesterol in adults without cardiovascular disease: The Interactive Cholesterol Advisory Tool.

PubMed

Block, Robert C; Abdolahi, Amir; Niemiec, Christopher P; Rigby, C Scott; Williams, Geoffrey C

2016-12-01

There is a lack of research on the use of electronic tools that guide patients toward reducing their cardiovascular disease risk. We conducted a 9-month clinical trial in which participants who were at low (n = 100) and moderate (n = 23) cardiovascular disease risk-based on the National Cholesterol Education Program III's 10-year risk estimator-were randomized to usual care or to usual care plus use of an Interactive Cholesterol Advisory Tool during the first 8 weeks of the study. In the moderate-risk category, an interaction between treatment condition and Framingham risk estimate on low-density lipoprotein and non-high-density lipoprotein cholesterol was observed, such that participants in the virtual clinician treatment condition had a larger reduction in low-density lipoprotein and non-high-density lipoprotein cholesterol as their Framingham risk estimate increased. Perceptions of the Interactive Cholesterol Advisory Tool were positive. Evidence-based information about cardiovascular disease risk and its management was accessible to participants without major technical challenges. © The Author(s) 2015.

Density-Dependent Regulation of Brook Trout Population Dynamics along a Core-Periphery Distribution Gradient in a Central Appalachian Watershed

PubMed Central

Huntsman, Brock M.; Petty, J. Todd

2014-01-01

Spatial population models predict strong density-dependence and relatively stable population dynamics near the core of a species' distribution with increasing variance and importance of density-independent processes operating towards the population periphery. Using a 10-year data set and an information-theoretic approach, we tested a series of candidate models considering density-dependent and density-independent controls on brook trout population dynamics across a core-periphery distribution gradient within a central Appalachian watershed. We sampled seven sub-populations with study sites ranging in drainage area from 1.3–60 km2 and long-term average densities ranging from 0.335–0.006 trout/m. Modeled response variables included per capita population growth rate of young-of-the-year, adult, and total brook trout. We also quantified a stock-recruitment relationship for the headwater population and coefficients of variability in mean trout density for all sub-populations over time. Density-dependent regulation was prevalent throughout the study area regardless of stream size. However, density-independent temperature models carried substantial weight and likely reflect the effect of year-to-year variability in water temperature on trout dispersal between cold tributaries and warm main stems. Estimated adult carrying capacities decreased exponentially with increasing stream size from 0.24 trout/m in headwaters to 0.005 trout/m in the main stem. Finally, temporal variance in brook trout population size was lowest in the high-density headwater population, tended to peak in mid-sized streams and declined slightly in the largest streams with the lowest densities. Our results provide support for the hypothesis that local density-dependent processes have a strong control on brook trout dynamics across the entire distribution gradient. However, the mechanisms of regulation likely shift from competition for limited food and space in headwater streams to competition for

Screening for Osteoporosis in Community-Dwelling Adults with Mental Retardation.

ERIC Educational Resources Information Center

Tyler, Carl V., Jr.; Snyder, Clint W.; Zyzanski, Stephen

2000-01-01

Osteoporosis screening of 107 adults, ages 40 to 60, with mental retardation who attended community-based training centers found 21 percent had osteoporosis and 34 percent had osteopenia. The most significant predictor of lower bone mineral densities were Down syndrome, mobility status, and race. (Contains references.) (Author/DB)

Low Bone Density

MedlinePlus

... Bone Density Exam/Testing › Low Bone Density Low Bone Density Low bone density is when your bone ... to people with normal bone density. Detecting Low Bone Density A bone density test will determine whether ...

Partitioning the sources of demographic variation reveals density-dependent nest predation in an island bird population

PubMed Central

Sofaer, Helen R; Sillett, T Scott; Langin, Kathryn M; Morrison, Scott A; Ghalambor, Cameron K

2014-01-01

Ecological factors often shape demography through multiple mechanisms, making it difficult to identify the sources of demographic variation. In particular, conspecific density can influence both the strength of competition and the predation rate, but density-dependent competition has received more attention, particularly among terrestrial vertebrates and in island populations. A better understanding of how both competition and predation contribute to density-dependent variation in fecundity can be gained by partitioning the effects of density on offspring number from its effects on reproductive failure, while also evaluating how biotic and abiotic factors jointly shape demography. We examined the effects of population density and precipitation on fecundity, nest survival, and adult survival in an insular population of orange-crowned warblers (Oreothlypis celata) that breeds at high densities and exhibits a suite of traits suggesting strong intraspecific competition. Breeding density had a negative influence on fecundity, but it acted by increasing the probability of reproductive failure through nest predation, rather than through competition, which was predicted to reduce the number of offspring produced by successful individuals. Our results demonstrate that density-dependent nest predation can underlie the relationship between population density and fecundity even in a high-density, insular population where intraspecific competition should be strong. PMID:25077023

Partitioning the sources of demographic variation reveals density-dependent nest predation in an island bird population.

PubMed

Sofaer, Helen R; Sillett, T Scott; Langin, Kathryn M; Morrison, Scott A; Ghalambor, Cameron K

2014-07-01

Ecological factors often shape demography through multiple mechanisms, making it difficult to identify the sources of demographic variation. In particular, conspecific density can influence both the strength of competition and the predation rate, but density-dependent competition has received more attention, particularly among terrestrial vertebrates and in island populations. A better understanding of how both competition and predation contribute to density-dependent variation in fecundity can be gained by partitioning the effects of density on offspring number from its effects on reproductive failure, while also evaluating how biotic and abiotic factors jointly shape demography. We examined the effects of population density and precipitation on fecundity, nest survival, and adult survival in an insular population of orange-crowned warblers (Oreothlypis celata) that breeds at high densities and exhibits a suite of traits suggesting strong intraspecific competition. Breeding density had a negative influence on fecundity, but it acted by increasing the probability of reproductive failure through nest predation, rather than through competition, which was predicted to reduce the number of offspring produced by successful individuals. Our results demonstrate that density-dependent nest predation can underlie the relationship between population density and fecundity even in a high-density, insular population where intraspecific competition should be strong.

Sex differences in fingerprint ridge density in a Turkish young adult population: a sample of Baskent University.

PubMed

Oktem, Hale; Kurkcuoglu, Ayla; Pelin, Ismail Can; Yazici, Ayse Canan; Aktaş, Gulnihal; Altunay, Fikret

2015-05-01

Fingerprints are considered to be one of the most reliable methods of identification. Identification of an individual plays a vital part of any medico-legal investigations. Dermatoglyphics is a branch of science that studies epidermal ridges and ridge patterns. Epidermal ridges are polygenic characteristics that form intrauterine 10-18 weeks and considered fully developed by the sixth month of fetal growth. Fingerprints are permanent morphological characteristics and criminal detection based on fingerprints is based on the principle that no two people can have identical fingerprints. Sex determination from fingerprints has been examined in different population. In this study we aimed to study fingerprint ridge density in Turkish population sample of Baskent University students. Fingerprints were obtained from 118 women, 88 men a total of 206 students aged between 17 and 28 years old by means of simple inking method. Fingerprints from all right and left hands fingers were collected in three different area of each. The ridges on fingerprints were counted diagonally on squares measuring 5 mm × 5 mm on radial, ulnar and inferior areas. The fingerprint ridge density in radial, ulnar and inferior areas and between sexes was compared statistically Mann Whitney U test and Friedman test. The ridge density was significantly greater in women in every region studied and in all fingers when compared to men. The fingerprint ridge density in the ulnar and radial areas of the fingerprints was significantly greater than the lower area. Fingerprint ridge density can be used by medico-legal examination for sex identification. Copyright © 2015 Elsevier Ltd and Faculty of Forensic and Legal Medicine. All rights reserved.

Extreme obesity reduces bone mineral density: complementary evidence from mice and women.

PubMed

Núñez, Nomelí P; Carpenter, Catherine L; Perkins, Susan N; Berrigan, David; Jaque, S Victoria; Ingles, Sue Ann; Bernstein, Leslie; Forman, Michele R; Barrett, J Carl; Hursting, Stephen D

2007-08-01

To evaluate the effects of body adiposity on bone mineral density in the presence and absence of ovarian hormones in female mice and postmenopausal women. We assessed percentage body fat, serum leptin levels, and bone mineral density in ovariectomized and non-ovariectomized C57BL/6 female mice that had been fed various calorically dense diets to induce body weight profiles ranging from lean to very obese. Additionally, we assessed percentage body fat and whole body bone mineral density in 37 overweight and extremely obese postmenopausal women from the Women's Contraceptive and Reproductive Experiences study. In mice, higher levels of body adiposity (>40% body fat) were associated with lower bone mineral density in ovariectomized C57BL/6 female mice. A similar trend was observed in a small sample of postmenopausal women. The complementary studies in mice and women suggest that extreme obesity in postmenopausal women may be associated with reduced bone mineral density. Thus, extreme obesity (BMI > 40 kg/m2) may increase the risk for osteopenia and osteoporosis. Given the obesity epidemic in the U.S. and in many other countries, and, in particular, the rising number of extremely obese adult women, increased attention should be drawn to the significant and interrelated public health issues of obesity and osteoporosis.

Age and sex differences in oxytocin and vasopressin V1a receptor binding densities in the rat brain: focus on the social decision-making network.

PubMed

Smith, Caroline J W; Poehlmann, Max L; Li, Sara; Ratnaseelan, Aarane M; Bredewold, Remco; Veenema, Alexa H

2017-03-01

Oxytocin (OT) and vasopressin (AVP) regulate various social behaviors via activation of the OT receptor (OTR) and the AVP V1a receptor (V1aR) in the brain. Social behavior often differs across development and between the sexes, yet our understanding of age and sex differences in brain OTR and V1aR binding remains incomplete. Here, we provide an extensive analysis of OTR and V1aR binding density throughout the brain in juvenile and adult male and female rats, with a focus on regions within the social decision-making network. OTR and V1aR binding density were higher in juveniles than in adults in regions associated with reward and socio-spatial memory and higher in adults than in juveniles in key regions of the social decision-making network and in cortical regions. We discuss possible implications of these shifts in OTR and V1aR binding density for the age-specific regulation of social behavior. Furthermore, sex differences in OTR and V1aR binding density were less numerous than age differences. The direction of these sex differences was region-specific for OTR but consistently higher in females than in males for V1aR. Finally, almost all sex differences in OTR and V1aR binding density were already present in juveniles and occurred in regions with denser binding in adults compared to juveniles. Possible implications of these sex differences for the sex-specific regulation of behavior, as well potential underlying mechanisms, are discussed. Overall, these findings provide an important framework for testing age- and sex-specific roles of OTR and V1aR in the regulation of social behavior.

Environmental fate model for ultra-low-volume insecticide applications used for adult mosquito management

USGS Publications Warehouse

Schleier, Jerome J.; Peterson, Robert K.D.; Irvine, Kathryn M.; Marshall, Lucy M.; Weaver, David K.; Preftakes, Collin J.

2012-01-01

One of the more effective ways of managing high densities of adult mosquitoes that vector human and animal pathogens is ultra-low-volume (ULV) aerosol applications of insecticides. The U.S. Environmental Protection Agency uses models that are not validated for ULV insecticide applications and exposure assumptions to perform their human and ecological risk assessments. Currently, there is no validated model that can accurately predict deposition of insecticides applied using ULV technology for adult mosquito management. In addition, little is known about the deposition and drift of small droplets like those used under conditions encountered during ULV applications. The objective of this study was to perform field studies to measure environmental concentrations of insecticides and to develop a validated model to predict the deposition of ULV insecticides. The final regression model was selected by minimizing the Bayesian Information Criterion and its prediction performance was evaluated using k-fold cross validation. Density of the formulation and the density and CMD interaction coefficients were the largest in the model. The results showed that as density of the formulation decreases, deposition increases. The interaction of density and CMD showed that higher density formulations and larger droplets resulted in greater deposition. These results are supported by the aerosol physics literature. A k-fold cross validation demonstrated that the mean square error of the selected regression model is not biased, and the mean square error and mean square prediction error indicated good predictive ability.

Coat condition of ringtailed lemurs, Lemur catta at Berenty Reserve, Madagascar: I. Differences by age, sex, density and tourism, 1996-2006.

PubMed

Jolly, Alison

2009-03-01

An index of coat condition can be a non-invasive tool for tracking health and stress at population level. Coat condition in ringtailed lemurs, Lemur catta, was recorded during September-November birth seasons of 1996, 1997, 1999, and 2001-2006 at Berenty Reserve, Madagascar. Condition was scored on a scale from 0: full, fluffy coat with guard hairs present, to 5: half or more of body hairless. Adult males did not differ overall from adult females. Coats were worse in adults than in 2-year-old subadults; 1-year-old juveniles were intermediate. Mothers and adult males lost coat condition as the season progressed: non-mother females maintained condition. Years 1999-2002 scored better coats than either 1996-1997 or 2003-2006. Lemurs in high population density areas had worse coats than in natural forest, but tourist presence had less effect than density. Monitoring coat condition in an apparently healthy population reveals differences between population segments, and in a forest fragment with limited immigration or emigration it can track progressive changes, correcting impressions of progressive improvement or degradation over time. Above all it gives a baseline for response to climate changes or eventual pathology. (c) 2008 Wiley-Liss, Inc.

Population density influences dispersal in female white-tailed deer

USGS Publications Warehouse

Lutz, Clayton L.; Diefenbach, Duane R.; Rosenberry, Christopher S.

2015-01-01

Dispersal behavior in white-tailed deer (Odocoileus virginianus) predominantly occurs in 1-year-old males; however, females of the same age also disperse. The timing of female dispersal during fawning season and low dispersal rates suggest that competition for mates and reduced inbreeding are not ultimate causes of female dispersal, as suggested for males. We proposed that female dispersal is the result of competition for space when pregnant females seek to isolate themselves before and after parturition. To test this hypothesis, we conducted a meta-analysis of female dispersal rates from 12 populations of white-tailed deer and predicted dispersal rate and distance were positively related to deer density. We found a positive relationship between dispersal rate and deer per forested km2 and between dispersal distance and deer per forested km2. These results are consistent with the hypothesis that female dispersal is density-dependent and caused by the exclusion of subordinate 1-year-olds as adult females seek isolation before and after parturition.

Survey on aedes mosquito density and pattern distribution of aedes aegypti and aedes albopictus in high and low incidence districts in north sumatera province

NASA Astrophysics Data System (ADS)

Siregar, Fazidah A.; Makmur, Tri

2018-03-01

Transmission and control of dengue hemorrhagic fever are related to its vectors. This study investigated vector density and distribution patterns of Aedes aegypty and Aedes albopictus in Medan and Langkat as high and low incidence district, respectively. An entomological survey was carried out in 304 households both in Medan and Langkat. The results showed that adult Ae. aegypti were predominantly in Medan, while adult Ae. albopictus was only in Langkat. Larvae indices (HI, CI, BI) for Aedes in Medan ( 35,13 and 43) were higher than langkat ( 22,8 and 30). Adult indices (AHI, AD, RR) for Ae. aegypti in Medan and for Ae. albopictus in Langkat were 20,38,24 and 3,5, and 5, respectively. Pattern distribution of Aedes larvae and adult mosquitoes in both district had similar pattern. Aedes larval indices and adult indices both in HIDs and LIDs were above the critical level, indicating potential high risk for DHF transmission. By multiple regression analysis, HI is predictor for DHF transmission in North Sumatera. Thus, in designing an effective control measures for dengue hemorrhagic fever, monitoring distribution and vector density is crucial.

Bird population density estimated from acoustic signals

USGS Publications Warehouse

Dawson, D.K.; Efford, M.G.

2009-01-01

Many animal species are detected primarily by sound. Although songs, calls and other sounds are often used for population assessment, as in bird point counts and hydrophone surveys of cetaceans, there are few rigorous methods for estimating population density from acoustic data. 2. The problem has several parts - distinguishing individuals, adjusting for individuals that are missed, and adjusting for the area sampled. Spatially explicit capture-recapture (SECR) is a statistical methodology that addresses jointly the second and third parts of the problem. We have extended SECR to use uncalibrated information from acoustic signals on the distance to each source. 3. We applied this extension of SECR to data from an acoustic survey of ovenbird Seiurus aurocapilla density in an eastern US deciduous forest with multiple four-microphone arrays. We modelled average power from spectrograms of ovenbird songs measured within a window of 0??7 s duration and frequencies between 4200 and 5200 Hz. 4. The resulting estimates of the density of singing males (0??19 ha -1 SE 0??03 ha-1) were consistent with estimates of the adult male population density from mist-netting (0??36 ha-1 SE 0??12 ha-1). The fitted model predicts sound attenuation of 0??11 dB m-1 (SE 0??01 dB m-1) in excess of losses from spherical spreading. 5.Synthesis and applications. Our method for estimating animal population density from acoustic signals fills a gap in the census methods available for visually cryptic but vocal taxa, including many species of bird and cetacean. The necessary equipment is simple and readily available; as few as two microphones may provide adequate estimates, given spatial replication. The method requires that individuals detected at the same place are acoustically distinguishable and all individuals vocalize during the recording interval, or that the per capita rate of vocalization is known. We believe these requirements can be met, with suitable field methods, for a significant

Intersections between nativity, ethnic density, and neighborhood SES: using an ethnic enclave framework to explore variation in Puerto Ricans' physical health.

PubMed

Roy, Amanda Leigh; Hughes, Diane; Yoshikawa, Hirokazu

2013-06-01

Although past research has demonstrated a "health disadvantage" for Puerto Rican adults, very little is known about correlates of health among this group. Given Puerto Ricans' unique experiences of migration and settlement, an ethnic enclave framework that integrates nativity, ethnic density, and neighborhood SES may offer insight into factors influencing Puerto Ricans' health. This study uses a sample of 449 adult mainland- and island-born Puerto Ricans living in New York City and Chicago. The data, collected as a part of the MIDUS Survey of Minority Groups, are stratified by neighborhood ethnic density and neighborhood SES, allowing for the examination of the individual and joint influences of neighborhood characteristics on physical health. Results revealed that ethnic density and neighborhood SES were not independently or interactively related to physical health for mainland-born Puerto Ricans. However, the interaction between ethnic density and neighborhood SES was related to self-reported health, functional limitations, and health symptoms for island-born Puerto Ricans. Island-born Puerto Ricans living in ethnically dense, low SES neighborhoods reported worse health than island-born Puerto Ricans living in other types of neighborhoods. This may be a result of isolation from resources both within and outside the neighborhood.

Bone mineral density in subjects using central nervous system-active medications.

PubMed

Kinjo, Mitsuyo; Setoguchi, Soko; Schneeweiss, Sebastian; Solomon, Daniel H

2005-12-01

Decreased bone mineral density defines osteoporosis according to the World Health Organization and is an important predictor of future fractures. The use of several types of central nervous system-active drugs, including benzodiazepines, anticonvulsants, antidepressants, and opioids, have all been associated with increased risk of fracture. However, it is unclear whether such an increase in risk is related to an effect of bone mineral density or to other factors, such as increased risk of falls. We sought to examine the relationship between bone mineral density and the use of benzodiazepines, anticonvulsants, antidepressants, and opioids in a representative US population-based sample. We analyzed data on adults aged 17 years and older from the Third National Health and Nutrition Examination Survey (NHANES III, 1988-1994). Total femoral bone mineral density of 7114 male and 7532 female participants was measured by dual-energy x-ray absorptiometry. Multivariable linear regression models were used to quantify the relation between central nervous system medication exposure and total femoral bone mineral density. Models controlled for relevant covariates, including age, sex, and body mass index. In linear regression models, significantly reduced bone mineral density was found in subjects taking anticonvulsants (0.92 g/cm2; 95% confidence interval [CI]: 0.89 to 0.94) and opioids (0.92 g/cm2; 95% CI: 0.88 to 0.95) compared with nonusers (0.95 g/cm2; 95% CI: 0.95 to 0.95) after adjusting for several potential confounders. The other central nervous system-active drugs--benzodiazepines or antidepressants--were not associated with significantly reduced bone mineral density. In cross-sectional analysis of NHANES III, anticonvulsants and opioids (but not benzodiazepines or antidepressants) were associated with significantly reduced bone mineral density. These findings have implications for fracture-prevention strategies.

Distribution and relative abundance of fishes in littoral areas of Chief Joseph Reservoir, Columbia River

USGS Publications Warehouse

Gadomski, Dena M.; Venditti, David A.; Robinson, T. Craig; Beeman, John W.; Maule, Alec G.

2004-01-01

We surveyed fish assemblages in littoral areas of Chief Joseph Reservoir of the upper Columbia River to aid in understanding this ecosystem. Fish distributions and abundances were examined during April-July 1999 in relation to environmental conditions in the reservoir. We also compared the fish assemblages in Chief Joseph reservoir in 1999 to a past study conducted during 1974-1975, and to assemblages in other areas of the Columbia River. During 67 hr of electrofishing and 78 beach seine hauls in Chief Joseph Reservoir, 7460 fishes representing 8 families were collected. The majority of the catch was native – northern pikeminnow; redside shiners; longnose, bridgelip, and largescale suckers; and sculpins. The most abundant introduced species was walleye, and one species, rainbow trout, was mostly of net-pen origin. Larger sizes of suckers and northern pikeminnow were most abundant in the upper reservoir, likely due to upstream spawning migrations. The lower reservoir contained greater abundances of smaller fishes, and this area had lower flows, smaller substrates, and more complex shorelines that offered these fishes refugia. Only adult suckers displayed significant differences in abundances related to substrate. The relative abundances of species appeared to have changed since the 1970s, when the dominant fishes were northern pikeminnow, peamouth, largescale suckers, and walleye. Fish assemblage differences between Chief Joseph Reservoir and lower Columbia River reservoirs were also evident due to the morphology of the reservoir, its more northerly location, and the lack of fish passage facilities at Chief Joseph Dam. Our study is one of the few descriptions of fishes in the upper Columbia Rivers.

Neighbourhood Ethnic Density Effects on Behavioural and Cognitive Problems Among Young Racial/Ethnic Minority Children in the US and England: A Cross-National Comparison.

PubMed

Zhang, Nan; Beauregard, Jennifer L; Kramer, Michael R; Bécares, Laia

2017-01-01

Studies on adult racial/ethnic minority populations show that the increased concentration of racial/ethnic minorities in a neighbourhood-a so-called ethnic density effect-is associated with improved health of racial/ethnic minority residents when adjusting for area deprivation. However, this literature has focused mainly on adult populations, individual racial/ethnic groups, and single countries, with no studies focusing on children of different racial/ethnic groups or comparing across nations. This study aims to compare neighbourhood ethnic density effects on young children's cognitive and behavioural outcomes in the US and in England. We used data from two nationally representative birth cohort studies, the US Early Childhood Longitudinal Study-Birth Cohort and the UK Millennium Cohort Study, to estimate the association between own ethnic density and behavioural and cognitive development at 5 years of age. Findings show substantial heterogeneity in ethnic density effects on child outcomes within and between the two countries, suggesting that ethnic density effects may reflect the wider social and economic context. We argue that researchers should take area deprivation into account when estimating ethnic density effects and when developing policy initiatives targeted at strengthening and improving the health and development of racial and ethnic minority children.

Molecular density functional theory of water including density-polarization coupling.

PubMed

Jeanmairet, Guillaume; Levy, Nicolas; Levesque, Maximilien; Borgis, Daniel

2016-06-22

We present a three-dimensional molecular density functional theory of water derived from first-principles that relies on the particle's density and multipolar polarization density and includes the density-polarization coupling. This brings two main benefits: (i) scalar density and vectorial multipolar polarization density fields are much more tractable and give more physical insight than the full position and orientation densities, and (ii) it includes the full density-polarization coupling of water, that is known to be non-vanishing but has never been taken into account. Furthermore, the theory requires only the partial charge distribution of a water molecule and three measurable bulk properties, namely the structure factor and the Fourier components of the longitudinal and transverse dielectric susceptibilities.

Liver Enzymes and Bone Mineral Density in the General Population.

PubMed

Breitling, Lutz Philipp

2015-10-01

Liver enzyme serum levels within and just above the normal range are strong predictors of incident morbidity and mortality in the general population. However, despite the close links between hepatic pathology and impaired bone health, the association of liver enzymes with osteoporosis has hardly been investigated. The aim of the present study was to clarify whether serum liver enzyme levels in the general population are associated with bone mineral density. This was an observational, cross-sectional study. Participants and Main Outcome: Data on 13 849 adult participants of the Third National Health and Nutrition Examination Survey were used to quantify the independent associations of γ-glutamyltransferase, alanine transaminase, and aspartate transaminase with femoral neck bone mineral density assessed by dual-energy x-ray absorptiometry. In multiple regression models adjusting for numerous confounding variables, γ-glutamyltransferase showed a weak inverse association with bone mineral density (P = .0063). There also was limited evidence of a nonmonotonous relationship with alanine transaminase, with peak bone mineral density in the second quartile of enzyme activity (P = .0039). No association was found for aspartate transaminase. Although mechanistically plausible associations were found in the present study, the rather weak nature of these patterns renders it unlikely that liver enzyme levels could be of substantial use for osteoporosis risk stratification in the general population.

TRPM7 Is Required for Normal Synapse Density, Learning, and Memory at Different Developmental Stages.

PubMed

Liu, Yuqiang; Chen, Cui; Liu, Yunlong; Li, Wei; Wang, Zhihong; Sun, Qifeng; Zhou, Hang; Chen, Xiangjun; Yu, Yongchun; Wang, Yun; Abumaria, Nashat

2018-06-19

The TRPM7 chanzyme contributes to several biological and pathological processes in different tissues. However, its role in the CNS under physiological conditions remains unclear. Here, we show that TRPM7 knockdown in hippocampal neurons reduces structural synapse density. The synapse density is rescued by the α-kinase domain in the C terminus but not by the ion channel region of TRPM7 or by increasing extracellular concentrations of Mg 2+ or Zn 2+ . Early postnatal conditional knockout of TRPM7 in mice impairs learning and memory and reduces synapse density and plasticity. TRPM7 knockdown in the hippocampus of adult rats also impairs learning and memory and reduces synapse density and synaptic plasticity. In knockout mice, restoring expression of the α-kinase domain in the brain rescues synapse density/plasticity and memory, probably by interacting with and phosphorylating cofilin. These results suggest that brain TRPM7 is important for having normal synaptic and cognitive functions under physiological, non-pathological conditions. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Increased stem density and competition may diminish the positive effects of warming at alpine treeline.

PubMed

Wang, Yafeng; Pederson, Neil; Ellison, Aaron M; Buckley, Hannah L; Case, Bradley S; Liang, Eryuan; Julio Camarero, J

2016-07-01

The most widespread response to global warming among alpine treeline ecotones is not an upward shift, but an increase in tree density. However, the impact of increasing density on interactions among trees at treeline is not well understood. Here, we test if treeline densification induced by climatic warming leads to increasing intraspecific competition. We mapped and measured the size and age of Smith fir trees growing in two treelines located in the southeastern Tibetan Plateau. We used spatial point-pattern and codispersion analyses to describe the spatial association and covariation among seedlings, juveniles, and adults grouped in 30-yr age classes from the 1860s to the present. Effects of competition on tree height and regeneration were inferred from bivariate mark-correlations. Since the 1950s, a rapid densification occurred at both sites in response to climatic warming. Competition between adults and juveniles or seedlings at small scales intensified as density increased. Encroachment negatively affected height growth and further reduced recruitment around mature trees. We infer that tree recruitment at the studied treelines was more cold-limited prior to 1950 and shifted to a less temperature-constrained regime in response to climatic warming. Therefore, the ongoing densification and encroachment of alpine treelines could alter the way climate drives their transitions toward subalpine forests. © 2016 by the Ecological Society of America.

Patterns in prey use among fur seals and seabirds in the Pribilof Islands

NASA Astrophysics Data System (ADS)

Sinclair, E. H.; Vlietstra, L. S.; Johnson, D. S.; Zeppelin, T. K.; Byrd, G. V.; Springer, A. M.; Ream, R. R.; Hunt, G. L., Jr.

2008-08-01

We explored correlation in diet trends for five piscivorous predators that reproduce on the Pribilof Islands as illustrative of the shifting structure of the Bering Sea ecosystem. We evaluated the size and species of prey consumed by adult female and juvenile northern fur seals ( Callorhinus ursinus) and adults and chicks of black-legged kittiwakes ( Rissa tridactyla), red-legged kittiwakes ( Rissa brevirostris), thick-billed murres ( Uria lomvia), and common murres ( Uria aalge) from data collected between July and October 1960-2000. Sample sources included stomachs from seals and seabirds collected on pelagic foraging grounds in the eastern Bering Sea, seal scats from rookeries and seabird regurgitations and whole prey from nest sites on St. Paul and St. George Islands of the Pribilof Island archipelago. Typical prey included small fish and invertebrates (⩽20 cm for seals and ⩽12 cm for seabirds) that concentrate along frontal boundaries of the continental shelf/slope and in the epi-pelagic zone. Squids and fishes including walleye pollock ( Theragra chalcogramma), capelin ( Mallotus villosus), and sand lance ( Ammodytes hexapterus) were variably important in the diet of all five predators. Some prey, such as capelin, were principal in predator diets during the 1960s (seals) and into the early 1980s (seabirds), but declined or disappeared from all predator diets thereafter while others, such as walleye pollock, occurred with increasing frequency from the 1970s forward. As the number of individuals consuming walleye pollock increased, the overall volume of pollock in seabird diets declined. This decline was coincident with a decrease in the age and body size of pollock consumed by both seabirds and fur seals. Squid and pollock were negatively correlated in the diets of their primary consumers, northern fur seals (Pearson's coefficient -0.71, p=0.016) and thick-billed murres (Pearson's coefficient=-0.74, p=0.015) from the 1970s forward. Inter-island variation

Density of Diadema antillarum (Echinodermata: Echinoidea) on live coral patch reefs and dead Acropora cervicornis rubble patches near Loggerhead Key, Dry Tortugas National Park, Florida, USA

EPA Science Inventory

Density of adult Diadema antillarum was assessed on live coral patch reefs and dead Acropora cervicornis rubble patches next to Loggerhead Key, Dry Tortugas National Park, Florida, USA in June 2009. Mean density on live coral patch reefs (0.49 individuals m-2) was not statistical...

Management of percids in Lake Erie, North America

USGS Publications Warehouse

Hatch, Richard W.; Nepszy, Stephen J.; Rawson, Michael R.; van Densen, W.L.T.; Steinmetz, B.; Hughes, R.H.

1990-01-01

Lake Erie's fish populations and their habitats have undergone very substantial changes since 1945. Of the four percid forms originally present, the blue pike (Stizostedion vitreum glaucum) is presumed extinct, and the sauger (S. canadense) was commercially extinct by the 1950's. The walleye (S. v. vitreum) has remained stable in eastern Lake Erie but the highly productive stock of the western basin collapsed in the 1960's. Closure of the walleye fishery from 1970 to 1973, necessitated by mercury contamination, provided an opportunity for the development of an international management plan for restoration of the stock. An inter-agency Scientific Protocol Committee evaluated walleye dynamics and recommended management by quota beginning in 1976. Although quotas have been exceeded several times, the walleye stock responded well to limited exploitation, steadily increased, and expanded its range. Landings of the yellow perch (Perca flavescens) increased during the 1950's, but a steady decline in abundance, beginning in the early 1970's led to the formation in 1980 of another international inter-agency task group to recommend a basis for quota management. The short-term management recommendation, reported and accepted in 1986, was to reduce fishing effort by 20% by 1990. Both management schemes evolved when the resource agencies of the five jurisdictions (New York, Pennsylvania, Ohio, Michigan, and Ontario), in the two nations surrounding Lake Erie, perceived a need for the increased and improved management of a shared resource. They sought an international forum in which to develop strategies, appointed inter-agency scientific task groups to develop a basis for management recommendations, and adopted a quota management scheme. Each jurisdiction is responsible for the enforcement and allocation of its portion of the quota between user groups. Reports of catch, effort, and biological observations on stock performance are submitted annually to a standing technical

Attitudes of neurology specialists toward older adults.

PubMed

Seferoğlu, Meral; Yıldız, Demet; Pekel, Nilüfer Büyükkoyuncu; Güneş, Aygül; Yıldız, Abdülmecit; Tufan, Fatih

2017-08-01

Attitude of healthcare providers toward older people is very important in the aging world. Neurologists contact older adults very frequently. We aimed to investigate the attitudes of neurologists toward older adults. We recorded participants age; sex; duration of clinical practice in neurology; existence of older adult relatives; and history of geriatrics education, nursing home visits, older adult patient density in their clinical practice, and participation in voluntary public activities. UCLA Geriatrics Attitude Scale was used to evaluate participants' attitudes. A total of 100 neurologists participated in this study. Seventy-seven percent had positive, 3 % had neutral, and 20 % had negative attitudes. Twenty-seven percent of the participants had history of geriatrics education, and these participants tended to have a higher rate of positive attitudes. Neurologists with positive attitudes tended to be older than those with negative attitudes. Participants with history of living with older adult relatives had lower rates of positive attitudes. The most common diagnoses of the patients the participants encountered were stroke and dementia. Independent factors associated with positive attitudes were history of geriatrics education and older age. History of living with older relatives tended to have a negative effect. Most of the negative items of the attitude scale were associated with the natural course and behavior of the common diseases in neurology practice. Generalization of geriatrics education may translate into a better understanding and improved care for older patients. Development of instruments and implementation of qualitative studies to assess attitudes of neurologists toward older adults are needed.

In situ cannulation, microgrid follow-up and low-density plating provide first passage endothelial cell masscultures for in vitro lining.

PubMed

Zilla, P; Fasol, R; Dudeck, U; Siedler, S; Preiss, P; Fischlein, T; Müller-Glauser, W; Baitella, G; Sanan, D; Odell, J

1990-08-01

A rapid and reliable harvest and culture technique was developed to provide a sufficient number of autologous endothelial cells for the confluent in vitro lining of cardiovascular prostheses. Enzymatic endothelial cell detachment was achieved by the in situ application of collagenase to short vessel segments. This harvest technique resulted in a complete lack of contaminating smooth muscle cells in all of 124 cultures from nonhuman primates and 13 cultures from human adults. The use of a microgrid technique enabled the daily in situ quantification of available endothelial cells. To assess ideal plating densities after passage the population doubling time was continuously related to the cell density. Surprisingly, a low plating density of 1.5 X 10(3) endothelial cells/cm2 achieved 43% shorter cell cycles than the usual plating density of 1.0 X 10(4) endothelial cells/cm2. Moreover, low density plating enabled mass cultures after one single cell passage, thereby reducing the cell damaging effect of trypsin. When the growth characteristics of endothelial cells from five anatomically different vessel sites were compared, the external jugular vein--which would be easily accessible and dispensable in each patient--proved to be an excellent source for endothelial cell cultures. By applying in situ administration of collagenase, low density plating and microgrid follow-up to adult human saphenous vein endothelial cells, 14,000,000 first passage endothelial cells--sufficient for the in vitro lining of long vascular prostheses--were obtained 26.2 days after harvest. (95% confidence interval:22.3 to 32.2 days).

Experimental Examination of Intraspecific Density-Dependent Competition during the Breeding Period in Monarch Butterflies (Danaus plexippus)

PubMed Central

Flockhart, D. T. Tyler; Martin, Tara G.; Norris, D. Ryan

2012-01-01

A central goal of population ecology is to identify the factors that regulate population growth. Monarch butterflies (Danaus plexippus) in eastern North America re-colonize the breeding range over several generations that result in population densities that vary across space and time during the breeding season. We used laboratory experiments to measure the strength of density-dependent intraspecific competition on egg laying rate and larval survival and then applied our results to density estimates of wild monarch populations to model the strength of density dependence during the breeding season. Egg laying rates did not change with density but larvae at high densities were smaller, had lower survival, and weighed less as adults compared to lower densities. Using mean larval densities from field surveys resulted in conservative estimates of density-dependent population reduction that varied between breeding regions and different phases of the breeding season. Our results suggest the highest levels of population reduction due to density-dependent intraspecific competition occur early in the breeding season in the southern portion of the breeding range. However, we also found that the strength of density dependence could be almost five times higher depending on how many life-stages were used as part of field estimates. Our study is the first to link experimental results of a density-dependent reduction in vital rates to observed monarch densities in the wild and show that the effects of density dependent competition in monarchs varies across space and time, providing valuable information for developing robust, year-round population models in this migratory organism. PMID:22984614

Lying in wait: Limiting factors on a low-density ungulate population and the latent traits that can facilitate escape from them

NASA Astrophysics Data System (ADS)

Joly, Kyle; Craig, Tim; Cameron, Matthew D.; Gall, Adrian E.; Sorum, Mathew S.

2017-11-01

Predation, habitat, hunting, and environmental conditions have all been implicated as regulatory mechanisms in ungulate populations. The low-density equilibrium hypothesis predicts that in low-density populations, predators regulate their prey and that the population will not escape unless predation pressure is eased. We evaluated survival of adult and juvenile moose (Alces alces) in north-central Alaska to determine whether or not the population supported the hypothesis. We instrumented adult male and female moose with radiocollars and used aerial observations to track parturition and subsequent survival of juvenile moose. Generalized linear mixed-effects models were used to assess survival. Adult annual survival rates were high (∼89%), but may be negatively influenced by winter conditions. Migratory status did not affect moose survivorship or productivity. Approximately 60% of the calf crop died before 5 months of age. Productivity was significantly lower in the northern section of the study area where there is less high-quality habitat, suggesting that, even in this low-density population, nutrition could be a limiting factor. It appears that predation on young calves, winter weather, and nutritional constraints may be interacting to limit this population. Latent traits, such as overproduction of calves and migratory behavior, which do not currently enhance fitness, may persist within this population so that individuals with these traits can reap benefits when environmental conditions change.

Traffic and outdoor air pollution levels near residences and poorly controlled asthma in adults.

PubMed

Meng, Ying-Ying; Wilhelm, Michelle; Rull, Rudolph P; English, Paul; Ritz, Beate

2007-05-01

Air pollution may exacerbate asthma. To investigate associations between traffic and outdoor air pollution levels near residences and poorly controlled asthma among adults diagnosed as having asthma in Los Angeles and San Diego counties, California. We estimated traffic density within 500 ft of 2001 California Health Interview Survey respondents' reported residential cross-street intersections. Additionally, we assigned annual average concentrations of ozone, nitrogen dioxide, particulate matter 2.5 and 10 micrometers or less in diameter, and carbon monoxide measured at government monitoring stations within a 5-mile radius of the reported residential cross-street intersections. We observed a 2-fold increase in poorly controlled asthma (odds ratio [OR], 2.11; 95% confidence interval [CI], 1.38-3.23) among asthmatic adults in the highest quintile of traffic density after adjusting for age, sex, race, and poverty. Similar increases were seen for nonelderly adults, men, and women, although associations seemed strongest in elderly adults (OR, 3.00; 95% CI, 1.13-7.91). Ozone exposures were associated with poorly controlled asthma among elderly adults (OR, 1.70; 95% CI, 0.91-3.18 per 1 pphm) and men (OR, 1.76; 95% CI, 1.05-2.94 per 1 pphm), whereas particulate matter 10 micrometers or less seemed to affect primarily women (OR, 2.06; 95% CI, 1.17-3.61), even at levels below the national air quality standard. Heavy traffic and high air pollution levels near residences are associated with poorly controlled asthma.