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1

The effect of deleterious mutations on neutral molecular variation.  

PubMed

Selection against deleterious alleles maintained by mutation may cause a reduction in the amount of genetic variability at linked neutral sites. This is because a new neutral variant can only remain in a large population for a long period of time if it is maintained in gametes that are free of deleterious alleles, and hence are not destined for rapid elimination from the population by selection. Approximate formulas are derived for the reduction below classical neutral values resulting from such background selection against deleterious mutations, for the mean times to fixation and loss of new mutations, nucleotide site diversity, and number of segregating sites. These formulas apply to random-mating populations with no genetic recombination, and to populations reproducing exclusively asexually or by self-fertilization. For a given selection regime and mating system, the reduction is an exponential function of the total mutation rate to deleterious mutations for the section of the genome involved. Simulations show that the effect decreases rapidly with increasing recombination frequency or rate of outcrossing. The mean time to loss of new neutral mutations and the total number of segregating neutral sites are less sensitive to background selection than the other statistics, unless the population size is of the order of a hundred thousand or more. The stationary distribution of allele frequencies at the neutral sites is correspondingly skewed in favor of rare alleles, compared with the classical neutral result. Observed reductions in molecular variation in low recombination genomic regions of sufficiently large size, for instance in the centromere-proximal regions of Drosophila autosomes or in highly selfing plant populations, may be partly due to background selection against deleterious mutations. PMID:8375663

Charlesworth, B; Morgan, M T; Charlesworth, D

1993-08-01

2

Betel nut chewing and its deleterious effects on oral cavity.  

PubMed

The habit of chewing betel nut has a long history of use. Betel nut and products derived from it are widely used as a masticatory product among various communities and in several countries across the world. Over a long period, several additives have been added to a simple betel nut preparation; thus, creating the betel quid (BQ) and encompassing chewing tobacco in the preparation. Betel nut has deleterious effects on oral soft tissues. Its effects on dental caries and periodontal diseases, two major oral diseases are less well-documented. Betel-induced lichenoid lesions mainly on buccal mucosa have been reported at quid retained sites. In chronic chewers, a condition called betel chewers mucosa is often found where the quid is placed. Betel nut chewing is implicated in oral submucous fibrosis (OSF) and its use along with tobacco can cause leukoplakia, both of which are potentially malignant in the oral cavity. Oral cancer often arises from such precancerous changes. Thus, public health measures to quit betel use are recommended to control disabling conditions such as OSF and oral cancer. PMID:25313728

Anand, Richa; Dhingra, Chandan; Prasad, Sumanth; Menon, Ipseeta

2014-01-01

3

Dominance Effects of Deleterious and Beneficial Mutations in a Single Gene of the RNA Virus ?6  

PubMed Central

Most of our knowledge of dominance stems from studies of deleterious mutations. From these studies we know that most deleterious mutations are recessive, and that this recessivity arises from a hyperbolic relationship between protein function (i.e., protein concentration or activity) and fitness. Here we investigate whether this knowledge can be used to make predictions about the dominance of beneficial and deleterious mutations in a single gene. We employed a model system – the bacteriophage ?6 – that allowed us to generate a collection of mutations in haploid conditions so that it was not biased toward either dominant beneficial or recessive deleterious mutations. Screening for the ability to infect a bacterial host that does not permit infection by the wildtype ?6, we generated a collection of mutations in P3, a gene involved in attachment to the host and in phage particle assembly. The resulting collection contained mutations with both deleterious and beneficial effects on fitness. The deleterious mutations in our collection had additive effects on fitness and the beneficial mutations were recessive. Neither of these observations were predicted from previous studies of dominance. This pattern is not consistent with the hyperbolic (diminishing returns) relationship between protein function and fitness that is characteristic of enzymatic genes, but could have resulted from a curve of increasing returns. PMID:24945910

Joseph, Sarah B.; Peck, Kayla M.; Burch, Christina L.

2014-01-01

4

Deleterious effects of magnesium intoxication upon the domestic broiler chick  

SciTech Connect

Dietary levels of 0.6 to 0.8% magnesium in a corn-soy basal were rachitogenic. These rickets appeared most like phosphorus deficiency. Bone Ca/P ratios were numerically quite low implying a lack of transformation from amorphous calcium phosphate to hydroxyapatite. Bone alkaline phosphatase activity was elevated. Additional dietary phosphorus ameliorated, but could not overcome the rachitogenic effects of magnesium. Tibial dyschondroplasia (TD), induced by elevated dietary P, was decreased by high levels of dietary Mg, but with no decrease in plasma phosphorus. Anticoccidial ionophores fed in conjunction with a moderate dietary challenge of Mg (0.48%) produced no clear changes in plasma calcium or Mg, but did interact to reduce body weight. The diarrhea caused by magnesium intoxication is not due to hyperosmotic loads of Mg per se. Rather, Cl was observed to be the major ionic constituent of the gut osmotic load implying different gut ionic fluxes in control versus magnesium intoxicated chicks. These data imply that the cathartic action of Mg is due to hypersecretion of the gut. Effects mediated or modified by the CNS changed in magnesium intoxicated chicks. Such chicks appeared cold and stayed near the heat. When startled, they exhibited extreme avoidance behavior and seizures similar to epilepsy and/or Cl deficiency. Brain tissue Mg content did not concomitantly increase. Whether these effects are due to central signals is unclear.

Lee, S.R.

1984-01-01

5

Sildenafil citrate attenuates the deleterious effects of elevated ammonia.  

PubMed

Ammonia is a bi-product of protein metabolism in the body. It is able to cross the blood-brain barrier and elevated ammonia levels are toxic to the brain. Rats with hyperammonemia showed impaired learning ability and impaired function of the glutamate-nitric oxide-cyclic guanosine monophosphate (glutamate-NO-cGMP) pathway in the brain. Chronic treatment with sildenafil restored learning ability. We therefore tested the hypothesis that sildenafil has a protective effect on the brains of hyperammonemic rats. Hyperammonemia was induced in male rats by daily intraperitoneal (i.p.) injection of ammonium chloride (100?mg/kg body weight) for 8 weeks. Sildenafil citrate was administered intraperitoneally (10?mg/kg body weight/3 days) for 8 weeks. Treatment with sildenafil resulted in a significant reduction in plasma liver enzymes, lipid profile as well as brain lipid peroxidation and caspase-3 mRNA. Meanwhile, plasma NO as well as cGMP, antioxidants and endothelial nitric oxide synthase (eNOS) gene expression were significantly elevated in the brains of hyperammonemic rats. Our results showed that sildenafil exerts a protective effect on the brain by reversing oxidative stress during hyperammonemia and this could be due to (i) cytoprotective, antioxidant and anti-apoptotic effects (ii) increasing cGMP and enhancing the proper metabolism of fats which could suppress oxygen radical generation and thus preventing oxidative damage in the brain. The exact protective mechanism of sildenafil has to be still investigated and further studies are warranted. Consequently, therapeutic modulation of the NO/cGMP pathway might have important clinical applications to improve brain functions in patients with hyperammonemia or clinical hepatic encephalopathy. PMID:23343352

Arafa, Manar H; Atteia, Hebatallah H

2013-07-01

6

Deleterious effects of nonthermal electrons in shock ignition concept  

NASA Astrophysics Data System (ADS)

Shock ignition concept is a promising approach to inertial confinement fusion that may allow obtaining high fusion energy gains with the existing laser technology. However, the spike driving laser intensities in the range of 1-10 PW/cm2 produces the energetic electrons that may have a significant effect on the target performance. The hybrid numerical simulations including a radiation hydrodynamic code coupled to a rapid Fokker-Planck module are used to asses the role of hot electrons in the shock generation and the target preheat in the time scale of 100 ps and spatial scale of 100 ?m. It is shown that depending on the electron energy distribution and the target density profile the hot electrons can either increase the shock amplitude or preheat the imploding shell. In particular, the exponential electron energy spectrum corresponding to the temperature of 30 keV in the present HiPER target design preheats the deuterium-tritium shell and jeopardizes its compression. Ways of improving the target performance are suggested.

Nicolaï, Ph.; Feugeas, J.-L.; Touati, M.; Ribeyre, X.; Gus'kov, S.; Tikhonchuk, V.

2014-03-01

7

Deleterious effects of coupled transients events into miniaturized circuit components  

NASA Astrophysics Data System (ADS)

Electromagnetic pulses (EMP) can be very destructive and protecting against them is crucial. This paper discusses a method to determine the effects an intentional EMP would have on an electrical system with multiple layers of different materials by simulating in ANSYS HFSS the exposure to electromagnetic waves. The electrical system used in these simulations is a hot-wire detonator. Although complex, it is generic enough to apply knowledge gained from analysis to other systems. It was selected because it is a known system with EMP susceptibilities. As stated the results of these simulations can be extrapolated to other systems with a small wire surrounded by a dielectric. This method will provide an efficient technique to determine the compatibilities of a system to EMPs. Worst case scenarios are tested by applying wavelengths that result in a resonant frequency through the object. The results show the magnitude of the current densities at the surface of the object induced by the EMP waves. The impact of the waves can be determined by reviewing the current density induced by the waves on the system.

Upia, Antonio

8

Deleterious effects of nonthermal electrons in shock ignition concept.  

PubMed

Shock ignition concept is a promising approach to inertial confinement fusion that may allow obtaining high fusion energy gains with the existing laser technology. However, the spike driving laser intensities in the range of 1-10 PW/cm2 produces the energetic electrons that may have a significant effect on the target performance. The hybrid numerical simulations including a radiation hydrodynamic code coupled to a rapid Fokker-Planck module are used to asses the role of hot electrons in the shock generation and the target preheat in the time scale of 100 ps and spatial scale of 100 ?m. It is shown that depending on the electron energy distribution and the target density profile the hot electrons can either increase the shock amplitude or preheat the imploding shell. In particular, the exponential electron energy spectrum corresponding to the temperature of 30 keV in the present HiPER target design preheats the deuterium-tritium shell and jeopardizes its compression. Ways of improving the target performance are suggested. PMID:24730956

Nicolaï, Ph; Feugeas, J-L; Touati, M; Ribeyre, X; Gus'kov, S; Tikhonchuk, V

2014-03-01

9

Similarity of Deleterious Effects of Divorce on Chinese and American Children.  

ERIC Educational Resources Information Center

Reviews and contrasts the effects of divorce on Chinese children's adjustment to American children of divorce. Results indicate that the deleterious effects of divorce on children's academic and social functioning appear to be similar to that experienced by American children. (Contains 23 references.) (GCP)

Zhou, Zheng; Bray, Melissa A.; Kehle, Thomas J.; Xin, Tao

2001-01-01

10

Potential Deleterious Effects of Vasopressin in Chronic Kidney Disease and Particularly Autosomal Dominant Polycystic Kidney Disease  

Microsoft Academic Search

The antidiuretic hormone vasopressin is crucial for regulating free water clearance in normal physiology. However, it has also been hypothesized that vasopressin has deleterious effects on the kidney. Vasopressin is elevated in animals and patients with chronic kidney disease. Suppression of vasopressin activity reduces proteinuria, renal hypertrophy, glomerulosclerosis and tubulointerstitial fibrosis in animal models. The potential detrimental influence of vasopressin

E. Meijer; W. E. Boertien; R. Zietse; R. T. Gansevoort

2011-01-01

11

The Effect of Deleterious Concentrations of Copper on the Photosynthesis of Chlorella pyrenoidosa.  

PubMed

If a single salt solution of CuSO(4) is used, Cu penetrates immediately iuto the plasma of Chlorella cells, reducing the rates of photosynthesis at both high and low illumination. If CuSO(4) is added to ordinary Österlind culture-medium (pH 8) it takes some hours before any influence of deleterious concentrations of Cu is observed and initially only at light saturation. The algae must have been illuminated during the whole period. Maximum influence of CuSO(4) is found duriug the first 24 hours of treatment. A significant deleterious influence of Cu concentrations as low as about 1 ?g/l is found. The influence of Cu increases with decreasing concentrations of the alga. If a culture medium at pH 5 is used instead of the ordinary one at pH 8, copper concentrations ahout 10 times as high must he used be order to obtain the same deleterious effect. An increase of the cotncentration of K reduces the influence of Cu to some extent. These facts show that the effect of deleterious concentrations of Cu in halanced solutions is not due to a marked penelration of this ion into the plasma but to a binding to the cytoplasmic membrane whereby the celts i.a. become more or less unable to divide. The cells become saturated with assimilation products which have a depressant effect on the rate of photosynthesis. Other cations compete with Cu for the "active sites" on the membranes. PMID:20925660

Nielsen, E S; Kamp-Nielsen, L; Wium-Andersen, S

1969-01-01

12

Deleterious Effects of Alcohol Intoxication: Diminished Cognitive Control and Its Behavioral Consequences  

Microsoft Academic Search

The authors tested the hypothesis that impaired behavioral performance during intoxication results partly from alcohol’s deleterious effects on cognitive control. The impact of alcohol on perseverative behavior was examined with an n-back working memory task that included manipulations of task complexity and prepotency of inclinations to respond or withhold responding. Thirty-two social drinkers (16 men) participated in either an alcohol

Todd S. Casbon; John J. Curtin; Alan R. Lang; Christopher J. Patrick

2003-01-01

13

Fitness effects of derived deleterious mutations in four closely related wild tomato species with spatial structure.  

PubMed

A key issue in evolutionary biology is an improved understanding of the genetic mechanisms by which species adapt to various environments. Using DNA sequence data, it is possible to quantify the number of adaptive and deleterious mutations, and the distribution of fitness effects of new mutations (its mean and variance) by simultaneously taking into account the demography of a given species. We investigated how selection functions at eight housekeeping genes of four closely related, outcrossing species of wild tomatoes that are native to diverse environments in western South America (Solanum arcanum, S. chilense, S. habrochaites and S. peruvianum). We found little evidence for adaptive mutations but pervasive evidence for strong purifying selection in coding regions of the four species. In contrast, the strength of purifying selection seems to vary among the four species in non-coding (NC) regions (introns). Using F(ST)-based measures of fixation in subdivided populations, we suggest that weak purifying selection has affected the NC regions of S. habrochaites, S. chilense and S. peruvianum. In contrast, NC regions in S. arcanum show a distribution of fitness effects with mutations being either nearly neutral or very strongly deleterious. These results suggest that closely related species with similar genetic backgrounds but experiencing contrasting environments differ in the variance of deleterious fitness effects. PMID:21245893

Tellier, A; Fischer, I; Merino, C; Xia, H; Camus-Kulandaivelu, L; Städler, T; Stephan, W

2011-09-01

14

[Optimal timing of pediatric surgery to prevent deleterious effects on associated cardiac defects].  

PubMed

Although cardiac defects are thought to have deleterious effects on the outcome of general pediatric surgery due to low cardiac output syndrome and hypoxemia, both pediatric surgery and cardiac surgery can be performed at the optimal timing with good results. However, some conditions requiring pediatric surgery may have deleterious effects on the outcome of cardiac surgery. Airway obstructive diseases sometimes require concomitant repair of the associated cardiac defects. In particular, tracheal stenosis may be repaired in cooperation with not only general pediatric and cardiac surgeons but also with pediatric thoracic surgeons who work in other healthcare institutions. Low birth-weight infants with symptomatic patent ductal artery are at risk of poor outcome. For patients with right isomerism, midgut malrotation or sliding hernia should be diagnosed early and repaired at the optimal timing to prevent urgent surgical intervention. Pediatric surgery should be performed at the optimal timing to prevent any deleterious effects on cardiac defects. Moreover, respiratory infection and neurologic disease should be treated to reduce late deaths. PMID:21819010

Kawata, Hiroaki

2011-07-01

15

Resveratrol inhibits the deleterious effects of diet-induced obesity on thymic function.  

PubMed

Obesity is associated with an increased risk of infectious diseases. It has been shown to have deleterious effects on cell-mediated immunity, including reducing thymocyte numbers and altering responses of thymocytes to pathogens. In the current study, we examined the efficacy of the antiobesity phytochemical resveratrol in preventing the deleterious effects of a high-fat diet on thymic anatomy and function. Compared to C57Bl/6 male mice fed a low-fat diet, mice on a high-fat diet had a significant increase in thymic weight and lipid content, and a disrupted anatomy, including a reduction of the medullary compartment and absence of a corticomedullary junction. There were a decrease in thymic cellularity and mature T-cell output, and a disrupted T-cell maturation, as evidenced by increased double-negative and decreased single- and double-positive thymocytes. Mice that had been fed resveratrol along with a high-fat diet had a dose-dependent reversal in all these parameters. Western blots from thymi showed that obese mice had lower levels of the key stimulators of lipid metabolism, phospho-5' adenosine monophosphate-activated protein kinase and its downstream target, carnitine palmitoyl transferase-1; this was restored to normal levels in resveratrol-fed mice. Resveratrol also reversed an increase in glycerol-3-phosphate acyltransferase-1, the enzyme that catalyzes the first step in triglycerol synthesis. Taken together, these results indicate that resveratrol is a potent inhibitor of the deleterious effects of diet-induced obesity on thymic anatomy and function, and this may hold promise in preventing obesity-related deficits in cell-mediated immunity. PMID:23561698

Gulvady, Apeksha A; Ciolino, Henry P; Cabrera, Robert M; Jolly, Christopher A

2013-09-01

16

Certitudes and controversies regarding the deleterious effects of low doses ionizing radiation.  

PubMed

The problem of the deleterious effects of ionizing radiation must be a constant preoccupation of the medical staff. We must never forget that radiations can cure (by increasing the diagnostic accuracy and by the benefic use of radiotherapy), but can also generate cancer and genomic instability. All the governments have the desire to use the "cheap" (it's cheap when you do not take into consideration all the spenditures regarding the monitorisation of radiation workers and the cost of decontamination) nuclear energy. We must underline, also, the fact that a too frequent exposure to ionizing radiation (especially by CT examinations) is generating undesired consequences, and that the direct irradiation and the bystander effect can create a genomic instability that is "transferred" to the following generation. As, nowadays, it is almost impossible to live in an environment devoid of risks, we must try to reduce them significantly. PMID:23610975

B?lan, H; B?l?ceanu, Alice Lavinia

2012-01-01

17

Morphine has latent deleterious effects on the ventilatory responses to a hypoxic-hypercapnic challenge  

PubMed Central

This study explored the concept that morphine has latent deleterious actions on the ventilatory control systems that respond to a hypoxic-hypercapnic challenge. In this study, we examined the ventilatory responses elicited by hypoxic-hypercapnic challenge in conscious rats at a time when the effects of morphine (10 mg/kg) on arterial blood-gas chemistry and minute ventilation had subsided. Morphine induced pronounced changes in arterial blood-gas chemistry (e.g., an increase in pCO2, decreases in pO2 and sO2) and decreases in minute ventilation. Despite the complete resolution of the morphine-induced changes in arterial blood-gas chemistry and minute ventilation and almost complete resolution of the effects on peak inspiratory flow and peak expiratory flow, subsequent exposure to hypoxic-hypercapnic challenge elicited markedly blunted increases in minute ventilation and in peak inspiratory and expiratory flows. These findings demonstrate that (1) the changes in arterial blood-gas chemistry elicited by morphine parallel changes in minute ventilation rather than PIF and PEF, and (2) morphine has latent untoward effects on the ventilatory responses to hypoxic-hypercapnic challenge. These novel findings raise the possibility that patients deemed to have recovered from the acute ventilatory depressant effects of morphine may still be susceptible to the latent effects of this opioid analgesic. The mechanisms underlying these latent effects remain to be elucidated. PMID:25045592

May, Walter J.; Henderson, Fraser; Gruber, Ryan B.; Discala, Joseph F.; Young, Alex P.; Bates, James N.; Palmer, Lisa A.; Lewis, Stephen J.

2014-01-01

18

Erythropoietin promotes deleterious cardiovascular effects and mortality risk in a rat model of chronic sports doping.  

PubMed

Athletes who abuse recombinant human erythropoietin (rhEPO) consider only the benefit to performance and usually ignore the potential short and long-term liabilities. Elevated haematocrit and dehydratation associated with intense exercise may reveal undetected cardiovascular risk, but the mechanisms underlying it remain to be fully explained. This study aimed to evaluate the cardiovascular effects of rhEPO in rats under chronic aerobic exercise. A ten week protocol was performed in four male Wistar rat groups: control--sedentary; rhEPO--50 IU kg(-1), 3 times/wk; exercised (EX)--swimming for 1 h, 3 times/wk; EX + rhEPO. One rat of the EX + rhEPO group suffered a sudden death episode during the week 8. rhEPO in trained rats promoted erythrocyte count increase, hypertension, heart hypertrophy, sympathetic and serotonergic overactivation. The suddenly died rat's tissues presented brain with vascular congestion; left ventricular hypertrophy, together with a "cardiac-liver", suggesting the hypothesis of heart failure as cause of sudden death. In conclusion, rhEPO doping in rats under chronic exercise promotes not only the expected RBC count increment, suggesting hyperviscosity, but also other serious deleterious cardiovascular and thromboembolic modifications, including mortality risk, which might be known and assumed by all sports authorities, including athletes and their physicians. PMID:19859831

Piloto, Nuno; Teixeira, Helena M; Teixeira-Lemos, Edite; Parada, Belmiro; Garrido, Patrícia; Sereno, José; Pinto, Rui; Carvalho, Lina; Costa, Elísio; Belo, Luís; Santos-Silva, Alice; Teixeira, Frederico; Reis, Flávio

2009-12-01

19

Multiple deleterious effects of experimentally aged sperm in a monogamous bird.  

PubMed

Sperm aging is known to be detrimental to reproductive performance. However, this apparently general phenomenon has seldom been studied in an evolutionary context. The negative impact of sperm aging on parental fitness should constitute a strong selective pressure for adaptations to avoid its effects. We studied the impact of sperm aging on black-legged kittiwakes (Rissa tridactyla), a monogamous seabird. Kittiwakes comprise a model system because (i) of evidence that females eject their mates' sperm to prevent fertilization by sperm that would be old and degraded by the time of fertilization and result in reduced reproductive performance and (ii) the lack of extra-pair fertilization in this species makes cryptic female choice an unlikely explanation of postcopulatory sperm ejection by females. We experimentally manipulated the age of the sperm fertilizing kittiwake eggs by fitting males with anti-insemination rings for variable periods of time preceding egg-laying. We found evidence that sperm aging negatively affected four sequential stages of reproduction: fertilization potential, rate of embryonic development, embryonic mortality, and chick condition at hatching. These results may be produced by a continuum of a single process of sperm aging that differentially affects various aspects of development, depending on the degree of damage incurred to the spermatozoa. The marked impact of sperm age on female fitness may thus drive postcopulatory sperm ejection by females. These results provide experimental evidence of deleterious effects of sperm aging on a nondomestic vertebrate, underlining its taxonomic generality and its potential to select for a wide array of adaptations. PMID:18779581

White, Joël; Wagner, Richard H; Helfenstein, Fabrice; Hatch, Scott A; Mulard, Hervé; Naves, Liliana C; Danchin, Etienne

2008-09-16

20

Guard crabs alleviate deleterious effects of vermetid snails on a branching coral  

NASA Astrophysics Data System (ADS)

Stony corals provide important structural habitat for microbes, invertebrates, and fishes, which in some cases has led to the evolution of beneficial interactions that may protect corals from environmental factors such as thermal stress, nutrient limitation, competitors, or predators. For example, guard crabs ( Trapezia spp.) protect corals ( Pocillopora sp.) from attacks by crown-of-thorn seastar and sedimentation. Here, a field experiment demonstrates that guard crabs ( Trapezia serenei) also ameliorate the strong negative effects of the giant vermetid ( Dendropoma maximum) on growth of Pocillopora. This experiment highlights the importance of this crab-coral mutualism: guard crabs facilitate the growth of corals in stressful environments (e.g., where vermetids are abundant), thereby preserving the ecological goods and services (e.g., food and shelter) that these corals may provide to other reef-associated species.

Stier, A. C.; McKeon, C. S.; Osenberg, C. W.; Shima, J. S.

2010-12-01

21

Deleterious cognitive and motoric effects of haloperidol in an adolescent with cerebral palsy: a case report.  

PubMed

This case report describes a 15-year-old male patient with spastic diplegic cerebral palsy, Gross Motor Function Classification System Level III, who developed severe new cognitive and motoric impairments after the administration of haloperidol. He received this dopamine antagonist and typical antipsychotic medication for an acute postoperative episode of agitation. He improved when he received the dopamine agonists amantadine and carbidopa/levodopa. This case suggests that dopamine blockade may be deleterious for individuals with cerebral palsy. Potential explanations for the events observed in this case are also presented. PMID:24332231

Mortimer, Diane; Gelfius, Carl D; Potts, Michelle A

2013-12-01

22

Duration of sexual harassment and generalized harassment in the workplace over ten years: effects on deleterious drinking outcomes.  

PubMed

Although harassment in the workplace has been linked to deleterious drinking outcomes, researchers have yet to examine the long-term effects of chronic workplace harassment. During a 10-year longitudinal mail survey, university employees (N = 2,265) were administered measures of sexual harassment, generalized workplace harassment, and problematic drinking. Using growth mixture modeling, two latent classes of workplace harassment emerged: infrequent and chronic. Demographic characteristics (gender, age, and race) predicted the shape of the trajectories and likelihood of class membership. As hypothesized, membership in the chronic harassment classes was linked to future problematic drinking, even after controlling for previous drinking. PMID:21745045

McGinley, Meredith; Richman, Judith A; Rospenda, Kathleen M

2011-01-01

23

Duration of Sexual Harassment and Generalized Harassment in the Workplace Over Ten Years: Effects on Deleterious Drinking Outcomes  

PubMed Central

While harassment in the workplace has been linked to deleterious drinking outcomes, researchers have yet to examine the long-term effects of chronic workplace harassment. During a ten year longitudinal mail survey, university employees (N = 2265) were administered measures of sexual harassment, generalized workplace harassment, and problematic drinking. Using growth mixture modeling, two latent classes of workplace harassment emerged: infrequent and chronic. Demographic characteristics (gender, age, and race) predicted the shape of the trajectories and likelihood of class membership. As hypothesized, membership in the chronic harassment classes was linked to future problematic drinking, even after controlling for previous drinking. PMID:21745045

McGinley, Meredith; Richman, Judith A.; Rospenda, Kathleen M.

2012-01-01

24

The role of aromatase inhibitors in ameliorating deleterious effects of ovarian stimulation on outcome of infertility treatment  

PubMed Central

Clinical utilization of ovulation stimulation to facilitate the ability of a couple to conceive has not only provided a valuable therapeutic approach, but has also yielded extensive information on the physiology of ovarian follicular recruitment, endometrial receptivity and early embryo competency. One of the consequences of the use of fertility enhancing agents for ovarian stimulation has been the creation of a hyperestrogenic state, which may influence each of these parameters. Use of aromatase inhibitors reduces hyperestrogenism inevitably attained during ovarian stimulation. In addition, the adjunct use of aromatase inhibitors during ovarian stimulation reduces amount of gonadotropins required for optimum stimulation. The unique approach of reducing hyperestrogenism, as well as lowering amount of gonadotropins without affecting the number of mature ovarian follicles is an exciting strategy that could result in improvement in the treatment outcome by ameliorating the deleterious effects of the ovarian stimulation on follicular development, endometrial receptivity, as well as oocyte and embryo quality. PMID:16202169

Mitwally, Mohamed FM; Casper, Robert F; Diamond, Michael P

2005-01-01

25

Maternal caloric restriction partially rescues the deleterious effects of advanced maternal age on offspring  

PubMed Central

SUMMARY While many studies have focused on the detrimental effects of advanced maternal age and harmful prenatal environments on progeny, little is known about the role of beneficial non-Mendelian maternal inheritance on aging. Here we report the effects of maternal age and maternal caloric restriction (CR) on the lifespan and healthspan of offspring for a clonal culture of the monogonont rotifer Brachionus manjavacas. Mothers on CR regimens of chronic CR (CCR) or intermittent fasting (IF) had increased lifespan compared to mothers fed ad libitum (AL). With increasing maternal age, lifespan and fecundity of female offspring of AL fed mothers decreased significantly and lifespan of male offspring was unchanged, while body size of both male and female offspring increased. Maternal CR partially rescued these effects, increasing the mean lifespan of AL fed female offspring but not male offspring and increasing the fecundity of AL fed female offspring compared to offspring of mothers of the same age. Both maternal CR regimens decreased male offspring body size, but only maternal IF decreased body size of female offspring, while maternal CCR caused a slight increase. Understanding the genetic and biochemical basis of these different maternal effects on aging may guide effective interventions to improve healthspan and lifespan. PMID:24661622

Gribble, Kristin E.; Jarvis, George; Bock, Martha; Mark Welch, David B.

2014-01-01

26

The Stigma of Mental Illness and its Deleterious Effects on Psychiatric Treatment and Recovery  

Microsoft Academic Search

In spite of the 1960s social justice movements, discrimination against the mentally ill remains a pervasive problem. The stigma that routinely accompanies the diagnosis of a mental disorder prevents victims suffering in silence from seeking treatment and inhibits the recovery of those patients who have already been diagnosed. This paper examines the nature of this prejudice and its tangible effects,

Ashley Doty

2006-01-01

27

Knowledge about the Deleterious Effects of Smoking and Its Relationship to Smoking Cessation among Pregnant Adolescents.  

ERIC Educational Resources Information Center

Examines adolescents' knowledge of the detrimental effects of smoking on pregnant women and fetuses and its relationship to efforts to quit smoking with a sample of pregnant adolescents (N=71). A three-group randomized intervention design -- Teen FreshStart, Teen Freshstart with buddy, and usual care control -- was used. Results show that…

Albrecht, Susan A.; Higgins, Linda W.; Lebow, Howard

2000-01-01

28

Genistein Induces Deleterious Effects during Its Acute Exposure in Swiss Mice  

PubMed Central

Genistein is a soy derived isoflavone. It has wide variety of therapeutic effects against certain diseases including cancer. Although toxic effects of genistein have been studied, its effect on the gene expression and the reason behind toxicity have not been identified yet. In the present study, genistein was administered to age and body weight matched Swiss mice at the doses of 125, 250, 500 and 1000?mg/kg. The biomarkers of hepatotoxicity in serum, liver histology, oxidative stress parameters in tissue homogenates, and global gene expression were examined. Elevated alanine aminotransferase (ALT), aspartate aminotransferase (AST), and alkaline phosphatase (ALP) levels and degenerated liver tissue were observed in 500, and 1000?mg/kg genistein treated groups. Oxidative stress was significant at these doses as considerable increase in lipid peroxidation (LPO) and decrease in total glutathione (GSH) were observed. Gene expression analysis showed 40 differentially expressed genes at twofold change and P < 0.05. Differentially expressed genes were corresponding to different biologically relevant pathways including metabolic and oxidative stress pathways. In 500?mg/kg group, Cyp4a14, Sult1e1, Gadd45g, Cidec, Mycs, and so forth genes were upregulated. These results suggested that the higher dose of genistein can produce several undesirable effects by affecting multiple cellular pathways. PMID:24967385

Singh, Prabhat; Sharma, Sharad; Kumar Rath, Srikanta

2014-01-01

29

Brief Report: Labelling Effects on the Perceived Deleterious Consequences of Pop Music Listening  

ERIC Educational Resources Information Center

Several correlational studies have supported the claim of conservative protestors that there exists a positive relationship between listening to pop music and adolescent problem behaviours. However, research on the so-called 'prestige effects' has shown that experimental participants' responses to music can be mediated by manipulations of prior…

North, A.C.; Hargreaves, D.J.

2005-01-01

30

Hyperfractionation decreases the deleterious effects of conventional radiation fractionation on vertebral growth in animals  

SciTech Connect

Craniospinal axis irradiation in the treatment of pediatric tumors is associated with serious long-term sequelae including decreased bone growth (short sitting stature). In this study, an animal model was used to determine the effects of smaller incremental doses of radiation on bone growth. Sprague-Dawley weanling rats were given 25 Gy to the spine in 8 to 9 days, with fraction sizes ranging from 1.0 to 1.8 Gy. The animals receiving smaller doses per fraction (1.0 or 1.25 Gy) showed significantly more growth of the vertebral bodies in the treated fields than animals given larger incremental doses (1.5 or 1.8 Gy). These findings indicate a protective effect on bone growth for hyperfractionated irradiation of vertebral bodies.

Hartsell, W.F.; Hanson, W.R.; Conterato, D.J.; Hendrickson, F.R.

1989-06-15

31

Deleterious effects of a low amount of ethanol on LTP-like plasticity in human cortex.  

PubMed

Ingesting ethanol (EtOH) at low doses during social drinking is a common human behavior for its facilitating effects on social interactions. However, low-dose EtOH may have also detrimental effects that so far are underexplored. Here we sought to test the effects of low-dose EtOH on long-term potentiation (LTP)-like plasticity in human motor cortex. Previous cellular experiments showed that low-dose EtOH potentiates extrasynaptic GABAAR and reduces NMDAR-mediated currents, processes that would limit the expression of LTP. Paired associative transcranial magnetic stimulation (PASLTP) was employed in nine healthy subjects for induction of LTP-like plasticity, indexed by a long-term increase in motor-evoked potential input-output curves. Synaptic ?1-GABAAR function was measured by saccadic peak velocity (SPV). Very low doses of EtOH (resulting in blood concentrations of <5 mM) suppressed LTP-like plasticity but did not affect SPV when compared with a placebo condition. In contrast, 1 mg of alprazolam, a classical benzodiazepine, or 10 mg of zolpidem, a non-benzodiazepine hypnotic, decreased SPV but did not significantly affect LTP-like plasticity when compared with placebo. This double dissociation of low-dose EtOH vs alprazolam/zolpidem effects is best explained by the putatively high affinity of EtOH but not alprazolam/zolpidem to extrasynaptic GABAARs and to NMDARs. Findings suggest that enhancement of extrasynaptic GABAAR-mediated tonic inhibition and/or reduction of NMDAR-mediated neurotransmission by EtOH blocks LTP-like plasticity in human cortex at very low doses that are easily reached during social drinking. Therefore, low-dose EtOH may jeopardize LTP-dependent processes, such as learning and memory formation. PMID:24385131

Lücke, Caroline; Heidegger, Tonio; Röhner, Mirjam; Toennes, Stefan W; Krivanekova, Lucia; Müller-Dahlhaus, Florian; Ziemann, Ulf

2014-05-01

32

Deleterious effects of cypermethrin on semen characteristics and testes of dwarf goats ( Capra hircus)  

Microsoft Academic Search

This study was carried out on 30 male dwarf goats to determine the effects of cypermethrin (CY) on semen characteristics and at tissue level in testes. Animals were divided randomly into five equal groups and each group was dipped with 0%, 0.1%, 0.4%, 0.8% or 1.6% CY, on days 0 and 15. The semen was collected at day 0, then

Maqbool Ahmad; Ijaz Hussain; Ahrar Khan; Najib-ur-Rehman

2009-01-01

33

Long-term treatment with strontium ranelate increases vertebral bone mass without deleterious effect in mice  

Microsoft Academic Search

It was previously shown that strontium ranelate (SR; S12911-PROTOS[reg ], Institut de Recherches Internationales Servier, Courbevoie, France) can modulate bone metabolism in rats and mice. To determine the long-term effects of SR on vertebral bone metabolism in adult mice, the compound or the vehicle was given in the diet to normal male and female mice for 104 weeks at the

P. Delannoy; D. Bazot; P. J. Marie

2002-01-01

34

Poloxomer 188 Has a Deleterious Effect on Dystrophic Skeletal Muscle Function  

PubMed Central

Duchenne muscular dystrophy (DMD) is an X-linked, fatal muscle wasting disease for which there is currently no cure and limited palliative treatments. Poloxomer 188 (P188) is a tri-block copolymer that has been proposed as a potential treatment for cardiomyopathy in DMD patients. Despite the reported beneficial effects of P188 on dystrophic cardiac muscle function, the effects of P188 on dystrophic skeletal muscle function are relatively unknown. Mdx mice were injected intraperitoneally with 460 mg/kg or 30 mg/kg P188 dissolved in saline, or saline alone (control). The effect of single-dose and 2-week daily treatment was assessed using a muscle function test on the Tibialis Anterior (TA) muscle in situ in anaesthetised mice. The test comprises a warm up, measurement of the force-frequency relationship and a series of eccentric contractions with a 10% stretch that have previously been shown to cause a drop in maximum force in mdx mice. After 2 weeks of P188 treatment at either 30 or 460 mg/kg/day the drop in maximum force produced following eccentric contractions was significantly greater than that seen in saline treated control mice (P?=?0.0001). Two week P188 treatment at either dose did not significantly change the force-frequency relationship or maximum isometric specific force produced by the TA muscle. In conclusion P188 treatment increases susceptibility to contraction-induced injury following eccentric contractions in dystrophic skeletal muscle and hence its suitability as a potential therapeutic for DMD should be reconsidered. PMID:24642557

Terry, Rebecca L.; Kaneb, Hannah M.; Wells, Dominic J.

2014-01-01

35

Deleterious effects of endotoxin on cultured endothelial cells: an in vitro model of vascular injury  

SciTech Connect

The effects of endotoxin-triggered granulocytes on the viability of endothelial cells in vitro was investigated. Endotoxin or its lipid A component caused granulocytes to adhere to and significantly damage cultured endothelial cells. Fresh serum is not necessary but does amplify both adherence and endothelial injury. Much of the endothelial injury was inhibited by free-radical scavengers or by blocking granulocyte adhesion to endothelial cells and appears to result from free radical production by the stimulated granulocyte. Studies in this model suggest a pathogenic role for the endotoxin-triggered granulocyte in the Shwartzman reaction and perhaps related clinical disorders.

Yamada, O.; Moldow, C.F.; Sacks, T.; Craddock, P.R.; Boogaerts, M.A.; Jacob, H.S.

1981-06-01

36

L-Cysteine ethyl ester reverses the deleterious effects of morphine on, arterial blood-gas chemistry in tracheotomized rats.  

PubMed

This study determined whether the membrane-permeable ventilatory stimulant, L-cysteine ethylester (L-CYSee), reversed the deleterious actions of morphine on arterial blood-gas chemistry in isoflurane-anesthetized rats. Morphine (2 mg/kg, i.v.) elicited sustained decreases in arterial blood pH, pO? and sO?, and increases in pCO? (all responses indicative of hypoventilation) and alveolar-arterial gradient (indicative of ventilation-perfusion mismatch). Injections of L-CYSee (100 ?mol/kg, i.v.) reversed the effects of morphine in tracheotomized rats but were minimally active in non-tracheotomized rats. L-cysteine or L-serine ethylester (100 ?mol/kg, i.v.) were without effect. It is evident that L-CYSee can reverse the negative effects of morphine on arterial blood-gas chemistry and alveolar-arterial gradient but that this positive activity is negated by increases in upper-airway resistance. Since L-cysteine and L-serine ethylester were ineffective, it is evident that cell penetrability and the sulfur moiety of L-CYSee are essential for activity. Due to its ready penetrability into the lungs, chest wall muscle and brain, the effects of L-CYSee on morphine-induced changes in arterial blood-gas chemistry are likely to involve both central and peripheral sites of action. PMID:23892097

Mendoza, James; Passafaro, Rachael; Baby, Santhosh; Young, Alex P; Bates, James N; Gaston, Benjamin; Lewis, Stephen J

2013-10-01

37

Acetaldehyde Content and Oxidative Stress in the Deleterious Effects of Alcohol Drinking on Rat Uterine Horn  

PubMed Central

After alcohol exposure through a standard Lieber and De Carli diet for 28 days, a severe atrophy in the rat uteirne horn was observed, accompanied by significant alterations in its epithelial cells. Microsomal pathway of acetaldehyde production was slightly increased. Hydroxyl radicals were detected in the cytosolic fraction, and this was attributed to participation of xanthine oxidoreductase. They were also observed in the microsomal fraction in the presence of NADPH generating system. No generation of 1-hydroxyethyl was evidenced. The t-butylhydroperoxide-induced chemiluminescence analysis of uterine horn homogenates revealed a significant increase in the chemiluminiscence emission due to ethanol exposure. In the animals repeatedly exposed to alcohol, sulfhydryl content from uterine horn proteins was decreased, but no significant changes were observed in the protein carbonyl content from the same samples. Minor but significant decreasing changes were observed in the GSH content accompanied by a tendency to decrease in the GSH/GSSG ratio. A highly significant finding was the diminished activity content of glutathione peroxidase. Results suggest that acetaldehyde accumulation plus the oxidative stress may play an additional effect to the alcohol-promoted hormonal changes in the uterus reported by others after chronic exposure to alcohol. PMID:24348548

Buthet, Lara Romina; Maciel, Maria Eugenia; Quintans, Leandro Nestor; Rodriguez de Castro, Carmen; Costantini, Martin Hernan; Castro, Jose Alberto

2013-01-01

38

No deleterious effect of low dose methotrexate on titanium implant osseointegration in a rabbit model  

PubMed Central

OBJECTIVE: To evaluate the effect of low dose methotrexate alone or in combination with glucocorticoid treatment on titanium implant osseointegration. METHODS: Groups of 6–8 adult New Zealand White rabbits were treated for 18 weeks with saline (control), methotrexate, glucocorticoid, or methotrexate plus glucocorticoid. The animals received a titanium implant in the tibia at week 6. Lumbar spine and tibia bone mineral densities were analyzed before and after treatment. Histomorphometric analysis of bone cortical thickness, total bone area around the implant, and % of bone to implant contact was performed. RESULTS: After 18 weeks, the change in the bone mineral density in the lumbar spines and tibias in the methotrexate group was comparable to the control group (0.035 vs. 0.055 g/cm2 and 0.021 vs. 0.041 g/cm2, respectively). In contrast, both the glucocorticoid group and glucocorticoid plus methotrexate group had significant reductions at both sites. Histomorphometric analysis of the tibia in the control and methotrexate groups revealed no significant changes in cortical thickness (133 vs. 126 µm), total bone area around the implant (33 vs. 30%), or bone to implant contact (40 vs. 38%). In contrast, glucocorticoid group had significant reductions compared to controls in tibia cortical thickness (99 vs. 133 µm), total bone area around the implant (24 vs. 33%), and bone to implant contact (27 vs. 40%). Similar reductions were observed in the glucocorticoid plus methotrexate group. CONCLUSIONS: Our results demonstrate that low dose methotrexate treatment does not affect titanium implant osseointegration, suggesting that this therapy is safe for surgical procedures requiring a titanium implant. PMID:21808875

Carvas, Janaina Badin; Pereira, Rosa Maria Rodrigues; Bonfa, Eloisa; Silveira, Celey Aparecida; Lima, Luiz Lapa; de Falco Caparbo, Valeria; de Mello, Suzana Beatriz Verissimo

2011-01-01

39

TLR4 Inhibits Mesenchymal Stem Cell (MSC) STAT3 Activation and Thereby Exerts Deleterious Effects on MSC-Mediated Cardioprotection  

PubMed Central

Background Bone marrow-derived mesenchymal stem cells (MSC) improve myocardial recovery after ischemia/reperfusion (I/R) injury. These effects are mediated in part by the paracrine secretion of angiogenic and tissue growth-promoting factors. Toll-like receptor 4 (TLR4) is expressed by MSC and induces apoptosis and inhibits proliferation in neuronal progenitors as well as many other cell types. It is unknown whether knock-out (KO) of TLR4 will change the paracrine properties of MSC and in turn improve MSC-associated myocardial protection. Methodology/Principal Findings This study explored the effect of MSC TLR4 on the secretion of angiogenic factors and chemokines in vitro by using ELISA and cytokine array assays and investigated the role of TLR4 on MSC-mediated myocardial recovery after I/R injury in an isolated rat heart model. We observed that MSC isolated from TLR4 KO mice exhibited a greater degree of cardioprotection in a rat model of myocardial I/R injury. This enhanced protection was associated with increased angiogenic factor production, proliferation and differentiation. TLR4-dificiency was also associated with decreased phosphorylation of PI-3K and AKT, but increased activation of STAT3. siRNA targeting of STAT3 resulted in attenuation of the enhanced cardioprotection of TLR4-deficient MSC. Conclusions/Significance This study indicates that TLR4 exerts deleterious effects on MSC-derived cardioprotection following I/R by a STAT3 inhibitory mechanism. PMID:21151968

Herrmann, Jeremy L.; Weil, Brent R.; Manukyan, Mariuxi C.; Poynter, Jeffrey A.; Meldrum, Daniel R.

2010-01-01

40

BCG and BCG/DNAhsp65 Vaccinations Promote Protective Effects without Deleterious Consequences for Experimental Autoimmune Encephalomyelitis  

PubMed Central

A prime-boost strategy conserving BCG is considered the most promising vaccine to control tuberculosis. A boost with a DNA vaccine containing the mycobacterial gene of a heat shock protein (pVAXhsp65) after BCG priming protected mice against experimental tuberculosis. However, anti-hsp65 immunity could worsen an autoimmune disease due to molecular mimicry. In this investigation, we evaluated the effect of a previous BCG or BCG/pVAXhsp65 immunization on experimental autoimmune encephalomyelitis (EAE) development. Female Lewis rats were immunized with BCG or BCG followed by pVAXhsp65 boosters. The animals underwent EAE induction and were daily evaluated for weight loss and clinical score. They were euthanized during recovery phase to assess immune response and inflammatory infiltration at the central nervous system. Previous immunization did not aggravate or accelerate clinical score or weight loss. In addition, this procedure clearly decreased inflammation in the brain. BCG immunization modulated the host immune response by triggering a significant reduction in IL-10 and IFN-? levels induced by myelin basic protein. These data indicated that vaccination protocols with BCG or BCG followed by boosters with pVAXhsp65 did not trigger a deleterious effect on EAE evolution. PMID:24288555

Zorzella-Pezavento, Sofia Fernanda Goncalves; Guerino, Clara Pires Fujiara; Chiuso-Minicucci, Fernanda; Franca, Thais Graziela Donega; Ishikawa, Larissa Lumi Watanabe; Masson, Ana Paula; Silva, Celio Lopes; Sartori, Alexandrina

2013-01-01

41

Tanshinol Attenuates the Deleterious Effects of Oxidative Stress on Osteoblastic Differentiation via Wnt/FoxO3a Signaling  

PubMed Central

There is now increasing evidence which suggests a pivotal role for oxidative stress in the development and progression of osteoporosis. We confirm herein the protective effects of natural antioxidant Tanshinol against oxidative stress in osteoblastic differentiation and the underlying mechanism. Our results show that hydrogen peroxide (H2O2) leads to accumulation of reactive oxygen species (ROS), decrease in cell viability, cell cycle arrest and apoptosis in a caspase-3-dependent manner, and inhibition of osteoblastic differentiation. Tanshinol reverses these deleterious consequence triggered by oxidative stress. Moreover, under the condition of oxidative stress, Tanshinol suppresses the activation of FoxO3a transcription factor and expressions of its target genes Gadd45a and catalase (CAT) and simultaneously counteracts the inhibition of Wnt signalling and expressions of target genes Axin2, alkaline phosphatase (ALP), and Osteoprotegerin (OPG). The findings are further consolidated using FoxO3a siRNA interference and overexpression of Tcf4. The results illustrate that Tanshinol attenuates oxidative stress via down-regulation of FoxO3a signaling, and rescues the decrease of osteoblastic differentiation through upregulation of Wnt signal under oxidative stress. The present findings suggest that the beneficial effects of Tanshinol may be adopted as a novel therapeutic approach in recently recognized conditions of niche targeting osteoporosis. PMID:24489983

Yang, Yajun; Su, Yanjie; Wang, Dongtao; Chen, Yahui; Wu, Tie; Li, Gang; Sun, Xuegang

2013-01-01

42

C5aR-antagonist significantly reduces the deleterious effect of a blunt chest trauma on fracture healing  

PubMed Central

Confirming clinical evidence, we recently demonstrated that a blunt chest trauma considerably impaired fracture healing in rats, possibly via the interaction of posttraumatic systemic inflammation with local healing processes, the underlying mechanisms being unknown. An important trigger of systemic inflammation is the complement system, with the potent anaphylatoxin C5a. Therefore, we investigated whether the impairment of fracture healing by a severe trauma resulted from systemically activated complement. Rats received a blunt chest trauma and a femur osteotomy stabilized with an external fixator. To inhibit the C5a dependent posttraumatic systemic inflammation, half of the rats received a C5aR-antagonist intravenously immediately and 12 h after the thoracic trauma. Compared to the controls (control peptide), the treatment with the C5aR-antagonist led to a significantly increased flexural rigidity (three-point-bending test), an improved bony bridging of the fracture gap, and a slightly larger and qualitatively improved callus (?CT, histomorphometry) after 35 days. In conclusion, immunomodulation by a C5aR-antagonist could abolish the deleterious effects of a thoracic trauma on fracture healing, possibly by influencing the function of inflammatory and bone cells locally at the fracture site. C5a could possibly represent a target to prevent delayed bone healing in patients with severe trauma. PMID:21922535

Recknagel, Stefan; Bindl, Ronny; Kurz, Julian; Wehner, Tim; Schongraf, Phillip; Ehrnthaller, Christian; Qu, Hongchang; Gebhard, Florian; Huber-Lang, Markus; Lambris, John D.; Claes, Lutz; Ignatius, Anita

2011-01-01

43

Ecological Effects in Malaria Vaccine Effectiveness in  

E-print Network

Ecological Effects in Malaria Vaccine Effectiveness in Lilongwe, Malawi Cameron Taylor B component to a GlaxoSmithKline phase III trial vaccine trial so that researchers can better understand distribution and the ecological effects of both malaria transmission intensity and vaccine efficacy

Doyle, Martin

44

Ecological effects of environmental change.  

PubMed

This Special Issue of Ecology Letters presents contributions from an international meeting organised by Centre National de la Recherche Scientifique (CNRS) and Ecology Letters on the broad theme of ecological effects of global environmental change. The objectives of these articles are to synthesise, hypothesise and illustrate the ecological effects of environmental change drivers and their interactions, including habitat loss and fragmentation, pollution, invasive species and climate change. A range of disciplines is represented, including stoichiometry, cell biology, genetics, evolution and biodiversity conservation. The authors emphasise the need to account for several key ecological factors and different spatial and temporal scales in global change research. They also stress the importance of ecosystem complexity through approaches such as functional group and network analyses, and of mechanisms and predictive models with respect to environmental responses to global change across an ecological continuum: population, communities and ecosystems. Lastly, these articles provide important insights and recommendations for environmental conservation and management, as well as highlighting future research priorities. PMID:23679008

Luque, Gloria M; Hochberg, Michael E; Holyoak, Marcel; Hossaert, Martine; Gaill, Françoise; Courchamp, Franck

2013-05-01

45

Harnessing Mechanistic Knowledge on Beneficial Versus Deleterious IFN-I Effects to Design Innovative Immunotherapies Targeting Cytokine Activity to Specific Cell Types  

PubMed Central

Type I interferons (IFN-I) were identified over 50?years ago as cytokines critical for host defense against viral infections. IFN-I promote anti-viral defense through two main mechanisms. First, IFN-I directly reinforce or induce de novo in potentially all cells the expression of effector molecules of intrinsic anti-viral immunity. Second, IFN-I orchestrate innate and adaptive anti-viral immunity. However, IFN-I responses can be deleterious for the host in a number of circumstances, including secondary bacterial or fungal infections, several autoimmune diseases, and, paradoxically, certain chronic viral infections. We will review the proposed nature of protective versus deleterious IFN-I responses in selected diseases. Emphasis will be put on the potentially deleterious functions of IFN-I in human immunodeficiency virus type 1 (HIV-1) infection, and on the respective roles of IFN-I and IFN-III in promoting resolution of hepatitis C virus (HCV) infection. We will then discuss how the balance between beneficial versus deleterious IFN-I responses is modulated by several key parameters including (i) the subtypes and dose of IFN-I produced, (ii) the cell types affected by IFN-I, and (iii) the source and timing of IFN-I production. Finally, we will speculate how integration of this knowledge combined with advanced biochemical manipulation of the activity of the cytokines should allow designing innovative immunotherapeutic treatments in patients. Specifically, we will discuss how induction or blockade of specific IFN-I responses in targeted cell types could promote the beneficial functions of IFN-I and/or dampen their deleterious effects, in a manner adapted to each disease.

Tomasello, Elena; Pollet, Emeline; Vu Manh, Thien-Phong; Uze, Gilles; Dalod, Marc

2014-01-01

46

Nonmicrowave health and ecological effects: Overview  

NASA Technical Reports Server (NTRS)

The potential environmental impacts due to the operation and construction of the Satellite Power System are discussed. The nonmicrowave health and ecological effects encompass impacts on the public, the terrestrial worker, the space worker, the ecology, and agriculture.

White, M. R.

1980-01-01

47

Effectiveness of fly ash in preventing deleterious expansion due to alkali-aggregate reaction [AAR] in normal and steam-cured concrete  

SciTech Connect

A non-reactive and several reactive aggregates were used in concrete specimens with and without two fly ashes (varying in total alkali content) at binder (cement + fly ash) alkali levels ranging from 0.46 to 2.5% and a binder content of 500 kg/m{sup 3} and fly ash/binder ratio of 0.25. Some specimens were steam cured at 75 C for eight hours, and then transferred to 40 C, 100% RH. The expansion behavior of the specimens was monitored over nearly six years, and showed that the effectiveness of the fly ash in preventing deleterious AAR expansion depended on the alkali content of the concrete. At the highest alkali content of 12.5 kg Na{sub 2}O equiv./m{sup 3}, the fly ashes only had a delaying effect (one to several years), whereas at 6.9 kg Na{sub 2}O equiv./m{sup 3} they eliminated deleterious AAR expansions. Generally, for more highly reactive aggregates, and at the 2.5% alkali level, fly ash was less effective at 40 C than 23 C because the rate of AAR expansion was much higher at 40 C. A measurable amount of chemical shrinkage occurred in the first few months in concretes containing fly ash and with high alkali contents, although some of these concretes later expanded and cracked as a result of aggregate reactivity. Fly ash was used in mortar specimens prepared for the expression and analysis of the pore solution and was found to be very effective in reducing the alkalinity of the pore solution a factor contributing to its preventive effects on AAR. It is concluded that the two fly ashes can be used to prevent deleterious AAR expansions in practical situations.

Shayan, A.; Diggins, R.; Ivanusec, I. [CSIRO, Highett, Victoria (Australia). Div. of Building, Construction and Engineering] [CSIRO, Highett, Victoria (Australia). Div. of Building, Construction and Engineering

1996-01-01

48

Testing the ability of non-methylamine osmolytes present in kidney cells to counteract the deleterious effects of urea on structure, stability and function of proteins.  

PubMed

Human kidney cells are under constant urea stress due to its urine concentrating mechanism. It is believed that the deleterious effect of urea is counteracted by methylamine osmolytes (glycine betaine and glycerophosphocholine) present in kidney cells. A question arises: Do the stabilizing osmolytes, non-methylamines (myo-inositol, sorbitol and taurine) present in the kidney cells also counteract the deleterious effects of urea? To answer this question, we have measured structure, thermodynamic stability (?G D (o)) and functional activity parameters (K m and k cat) of different model proteins in the presence of various concentrations of urea and each non-methylamine osmolyte alone and in combination. We observed that (i) for each protein myo-inositol provides perfect counteraction at 1?2 ([myo-inositol]:[urea]) ratio, (ii) any concentration of sorbitol fails to refold urea denatured proteins if it is six times less than that of urea, and (iii) taurine regulates perfect counteraction in a protein specific manner; 1.5?2.0, 1.2?2.0 and 1.0?2.0 ([taurine]:[urea]) ratios for RNase-A, lysozyme and ?-lactalbumin, respectively. PMID:24039776

Khan, Sheeza; Bano, Zehra; Singh, Laishram R; Hassan, Md Imtaiyaz; Islam, Asimul; Ahmad, Faizan

2013-01-01

49

Testing the Ability of Non-Methylamine Osmolytes Present in Kidney Cells to Counteract the Deleterious Effects of Urea on Structure, Stability and Function of Proteins  

PubMed Central

Human kidney cells are under constant urea stress due to its urine concentrating mechanism. It is believed that the deleterious effect of urea is counteracted by methylamine osmolytes (glycine betaine and glycerophosphocholine) present in kidney cells. A question arises: Do the stabilizing osmolytes, non-methylamines (myo-inositol, sorbitol and taurine) present in the kidney cells also counteract the deleterious effects of urea? To answer this question, we have measured structure, thermodynamic stability (?GDo) and functional activity parameters (Km and kcat) of different model proteins in the presence of various concentrations of urea and each non-methylamine osmolyte alone and in combination. We observed that (i) for each protein myo-inositol provides perfect counteraction at 1?2 ([myo-inositol]:[urea]) ratio, (ii) any concentration of sorbitol fails to refold urea denatured proteins if it is six times less than that of urea, and (iii) taurine regulates perfect counteraction in a protein specific manner; 1.5?2.0, 1.2?2.0 and 1.0?2.0 ([taurine]:[urea]) ratios for RNase-A, lysozyme and ?-lactalbumin, respectively. PMID:24039776

Khan, Sheeza; Bano, Zehra; Singh, Laishram R.; Hassan, Md. Imtaiyaz; Islam, Asimul; Ahmad, Faizan

2013-01-01

50

Pyrrolidine Dithiocarbamate Prevents Deleterious Effects of Remote Ischemia\\/Reperfusion Injury on Healing of Colonic Anastomoses in Rats  

Microsoft Academic Search

Background  Pyrrolidine dithiocarbamate (PDTC) is a low-molecular-weight thiol antioxidant and potent inhibitor of nuclear factor-?B (NF-?B)\\u000a activation. It has been shown to attenuate local harmful effects of ischemia\\/reperfusion (I\\/R) injury in many organs. In recent\\u000a animal studies, a delaying effect of remote organ I\\/R injury on the healing of colonic anastomoses has been demonstrated.\\u000a In this study we investigated whether PDTC

Zafer Teke; Faruk Onder Aytekin; Burhan Kabay; Cigdem Yenisey; Cagatay Aydin; Koray Tekin; Mustafa Sacar; Akin Ozden

2007-01-01

51

Cannabidiol provides long-lasting protection against the deleterious effects of inflammation in a viral model of multiple sclerosis: a role for A2A receptors.  

PubMed

Inflammation in the central nervous system (CNS) is a complex process that involves a multitude of molecules and effectors, and it requires the transmigration of blood leukocytes across the blood-brain barrier (BBB) and the activation of resident immune cells. Cannabidiol (CBD), a non-psychotropic cannabinoid constituent of Cannabis sativa, has potent anti-inflammatory and immunosuppressive properties. Yet, how this compound modifies the deleterious effects of inflammation in TMEV-induced demyelinating disease (TMEV-IDD) remains unknown. Using this viral model of multiple sclerosis (MS), we demonstrate that CBD decreases the transmigration of blood leukocytes by downregulating the expression of vascular cell adhesion molecule-1 (VCAM-1), chemokines (CCL2 and CCL5) and the proinflammatory cytokine IL-1?, as well as by attenuating the activation of microglia. Moreover, CBD administration at the time of viral infection exerts long-lasting effects, ameliorating motor deficits in the chronic phase of the disease in conjunction with reduced microglial activation and pro-inflammatory cytokine production. Adenosine A2A receptors participate in some of the anti-inflammatory effects of CBD, as the A2A antagonist ZM241385 partially blocks the protective effects of CBD in the initial stages of inflammation. Together, our findings highlight the anti-inflammatory effects of CBD in this viral model of MS and demonstrate the significant therapeutic potential of this compound for the treatment of pathologies with an inflammatory component. PMID:23851307

Mecha, M; Feliú, A; Iñigo, P M; Mestre, L; Carrillo-Salinas, F J; Guaza, C

2013-11-01

52

N-Acetylcysteine Prevents Deleterious Effects of Ischemia\\/Reperfusion Injury on Healing of Colonic Anastomosis in Rats  

Microsoft Academic Search

This study was designed to determine the effects of intraperitoneally or orally administered N-acetylcysteine (NAC) on wound healing following resection and anastomosis of a colon segment with ischemia\\/reperfusion injury. Forty female Spraque-Dawley rats were randomly allocated to one of four groups containing 10 rats each: (1) normal resection plus anastomosis; (2) ischemia\\/reperfusion plus resection plus anastomosis; (3) ischemia\\/reperfusion plus resection

B. Kabali; S. Girgin; E. Gedik; H. Ozturk; E. Kale; H. Buyukbayram

2009-01-01

53

Unexpected Lack of Deleterious Effects of Uranium on Physiological Systems following a Chronic Oral Intake in Adult Rat  

PubMed Central

Uranium level in drinking water is usually in the range of microgram-per-liter, but this value may be as much as 100 to 1000 times higher in some areas, which may raise question about the health consequences for human populations living in these areas. Our purpose was to improve knowledge of chemical effects of uranium following chronic ingestion. Experiments were performed on rats contaminated for 9 months via drinking water containing depleted uranium (0.2, 2, 5, 10, 20, 40, or 120?mg/L). Blood biochemical and hematological indicators were measured and several different types of investigations (molecular, functional, and structural) were conducted in organs (intestine, liver, kidneys, hematopoietic cells, and brain). The specific sensitivity of the organs to uranium was deduced from nondeleterious biological effects, with the following thresholds (in mg/L): 0.2 for brain, >2 for liver, >10 for kidneys, and >20 for intestine, indicating a NOAEL (No-Observed-Adverse-Effect Level) threshold for uranium superior to 120?m?g/L. Based on the chemical uranium toxicity, the tolerable daily intake calculation yields a guideline value for humans of 1350??g/L. This value was higher than the WHO value of 30??g/L, indicating that this WHO guideline for uranium content in drinking water is very protective and might be reconsidered. PMID:24693537

Dublineau, Isabelle; Souidi, Maamar; Gueguen, Yann; Lestaevel, Philippe; Bertho, Jean-Marc; Manens, Line; Delissen, Olivia; Grison, Stephane; Paulard, Anais; Monin, Audrey; Kern, Yseult; Rouas, Caroline; Loyen, Jeanne; Gourmelon, Patrick; Aigueperse, Jocelyne

2014-01-01

54

Age Shall Not Weary Us: Deleterious Effects of Self-Regulation Depletion Are Specific to Younger Adults  

PubMed Central

Self-regulation depletion (SRD), or ego-depletion, refers to decrements in self-regulation performance immediately following a different self-regulation-demanding activity. There are now over a hundred studies reporting SRD across a broad range of tasks and conditions. However, most studies have used young student samples. Because prefrontal brain regions thought to subserve self-regulation do not fully mature until 25 years of age, it is possible that SRD effects are confined to younger populations and are attenuated or disappear in older samples. We investigated this using the Stroop color task as an SRD induction and an autobiographical memory task as the outcome measure. We found that younger participants (<25 years) were susceptible to depletion effects, but found no support for such effects in an older group (40–65 years). This suggests that the widely-reported phenomenon of SRD has important developmental boundary conditions casting doubt on claims that it represents a general feature of human cognition. PMID:22039469

Dahm, Theresa; Neshat-Doost, Hamid Taher; Golden, Ann-Marie; Horn, Elizabeth; Hagger, Martin; Dalgleish, Tim

2011-01-01

55

Nitrate causes deleterious effects on the behaviour and reproduction of the aquatic snail Potamopyrgus antipodarum (Hydrobiidae, Mollusca).  

PubMed

Nitrate (NO3 (-)) is present in aquatic ecosystems as a natural component of the nitrogen cycle. However, in the last decades, several human activities are the causes of the rising amounts of organic matter and inorganic nitrogen nutrients in aquatic ecosystems, causing notable increase of nitrate above background natural levels. In spite of the toxicity of nitrate to aquatic animals, there are relatively few studies on the chronic toxicity of this compound to invertebrates. The aim of our study is to assess the effect of chronic (35 days) exposure to nitrate on the behaviour (velocity of movement) and reproduction (number of newborns) of the aquatic snail Potamopyrgus antipodarum. Four actual concentrations of nitrate were used (21.4, 44.9, 81.8 and 156.1 mg?N-NO3 (-)/L). In each treatment, 12 animals were individually monitored for velocity (weekly) and newborn production (every 3-4 days). Velocity was recorded using quantitative video monitoring. Our results showed that nitrate did not cause mortality, but it reduced the velocity of movement (at 44.9, 81.8 and 156.1 mg?N-NO3 (-)/L) and number of live newborns (in all tested concentrations). Reproductive impairment was caused at realistic nitrate concentrations which is relevant to the risk assessment of this compound. Our study contributes to the knowledge of the chronic effects of nitrate on the behaviour and reproduction of an aquatic snail. PMID:23417439

Álonso, Alvaro; Camargo, Julio A

2013-08-01

56

A novel U-STAT3-dependent mechanism mediates the deleterious effects of chronic nicotine exposure on renal injury  

PubMed Central

Previous data from our group have demonstrated (Arany I, Grifoni S, Clark JS, Csongradi, Maric C, Juncos LA. Am J Physiol Renal Physiol 301: F125–F133, 2011) that chronic nicotine (NIC) exposure exacerbates acute renal ischemic injury (AKI) in mice that could increase the risk for development and progression of chronic kidney disease (CKD). It has been shown that proximal tubules of the kidney can acquire characteristics that may compromise structural recovery and favor development of inflammation and fibrosis following injury. Chronic NIC exposure can amplify this epithelial process although the mechanism is not identified. Recently, the unphosphorylated form of signal transducer and activator of transcription-3 (U-STAT3) has emerged as a noncanonical mediator of inflammation and fibrosis that may be responsible for the effects of chronic NIC. We found that levels of transforming growth factor ?-1 (TGF-?1), ?-smooth muscle actin (?-SMA), fibronectin, monocyte chemotactic protein-1 (MCP-1), and expression of U-STAT3 were increased in the ischemic kidneys of NIC-exposed mice. Chronic NIC exposure also increased TGF-?1-dependent F-actin reorganization, vimentin, fibronectin, and ?-SMA expression as well as promoter activity of ?-SMA and MCP-1 without significant loss of epithelial characteristics (E-cadherin) in cultured renal proximal tubule cells. Importantly, transduction of cells with a U-STAT3 mimetic (Y705F-STAT3) augmented stress fiber formation and also amplified NIC+TGF-?1-induced expression of ?-SMA, vimentin, fibronectin, as well as promoter activity of ?-SMA and MCP-1. Our results reveal a novel, chronic NIC-exposure-related and U-STAT3-dependent mechanism as mediator of a sustained transcription of genes that are linked to remodeling and inflammation in the kidney during injury. This process may facilitate progression of AKI to CKD. The obtained data may lead to devising therapeutic methods to specifically enhance the protective and/or inhibit adverse effects of STAT3 in the kidney. PMID:22169004

Reed, Dustin K.; Grifoni, Samira C.; Chandrashekar, Kiran; Booz, George W.; Juncos, Luis A.

2012-01-01

57

In vitro drug treatments reduce the deleterious effects of aggregates containing polyAla expanded PHOX2B proteins.  

PubMed

Heterozygous in frame duplications of the PHOX2B gene, leading to polyalanine (polyAla) expansions ranging from +5 to +13 residues of a 20-alanine stretch, have been identified in the vast majority of patients affected with Congenital Central Hypoventilation Syndrome (CCHS), a rare neurocristopathy characterized by absence of adequate autonomic control of respiration with decreased sensitivity to hypoxia and hypercapnia. Ventilatory supports such as tracheostomy, nasal mask or diaphragm pacing represent the only options available for affected. We have already shown that the severity of the CCHS phenotype correlates with the length of polyAla expansions, ultimately leading to formation of toxic intracytoplasmic aggregates and impaired PHOX2B mediated transactivation of target gene promoters, such as DBH. At present, there is no specific treatment to reduce cell aggregates and to ameliorate patients' respiration. In this work, we have undertaken in vitro analyses aimed at assessing the effects of molecules on the cellular response to polyAla PHOX2B aggregates. In particular, we tested 17-AAG, ibuprofen, 4-PBA, curcumin, trehalose, congo red and chrysamine G for their ability to i) recover the nuclear localisation of polyAla expanded PHOX2B, ii) rescue of PHOX2B mediated transactivation of the DBH promoter, and iii) clearance of PHOX2B (+13 Ala) aggregates. Our data have suggested that 17-AAG and curcumin are effective in vitro in both rescuing the nuclear localization and transactivation activity of PHOX2B carrying the largest expansion of polyAla and promoting the clearance of aggregates of these mutant proteins inducing molecular mechanisms such as ubiquitin-proteasome (UPS), autophagy and heat shock protein (HSP) systems. PMID:21964250

Di Zanni, Eleonora; Bachetti, Tiziana; Parodi, Sara; Bocca, Paola; Prigione, Ignazia; Di Lascio, Simona; Fornasari, Diego; Ravazzolo, Roberto; Ceccherini, Isabella

2012-01-01

58

Lack of deleterious effect of slow-release sodium fluoride treatment on cortical bone histology and quality in osteoporotic patients  

NASA Technical Reports Server (NTRS)

We evaluated the effects of intermittent slow-release sodium fluoride (SRNaF) and continuous calcium citrate therapy on cortical bone histology, reflection ultrasound velocity (material strength) and back-scattered electron image analysis (BEI) in 26 osteoporotic patients before and following therapy. All measurements were made on transiliac crest bone biopsies obtained before and following 2 years of therapy in each patient. For all 26 patients there were no significant changes in cortical bone histomorphometric parameters. In 15 patients in whom bone material quality was assessed by reflection ultrasound, there was no change in velocity (4000 +/- 227 SD to 4013 +/- 240 m/s). BEI disclosed no mineralization defects or the presence of woven bone. Mean atomic number (density) of bone increased slightly, but significantly (9.261 +/- 0.311 to 9.457 +/- 0.223, P = 0.031). While these changes are less marked than those observed for cancellous bone, they indicate that this form of therapy does not adversely affect cortical bone remodelling.

Zerwekh, J. E.; Antich, P. P.; Sakhaee, K.; Prior, J.; Gonzales, J.; Gottschalk, F.; Pak, C. Y.

1992-01-01

59

Balance of beneficial and deleterious health effects of quinones: a case study of the chemical properties of genistein and estrone quinones.  

PubMed

Substances containing a phenolic moiety are often metabolized to quinones whose high reactivity makes them difficult to study. Some of these precursors have clear health benefits, and some quinones themselves are used in cancer therapy, whereas others are deleterious. For example, dietary intake of phytoestrogen, genistein (Gen), seems to play a preventive role in breast cancer (BC) whereas prolonged exposure to chemically similar mammalian estrogens is clearly associated with elevated incidence of BC. Although both can be metabolized to reactive quinones, the catechol estrogen quinones (CEQs) modify DNA by redox cycling and/or depurination via a Michael addition. Here, we report an investigation of the chemical reactivity of Gen and estrone quinones to determine the chemical differences of these two biologically important molecules. The catechol genistein quinone (CGenQ), has a half-life of 4 +/- 1 s under physiological condition, as determined by glutathione trapping. It disappears by reacting with H2O to give a dihydrate, CGenQ x (H2O)2, whose structure was proved by NMR. Under reductive conditions, CGenQ x (H2O)2 is readily reduced to reform the catechol genistein (CGen). This reversible oxidation of CGen to CGenQ and the prompt moderation of its reactivity by hydration to CGenQ x (H2O)2 effectively hinders any redox cycling or depurination reaction of CGenQ with DNA. Catechol estrogen quinones, on the other hand, are sufficiently long-lived that they can damage DNA via a Michael addition or by redox cycling. Although the reactivity of CEQ in a nonaqueous solvent is similar to that of CGenQ, its reactivity in aqueous media with the free Ade base is more than 600 times that of CGenQ. These results suggest that rapid hydration of a quinone can moderate its reactivity toward biomolecules, allowing them to express, for example, estrogen-like properties without exhibiting the deleterious properties of redox cycling or directly damaging DNA via depurination reactions. PMID:19115854

Zhang, Qiang; Tu, Tingting; d'Avignon, D André; Gross, Michael L

2009-01-28

60

The Balance of Beneficial and Deleterious Health Effects of Quinones: A Case Study of the Chemical Properties of Genistein and Estrone Quinones  

PubMed Central

Substances containing a phenolic moiety are often metabolized to quinones whose high reactivity makes them difficult to study. Some of these precursors have clear health benefits, and some quinones themselves are used in cancer therapy, whereas others are deleterious. For example, dietary intake of phytoestrogen, genistein (Gen), seems to play a preventive role in breast cancer (BC) whereas prolonged exposure to chemically similar mammalian estrogens is clearly associated with elevated incidence of BC. Although both can be metabolized to reactive quinones, the catechol estrogen quinones (CEQs) modify DNA by redox cycling and/or depurination via a Michael addition. Here, we report an investigation of the chemical reactivity of Gen and estrone quinones to determine the chemical differences in of these two biologically important molecules. The catechol genistein quinone (CGenQ), has a half life of 4 ± 1 s under physiological condition, as determined by glutathione trapping. It disappears by reacting with H2O to give a dihydrate, CGenQ·(H2O)2, whose structure was proved by NMR. Under reductive conditions, CGenQ·(H2O)2 is readily reduced to reform the catechol genistein (CGen). This reversible oxidation of CGen to CGenQ and the prompt moderation of its reactivity by hydration to CGenQ·(H2O)2 effectively moderates any redox cycling or depurination reaction of CGenQ with DNA. Catechol estrogen quinones, on the other hand, are sufficiently long-lived that they can damage DNA via a Michael addition or by redox cycling. Although the reactivity of CEQ in a nonaqueous solvent is similar to that of CGenQ, its reactivity in aqueous media with the free Ade base is more than 600 times that of CGenQ. These results suggest that rapid hydration of a quinone can moderate its reactivity toward biomolecules, allowing them to express, for example, estrogen-like properties without exhibiting the deleterious properties of redox cycling or directly damaging DNA via depurination reactions. PMID:19115854

Zhang, Qiang; Tu, Tingting; d'Avignon, D. Andre; Gross, Michael L.

2009-01-01

61

Deleterious background selection with recombination  

SciTech Connect

An analytic expression for the expected nucleotide diversity is obtained for a neutral locus in a region with deleterious mutation and recombination. Our analytic results are used to predict levels of variation for the entire third chromosome of Drosophila melanogaster. The predictions are consistent with the low levels of variation that have been observed at loci near the centromeres of the third chromosome of D. melanogaster. However, the low levels of variation observed near the tips of this chromosome are not predicted using currently available estimates of the deleterious mutation rate and of selection coefficients. If considerably smaller selection coefficients are assumed, the low observed levels of variation at the tips of the third chromosome are consistent with the background selection model. 33 refs., 4 figs., 1 tab.

Hudson, R.R. [Univ. of California, Irvine, CA (United States); Kaplan, N.L. [National Institute of Environmental Health Sciences, Research Triangle Park, NC (United States)

1995-12-01

62

Developmental expression of Musashi-1 and Musashi-2 RNA-binding proteins during spermatogenesis: analysis of the deleterious effects of dysregulated expression.  

PubMed

Spermatogenesis is a complex developmental process whereby diploid spermatogenic stem cells become haploid and undergo a series of morphological changes to produce physically mature spermatozoa. Crucial to this process are a number of RNA-binding proteins, responsible for the posttranscriptional control of essential mRNAs and particularly pertinent to the two periods of inactive transcription that occur in spermatogenesis. One such group of RNA-binding proteins is the Musashi family, specifically Musashi-1 (MSI1) and Musashi-2 (MSI2), which act as key translational regulators in various stem cell populations and have been linked with the induction of tumorigenesis. In the present study, we examined the differential expression of mammalian MSI1 and MSI2 during germ cell development in the mouse testis. MSI1 was found to be predominately localized in mitotic gonocytes and spermatogonia, whereas MSI2 was detected in meiotic spermatocytes and differentiating spermatids. Extensive examination of the function of Musashi in spermatogenesis was achieved through the use of two transgenic mouse models with germ cell-specific overexpression of full-length isoforms of Msi1 or Msi2. These models demonstrated that aberrant expression of either Msi1 or Msi2 has deleterious effects on normal spermatogenesis, with Msi2 overexpression resulting in male sterility. Studies undertaken on human testicular seminoma tumors provide further insights into the relevance of MSI1 and MSI2 overexpression as diagnostic markers to human stem cell cancers. Overall this study provides further evidence for the unique functions that RNA-binding protein isoforms occupy within spermatogenesis, and introduces the potential manipulation of the Musashi family proteins to elucidate the mechanisms of posttranscriptional gene expression during germ cell development. PMID:24671879

Sutherland, Jessie M; Fraser, Barbara A; Sobinoff, Alexander P; Pye, Victoria J; Davidson, Tara-Lynne; Siddall, Nicole A; Koopman, Peter; Hime, Gary R; McLaughlin, Eileen A

2014-05-01

63

Marine reserves: Fish life history and ecological traits matter  

Microsoft Academic Search

Marine reserves are assumed to protect a wide range of species from deleterious effects stemming from exploitation. However, some species, due to their ecological characteristics, may not respond positively to protection. Very little is known about the effects of life history and ecological traits (e.g., mobility, growth, and habitat) on responses of fish species to marine reserves. Using 40 data

Joachim Claudet; Craig W. Osenberg; Paolo Domenici; F. Badalamenti; M. Milazzo; J. M. Falcón; I. Bertocci; L. Benedetti-Cecchi; J. A. García-Charton; R. Goñi; J. A. Borg; A. Forcada; G. A. de Lucia; Á Pérez-Ruzafa; P. Afonso; A. Brito; I. Guala; L. Le Diréach; P. Sanchez-Jerez; P. J. Somerfield; S. Planes

2010-01-01

64

An assessment of the ecological effects of acidic deposition  

Microsoft Academic Search

Research on the ecological effects of acidic deposition has yielded information that currently permits a partial assessment of these effects. Establishing a relationship between deposition of acidity and ecological effects is a difficult, lengthy process; the complexity of ecosystems requires an integrated mechanism-level approach in order to obtain quantitative and predictive information. Known ecological effects of acidic deposition appear in

John W. Huckabee; Jack S. Mattice; Louis F. Pitelka; Donald B. Porcella; Robert A. Goldstein

1989-01-01

65

OVERVIEW OF CLIMATE INFORMATION NEEDS FOR ECOLOGICAL EFFECTS MODELS  

EPA Science Inventory

Atmospheric scientists engaged in climate change research require a basic understanding of how ecological effects models incorporate climate. This report provides an overview of existing ecological models that might be used to model climate change effects on vegetation. ome agric...

66

Ecology of estuaries: Anthropogenic effects  

SciTech Connect

Estuaries and near-shore oceanic water are subjected to a multitude of human wastes. The principal objective of this book is to examine anthropogenic effects on estuaries, and it focuses primarily on contaminants in coastal systems. Covered within various chapters are the following topics: waste disposal strategies; definition and classification of pollutants (including organic loading, oil pollution, polynuclear aromatic hydrocarbons; chlorinated hydrocarbons; heavy metals; radionuclides) biological impacts; waste management; impacts of power plants; dredging and spoil disposal; case studies, primarily Chesapeake Bay. The book serves as a text and as a reference.

Kennish, M.J.

1992-01-01

67

Cascading ecological effects of eliminating fishery discards  

PubMed Central

Discarding by fisheries is perceived as contrary to responsible harvesting. Legislation seeking to end the practice is being introduced in many jurisdictions. However, discarded fish are food for a range of scavenging species; so, ending discarding may have ecological consequences. Here we investigate the sensitivity of ecological effects to discarding policies using an ecosystem model of the North Sea—a region where 30–40% of trawled fish catch is currently discarded. We show that landing the entire catch while fishing as usual has conservation penalties for seabirds, marine mammals and seabed fauna, and no benefit to fish stocks. However, combining landing obligations with changes in fishing practices to limit the capture of unwanted fish results in trophic cascades that can benefit birds, mammals and most fish stocks. Our results highlight the importance of considering the broader ecosystem consequences of fishery management policy, since species interactions may dissipate or negate intended benefits. PMID:24820200

Heath, Michael R.; Cook, Robin M.; Cameron, Angus I.; Morris, David J.; Speirs, Douglas C.

2014-01-01

68

Cascading ecological effects of eliminating fishery discards.  

PubMed

Discarding by fisheries is perceived as contrary to responsible harvesting. Legislation seeking to end the practice is being introduced in many jurisdictions. However, discarded fish are food for a range of scavenging species; so, ending discarding may have ecological consequences. Here we investigate the sensitivity of ecological effects to discarding policies using an ecosystem model of the North Sea--a region where 30-40% of trawled fish catch is currently discarded. We show that landing the entire catch while fishing as usual has conservation penalties for seabirds, marine mammals and seabed fauna, and no benefit to fish stocks. However, combining landing obligations with changes in fishing practices to limit the capture of unwanted fish results in trophic cascades that can benefit birds, mammals and most fish stocks. Our results highlight the importance of considering the broader ecosystem consequences of fishery management policy, since species interactions may dissipate or negate intended benefits. PMID:24820200

Heath, Michael R; Cook, Robin M; Cameron, Angus I; Morris, David J; Speirs, Douglas C

2014-01-01

69

Efficient Purging of Deleterious Mutations in Plants with Haploid Selfing  

PubMed Central

In diploid organisms, selfing reduces the efficiency of selection in removing deleterious mutations from a population. This need not be the case for all organisms. Some plants, for example, undergo an extreme form of selfing known as intragametophytic selfing, which immediately exposes all recessive deleterious mutations in a parental genome to selective purging. Here, we ask how effectively deleterious mutations are removed from such plants. Specifically, we study the extent to which deleterious mutations accumulate in a predominantly selfing and a predominantly outcrossing pair of moss species, using genome-wide transcriptome data. We find that the selfing species purge significantly more nonsynonymous mutations, as well as a greater proportion of radical amino acid changes which alter physicochemical properties of amino acids. Moreover, their purging of deleterious mutation is especially strong in conserved regions of protein-coding genes. Our observations show that selfing need not impede but can even accelerate the removal of deleterious mutations, and do so on a genome-wide scale. PMID:24879432

Szovenyi, Peter; Devos, Nicolas; Weston, David J.; Yang, Xiaohan; Hock, Zsofia; Shaw, Jonathan A.; Shimizu, Kentaro K.; McDaniel, Stuart F.; Wagner, Andreas

2014-01-01

70

Efficient purging of deleterious mutations in plants with haploid selfing.  

PubMed

In diploid organisms, selfing reduces the efficiency of selection in removing deleterious mutations from a population. This need not be the case for all organisms. Some plants, for example, undergo an extreme form of selfing known as intragametophytic selfing, which immediately exposes all recessive deleterious mutations in a parental genome to selective purging. Here, we ask how effectively deleterious mutations are removed from such plants. Specifically, we study the extent to which deleterious mutations accumulate in a predominantly selfing and a predominantly outcrossing pair of moss species, using genome-wide transcriptome data. We find that the selfing species purge significantly more nonsynonymous mutations, as well as a greater proportion of radical amino acid changes which alter physicochemical properties of amino acids. Moreover, their purging of deleterious mutation is especially strong in conserved regions of protein-coding genes. Our observations show that selfing need not impede but can even accelerate the removal of deleterious mutations, and do so on a genome-wide scale. PMID:24879432

Szövényi, Péter; Devos, Nicolas; Weston, David J; Yang, Xiaohan; Hock, Zsófia; Shaw, Jonathan A; Shimizu, Kentaro K; McDaniel, Stuart F; Wagner, Andreas

2014-05-01

71

TEAM EFFECTIVENESS IN VIRTUAL ENVIRONMENTS: AN ECOLOGICAL APPROACH  

Microsoft Academic Search

This chapter attempts to address the need for more research on virtual team effectiveness and outlines an ecological theoretical framework that is applicable to virtual learning environments (VLE). Prior empirical studies on virtual team effectiveness used frameworks of traditional team effectiveness and mainly followed Hackman's normative model (input-process-output). We propose an ecological approach for virtual team effectiveness that accounts for

Pnina Shachaf; Noriko Hara

72

N-CARBAMYLGLUTAMATE ENHANCEMENT OF UREAGENESIS LEADS TO DISCOVERY OF A NOVEL DELETERIOUS MUTATION IN A NEWLY DEFINED ENHANCER OF THE NAGS GENE AND TO EFFECTIVE THERAPY  

PubMed Central

NAGS catalyzes the conversion of glutamate and acetyl-CoA to N-acetylglutamate (NAG) the essential allosteric activator of carbamyl phosphate synthetase I, the first urea cycle enzyme in mammals. A 17-year-old female with recurrent hyperammonemia attacks, the cause of which remained undiagnosed for 8 years in spite of multiple molecular and biochemical investigations, showed markedly enhanced ureagenesis (measured by isotope incorporation) in response to N-carbamylglutamate (NCG). This led to sequencing of the regulatory regions of the NAG synthase (NAGS) gene and identification of a deleterious single-base substitution in the upstream enhancer. The homozygous mutation (-3063C>A), affecting a highly conserved nucleotide within the Hepatic Nuclear Factor 1 (HNF-1) binding site, was not found in SNP databases and in a screen of 1086 alleles from a diverse population. Functional assays demonstrated that this mutation decreases transcription and binding of HNF-1 to the NAGS gene, while a consensus HNF-1 binding sequence enhances binding to HNF-1 and increases transcription. Oral daily NCG therapy appears to have restored ureagenesis in this patient, normalizing her biochemical markers, and allowing discontinuation of alternate pathway therapy and normalization of her diet with no recurrence of hyperammonemia. PMID:21681857

Heibel, Sandra K.; Mew, Nicholas Ah; Caldovic, Ljubica; Daikhin, Yevgeny; Yudkoff, Marc; Tuchman, Mendel

2014-01-01

73

Protective Effects of EPA and Deleterious Effects of DHA on eNOS Activity in Ea hy 926 Cultured with Lysophosphatidylcholine  

Microsoft Academic Search

Oxidized low density lipoprotein (Ox-LDL) is a well-established risk factor in atherosclerosis and lysophosphatidylcholine\\u000a (LysoPtdCho) is considered to be one of the major atherogenic component of Ox-LDL. The purpose of this work was to investigate\\u000a the effects of two membrane n-3 long chain polyunsaturated fatty acids (n-3 PUFAs), EPA (eicosapentaenoic acid) and DHA (docosahexaenoic\\u000a acid) compared to n-6 PUFA, ARA

Sylviane Tardivel; Aurélie Gousset-Dupont; Véronique Robert; Marie-Luce Pourci; Alain Grynberg; Bernard Lacour

2009-01-01

74

Ecological and Landscape Effects of Ditches on Farmland Ecosystem  

Microsoft Academic Search

Ditches as important components of farmland ecosystem have definite effects, not only on hydrological cycle but also on ecology and landscape. Its irrigation and drainage functions were widely accepted, while ecological and landscape functions were seldom studied. Depended on the investigation combined with field and lab experiments, three main effects were proved in this paper. Firstly, ditches could intercept, absorb

Liqin Zhu; Cuiling Jiang; Xiangqian Xie; Minghua Xie; Xiaoqin Hu; Junyu Cheng

2009-01-01

75

Palytoxin and Analogs: Biological and Ecological Effects  

PubMed Central

Palytoxin (PTX) is a potent marine toxin that was originally found in soft corals from tropical areas of the Pacific Ocean. Soon after, its occurrence was observed in numerous other marine organisms from the same ecological region. More recently, several analogs of PTX were discovered, remarkably all from species of the dinoflagellate genus Ostreopsis. Since these dinoflagellates are also found in other tropical and even in temperate regions, the formerly unsuspected broad distribution of these toxins was revealed. Toxicological studies with these compounds shows repeatedly low LD50 values in different mammals, revealing an acute toxic effect on several organs, as demonstrated by different routes of exposure. Bioassays tested for some marine invertebrates and evidences from environmental populations exposed to the toxins also give indications of the high impact that these compounds may have on natural food webs. The recognition of its wide distribution coupled with the poisoning effects that these toxins can have on animals and especially on humans have concerned the scientific community. In this paper, we review the current knowledge on the effects of PTX and its analogs on different organisms, exposing the impact that these toxins may have in coastal ecosystems. PMID:20714422

Ramos, Vitor; Vasconcelos, Vitor

2010-01-01

76

ECOSYSTEM ECOLOGY Effects of the herbivorous minnow, southern redbelly dace  

E-print Network

ECOSYSTEM ECOLOGY Effects of the herbivorous minnow, southern redbelly dace (Phoxinus erythrogaster field and mesocosm experiments to measure effects of southern redbelly dace (Phoxinus erythrogaster primary productivity. Our experiments showed that moderate densities of Phoxinus tempo- rarily reduced

Gido, Keith B.

77

21 CFR 509.6 - Added poisonous or deleterious substances.  

...false Added poisonous or deleterious substances. 509.6 Section 509.6 Food...6 Added poisonous or deleterious substances. (a) Use of an added poisonous or deleterious substance, other than a pesticide...

2014-04-01

78

21 CFR 109.6 - Added poisonous or deleterious substances.  

...false Added poisonous or deleterious substances. 109.6 Section 109.6 Food...6 Added poisonous or deleterious substances. (a) Use of an added poisonous or deleterious substance, other than a pesticide...

2014-04-01

79

SPS microwave health and ecological effects: Program area overview  

NASA Technical Reports Server (NTRS)

The potential microwave health and ecological effects due to the operations of the Satellite Power System are discussed. An outline of the research needed to insure public acceptance of the program is presented.

Cahill, D. F.

1980-01-01

80

Ecological effects of the North Atlantic Oscillation  

Microsoft Academic Search

Climatic oscillations as reflected in atmospheric modes such as the North Atlantic Oscillation (NAO) may be seen as a proxy for regulating forces in aquatic and terrestrial ecosystems. Our review highlights the variety of climate processes related to the NAO and the diversity in the type of ecological responses that different biological groups can display. Available evidence suggests that the

Geir Ottersen; Benjamin Planque; Andrea Belgrano; Eric Post; Philip C. Reid; Nils C. Stenseth

2001-01-01

81

Ecological Effects of the War in Vietnam  

ERIC Educational Resources Information Center

Research report on the severe ecological consequences of the defoliation program by American military forces in Vietnam. A significant fraction of mature trees in most forests are killed by single application of herbicides and almost completely killed by repeated sprayings. AAAS is urged to set up an international research program on the…

Orians, Gordon H.; Pfeiffer, E. W.

1970-01-01

82

Pregnancy and lactation have no long-term deleterious effect on measures of bone mineral in healthy women: a twin study1-3  

Microsoft Academic Search

Background: The long-term effects of pregnancy and lactation on measures of bone mineral in women remain unclear. Objective: We studied whether pregnancy or lactation has dele- terious long-term effects on bone mineral in healthy women. Design: We measured bone mineral density (BMD; g\\/cm2) in women aged ? 18 y. Analyses were performed on 3 data sets: study 1, 83 female

Lynda M Paton; Jo L Alexander; Caryl A Nowson; Claire Margerison; Mandy G Frame; Bahtiyar Kaymakci; John D Wark

83

Ecology.  

ERIC Educational Resources Information Center

This set of teaching aids consists of nine Audubon Nature Bulletins, providing teachers and students with informational reading on various ecological topics. The bulletins have these titles: Schoolyard Laboratories, Owls and Predators, The Forest Community, Life in Freshwater Marshes, Camouflage in the Animal World, Life in the Desert, The…

National Audubon Society, New York, NY.

84

Experiments on the role of deleterious mutations as stepping stones in adaptive evolution.  

PubMed

Many evolutionary studies assume that deleterious mutations necessarily impede adaptive evolution. However, a later mutation that is conditionally beneficial may interact with a deleterious predecessor before it is eliminated, thereby providing access to adaptations that might otherwise be inaccessible. It is unknown whether such sign-epistatic recoveries are inconsequential events or an important factor in evolution, owing to the difficulty of monitoring the effects and fates of all mutations during experiments with biological organisms. Here, we used digital organisms to compare the extent of adaptive evolution in populations when deleterious mutations were disallowed with control populations in which such mutations were allowed. Significantly higher fitness levels were achieved over the long term in the control populations because some of the deleterious mutations served as stepping stones across otherwise impassable fitness valleys. As a consequence, initially deleterious mutations facilitated the evolution of complex, beneficial functions. We also examined the effects of disallowing neutral mutations, of varying the mutation rate, and of sexual recombination. Populations evolving without neutral mutations were able to leverage deleterious and compensatory mutation pairs to overcome, at least partially, the absence of neutral mutations. Substantially raising or lowering the mutation rate reduced or eliminated the long-term benefit of deleterious mutations, but introducing recombination did not. Our work demonstrates that deleterious mutations can play an important role in adaptive evolution under at least some conditions. PMID:23918358

Covert, Arthur W; Lenski, Richard E; Wilke, Claus O; Ofria, Charles

2013-08-20

85

Brain tissue oxidative damage as a possible mechanism for the deleterious effect of a chronic high dose of estradiol on learning and memory in ovariectomized rats.  

PubMed

In addition to antioxidative effects, estrogens also exert pro-oxidative actions. The effect of chronic administration of a high dose of estradiol valerate on Morris water maze tasks and brain tissues oxidative damage was investigated. The Sham-Est and OVX-Est groups were treated with estradiol valerate (4 mg/kg) for 12 weeks. Escape latency and traveled path in the Sham-Est and OVX-Est groups were significantly higher than in the Sham and OVX groups (p<0.01 and p<0.001). In the probe trial, the animals of the Sham-Est and OVX-Est groups spent lower time in Q1 compared to Sham and OVX groups (p<0.05 and p<0.001). In Sham-Est and OVX-Est groups, the brain tissue total thiol concentration was significantly lower, and malondialdehyde (MDA) concentrations were higher than in the Sham and OVX groups (p<0.05 and p<0.001). It is concluded that administration of high exogenous levels of estradiol impairs performance and enhances oxidative stress. PMID:23689409

Khodabandehloo, Fatimeh; Hosseini, Mahmoud; Rajaei, Ziba; Soukhtanloo, Mohammad; Farrokhi, Esmaeil; Rezaeipour, Mohsen

2013-05-01

86

Reversal of the deleterious effects of chronic dietary HFCS-55 intake by PPAR-? agonism correlates with impaired NLRP3 inflammasome activation.  

PubMed

Although high-fructose corn syrup (HFCS-55) is the major sweetener in foods and soft-drinks, its potential role in the pathophysiology of diabetes and obesity ("diabesity") remains unclear. Peroxisome-proliferator activated receptor (PPAR)-? agonists have never been tested in models of sugar-induced metabolic abnormalities. This study was designed to evaluate (i) the metabolic and renal consequences of HFCS-55 administration (15% wt/vol in drinking water) for 30 weeks on male C57Bl6/J mice and (ii) the effects of the selective PPAR-? agonist GW0742 (1 mg/kg/day for 16 weeks) in this condition. HFCS-55 caused (i) hyperlipidemia, (ii) insulin resistance, and (iii) renal injury/inflammation. In the liver, HFCS-55 enhanced the expression of fructokinase resulting in hyperuricemia and caused abnormalities in known insulin-driven signaling events. In the kidney, HFCS-55 enhanced the expression of the NLRP3 (nucleotide-binding domain and leucine-rich-repeat-protein 3) inflammasome complex, resulting in caspase-1 activation and interleukin-1? production. All of the above effects of HFCS-55 were attenuated by the specific PPAR-? agonist GW0742. Thus, we demonstrate for the first time that the specific PPAR-? agonist GW0742 attenuates the metabolic abnormalities and the renal dysfunction/inflammation caused by chronic HFCS-55 exposure by preventing upregulation of fructokinase (liver) and activation of the NLRP3 inflammasome (kidney). PMID:23103566

Collino, Massimo; Benetti, Elisa; Rogazzo, Mara; Mastrocola, Raffaella; Yaqoob, Muhammed M; Aragno, Manuela; Thiemermann, Christoph; Fantozzi, Roberto

2013-01-15

87

Impact of deleterious passenger mutations on cancer progression  

PubMed Central

Cancer progression is driven by the accumulation of a small number of genetic alterations. However, these few driver alterations reside in a cancer genome alongside tens of thousands of additional mutations termed passengers. Passengers are widely believed to have no role in cancer, yet many passengers fall within protein-coding genes and other functional elements that can have potentially deleterious effects on cancer cells. Here we investigate the potential of moderately deleterious passengers to accumulate and alter the course of neoplastic progression. Our approach combines evolutionary simulations of cancer progression with an analysis of cancer sequencing data. From simulations, we find that passengers accumulate and largely evade natural selection during progression. Although individually weak, the collective burden of passengers alters the course of progression, leading to several oncological phenomena that are hard to explain with a traditional driver-centric view. We then tested the predictions of our model using cancer genomics data and confirmed that many passengers are likely damaging and have largely evaded negative selection. Finally, we use our model to explore cancer treatments that exploit the load of passengers by either (i) increasing the mutation rate or (ii) exacerbating their deleterious effects. Though both approaches lead to cancer regression, the latter is a more effective therapy. Our results suggest a unique framework for understanding cancer progression as a balance of driver and passenger mutations. PMID:23388632

McFarland, Christopher D.; Korolev, Kirill S.; Kryukov, Gregory V.; Sunyaev, Shamil R.; Mirny, Leonid A.

2013-01-01

88

The deleterious effects of cortisol implantation on reproductive function in two species of trout, Salmo trutta L. and Salmo gairdneri Richardson.  

PubMed

Implantation of a cortisol-releasing pellet (60 mg kg-1 fish) into the peritoneal cavity of brown trout, Salmo trutta L. (sexually maturing males and females), and rainbow trout, Salmo gairdneri Richardson (maturing males and immature fish of both sexes), significantly elevated their plasma cortisol level. At 18 days postimplantation, cortisol-implanted sexually maturing male brown trout had smaller gonads, a lower plasma testosterone level, and less gonadotropin in their pituitary gland than control fish. Plasma levels of 11-ketotestosterone and gonadotropin were not significantly affected. Cortisol-implanted sexually maturing female brown trout had smaller gonads, reduced plasma levels of 17 beta-oestradiol, testosterone, and vitellogenin, and a lower pituitary gland gonadotropin content than control fish. The plasma gonadotropin level was unaffected. At 36 days post-implantation, cortisol treatment of maturing male rainbow trout significantly suppressed plasma gonadotropin levels. Plasma levels of testosterone, 11-ketotestosterone, and 17 alpha,20 beta-dihydroxy-4-pregnen-3-one, pituitary gonadotropin content, and gonad size were not significantly affected. In sexually immature female rainbow trout, cortisol administration suppressed the level of vitellogenin in the plasma, compared to control-implanted fish. The 17 beta-oestradiol level was not affected. Cortisol implantation did not affect the plasma testosterone level in sexually immature male trout. These results suggest that prolonged elevation of plasma cortisol, to levels well within physiological range, can affect a wide range of reproductive parameters in both brown and rainbow trout. Further, some effects are manifest in immature as well as in mature fish. These findings are discussed in relation to the effects of cortisol treatment on the state of health of the treated fish. PMID:2591721

Carragher, J F; Sumpter, J P; Pottinger, T G; Pickering, A D

1989-11-01

89

Epstein-Barr virus protein EB2 stimulates cytoplasmic mRNA accumulation by counteracting the deleterious effects of SRp20 on viral mRNAs.  

PubMed

The Epstein-Barr Virus (EBV) protein EB2 (also called Mta, SM and BMLF1), is an essential nuclear protein produced during the replicative cycle of EBV. EB2 is required for the efficient cytoplasmic accumulation of viral mRNAs derived from intronless genes. EB2 is an RNA-binding protein whose expression has been shown to influence RNA stability, splicing, nuclear export and translation. Using a yeast two-hybrid screen, we have identified three SR proteins, SF2/ASF, 9G8 and SRp20, as cellular partners of EB2. Then, by using siRNA to deplete cells of specific SR proteins, we found that SRp20 plays an essential role in the processing of several model mRNAs: the Renilla luciferase reporter mRNA, the human ?-globin cDNA transcript and two EBV late mRNAs. These four mRNAs were previously found to be highly dependent on EB2 for their efficient cytoplasmic accumulation. Here, we show that SRp20 depletion results in an increase in the accumulation of these mRNAs, which correlates with an absence of additive effect of EB2, suggesting that EB2 functions by antagonizing SRp20. Moreover, by using RNA-immunoprecipitation assays we found that EB2 enhances the association of SRp20 with the ?-globin transcript suggesting that EB2 acts by stabilizing SRp20's labile interactions with the RNA. PMID:22505578

Juillard, Franceline; Bazot, Quentin; Mure, Fabrice; Tafforeau, Lionel; Macri, Christophe; Rabourdin-Combe, Chantal; Lotteau, Vincent; Manet, Evelyne; Gruffat, Henri

2012-08-01

90

Epstein-Barr virus protein EB2 stimulates cytoplasmic mRNA accumulation by counteracting the deleterious effects of SRp20 on viral mRNAs  

PubMed Central

The Epstein–Barr Virus (EBV) protein EB2 (also called Mta, SM and BMLF1), is an essential nuclear protein produced during the replicative cycle of EBV. EB2 is required for the efficient cytoplasmic accumulation of viral mRNAs derived from intronless genes. EB2 is an RNA-binding protein whose expression has been shown to influence RNA stability, splicing, nuclear export and translation. Using a yeast two-hybrid screen, we have identified three SR proteins, SF2/ASF, 9G8 and SRp20, as cellular partners of EB2. Then, by using siRNA to deplete cells of specific SR proteins, we found that SRp20 plays an essential role in the processing of several model mRNAs: the Renilla luciferase reporter mRNA, the human ?-globin cDNA transcript and two EBV late mRNAs. These four mRNAs were previously found to be highly dependent on EB2 for their efficient cytoplasmic accumulation. Here, we show that SRp20 depletion results in an increase in the accumulation of these mRNAs, which correlates with an absence of additive effect of EB2, suggesting that EB2 functions by antagonizing SRp20. Moreover, by using RNA-immunoprecipitation assays we found that EB2 enhances the association of SRp20 with the ?-globin transcript suggesting that EB2 acts by stabilizing SRp20’s labile interactions with the RNA. PMID:22505578

Juillard, Franceline; Bazot, Quentin; Mure, Fabrice; Tafforeau, Lionel; Macri, Christophe; Rabourdin-Combe, Chantal; Lotteau, Vincent; Manet, Evelyne; Gruffat, Henri

2012-01-01

91

The role of the interactome in the maintenance of deleterious variability in human populations.  

PubMed

Recent genomic projects have revealed the existence of an unexpectedly large amount of deleterious variability in the human genome. Several hypotheses have been proposed to explain such an apparently high mutational load. However, the mechanisms by which deleterious mutations in some genes cause a pathological effect but are apparently innocuous in other genes remain largely unknown. This study searched for deleterious variants in the 1,000 genomes populations, as well as in a newly sequenced population of 252 healthy Spanish individuals. In addition, variants causative of monogenic diseases and somatic variants from 41 chronic lymphocytic leukaemia patients were analysed. The deleterious variants found were analysed in the context of the interactome to understand the role of network topology in the maintenance of the observed mutational load. Our results suggest that one of the mechanisms whereby the effect of these deleterious variants on the phenotype is suppressed could be related to the configuration of the protein interaction network. Most of the deleterious variants observed in healthy individuals are concentrated in peripheral regions of the interactome, in combinations that preserve their connectivity, and have a marginal effect on interactome integrity. On the contrary, likely pathogenic cancer somatic deleterious variants tend to occur in internal regions of the interactome, often with associated structural consequences. Finally, variants causative of monogenic diseases seem to occupy an intermediate position. Our observations suggest that the real pathological potential of a variant might be more a systems property rather than an intrinsic property of individual proteins. PMID:25261458

Garcia-Alonso, Luz; Jiménez-Almazán, Jorge; Carbonell-Caballero, Jose; Vela-Boza, Alicia; Santoyo-López, Javier; Antiñolo, Guillermo; Dopazo, Joaquin

2014-01-01

92

Positive Selection of Deleterious Alleles through Interaction with a Sex-Ratio Suppressor Gene in African Buffalo: A Plausible New Mechanism for a High Frequency Anomaly  

PubMed Central

Although generally rare, deleterious alleles can become common through genetic drift, hitchhiking or reductions in selective constraints. Here we present a possible new mechanism that explains the attainment of high frequencies of deleterious alleles in the African buffalo (Syncerus caffer) population of Kruger National Park, through positive selection of these alleles that is ultimately driven by a sex-ratio suppressor. We have previously shown that one in four Kruger buffalo has a Y-chromosome profile that, despite being associated with low body condition, appears to impart a relative reproductive advantage, and which is stably maintained through a sex-ratio suppressor. Apparently, this sex-ratio suppressor prevents fertility reduction that generally accompanies sex-ratio distortion. We hypothesize that this body-condition-associated reproductive advantage increases the fitness of alleles that negatively affect male body condition, causing genome-wide positive selection of these alleles. To investigate this we genotyped 459 buffalo using 17 autosomal microsatellites. By correlating heterozygosity with body condition (heterozygosity-fitness correlations), we found that most microsatellites were associated with one of two gene types: one with elevated frequencies of deleterious alleles that have a negative effect on body condition, irrespective of sex; the other with elevated frequencies of sexually antagonistic alleles that are negative for male body condition but positive for female body condition. Positive selection and a direct association with a Y-chromosomal sex-ratio suppressor are indicated, respectively, by allele clines and by relatively high numbers of homozygous deleterious alleles among sex-ratio suppressor carriers. This study, which employs novel statistical techniques to analyse heterozygosity-fitness correlations, is the first to demonstrate the abundance of sexually-antagonistic genes in a natural mammal population. It also has important implications for our understanding not only of the evolutionary and ecological dynamics of sex-ratio distorters and suppressors, but also of the functioning of deleterious and sexually-antagonistic alleles, and their impact on population viability. PMID:25372610

van Hooft, Pim; Greyling, Ben J.; Getz, Wayne M.; van Helden, Paul D.; Zwaan, Bas J.; Bastos, Armanda D. S.

2014-01-01

93

The ecological effects of biological invasions on birds  

Microsoft Academic Search

Biological invasion is recognized as one of the greatest threats to the global biodiversity because invasive exotic species not only alter the local environments but also have serious ecological effects on native species. Birds are positioned at high trophic level within the food web in the ecosystem, and thus any changes within the system can affect the birds in one

Gan Xiaojing; Bo Li; Jiakuan Chen; Zhijun Ma

2007-01-01

94

ECOLOGICAL EFFECTS OF NITROGEN DEPOSITION IN THE WESTERN UNITED STATES  

EPA Science Inventory

Article synthesizes existing studies (biological, ecological, biogeochemical) on the effects of nitrogen deposition to aquatic and terrestrial ecosystems in the western United States. In the western U.S, vast acreages of land are exposed to low levels of atmospheric deposition, w...

95

Deleterious amino acid polymorphisms in Arabidopsis thaliana and rice  

Microsoft Academic Search

Plant genetic diversity has been mainly investigated with neutral markers, but large-scale DNA sequencing projects now enable\\u000a the identification and analysis of different classes of genetic polymorphisms, such as non-synonymous single nucleotide polymorphisms\\u000a (nsSNPs) in protein coding sequences. Using the SIFT and MAPP programs to predict whether nsSNPs are tolerated (i.e., effectively\\u000a neutral) or deleterious for protein function, genome-wide nsSNP

Torsten Günther; Karl J. Schmid

2010-01-01

96

Integrated Modeling for the Assessment of Ecological Impacts of Sea Level Rise  

Microsoft Academic Search

Sea level rise (SLR) has the potential to affect a variety of coastal habitats with a myriad of deleterious ecological effects and to overwhelm human settlements along the coast. SLR should be given serious consideration when more than half of the U.S. population lives within 50 miles of the coast. SLR effects will be felt along coastal beaches and in

S. C. Hagen; G. Lewis; R. Bartel; B. Batten; W. Huang; J. Morris; D. N. Slinn; J. Sparks; L. Walters; D. Wang; J. Weishampel; G. Yeh

2010-01-01

97

Estimated ecological effects of triazine use of surface waters  

SciTech Connect

Based on the current intensive use of triazines in agriculture in the northern portions of the Midwest, ecological impacts have been evaluated in surface waters. Considerations from application methods to stream concentrations predict a range of impacts using current toxicity models. Standard {open_quotes}static{close_quotes} LC{sub 50}s predict only algal mortality at peak runoff, while laboratory flow-through systems indicate seasonal impacts on primary stream productivity. Mesocosms further observe indirect effects on numerous species during the year. Microcosm and flow-through wetland mesocosm studies indicate primary effects during the growing season on algal populations, magnified by zooplankton bloom stresses and indirect effects on dissolved oxygen and nutrient concentrations. If the river continuum model is considered in combination with triazine concentrations, clear untoward effects on stream ecosystems occur with current practices. The use of banding application or other remediation techniques for positive ecological and economic gains as proven alternatives to current uses are encouraged.

Mercurio, S.D.

1996-10-01

98

Effects of Fisheries on Seabird Community Ecology  

Microsoft Academic Search

Significant depletions of marine fish populations due to overfishing are becoming more and more common. Such depletions have serious consequences not only for the fished species, but also for those organisms that depend on them for food. For seabirds, in particular, the effects of fisheries can be felt via a number of pathways. However, few studies have considered those effects

Eric L. Wagner; P. Dee Boersma

2011-01-01

99

40 CFR 158.240 - Experimental use permit data requirements for ecological effects.  

Code of Federal Regulations, 2010 CFR

...2010-07-01 false Experimental use permit data requirements for ecological effects. 158.240 Section 158.240 Protection of...158.240 Experimental use permit data requirements for ecological effects. All data for terrestrial nontarget organisms...

2010-07-01

100

Spatial heterogeneity in the strength of selection against deleterious alleles and the mutation load.  

PubMed

According to current estimates of genomic deleterious mutation rates (which are often of the order 0.1-1) the mutation load (defined as a reduction in the average fitness of a population due to the presence of deleterious alleles) may be important in many populations. In this paper, I use multilocus simulations to explore the effect of spatial heterogeneity in the strength of selection against deleterious alleles on the mutation load (for example, it has been suggested that stressful environments may increase the strength of selection). These simulations show contrasted results: in some situations, spatial heterogeneity may greatly reduce the mutation load, due to the fact that migrants coming from demes under stronger selection carry relatively few deleterious alleles, and benefit from a strong advantage within demes under weaker selection (where individuals carry many more deleterious alleles); in other situations, however, deleterious alleles accumulate within demes under stronger selection, due to migration pressure from demes under weaker selection, leading to fitness erosion within those demes. This second situation is more frequent when the productivity of the different demes is proportional to their mean fitness. The effect of spatial heterogeneity is greatly reduced, however, when the response to environmental differences is inconsistent across loci. PMID:22588129

Roze, D

2012-09-01

101

Characteristics of Neutral and Deleterious Protein-Coding Variation among Individuals and Populations.  

PubMed

Whole-genome and exome data sets continue to be produced at a frenetic pace, resulting in massively large catalogs of human genomic variation. However, a clear picture of the characteristics and patterns of neutral and deleterious variation within and between populations has yet to emerge, given that recent large-scale sequencing studies have often emphasized different aspects of the data and sometimes appear to have conflicting conclusions. Here, we comprehensively studied characteristics of protein-coding variation in high-coverage exome sequence data from 6,515 European American (EA) and African American (AA) individuals. We developed an unbiased approach to identify putatively deleterious variants and investigated patterns of neutral and deleterious single-nucleotide variants and alleles between individuals and populations. We show that there are substantial differences in the composition of genotypes between EA and AA populations and that small but statistically significant differences exist in the average number of deleterious alleles carried by EA and AA individuals. Furthermore, we performed extensive simulations to delineate the temporal dynamics of deleterious alleles for a broad range of demographic models and use these data to inform the interpretation of empirical patterns of deleterious variation. Finally, we illustrate that the effects of demographic perturbations, such as bottlenecks and expansions, often manifest in opposing patterns of neutral and deleterious variation depending on whether the focus is on populations or individuals. Our results clarify seemingly disparate empirical characteristics of protein-coding variation and provide substantial insights into how natural selection and demographic history have patterned neutral and deleterious variation within and between populations. PMID:25279984

Fu, Wenqing; Gittelman, Rachel M; Bamshad, Michael J; Akey, Joshua M

2014-10-01

102

Quantifying genetic diversity under a broad spectrum of deleterious mutations  

NASA Astrophysics Data System (ADS)

Recent studies have shown that selection against deleterious mutations may play a major role in shaping observed patterns of sequence variation in natural populations. However, our understanding of these patterns remains limited, since selection creates correlations along the genome that are difficult to disentangle from each other. Previous theoretical work has focused on the qualitative effects of selection on sequence diversity, using simplified models in which all selected mutations have the same fitness cost. Yet is known that deleterious mutations follow a wide distribution in most organisms, so it is necessary to extend our theoretical predictions to this more general case before we can make quantitative connections with existing data. The evolutionary dynamics of this regime are complicated: extant mutant lineages represent large, correlated fluctuations away from the background expectation, which hinders efforts to apply existing methods based on deterministic or ``mean-field'' approximations. Here, we will describe recent progress towards this goal, which is based on a ``coarse-graining'' of the underlying distribution of fitnesses in the population.

Good, Benjamin; Desai, Michael

2013-03-01

103

A New Approach to Ecological Risk Assessment: Simulating Effects of Global Warming on Complex Ecological Networks  

NASA Astrophysics Data System (ADS)

The field of Ecological Risk Assessment (ERA) has been under development since the 1970s. Early ERA borrowed basic concepts from human health risk assessment (HRA) methodology [NAS 1983]. However, because of the nature of an ecosystem, there is a fundamental difference between HRA and ERA. In an HRA, the only receptor is a single human being and the concerned endpoints are always associated with human health issues, such as the risk of cancer. In ERA, however, entire populations, communities and ecosystems are at risk, and ERA must rigorously assess these more complex and larger scaled concerns. Many investigators have attempted to develop a new paradigm for ERA that can deal with this intrinsic distinction. Currently, a six-step framework is now widely used by the U.S. EPA and its contractors. This new paradigm is characterized by: (1) receptor identification, (2) hazard identification, (3) endpoint identification, (4) exposure assessment, (5) doseresponse assessment and (6) risk characterization [Lipton et al. 1993, Suter 1993]. The six-step framework identifies receptors at risk, possible hazards related to certain receptors, and chooses appropriate assessment and measurement endpoints [Suter 1990]. While the additional receptor and endpoint identifications improve on the traditional framework, single-species laboratory toxicity tests typically estimate ecological responses simply by predicting an environmental concentration associated with a certain stressor divided by the no-observed effect concentration (NOEC) for that stressor. This "Hazard Quotient" (HQ) approach ignores interactions between species that are critical to the functioning of communities and ecosystems.

Zhou, Yun; Brose, Ulrich; Kastenberg, William; Martinez, Neo D.

104

A METHOD TO INCORPORATE ECOLOGY INTO RESIDENCE TIME OF CHEMICALS IN EMBAYMENTS: LOCAL EFFECT TIME  

EPA Science Inventory

Residence times are classically defined by the physical and chemical aspects of water bodies rather than by their ecological implications. Therefore, a more clear and direct connection between the residence times and ecological effects is necessary to quantitatively relate these ...

105

ECOLOGICAL TAX REFORM: Estimated Environmental and Employment Effects in British Columbia  

E-print Network

i ECOLOGICAL TAX REFORM: Estimated Environmental and Employment Effects in British Columbia by Amy in British Columbia. To do this, I simulated ecological taxes on water consumption, solid waste and carbon

106

Ecological and socioeconomic effects of China's policies for ecosystem services  

PubMed Central

To address devastating environmental crises and to improve human well-being, China has been implementing a number of national policies on payments for ecosystem services. Two of them, the Natural Forest Conservation Program (NFCP) and the Grain to Green Program (GTGP), are among the biggest programs in the world because of their ambitious goals, massive scales, huge payments, and potentially enormous impacts. The NFCP conserves natural forests through logging bans and afforestation with incentives to forest enterprises, whereas the GTGP converts cropland on steep slopes to forest and grassland by providing farmers with grain and cash subsidies. Overall ecological effects are beneficial, and socioeconomic effects are mostly positive. Whereas there are time lags in ecological effects, socioeconomic effects are more immediate. Both the NFCP and the GTGP also have global implications because they increase vegetative cover, enhance carbon sequestration, and reduce dust to other countries by controlling soil erosion. The future impacts of these programs may be even bigger. Extended payments for the GTGP have recently been approved by the central government for up to 8 years. The NFCP is likely to follow suit and receive renewed payments. To make these programs more effective, we recommend systematic planning, diversified funding, effective compensation, integrated research, and comprehensive monitoring. Effective implementation of these programs can also provide important experiences and lessons for other ecosystem service payment programs in China and many other parts of the world. PMID:18621700

Liu, Jianguo; Li, Shuxin; Ouyang, Zhiyun; Tam, Christine; Chen, Xiaodong

2008-01-01

107

Sexual selection against deleterious mutations via variable male search success  

PubMed Central

In many species, successful mating requires the initial step of actively searching for and locating a female. The overall health or condition of a male is likely to affect their ability to do this, making search effort a potentially important component of sexual fitness that may have important consequences for population mean fitness. We investigated the potential population genetic consequences of search effort using 10 populations of Drosophila melanogaster, each fixed for a different recessive mutation with a visible phenotypic effect. Mate choice trials were conducted in arenas of varying size, requiring different levels of search ability. Sexual selection against mutant males was stronger when increased search effort was included than when it was excluded. Varying abilities to find mates can substantially increase the strength of selection against deleterious alleles. PMID:19625301

MacLellan, Kelsie; Whitlock, Michael C.; Rundle, Howard D.

2009-01-01

108

Predicting ecological effects of pollutants: A role for marine mesocosms  

SciTech Connect

The major uncertainty in predicting the ecological effects of a pollutant is the relationship between dose and the ecological response. Mesocosms may be used to simulate population-level biological processes and to estimate the nature and shape of dose-related responses to pollutants, for use in predictive evaluations of pollutant impacts. To ensure that responses observed in mesocosm tests are representative it is necessary to confirm that the simulated processes operate at rates similar to those found in the field. Pilot experiments were conducted in small marine mesocosms simulating major processes in two local habitat types: unvegetated sand and sand colonized by the brown macroalga Sargassum. The results showed that for a range of variates (such as the % of egg-bearing harpacticoid copepods, or the chlorophyll a concentration in surface sediments) the mean values for measurements in the tanks over a 9 week period did not consistently converge or diverge from those in the field. Also, for a number of the variates, a modelled decrease of more than about 60% in the mean could be detected with greater than 80% statistical power. This indicates that the effects of a pollutant could be detected with acceptable power. Use of a combination of such variates based on different functional or taxonomic groups for pollutant effects testing could greatly decrease uncertainty about the predicted effects of pollutants discharged to these habitats.

Ward, T.J. [CSIRO Marine Labs., Perth (Australia)

1994-12-31

109

Potential Biological and Ecological Effects of Flickering Artificial Light  

PubMed Central

Organisms have evolved under stable natural lighting regimes, employing cues from these to govern key ecological processes. However, the extent and density of artificial lighting within the environment has increased recently, causing widespread alteration of these regimes. Indeed, night-time electric lighting is known significantly to disrupt phenology, behaviour, and reproductive success, and thence community composition and ecosystem functioning. Until now, most attention has focussed on effects of the occurrence, timing, and spectral composition of artificial lighting. Little considered is that many types of lamp do not produce a constant stream of light but a series of pulses. This flickering light has been shown to have detrimental effects in humans and other species. Whether a species is likely to be affected will largely be determined by its visual temporal resolution, measured as the critical fusion frequency. That is the frequency at which a series of light pulses are perceived as a constant stream. Here we use the largest collation to date of critical fusion frequencies, across a broad range of taxa, to demonstrate that a significant proportion of species can detect such flicker in widely used lamps. Flickering artificial light thus has marked potential to produce ecological effects that have not previously been considered. PMID:24874801

Inger, Richard; Bennie, Jonathan; Davies, Thomas W.; Gaston, Kevin J.

2014-01-01

110

Genomic Background and Generation Time Influence Deleterious Mutation Rates in Daphnia  

PubMed Central

Understanding how genetic variation is generated and how selection shapes mutation rates over evolutionary time requires knowledge of the factors influencing mutation and its effects on quantitative traits. We explore the impact of two factors, genomic background and generation time, on deleterious mutation in Daphnia pulicaria, a cyclically parthenogenic aquatic microcrustacean, using parallel mutation-accumulation experiments. The deleterious mutational properties of life-history characters for individuals from two different populations, and for individuals maintained at two different generation times, were quantified and compared. Mutational properties varied between populations, especially for clutch size, suggesting that genomic background influences mutational properties for some characters. Generation time was found to have a greater effect on mutational properties, with higher per-generation deleterious mutation rates in lines with longer generation times. These results suggest that differences in genetic architecture among populations and species may be explained in part by demographic features that significantly influence generation time and therefore the rate of mutation. PMID:23183667

Latta, Leigh C.; Morgan, Kendall K.; Weaver, Casse S.; Allen, Desiree; Schaack, Sarah; Lynch, Michael

2013-01-01

111

ASTER: AN INTEGRATION OF THE AQUIRE DATABASE AND THE QSAR SYSTEM FOR USE IN ECOLOGICAL RISK ASSESSMENTS  

EPA Science Inventory

Ecological risk assessments are used by the U.S. Environmental Protection Agency (USEPA) and other governmental agencies to assist in determining the probability and magnitude of deleterious effects of hazardous chemicals on plants and animals. hese assessments are important step...

112

ASTER: AN INTEGRATION OF THE AQUIRE DATABASE AND THE QSAR SYSTEM FOR USE IN ECOLOGICAL RISK ASSESSMENT  

EPA Science Inventory

Ecological risk assessments are used by the U.S. Environmental Protection Agency (USEPA) and other governmental agencies to assist in determining the probability and magnitude of deleterious effects of hazardous chemicals on plants and animals. hese assessments are important step...

113

Ecological effects of contaminants and remedial actions in Bear Creek  

SciTech Connect

Ecological studies of the Bear Creek watershed, which drains the area surrounding several Oak Ridge Y-12 Plant waste disposal facilities, were initiated in May 1984 and are continuing at present. These studies consisted of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek, and they were followed by a presently ongoing monitoring phase that involves reduced sampling intensities. The characterization phase utilized two approaches: (1) instream sampling of benthic invertebrate and fish communities in Bear Creek to identify spatial and temporal patterns in distribution and abundance and (2) laboratory bioassays on water samples from Bear Creek and selected tributaries to identify potential sources of toxicity to biota. The monitoring phase of the ecological program relates to the long-term goals of identifying and prioritizing contaminant sources and assessing the effectiveness of remedial actions. It continues activities of the characterization phase at less frequent intervals. The Bear Greek Valley is a watershed that drains the area surrounding several closed Oak Ridge Y-12 Plant waste disposal facilities. Past waste disposal practices in Bear Creek Valley resulted in contamination of Bear Creek and consequent ecological damage. Extensive remedial actions have been proposed at waste sites, and some of the have been implemented or are now underway. The proposed study plan consists of an initial, detailed characterization of the benthic invertebrate and fish communities in Bear Creek in the first year followed by a reduction in sampling intensity during the monitoring phase of the plan. The results of sampling conducted from May 1984 through early 1989 are presented in this report.

Southworth, G.R.; Loar, J.M.; Ryon, M.G.; Smith, J.G.; Stewart, A.J. (Oak Ridge National Lab., TN (United States)); Burris, J.A. (C. E. Environmental, Inc., Tallahassee, FL (United States))

1992-01-01

114

Physiological Ecology of Freshwater Mussel Communities: Effects of Temperature on Community Structure and Ecological Services.  

NASA Astrophysics Data System (ADS)

Recent work suggests that freshwater mussel communities significantly influence stream ecosystem function through benthic-pelagic coupling of energy and nutrients. Mussel beds increase sediment organic matter and benthic algal production, facilitating the abundance and diversity of co-occurring benthic invertebrates. The magnitude of these effects appear to be regulated by abiotic factors such as temperature and flow, which influence hydraulic residence time and biological rates of reaction. We are using an integrative approach to examine the role of temperature on measures of physiological condition (metabolic rate, glycogen concentration, RNA: DNA) and measures of ecosystem services (nutrient excretion, biodeposition and clearance rate). Eight different species of unionids were removed from a mussel bed in the Little River, OK and acclimated to four temperatures (5, 15, 25, and 35C) for two weeks prior to the experiment. Measures of condition and ecosystem services were taken for all species at each temperature. Data collected to date suggest that there is significant variation in species-specific thermal performance. These performance curves influence resource acquisition, potentially shaping community structure (species dominance) and subsequent ecological function.

Spooner, D. E.; Vaughn, C. C.

2005-05-01

115

Status and ecological effects of the world's largest carnivores.  

PubMed

Large carnivores face serious threats and are experiencing massive declines in their populations and geographic ranges around the world. We highlight how these threats have affected the conservation status and ecological functioning of the 31 largest mammalian carnivores on Earth. Consistent with theory, empirical studies increasingly show that large carnivores have substantial effects on the structure and function of diverse ecosystems. Significant cascading trophic interactions, mediated by their prey or sympatric mesopredators, arise when some of these carnivores are extirpated from or repatriated to ecosystems. Unexpected effects of trophic cascades on various taxa and processes include changes to bird, mammal, invertebrate, and herpetofauna abundance or richness; subsidies to scavengers; altered disease dynamics; carbon sequestration; modified stream morphology; and crop damage. Promoting tolerance and coexistence with large carnivores is a crucial societal challenge that will ultimately determine the fate of Earth's largest carnivores and all that depends upon them, including humans. PMID:24408439

Ripple, William J; Estes, James A; Beschta, Robert L; Wilmers, Christopher C; Ritchie, Euan G; Hebblewhite, Mark; Berger, Joel; Elmhagen, Bodil; Letnic, Mike; Nelson, Michael P; Schmitz, Oswald J; Smith, Douglas W; Wallach, Arian D; Wirsing, Aaron J

2014-01-10

116

Quantitative analysis of ecological effects for land use planning based on ecological footprint method: a case research in Nanyang City  

Microsoft Academic Search

The research of coordinated development between land use and ecological building is a new problem with the development of country economy, whose intention is to improve economy development and protect eco-environment in order to realize regional sustainable development. Evaluating human effects on the ecosystem by a comprehensive, scientific and quantitative method is a critical issue in the process of general

Jing Zhang; Yaolin Liu; Xinming Chen

2008-01-01

117

Parental effects in ecology and evolution: mechanisms, processes and implications  

PubMed Central

As is the case with any metaphor, parental effects mean different things to different biologists—from developmental induction of novel phenotypic variation to an evolved adaptation, and from epigenetic transference of essential developmental resources to a stage of inheritance and ecological succession. Such a diversity of perspectives illustrates the composite nature of parental effects that, depending on the stage of their expression and whether they are considered a pattern or a process, combine the elements of developmental induction, homeostasis, natural selection, epigenetic inheritance and historical persistence. Here, we suggest that by emphasizing the complexity of causes and influences in developmental systems and by making explicit the links between development, natural selection and inheritance, the study of parental effects enables deeper understanding of developmental dynamics of life cycles and provides a unique opportunity to explicitly integrate development and evolution. We highlight these perspectives by placing parental effects in a wider evolutionary framework and suggest that far from being only an evolved static outcome of natural selection, a distinct channel of transmission between parents and offspring, or a statistical abstraction, parental effects on development enable evolution by natural selection by reliably transferring developmental resources needed to reconstruct, maintain and modify genetically inherited components of the phenotype. The view of parental effects as an essential and dynamic part of an evolutionary continuum unifies mechanisms behind the origination, modification and historical persistence of organismal form and function, and thus brings us closer to a more realistic understanding of life's complexity and diversity. PMID:19324619

Badyaev, Alexander V.; Uller, Tobias

2009-01-01

118

Indirect genetic effects from ecological interactions in Arabidopsis thaliana.  

PubMed

Indirect genetic effects arise when genes expressed in one individual affect the expression of traits in other individuals. The importance of indirect genetic effects has been recognized for a diversity of evolutionary processes including kin selection, sexual selection, community structure and multilevel selection, but data regarding their genetic architecture and prevalence throughout the genome remain scarce, especially for interactions between unrelated individuals. Using a set of 411 Bay-0 x Shahdara Arabidopsis recombinant inbred lines grown with Landsberg neighbours, we examined quantitative trait loci (QTL) having direct and indirect effects on size, developmental, and fitness related traits. Using an interval mapping approach, we identified 15 QTL with direct effects and found that 13 of these QTL had significant indirect effects on trait expression in neighbouring plants. These results suggest widespread pleiotropy, as nearly all direct effect QTL have associated pleiotropic indirect effects. Paradoxically, most indirect effects were of the same sign as direct effects, creating a pattern of nearly universal positive pleiotropy that makes most covariances between direct and indirect effects positive. These results are consistent with a complex genetic basis for intraspecific interactions, but suggest that interactions between neighbouring plants are largely positive, rather than negative as would be expected for competition. In addition to their evolutionary and ecological importance, these pleiotropic relationships between DGE and IGE loci have implications for quantitative genetic studies of natural populations as well as experimental design considerations. Additionally, studies that ignore IGEs may over- or underestimate quantitative genetic parameters, as well as the effect of and variance contributed by QTL. PMID:17561898

Mutic, Joshua J; Wolf, Jason B

2007-06-01

119

Computational evaluation of cellular metabolic costs successfully predicts genes whose expression is deleterious.  

PubMed

Gene suppression and overexpression are both fundamental tools in linking genotype to phenotype in model organisms. Computational methods have proven invaluable in studying and predicting the deleterious effects of gene deletions, and yet parallel computational methods for overexpression are still lacking. Here, we present Expression-Dependent Gene Effects (EDGE), an in silico method that can predict the deleterious effects resulting from overexpression of either native or foreign metabolic genes. We first test and validate EDGE's predictive power in bacteria through a combination of small-scale growth experiments that we performed and analysis of extant large-scale datasets. Second, a broad cross-species analysis, ranging from microorganisms to multiple plant and human tissues, shows that genes that EDGE predicts to be deleterious when overexpressed are indeed typically down-regulated. This reflects a universal selection force keeping the expression of potentially deleterious genes in check. Third, EDGE-based analysis shows that cancer genetic reprogramming specifically suppresses genes whose overexpression impedes proliferation. The magnitude of this suppression is large enough to enable an almost perfect distinction between normal and cancerous tissues based solely on EDGE results. We expect EDGE to advance our understanding of human pathologies associated with up-regulation of particular transcripts and to facilitate the utilization of gene overexpression in metabolic engineering. PMID:24198337

Wagner, Allon; Zarecki, Raphy; Reshef, Leah; Gochev, Camelia; Sorek, Rotem; Gophna, Uri; Ruppin, Eytan

2013-11-19

120

Computational evaluation of cellular metabolic costs successfully predicts genes whose expression is deleterious  

PubMed Central

Gene suppression and overexpression are both fundamental tools in linking genotype to phenotype in model organisms. Computational methods have proven invaluable in studying and predicting the deleterious effects of gene deletions, and yet parallel computational methods for overexpression are still lacking. Here, we present Expression-Dependent Gene Effects (EDGE), an in silico method that can predict the deleterious effects resulting from overexpression of either native or foreign metabolic genes. We first test and validate EDGE’s predictive power in bacteria through a combination of small-scale growth experiments that we performed and analysis of extant large-scale datasets. Second, a broad cross-species analysis, ranging from microorganisms to multiple plant and human tissues, shows that genes that EDGE predicts to be deleterious when overexpressed are indeed typically down-regulated. This reflects a universal selection force keeping the expression of potentially deleterious genes in check. Third, EDGE-based analysis shows that cancer genetic reprogramming specifically suppresses genes whose overexpression impedes proliferation. The magnitude of this suppression is large enough to enable an almost perfect distinction between normal and cancerous tissues based solely on EDGE results. We expect EDGE to advance our understanding of human pathologies associated with up-regulation of particular transcripts and to facilitate the utilization of gene overexpression in metabolic engineering. PMID:24198337

Wagner, Allon; Zarecki, Raphy; Reshef, Leah; Gochev, Camelia; Sorek, Rotem; Gophna, Uri; Ruppin, Eytan

2013-01-01

121

ELSEVIER Ecological Economics 10 (1994) 249-263 Ecological and economic effects of forest landscape structure  

E-print Network

model that simulates animal population dynamics and economic yield from timber harvests based on forest the population dynamics and extinction probability of Rachman's Sparrow (Aimophila aestiualis), a species caused serious ecological problems, includ- ing the rapid extinction of species (May, 1988). #12;250 J

122

THE LOCAL EFFECT TIME (LET) AND HOW IT INCORPORATES ECOLOGY INTO RESIDENCE TIME  

EPA Science Inventory

A clear and direct connection between constituent/water residence times and ecological effects is necessary to quantitatively relate these time scales to ecology. The concept of "local effect time" (LET) is proposed here as a time scale with adequate spatial resolution to relate ...

123

195BACH, KELLY: FOREST EDGE EFFECTS AND HERBIVORY New Zealand Journal of Ecology (2004) 28(2): 195-205 New Zealand Ecological Society  

E-print Network

195BACH, KELLY: FOREST EDGE EFFECTS AND HERBIVORY New Zealand Journal of Ecology (2004) 28(2): 195-205 ©New Zealand Ecological Society Effects of forest edges on herbivory in a New Zealand mistletoe, Alepis and in forest interior were compared, and effects of plant size and the neighbouring conspecific plant community

Canterbury, University of

124

Acidic precipitation, Vol. 2: Biological and ecological effects  

SciTech Connect

Acidic precipitation has its origin in emissions to the atmosphere of numerous compounds from both natural and man-made sources. The chapters in this volume cover a wide array of topics on the biological and ecological effects of acidic precipitation. A chapter on soil productivity emphasizes changes in biological and chemical characters of forest soils impacted by acidic deposition. Additional chapters discuss specific effects on soil microorganisms, trees, and crops. The importance of aluminum in this environmental issue is highlighted by a discussion on the mobility and phytotoxicity of this element in acidic soils. This chapter puts into perspective the biology of Al stressed plants. Two major chapters discuss the effect of acidic precipitation on forest ecosystems; one emphasizing North America, and the other Europe. Effects of soil acidification on key soil processes, including litter decomposition and depletion of essential plant nutrients in the soil profile are emphasized. Finally, three major chapters comprehensively cover limnological ecosystems and their response to acidic perturbation. These chapters discuss the response of stream and lake communities, both floral and faunal, to water acidification, including reduced biodiversity in these systems. Ten chapters have been processed separately for inclusion in the appropriate data bases.

Adriano, D.C.; Johnson, A.H. (eds.)

1989-01-01

125

Ecological Engineering Flowchart Colorado State University Effective Fall 2013  

E-print Network

Spring ENVE 322 - 3 F,S Basic Hydrology ENVE 438 - 3 F,S Envir Engr Concepts CIVE 330 - 3 S Ecological Soil Science Advanced Writing - 3 16 CIVE 261 (MECH 237) (MATH 340) (CIVE 300) MATH 161 or MATH 255 Eng. Life 320 - 3 Ecology Science Tech Elective- 3 Historical Perspectives - 3 18 CIVE 300;CIVE 303

126

Ecological Engineering Flowchart Colorado State University Effective Fall 2014  

E-print Network

Spring CIVE 322 - 3 F,S Basic Hydrology CIVE 438 - 3 F,S Envir Engr Concepts CIVE 330 - 3 S Ecological Soil Science Advanced Writing - 3 16 CIVE 261 (MECH 237) (MATH 340) (CIVE 300) MATH 161 or MATH 255 Eng. Life 320 - 3 Ecology Science Tech Elective- 3 Historical Perspectives - 3 18 CIVE 300;CIVE 303

127

Ecological Engineering Flowchart Colorado State University Effective Spring 2014  

E-print Network

Spring ENVE 322 - 3 F,S Basic Hydrology ENVE 438 - 3 F,S Envir Engr Concepts CIVE 330 - 3 S Ecological Soil Science Advanced Writing - 3 16 CIVE 261 (MECH 237) (MATH 340) (CIVE 300) MATH 161 or MATH 255 Eng. Life 320 - 3 Ecology Science Tech Elective- 3 Historical Perspectives - 3 18 CIVE 300;CIVE 303

128

Most Rare Missense Alleles Are Deleterious in Humans: Implications for Complex Disease and Association Studies  

PubMed Central

The accumulation of mildly deleterious missense mutations in individual human genomes has been proposed to be a genetic basis for complex diseases. The plausibility of this hypothesis depends on quantitative estimates of the prevalence of mildly deleterious de novo mutations and polymorphic variants in humans and on the intensity of selective pressure against them. We combined analysis of mutations causing human Mendelian diseases, of human-chimpanzee divergence, and of systematic data on human genetic variation and found that ?20% of new missense mutations in humans result in a loss of function, whereas ?27% are effectively neutral. Thus, the remaining 53% of new missense mutations have mildly deleterious effects. These mutations give rise to many low-frequency deleterious allelic variants in the human population, as is evident from a new data set of 37 genes sequenced in >1,500 individual human chromosomes. Surprisingly, up to 70% of low-frequency missense alleles are mildly deleterious and are associated with a heterozygous fitness loss in the range 0.001–0.003. Thus, the low allele frequency of an amino acid variant can, by itself, serve as a predictor of its functional significance. Several recent studies have reported a significant excess of rare missense variants in candidate genes or pathways in individuals with extreme values of quantitative phenotypes. These studies would be unlikely to yield results if most rare variants were neutral or if rare variants were not a significant contributor to the genetic component of phenotypic inheritance. Our results provide a justification for these types of candidate-gene (pathway) association studies and imply that mutation-selection balance may be a feasible evolutionary mechanism underlying some common diseases. PMID:17357078

Kryukov, Gregory V.; Pennacchio, Len A.; Sunyaev, Shamil R.

2007-01-01

129

Quantitative analysis of ecological effects for land use planning based on ecological footprint method: a case research in Nanyang City  

NASA Astrophysics Data System (ADS)

The research of coordinated development between land use and ecological building is a new problem with the development of country economy, whose intention is to improve economy development and protect eco-environment in order to realize regional sustainable development. Evaluating human effects on the ecosystem by a comprehensive, scientific and quantitative method is a critical issue in the process of general land use planning. At present, ecological footprint methodology, as an excellent educational tool applicable to global issues, is essential for quantifying humanity's consumption of natural capital, for overall assessments of human impact on earth as well as for general land use planning. However, quantitative studies on the development trends of ecological footprint (EF) time series and biological capacity (BC) time series in a given region are still rare. Taking Nanyang City as a case study, this paper presents two quantitative estimate indices over time scale called the change rate and scissors difference to quantitatively analyze the trends of EF and BC over the planning period in general land use planning form 1997-2004 and to evaluate the ecological effects of the land use general planning form 1997 to.2010. The results showed that: 1 In Nanyang city, trends of the per capita EF and BC were on the way round, and the ecological deficit enhanced from 1997 to 2010. 2 The difference between the two development trends of per capita EF and BC had been increasing rapidly and the conflict between the EF and BC was aggravated from 1997 to 2010. 3 The general land use planning (1997 - 2010) of Nanyang city had produced some positive effects on the local ecosystem, but the expected biological capacity in 2010 can hardly be realized following this trend. Therefore, this paper introduces a "trinity" land use model in the guidelines of environment- friendly land use pattern and based on the actual situation of Nanyang city, with the systemic synthesis of land utilization of the cities, the village and the suburb as a principal part and the land development reorganization and the ecological environment construction as the key point.

Zhang, Jing; Liu, Yaolin; Chen, Xinming

2008-10-01

130

Uncovering the diversification history of marine tetrapods: ecology influences the effect of geological sampling biases  

E-print Network

Uncovering the diversification history of marine tetrapods: ecology influences the effect the ichthyosaurs, sauropterygians, thalattosaurs, crocodyliforms, turtles, squamates, and other line- ages. Many. This is congruent with studies of shallow marine invertebrate diversity and suggests that `common cause' effects

Cambridge, University of

131

Effects of ecological soil management on workability and trafficability of a loamy soil in the Netherlands  

Microsoft Academic Search

Effects of ecological and conventional farming in an identical loamy soil were expressed in terms of the land qualities workability and trafficability using conditions in an old meadow as a reference. Threshold values for workability, determined by the lower plastic limit occurred at matric potentials of - 120, -45 and -35 cm for the ecological, conventional and old meadow system,

P. Droogers; A. Fermont; J. Bouma

1996-01-01

132

Genet. Res., Camb. (2000), 75, pp. 7581. With 3 figures. Printed in the United Kingdom # 2000 Cambridge University Press 75 Inbreeding depression due to mildly deleterious mutations in  

E-print Network

on the inbreeding depression caused by mildly deleterious alleles. Since our interest is in part motivated by plant Cambridge University Press 75 Inbreeding depression due to mildly deleterious mutations in finite We studied the effects of population size on the inbreeding depression and genetic load caused

Bataillon, Thomas

133

Prevention of deleterious deposits in a coal liquefaction system  

DOEpatents

A process for preventing the formation of deleterious coke deposits on the walls of coal liquefaction reactor vessels involves passing hydrogen and a feed slurry comprising feed coal and recycle liquid solvent to a coal liquefaction reaction zone while imparting a critical mixing energy of at least 3500 ergs per cubic centimeter of reaction zone volume per second to the reacting slurry.

Carr, Norman L. (Allison Park, PA); Prudich, Michael E. (Pittsburgh, PA); King, Jr., William E. (Gibsonia, PA); Moon, William G. (Cheswick, PA)

1984-07-03

134

Efficient Purging of Deleterious Mutations in Plants with Haploid Selfing  

E-print Network

, diploid, haploid-dominant life cycle, intragametophytic selfing, outcrossing, deleterious mutations 8 Bioinformatics Institute, Agency for Science, Technology and Research (A*STAR), Singapore 9 with a diploid-dominant life phase, selfing increases genome-wide GBE � The Author(s) 2014. Published by Oxford

Wagner, Andreas

135

Climate Change Has Cascading Ecological Effects on Mountain Ecosystems  

NASA Astrophysics Data System (ADS)

Evidence that ecosystems of the Northern Rocky Mountains are responding to climate change abounds. Alpine glaciers, as iconic landscape features, are disappearing rapidly with some glaciers losing one half of their area in five years. A model developed in the 1990s to predict future rates of melt has proved too conservative when compared to recent measurements. The largest glaciers in Glacier National Park are almost 10 years ahead of schedule in their retreat. The cascading ecological effects of losing glaciers in high-elevation watersheds includes shifts in distribution and dominance of temperature-sensitive stream macroinvertebrates as stream volume dwindles (or disappears) in later summer months and water temperatures increase. Critical spawning areas for threatened bull trout (Salvelinus confluentus) will be lost without the consistent supply of cold water that melting snow and ice provide and raise management questions regarding the efficacy of recovery efforts. Snowpacks are documented as becoming smaller and melting earlier in the spring, facilitating the invasion of subalpine meadows by trees and reducing habitat for current alpine wildlife. Even vital ecosystem disturbances, such as periodic snow avalanches that clear mountain slope forests, have been shown by tree-ring studies to be responsive to climatic trends and are likely to become less prevalent. Monitoring of high-elevation mountain environments is difficult and has largely been opportunistic despite the fact that these areas have experienced three times the temperature increases over the past century when compared to lowland environments. A system of alpine observatories is sorely needed. Tighter integration of mountains studies, and comparisons among diverse mountain systems of the western U.S. has been initiated by the USGS-sponsored Western Mountain Initiative and the Consortium for Integrated Climate Research in Western Mountains to begin addressing this need.

Fagre, D. B.

2007-12-01

136

Contrasted Effects of Diversity and Immigration on Ecological Insurance in Marine Bacterioplankton  

E-print Network

Contrasted Effects of Diversity and Immigration on Ecological Insurance in Marine Bacterioplankton of the two lagoons. We manipulated initial bacterial diversity for experimental communities and immigration. Immigration was only marginally beneficial to bacterial communities, probably because microbial communities

Mouquet, Nicolas

137

Environmental variability and the ecological effects of spawning Pacific salmon on stream biofilm  

E-print Network

Environmental variability and the ecological effects of spawning Pacific salmon on stream biofilm by resource subsidies and disturbance by ecosystem engineering) on benthic biofilm. 2. We sampled seven, stream environmental characteristics and their influence on responses of benthic biofilm [mean

Tiegs, Scott

138

Landscape Sources, Ecological Effects, and Management of Nutrients in Lakes of Northeastern USA  

EPA Science Inventory

Lakes face escalating pressures associated with land cover change and growing human populations. Ecological responses provide context for identifying stressor severity, land use impacts, and management effectiveness. We used EPA National Lakes Assessment data and GIS to develop i...

139

Fashion Merchandising & Retail Studies, BS IPC: 2013 School of Human Ecology EFFECTIVE: 2013  

E-print Network

Fashion Merchandising & Retail Studies, BS IPC: 2013 School of Human Ecology EFFECTIVE: 2013 STUDENT: CWID#: DATE ENTERED: ADVISOR: GENERAL EDUCATION REQUIREMENTS: FASHION MERCHANDISING & RETAIL the following: Accounting, Art, Fashion Merchandising & Retail Studies. All must be approved by academic advisor

Selmic, Sandra

140

LANDSCAPE-SCALE EFFECTS OF TOXIC EVENTS FOR ECOLOGICAL RISK ASSESSMENT  

EPA Science Inventory

The effect of spatial heterogeneity on response of organisms has rarely been considered in ecological risk assessment or in ecotoxicological studies. ncreased and widespread use of agricultural pesticides has been linked with population declines of plants, invertebrate and verteb...

141

Environmental Fluoride in Australasia: Ecological Effects, Regulation and Management  

Microsoft Academic Search

Fluorine compounds (fluorides) are introduced into the Australian and New Zealand atmospheres principally as a result of coal- fired electric power generation, aluminium smelting and ceramics. Addition of fluorides to water supplies as a public health measure represent the largest single addition to waters. An ecologically important, but quantitatively small source of fluoride in soil is associated with superphosphate application

D. Doley; R. J. Hill; R. H. Riese

142

Ecological Effects of Weather Modification: A Problem Analysis.  

ERIC Educational Resources Information Center

This publication reviews the potential hazards to the environment of weather modification techniques as they eventually become capable of producing large scale weather pattern modifications. Such weather modifications could result in ecological changes which would generally require several years to be fully evident, including the alteration of…

Cooper, Charles F.; Jolly, William C.

143

Amino acid composition of proteins reduces deleterious impact of mutations  

NASA Astrophysics Data System (ADS)

The evolutionary origin of amino acid occurrence frequencies in proteins (composition) is not yet fully understood. We suggest that protein composition works alongside the genetic code to minimize impact of mutations on protein structure. First, we propose a novel method for estimating thermodynamic stability of proteins whose sequence is constrained to a fixed composition. Second, we quantify the average deleterious impact of substituting one amino acid with another. Natural proteome compositions are special in at least two ways: 1) Natural compositions do not generate more stable proteins than the average random composition, however, they result in proteins that are less susceptible to damage from mutations. 2) Natural proteome compositions that result in more stable proteins (i.e. those of thermophiles) are also tuned to have a higher tolerance for mutations. This is consistent with the observation that environmental factors selecting for more stable proteins also enhance the deleterious impact of mutations.

Hormoz, Sahand

2013-10-01

144

Ecological effects of soil contamination at Aberdeen Proving Ground, Maryland  

SciTech Connect

Assessment of the ecological condition of contaminated soil was conducted in portions of the U.S. Army's Aberdeen Proving Ground, Maryland as part of an ecological risk assessment. This area is covered by open fields, woods and nontidal marshes. Chemicals disposed of in open burning pits included methylphosphonothioic acid, dichlorodiethyl sulfide, and titanium tetrachloride and sulfur trioxide/chlorosulfonic acid. Previous soil analysis showed extensive surface soil contamination with metals, nitrate, PCBs and pesticides. This assessment included characterizing soil biota, biologically-mediated processes in soil and aboveground biomass. Field surveys of the soil invertebrate communities showed significant reductions in the total abundance of animals, reductions in the abundance of several taxonomic and functional groups of soil invertebrates, and changes in the activity of epigeic arthropods in contaminated areas when compared with the local [open quotes]background[close quotes] area. Laboratory toxicity tests also demonstrated that microbial activity and success of egg hatching of ground beetle Harpalus pensylvanicus were reduced in contaminated soils. These results suggest that impacts to soil ecosystems should be explicitly considered in ecological risk assessment.

Kuperman, R.G.; Dunn, C.P. (Argonne National Laboratory, IL (United States))

1994-06-01

145

THE EFFECTS OF PATCH SHAPE ON INDIGO BUNTINGS:; EVIDENCE FOR AN ECOLOGICAL TRAP  

Microsoft Academic Search

Weldon, Aimee, J., and Nick M. Haddad. 2005. The effect of patch shape on indigo buntings: Evidence for an ecological trap. Ecology 86(6):1422-1431.;\\u000a;\\u000aAbstract. Habitat loss and fragmentation have led to a widespread increase in the;\\u000aproportion of edge habitat in the landscape. Disturbance-dependent bird species are widely;\\u000aassumed to benefit from these edges. However, anthropogenic edges may concentrate

AIMEE J. WELDON; NICK M. HADDAD

2005-01-01

146

The socioeconomic effects of uranium development in south Texas: a human ecological approach  

E-print Network

THE SOCIOECONOMIC FFFECTS OF URANIUM DEVELOPMENT IN SOUTH TEXAS: A HUMAN ECOLOGICAL APPROACH A Thesis by PAMELA CHRIS HOPKINS Submitted to tne Graduate College of Texas A&M University in partial fulfillment of the requirement for the degree... of MASTER OF SCIENCE August 1962 Major Subject: Sociology THE SOCIOECONOMIC EFFECTS OF URANIUM DEVELOPMENT IN SOUTH TEXAS: A HUMAN ECOLOGICAL APPROACH A Thesis by PAMELA CHRIS HOPKINS Approved as to style and content by: (Chairman of Committee...

Hopkins, Pamela Chris

2012-06-07

147

A review of behavioural ecology of whale sharks ( Rhincodon typus)  

Microsoft Academic Search

Behavioural ecology of whale sharks is very incompletely known. Recent rapid development of whale shark-based ecotourism at several widespread localities risks deleterious impacts on the behaviour, habitat, and ecology of the target species. Available information on behavioural ecology of whale sharks is synthesised from the published literature (including inferences from related species) and personal observations. This information is reviewed within

R. Aidan Martin

2007-01-01

148

Protective action of Citrullus colocynthis seed extracts against the deleterious effect of streptozotocin on both in vitro glucose-stimulated insulin release from rat pancreatic islets and in vivo glucose homeostasis  

PubMed Central

Citrullus colocynthis extracts improve glucose homeostasis in alloxan- or streptozotocin (STZ)-induced diabetic rats. Little is known, however, regarding the protective effect of these extracts against the ?-cytotoxic action of STZ. In the present study, an H2O-methanol extract was found to suppress the inhibition of glucose-stimulated insulin secretion by STZ in rat-isolated pancreatic islets. Similarly, when an aqueous extract from Citrullus colocynthis seeds was injected daily for 21 days prior to STZ administration, the perturbation of glucose homeostasis otherwise generated by the ?-cytotoxic agent was minimized in rats. PMID:24648906

BENARIBA, NABILA; BELLAKDHAR, WAFAA; DJAZIRI, RABEH; HUPKENS, EMELINE; LOUCHAMI, KARIM; MALAISSE, WILLY J.

2013-01-01

149

From roadkill to road ecology: A review of the ecological effects of roads  

Microsoft Academic Search

Transportation infrastructure affects the structure of ecosystems, the dynamics of ecosystem function, and has direct effects on ecosystem components, including their species composition. Clearly, the construction of transport lines results in the direct destruction and removal of existing ecosystems, and the reconfiguration of local landforms. However, transportation systems, and more specifically, roads, have a wide variety of primary, or direct,

Alisa W. Coffin

2007-01-01

150

Physiological Ecology of Freshwater Mussel Communities: Effects of Temperature on Community Structure and Ecological Services  

Microsoft Academic Search

Recent work suggests that freshwater mussel communities significantly influence stream ecosystem function through benthic-pelagic coupling of energy and nutrients. Mussel beds increase sediment organic matter and benthic algal production, facilitating the abundance and diversity of co-occurring benthic invertebrates. The magnitude of these effects appear to be regulated by abiotic factors such as temperature and flow, which influence hydraulic residence time

D. E. Spooner; C. C. Vaughn

2005-01-01

151

LineUp: Identifying Deleterious Mutations Using Protein Domain Alignment - Brady Bernard, TCGA Scientific Symposium 2014  

Cancer.gov

Home News and Events Multimedia Library Videos LineUp: Identifying Deleterious Mutations Using Protein Domain Alignment - Brady Bernard LineUp: Identifying Deleterious Mutations Using Protein Domain Alignment - Brady Bernard, TCGA Scientific Symposium

152

Ecological effects of atmospheric releases from synthetic fuels processes. [Phytotoxicity of selected gas-stream emissions  

Microsoft Academic Search

The primary ecological effects of exposure to synthetic fuels gas-stream emissions are discussed. The primary impacts will be on vegetation due to a combination of phytotoxic gases. Little is known about the effects of potential trace gas emissions such as COS, CSâ, hydrocarbons, and volatile metals, but the most important phytoactive gases are COâ and HâS. With the aid of

J. H. Shinn; J. R. Kercher

1978-01-01

153

Release of genetically engineered insects: a framework to identify potential ecological effects.  

PubMed

Genetically engineered (GE) insects have the potential to radically change pest management worldwide. With recent approvals of GE insect releases, there is a need for a synthesized framework to evaluate their potential ecological and evolutionary effects. The effects may occur in two phases: a transitory phase when the focal population changes in density, and a steady state phase when it reaches a new, constant density. We review potential effects of a rapid change in insect density related to population outbreaks, biological control, invasive species, and other GE organisms to identify a comprehensive list of potential ecological and evolutionary effects of GE insect releases. We apply this framework to the Anopheles gambiae mosquito - a malaria vector being engineered to suppress the wild mosquito population - to identify effects that may occur during the transitory and steady state phases after release. Our methodology reveals many potential effects in each phase, perhaps most notably those dealing with immunity in the transitory phase, and with pathogen and vector evolution in the steady state phase. Importantly, this framework identifies knowledge gaps in mosquito ecology. Identifying effects in the transitory and steady state phases allows more rigorous identification of the potential ecological effects of GE insect release. PMID:24198955

David, Aaron S; Kaser, Joe M; Morey, Amy C; Roth, Alexander M; Andow, David A

2013-10-01

154

Release of genetically engineered insects: a framework to identify potential ecological effects  

PubMed Central

Genetically engineered (GE) insects have the potential to radically change pest management worldwide. With recent approvals of GE insect releases, there is a need for a synthesized framework to evaluate their potential ecological and evolutionary effects. The effects may occur in two phases: a transitory phase when the focal population changes in density, and a steady state phase when it reaches a new, constant density. We review potential effects of a rapid change in insect density related to population outbreaks, biological control, invasive species, and other GE organisms to identify a comprehensive list of potential ecological and evolutionary effects of GE insect releases. We apply this framework to the Anopheles gambiae mosquito – a malaria vector being engineered to suppress the wild mosquito population – to identify effects that may occur during the transitory and steady state phases after release. Our methodology reveals many potential effects in each phase, perhaps most notably those dealing with immunity in the transitory phase, and with pathogen and vector evolution in the steady state phase. Importantly, this framework identifies knowledge gaps in mosquito ecology. Identifying effects in the transitory and steady state phases allows more rigorous identification of the potential ecological effects of GE insect release. PMID:24198955

David, Aaron S; Kaser, Joe M; Morey, Amy C; Roth, Alexander M; Andow, David A

2013-01-01

155

Ecological Modelling 134 (2000) 283297 Effects of leaf area profiles and canopy stratification on  

E-print Network

We investigated the effects of the shape of leaf area profiles and the number of canopy layersEcological Modelling 134 (2000) 283­297 Effects of leaf area profiles and canopy stratification leaf area in the vertical direction, how does the shape of the leaf area profile affect simulation

Wu, Jianguo "Jingle"

156

THE YEAR IN ECOLOGY AND CONSERVATION BIOLOGY, 2009 Effects of Air Pollution on Ecosystems  

E-print Network

THE YEAR IN ECOLOGY AND CONSERVATION BIOLOGY, 2009 Effects of Air Pollution on Ecosystems change, and invasive species as prime threats to biodiversity conservation. Although air pollution. In this synthesis, the state of scientific knowledge on the effects of air pollution on plants and animals

Weathers, Kathleen C.

157

Increasing Public Access to Scientific Research through Stakeholder Involvement: Ecological Effects of Sea Level Rise in the Northern Gulf of Mexico  

NASA Astrophysics Data System (ADS)

Sea level rise (SLR) has the potential to have a myriad of deleterious effects on coastal ecology and human infrastructure. Stakeholders, including managers of coastal resources, must be aware of potential consequences of SLR and adjust their plans accordingly to protect and preserve the resources under their care. Members of the public, particularly those who live or work in coastal areas, should also be informed about the results of scientific research on the effects of SLR. However, research results are frequently published in venues or formats to which resource managers and the broader public have limited access. It is imperative for scientists to move beyond traditional publication venues in order to more effectively disseminate the results of their research (Dennison, W. 2007, Estu. Coast. Shelf Sci. 77, 185). One potentially effective way to advance public access to research is to incorporate stakeholder involvement into the research project process in order to target study objectives and tailor communication products toward stakeholder needs (Lemos, M. & Morehouse, B. 2005, Glob. Env. Chg. 15, 57). However, it is important to manage communication and clarify participant expectations during this type of research (Gawith, M. et al. 2009, Glob. Env. Chg. 19, 113). This presentation describes the process being undertaken by an ongoing 5-year multi-disciplinary NOAA-funded project, Ecological Effects of Sea Level Rise in the Northern Gulf of Mexico (EESLR-NGOM), to improve accessibility and utility of scientific research results through stakeholder engagement. The EESLR-NGOM project is assessing the ecological risks from SLR along the Mississippi, Alabama and Florida Panhandle coasts, coastal habitats, and floodplains. It has incorporated stakeholder involvement throughout the research process so as to better target and tailor the emerging research products to meet resource managers' needs, as well as to facilitate eventual public dissemination of results. An important component of the EESLR-NGOM project is annual stakeholder committee workshops that engage regional coastal resource managers. These workshops are designed to identify managers' concerns about the scientific project objectives, solicit input on the content and format of the emerging research products, identify gaps in products and target audiences, and connect this project to other ongoing SLR research and extension efforts. We describe how this innovative project process has functioned to shape scientific objectives, the eventual SLR impact decision support tools, and other products that will help managers and the public use the project's results most effectively.

Hagen, S. C.; Stephens, S. H.; DeLorme, D. E.; Ruple, D.; Graham, L.

2013-12-01

158

Do all frogs swim alike? The effect of ecological specialization on swimming kinematics in frogs.  

PubMed

Frog locomotion has attracted wide scientific interest because of the unusual and derived morphology of the frog pelvic girdle and hind limb. Previous authors have suggested that the design of the frog locomotor system evolved towards a specialized jumping morphology early in the radiation of the group. However, data on locomotion in frogs are biased towards a few groups and most of the ecological and functional diversity remains unexplored. Here, we examine the kinematics of swimming in eight species of frog with different ecologies. We use cineradiography to quantify movements of skeletal elements from the entire appendicular skeleton. Our results show that species with different ecologies do differ in the kinematics of swimming, with the speed of limb extension and especially the kinematics of the midfoot being different. Our results moreover suggest that this is not a phylogenetic effect because species from different clades with similar ecologies converge on the same swimming kinematics. We conclude that it is important to analyze frog locomotion in a broader ecological and evolutionary context if one is to understand the evolutionary origins of this behavior. PMID:25189370

Robovska-Havelkova, Pavla; Aerts, Peter; Rocek, Zbynek; Prikryl, Tomas; Fabre, Anne-Claire; Herrel, Anthony

2014-10-15

159

Ecological effects of invasive alien insects Marc Kenis Marie-Anne Auger-Rozenberg Alain Roques Laura Timms  

E-print Network

Ecological effects of invasive alien insects Marc Kenis Ã? Marie-Anne Auger-Rozenberg Ã? Alain Roques identified 403 primary research publications that investigated the ecological effects of invasive alien, preda- tion or parasitism. Alien species may also affect native species and communities through more com

Schweik, Charles M.

160

Evolutionary and Ecological Effects of Multi-Generational Exposures to Anthropogenic Stressors  

Microsoft Academic Search

Biological and ecological responses to stress are dictated by duration and frequency, as well as instantaneous magnitude. Conditional compensatory responses at the physiological and behavioral levels, referred to as ‘acclimation’, may mitigate effects on individuals experiencing brief or infrequent periods of moderate stress. However, even modest stress over extended periods may reduce the fitness of some or all exposed individuals.

Diane E. Nacci; Timothy R. Gleason; Wayne R. Munns

2002-01-01

161

Evolvability in the face of climate change: understanding developmental effects on bone and its ecological consequences  

E-print Network

Evolvability in the face of climate change: understanding developmental effects on bone and its ecological consequences kevin.parsons@glasgow.ac.uk Kevin Parsons, Neil Metcalfe, Pat Monaghan (Institute, and genetic changes. While these studies focus on dietary differences, there are many environmental factors

Guo, Zaoyang

162

COMMUNITY ECOLOGY -ORIGINAL RESEARCH Effects of experimental rainfall manipulations on Chihuahuan  

E-print Network

). For example, summer and winter rainfall affect species diversity (Chesson et al. 2004), net primary proCOMMUNITY ECOLOGY - ORIGINAL RESEARCH Effects of experimental rainfall manipulations on Chihuahuan shrubs into C4-dominated grasslands. We conducted a long-term rainfall manipulation experiment in native

Small, Eric

163

COMMUNITY ECOLOGY -ORIGINAL RESEARCH Effects of experimental rainfall manipulations on Chihuahuan  

E-print Network

; Reynolds et al. 2004; Schwinning and Sala 2004). For example, summer and winter rainfall affect speciesCOMMUNITY ECOLOGY - ORIGINAL RESEARCH Effects of experimental rainfall manipulations on Chihuahuan-term rainfall manipulation experiment in native grassland, shrubland and the grass�shrub ecotone in the northern

164

Ecological Modelling 152 (2002) 205211 The effectiveness of various rabies spatial vaccination  

E-print Network

Ecological Modelling 152 (2002) 205­211 The effectiveness of various rabies spatial vaccination, periodic episodes of rabies epidemics erupt every 5­7 years despite low densities of the main reservoir species of rabies in this area. Canids in this desert are spread non-uniformly over space, with high

Bohrer, Gil

165

ECOSYSTEM ECOLOGY The effects of tree establishment on water and salt dynamics  

E-print Network

ECOSYSTEM ECOLOGY The effects of tree establishment on water and salt dynamics in naturally salt through changes in the water balance in naturally salt-affected landscapes of Hortobagy (Hungary. At greater depth, closer to the current water table level, the salt balance was reversed, with tree

Nacional de San Luis, Universidad

166

Pleistocene and ecological effects on continental-scale genetic differentiation in the bobcat (Lynx rufus)  

E-print Network

of genetic structure. Keywords: bobcat, landscape genetics, Lynx rufus, phylogeography, Pleistocene, suturePleistocene and ecological effects on continental-scale genetic differentiation in the bobcat (Lynx rufus) DAWN M. REDING,* ANNE M. BRONIKOWSKI,* WARREN E. JOHNSON and WILLIAM R. CLARK* *Department

Bronikowski, Anne

167

COMMUNITY AND ECOSYSTEM ECOLOGY Multitrophic Effects of Elevated Atmospheric CO2 on Understory Plant  

E-print Network

. Entomol. 33(6): 1609Ð1616 (2004) ABSTRACT Rising levels of atmospheric [CO2] will directly affect. These results, although preliminary, suggest that community-level responses to future atmospheric [CO2COMMUNITY AND ECOSYSTEM ECOLOGY Multitrophic Effects of Elevated Atmospheric CO2 on Understory

Sanders, Nathan J.

168

Impact: Toward a Framework for Understanding the Ecological Effects of Invaders  

Microsoft Academic Search

Although ecologists commonly talk about the impacts of nonindigenous species, little formal attention has been given to defining what we mean by impact, or connecting ecological theory with particular measures of impact. The resulting lack of generalizations regarding invasion impacts is more than an academic problem; we need to be able to distinguish invaders with minor effects from those with

I. M. Parker; D. Simberloff; W. M. Lonsdale; K. Goodell; M. Wonham; P. M. Kareiva; M. H. Williamson; B. Von Holle; P. B. Moyle; J. E. Byers; L. Goldwasser

1999-01-01

169

Salt marsh geomorphology: Physical and ecological effects on landform Keywords: salt marsh geomorphology; AGU Chapman Conference  

E-print Network

Editorial Salt marsh geomorphology: Physical and ecological effects on landform Keywords: salt marsh geomorphology; AGU Chapman Conference Evidence that the three-dimensional structure of salt marsh, and the ratio of marsh edge:marsh interior have all been shown to affect the distribution and density of salt

Fagherazzi, Sergio

170

GLOBAL CHANGE ECOLOGY -ORIGINAL RESEARCH Ecosystems effects 25 years after Chernobyl: pollinators,  

E-print Network

GLOBAL CHANGE ECOLOGY - ORIGINAL RESEARCH Ecosystems effects 25 years after Chernobyl: pollinators, fruit abundance and abundance of frugivores. Given that the Chernobyl disaster happened 25 years ago of a suppressed pollinator community on ecosystem functioning. Keywords Chernobyl Á Ecosystem functioning Á Fruits

Mousseau, Timothy A.

171

GLOBAL CHANGE ECOLOGY -ORIGINAL RESEARCH Ecosystems effects 25 years after Chernobyl: pollinators,  

E-print Network

GLOBAL CHANGE ECOLOGY - ORIGINAL RESEARCH Ecosystems effects 25 years after Chernobyl: pollinators, pollinator abundance, fruit abundance and abundance of frugivores. Given that the Chernobyl disaster happened of a suppressed pollinator community on ecosystem functioning. Keywords Chernobyl Á Ecosystem functioning Á Fruits

Mousseau, Timothy A.

172

Ecological and toxicological effects of inorganic nitrogen pollution in aquatic ecosystems: A global assessment  

Microsoft Academic Search

We provide a global assessment, with detailed multi-scale data, of the ecological and toxicological effects generated by inorganic nitrogen pollution in aquatic ecosystems. Our synthesis of the published scientific literature shows three major environmental problems: (1) it can increase the concentration of hydrogen ions in freshwater ecosystems without much acid-neutralizing capacity, resulting in acidification of those systems; (2) it can

Julio A. Camargo; Álvaro Alonso

2006-01-01

173

Alien species in fresh waters: ecological effects, interactions with other stressors, and prospects for the  

E-print Network

are poorly studied. Keywords: alien species, exotic species, introduced species, invasive species, noAlien species in fresh waters: ecological effects, interactions with other stressors, and prospects invasions are numerous in fresh waters around the world. At least hundreds of freshwater species have been

174

Studying Pretrial Publicity Effects: New Methods for Improving Ecological Validity and Testing External Validity  

Microsoft Academic Search

Although research examining the effects of pretrial publicity (PTP) on individuals' appraisals of a defendant and verdict decision making generally has been found to be internally valid, the external validity has been questioned by some social scientists as well as lawyers and judges. It is often proposed that the verisimilitude (or ecological validity) of the research should be increased in

Christina A. Studebaker; Jennifer K. Robbennolt; Steven D. Penrod; Maithilee K. Pathak-Sharma; Jennifer L. Groscup; Jennifer L. Devenport

2002-01-01

175

Effect of Computer-Assisted Instruction on Secondary School Students' Achievement in Ecological Concepts  

ERIC Educational Resources Information Center

This study investigated the effects of computer-assisted instruction (CAI) on students' achievement in ecological concepts. Quasi-experimental design, specifically the pre-test post test non-equivalent control group design was adopted. The sample consisted of sixty-six (66) senior secondary year two (SS II) biology students, drawn from two…

Nkemdilim, Egbunonu Roseline; Okeke, Sam O. C.

2014-01-01

176

The Effect of Conceptual Change Approach on Students' Ecology Achievement and Attitude towards Biology  

ERIC Educational Resources Information Center

This study investigated the effectiveness of conceptual change texts oriented instruction accompanied by demonstrations in small groups on students' ecology achievement and attitude towards biology. 78 ninth grade students in a public high school participated in this study. While the control group was taught with the traditional method, the…

Cetin, Gulcan; Ertepinar, Hamide; Geban, Omer

2004-01-01

177

Genetic and ecological effects of salmon farming on wild salmon: modelling from experimental results  

Microsoft Academic Search

Hindar, K., Fleming, I. A., McGinnity, P., and Diserud, O. 2006. Genetic and ecological effects of salmon farming on wild salmon: modelling from experimental results. ? ICES Journal of Marine Science, 63: 1234e1247. Cultured salmonids are released or escape into the wild in large numbers and may make up significant proportions of wild salmonid populations in fresh- and saltwater, causing

Kjetil Hindar; Ian A. Fleming; Philip McGinnity; Ola Diserud

2006-01-01

178

Self-Monitoring Effects in a Four-Year-Old Child: An Ecological Behavior Analysis.  

ERIC Educational Resources Information Center

Investigated effects of a self-monitoring (SM) procedure on the sustained schoolwork (SS) behavior of a four-year-old. Results indicated SM resulted in an increased rate of SS behavior in the absence of a clear functional relation between ecological variables (e.g., teacher attention) and SS and an increase in compliance behavior. (Author)

Workman, Edward A.; And Others

1982-01-01

179

INFLUENCE OF SIZE ON FATE AND ECOLOGICAL EFFECTS OF KEPONE IN PHYSICAL MODELS  

EPA Science Inventory

Three different sizes of marine microcosms were used to study the influence of two features of spatial scale on the chemical fate and ecological effects of the pesticide Kepone. ncreasing the size of microcosms reduced the ratio of wall surface area to volume of contained sea wat...

180

POPULATION ECOLOGY Environmentally Based Maternal Effects on Development Time in the  

E-print Network

in response to food stress (e.g., Fox et al. 1996, Fox and Savalli 1998). Phenotypic plasticity in body sizePOPULATION ECOLOGY Environmentally Based Maternal Effects on Development Time in the Seed Beetle) reared at high density ( 20 eggs per seed) matured at a substantially smaller adult body size than

Savalli, Udo M.

181

The Effects of Poverty on Children's Socioemotional Development: An Ecological Systems Analysis.  

ERIC Educational Resources Information Center

Bronfenbrenner's process-person-context-time model is used to examine theories that explain adverse effects of economic deprivation on children's socioemotional development. Processes of not only the family, but also those of the peer group and school, and in other levels of the ecological environment may also explain the relation between economic…

Eamon, Mary Keegan

2001-01-01

182

POPULATION ECOLOGY -ORIGINAL PAPER The effects of sex, age and breeding success on breeding dispersal  

E-print Network

POPULATION ECOLOGY - ORIGINAL PAPER The effects of sex, age and breeding success on breeding processes in population dynamics (Clobert et al. 2001). The breeding dispersal rates may vary according by environmental conditions, such as food availability, habitat quality, or population density (Ims and Hjermann

Laaksonen, Toni

183

GLOBAL CHANGE ECOLOGY -ORIGINAL RESEARCH Local effects of a global problem: modelling the risk of parasite-  

E-print Network

and pathogens in relation to climate change, especially global warming, has been of major concern in many predicted climate change--especially global warming--and parasitism may impact on marine host populationsGLOBAL CHANGE ECOLOGY - ORIGINAL RESEARCH Local effects of a global problem: modelling the risk

Poulin, Robert

184

Wildfire-contingent effects of fuel treatments can promote ecological resilience in seasonally dry conifer forests  

E-print Network

ARTICLE Wildfire-contingent effects of fuel treatments can promote ecological resilience suppression has made many seasonally dry conifer forests more susceptible to high-severity wildfires, which resilience to recurring wildfire events. To address this question, we established 664 plots across 12

North, Malcolm

185

ECOSYSTEM ECOLOGY -ORIGINAL PAPER Pacific salmon effects on stream ecosystems: a quantitative  

E-print Network

ECOSYSTEM ECOLOGY - ORIGINAL PAPER Pacific salmon effects on stream ecosystems: a quantitative during their annual spawning runs, leading researchers to classify these fish as ecosystem engineers-analysis to evaluate potential sources of variability among studies in stream ecosystem responses to salmon. Results

Tiegs, Scott

186

Research Plan for Study of Biological and Ecological Effects of the Solar Power Satellite Transmission System  

NASA Technical Reports Server (NTRS)

A programmatic research plan for a three year study is presented to generate knowledge on effects of the continuous wave 2.45 GHz microwave power transmission that the Solar Power Satellite might have on biological and ecological elements, within and around the rectenna receiving site.

Newsom, B. D.

1978-01-01

187

Probabilistic ecological hazard assessment: Evaluating pharmaceutical effects on aquatic higher plants as an example  

Microsoft Academic Search

The practicality of a probabilistic ecological hazard assessment (PEHA) methodology using intraspecies endpoint sensitivity distributions (IESDs) and chemical toxicity distributions (CTDs) was evaluated on data sets of pharmaceutical toxicity to aquatic macrophytes. A PEHA does not use an exposure distribution but rather uses a point estimate, which is useful for applications with sufficient effects data but lacking in comprehensive exposure

Richard A. Brain; Hans Sanderson; Paul K. Sibley; Keith R. Solomon

2006-01-01

188

Ecological Effects of Micropterus Introductions: the Dark Side of Black Bass  

E-print Network

Micropterus salmoides and smallmouth bass M. dolomieu are two widely introduced species of fish prized environments, angling for bass, in particular largemouth bass Micropterus salmoides and smallmouth bass M1 Ecological Effects of Micropterus Introductions: the Dark Side of Black Bass DONALD A. JACKSON

Jackson, Don

189

Integrating fundamental concepts of ecology, biogeography, and sampling into effective ecological niche modeling and species distribution modeling  

E-print Network

of the accessible area in ecological niche modeling and species distribution modeling. Ecological Modelling 222:1810?1819. Beale CM, Lennon JJ, Gimona A. 2008. Opening the climate envelope reveals no macroscale associations with climate in European birds... versus conservatism: Quantitative approaches to niche evolution. Evolution 62:2868?2883. Wiley EO. 1981. The Theory and Practice of Phylogenetic Systematics. 1st edition. New York: John Wiley & Sons. Figure 1. Summary of representation...

Peterson, A. Townsend; Soberó n, Jorge

2012-10-30

190

Ecological significance of residual exposures and effects from the Exxon Valdez oil spill.  

PubMed

An ecological significance framework is used to assess the ecological condition of Prince William Sound (PWS), Alaska, USA, in order to address the current management question: 17 y following the Exxon Valdez oil spill (EVOS), are there any remaining and continuing ecologically significant exposures or effects on the PWS ecosystem caused by EVOS? We examined the extensive scientific literature funded by the Exxon Valdez Trustees or by ExxonMobil to assess exposures and effects from EVOS. Criteria to assess ecological significance include whether a change in a valued ecosystem component (VEC) is sufficient to affect the structure, function, and/or health of the system and whether such a change exceeds natural variability. The EVOS occurred on 24 March 1989, releasing over 250,000 barrels of crude oil into PWS. Because PWS is highly dynamic, the residual oil was largely eliminated in the first few years, and now only widely dispersed, highly weathered, or isolated small pockets of residual contamination remain. Many other sources of polycyclic aromatic hydrocarbons (PAHs) exist in PWS from past or present human activities or natural oil seeps. Multiple-lines-of-evidence analyses indicate that residual PAHs from EVOS no longer represent an ecologically significant exposure risk to PWS. To assess the ecological significance of any residual effects from EVOS, we examined the literature on more than 20 VECs, including primary producers, filter feeders, fish and bird primary consumers, fish and bird top predators, a bird scavenger, mammalian primary consumers and top predators, biotic communities, ecosystem-level properties of trophodynamics and biogeochemical processes, and landscape-level properties of habitat mosaic and wilderness quality. None of these has any ecologically significant effects that are detectable at present, with the exception of 1 pod of orcas and possibly 1 subpopulation of sea otters; however, in both those cases, PWS-wide populations appear to have fully recovered. Many other stressors continue to affect PWS adversely, including climate and oceanographic variability, increased tourism and shipping, invasive species, the 1964 earthquake, and overexploitation of marine resources, with associated cascading effects on populations of PWS fish and predators. We conclude that the PWS ecosystem has now effectively recovered from EVOS. PMID:16869437

Harwell, Mark A; Gentile, John H

2006-07-01

191

Allelic Expression of Deleterious Protein-Coding Variants across Human Tissues  

PubMed Central

Personal exome and genome sequencing provides access to loss-of-function and rare deleterious alleles whose interpretation is expected to provide insight into individual disease burden. However, for each allele, accurate interpretation of its effect will depend on both its penetrance and the trait's expressivity. In this regard, an important factor that can modify the effect of a pathogenic coding allele is its level of expression; a factor which itself characteristically changes across tissues. To better inform the degree to which pathogenic alleles can be modified by expression level across multiple tissues, we have conducted exome, RNA and deep, targeted allele-specific expression (ASE) sequencing in ten tissues obtained from a single individual. By combining such data, we report the impact of rare and common loss-of-function variants on allelic expression exposing stronger allelic bias for rare stop-gain variants and informing the extent to which rare deleterious coding alleles are consistently expressed across tissues. This study demonstrates the potential importance of transcriptome data to the interpretation of pathogenic protein-coding variants. PMID:24786518

Kukurba, Kimberly R.; Zhang, Rui; Li, Xin; Smith, Kevin S.; Knowles, David A.; How Tan, Meng; Piskol, Robert; Lek, Monkol; Snyder, Michael; MacArthur, Daniel G.; Li, Jin Billy; Montgomery, Stephen B.

2014-01-01

192

Allelic expression of deleterious protein-coding variants across human tissues.  

PubMed

Personal exome and genome sequencing provides access to loss-of-function and rare deleterious alleles whose interpretation is expected to provide insight into individual disease burden. However, for each allele, accurate interpretation of its effect will depend on both its penetrance and the trait's expressivity. In this regard, an important factor that can modify the effect of a pathogenic coding allele is its level of expression; a factor which itself characteristically changes across tissues. To better inform the degree to which pathogenic alleles can be modified by expression level across multiple tissues, we have conducted exome, RNA and deep, targeted allele-specific expression (ASE) sequencing in ten tissues obtained from a single individual. By combining such data, we report the impact of rare and common loss-of-function variants on allelic expression exposing stronger allelic bias for rare stop-gain variants and informing the extent to which rare deleterious coding alleles are consistently expressed across tissues. This study demonstrates the potential importance of transcriptome data to the interpretation of pathogenic protein-coding variants. PMID:24786518

Kukurba, Kimberly R; Zhang, Rui; Li, Xin; Smith, Kevin S; Knowles, David A; How Tan, Meng; Piskol, Robert; Lek, Monkol; Snyder, Michael; Macarthur, Daniel G; Li, Jin Billy; Montgomery, Stephen B

2014-05-01

193

Ecological and socioeconomic effects of China's policies for ecosystem services  

E-print Network

Academy of Sciences, Beijing 100085, China; and §Department of Biology and Natural Capital Project, Woods. To make these programs more effective, we recommend systematic planning, diversified funding, effective and implementation of the Natural Forest Conservation Program (NFCP, also known as the Natural Forest Protection

194

Ecological effects, transport, and fate of mercury: a general review  

Microsoft Academic Search

Mercury at low concentrations represents a major hazard to microorganisms. Inorganic mercury has been reported to produce harmful effects at 5 ?g\\/l in a culture medium. Organomercury compounds can exert the same effect at concentrations 10 times lower than this. The organic forms of mercury are generally more toxic to aquatic organisms and birds than the inorganic forms. Aquatic plants

Dean W. Boening

2000-01-01

195

Global ecology  

SciTech Connect

A general description of the earth as a biosphere is presented. Divergent views of near-future world scenarios are presented; the Global 2000 report, and the analysis of Simon and Kahn. The basic principles and trends in global ecology are outlined, and the basic pollution and environmental degradation problems are discussed. Humanistic considerations which affect global ecology (population control, the effects of largescale nuclear war, and third-world socio-economics) are discussed.

Southwick, C.H. (ed.)

1985-01-01

196

Evaluation of model predictions of the ecological effects of 4-nonylphenol -- before and after model refinement  

SciTech Connect

The Littoral Ecosystem Risk Assessment Model (LERAM) is a bioenergetic ecosystem effects model. It links single species toxicity data to a bioenergetic model of the trophic structure of an ecosystem in order to simulate community and ecosystem level effects of chemical stressors. LERAM was used in 1992 to simulate the ecological effects of diflubenzuron. When compared to the results from a littoral enclosure study, the model exaggerated the cascading of effects through the trophic levels of the littoral ecosystem. It was hypothesized that this could be corrected by making minor changes in the representation of the littoral food web. Two refinements of the model were therefore performed: (1) the plankton and macroinvertebrate model populations [eg., predatory Copepoda, herbivorous Insecta, green phytoplankton, etc.] were changed to better represent the habitat and feeding preferences of the endemic taxa; and (2) the method for modeling the microbial degradation of detritus (and the resulting nutrient remineralization) was changed from simulating bacterial populations to simulating bacterial function. Model predictions of the ecological effects of 4-nonylphenol were made before and after these refinements. Both sets of predictions were then compared to the results from a littoral enclosure study of the ecological effects of 4-nonylphenol. The changes in the LERAM predictions were then used to determine the success of the refinements, to guide. future research, and to further define LERAM`s domain of application.

Hanratty, M.P.; Liber, K. [Univ. of Wisconsin, Superior, WI (United States)

1994-12-31

197

EFFECTS OF ECOLOGICAL COMFORT AND ECOLO- GICAL STRESS ON PRODUCTIVE TRAITS OF BROILER TURKEYS WITH EXPERIMENTALLY INDUCED MUSCULAR DYSTROPHY  

Microsoft Academic Search

Summary Oblakova, M., ?. Stoyanchev, N. Bozakova, ?. Lalev & I. Yotova, 2009. Effects of eco- logical comfort and ecological stress on productive traits of broiler turkeys with experimen- tally induced muscular dystrophy. Bulg. J. Vet. Med., 12, No 3, 192?198. The experiment was performed with four groups of broiler turkeys: I - control, reared under condi- tions of ecological

I. YOTOVA

198

Dominance and overdominance of mildly deleterious induced mutations for fitness traits in Caenorhabditis elegans.  

PubMed Central

We estimated the average dominance coefficient of mildly deleterious mutations (h, the proportion by which mutations in the heterozygous state reduce fitness components relative to those in the homozygous state) in the nematode Caenorhabditis elegans. From 56 worm lines that carry mutations induced by the point mutagen ethyl methanesulfonate (EMS), we selected 19 lines that are relatively high in fitness and estimated the viabilities, productivities, and relative fitnesses of heterozygotes and homozygotes compared to the ancestral wild type. There was very little effect of homozygous or heterozygous mutations on egg-to-adult viability. For productivity and relative fitness, we found that the average dominance coefficient, h, was approximately 0.1, suggesting that mildly deleterious mutations are on average partially recessive. These estimates were not significantly different from zero (complete recessivity) but were significantly different from 0.5 (additivity). In addition, there was a significant amount of variation in h among lines, and analysis of average dominance coefficients of individual lines suggested that several lines showed overdominance for fitness. Further investigation of two of these lines partially confirmed this finding. PMID:14573472

Peters, A D; Halligan, D L; Whitlock, M C; Keightley, P D

2003-01-01

199

Purging deleterious mutations in conservation programmes: combining optimal contributions with inbred matings  

PubMed Central

Conservation programmes aim at minimising the loss of genetic diversity, which allows populations to adapt to potential environmental changes. This can be achieved by calculating how many offspring every individual should contribute to the next generation to minimise global coancestry. However, an undesired consequence of this strategy is that it maintains deleterious mutations, compromising the viability of the population. In order to avoid this, optimal contributions could be combined with inbred matings, to expose and eliminate recessive deleterious mutations by natural selection in a process known as purging. Although some populations that have undergone purging experienced reduced inbreeding depression, this effect is not consistent across species. Whether purging by inbred matings is efficient in conservation programmes depends on the balance between the loss of diversity, the initial decrease in fitness and the reduction in mutational load. Here we perform computer simulations to determine whether managing a population by combining optimal contributions with inbred matings improves its long-term viability while keeping reasonable levels of diversity. We compare the management based on genealogical information with management based on molecular data to calculate coancestries. In the scenarios analysed, inbred matings never led to higher fitness and usually maintained lower diversity than random or minimum coancestry matings. Replacing genealogical with molecular coancestry can maintain a larger genetic diversity but can also lead to a lower fitness. Our results are strongly dependent on the mutational model assumed for the trait under selection, the population size during management and the reproductive rate. PMID:23321706

de Cara, M A R; Villanueva, B; Toro, M A; Fernandez, J

2013-01-01

200

[Management modes of different ownership forests and their ecological effects: a review].  

PubMed

China is in a critical period for the ownership reform of state-owned and collectively owned forests, which desiderates theoretical support and practical experience. However, the researches on the management modes of these forests and their ecological effects are scarce. In Europe and America, manifold ownership forest management has a long history, and relevant experts have made many researches on the ownership management contents and modes, as well as their effects on forest timber productivity, biodiversity, and landscape feature. To summarize and refer to these research harvests is definitely necessary and imminence for our forest ownership reform. This paper reviewed the management aims, modes, and ecological effects of state-owned and privately owned (industrial private and non-industrial private) forests, the parcelization and divestiture of forest ownership, and the associated protection policies of different ownership forests in the representative countries and regions in Europe and North America. The research prospect was also put forward. PMID:21941768

Li, Na-Na; Li, Yue-Hui

2011-06-01

201

ECOLOGICAL EFFECTS OF PESTICIDES ON NON-TARGET SPECIES  

EPA Science Inventory

This report was done in 1971 when there was no single source of data on the environmental effects of pesticides. It is a comprehensive compilation of published data. The judgments on what to include and what not to include are those of the author, though many individuals in the F...

202

The Ecological Effects in Acculturation of Puerto Rican Migrants.  

ERIC Educational Resources Information Center

Various studies discuss the influences on and effects of the process of adjustment to a new environment among Puerto Rican migrants to the United States mainland. In confronting cultural differences, Puerto Ricans may experience culture shock and identity problems and suffer disassociation leading to schizophrenia and hysteria, stress,…

Lopez-Ramirez, Norma Iris

203

Sustainable ecological development reducing negative effects of road maintenance salts  

Microsoft Academic Search

To ensure traffic safety in winter, large amounts of technical salts (chlorides) are applied on roads. De?icing salts directly or indirectly contaminate the road environment and have a negative effect on the components of road environment. The analysis of the situation raises a question: how to ensure traffic safety in wintertime applying salts and achieve sustainable development. The article presents

Pranas Baltrenas; Agne Kazlauskiene

2009-01-01

204

PHYSIOLOGICAL ECOLOGY Effect of Food Resources on Adult Glyptapanteles militaris  

E-print Network

frequently require access to food and adequate microclimates to maximize host location and parasitization of extra-host resources. Previous studies have demon- strated a signiÃ?cant effect of landscape structure microclimates may signiÃ?cantly increase the life span and parasitism of these parasitoids. However, the greater

Landis, Doug

205

Appendix 30 Fire Effects on Key Ecological Processes in Forested  

E-print Network

paragraphs on fire effects on forest succession are from Stickney (1982) Forest Succession ...the severity survivors derive from plants already established at the time of disturbance, it is possible...to determine becomes more favorable as a site for germination and establishment of colonizer plants. Increases

206

THE EFFECTS OF PATCH SHAPE ON INDIGO BUNTINGS: EVIDENCE FOR AN ECOLOGICAL TRAP  

SciTech Connect

Weldon, Aimee, J., and Nick M. Haddad. 2005. The effect of patch shape on indigo buntings: Evidence for an ecological trap. Ecology 86(6):1422-1431. Abstract. Habitat loss and fragmentation have led to a widespread increase in the proportion of edge habitat in the landscape. Disturbance-dependent bird species are widely assumed to benefit from these edges. However, anthropogenic edges may concentrate nest predators while retaining habitat cues that birds use to select breeding habitat. This may lead birds to mistakenly select dangerous habitat?a phenomenon known as an ??ecological trap.?? We experimentally demonstrated how habitat shape, and thus amount of edge, can adversely affect nest site selection and reproductive success of a disturbance-dependent bird species, the Indigo Bunting (Passerina cyanea). We did so within a landscape-scale experiment composed of equal-area habitat patches that differed in their amount of edge. Indigo Buntings preferentially selected edgy patches, which contained 50% more edge than more compact rectangular patches. Further, buntings fledged significantly fewer young per pair in edgy patches than in rectangular patches. These results provide the first experimental evidence that edges can function as ecological traps.

AIMEE J. WELDON; NICK M. HADDAD

2005-01-01

207

Environmental and Ontogenetic Effects on Intraspecific Trait Variation of a Macrophyte Species across Five Ecological Scales  

PubMed Central

Although functional trait variability is increasingly used in community ecology, the scale- and size-dependent aspects of trait variation are usually disregarded. Here we quantified the spatial structure of shoot height, branch length, root/shoot ratio and leaf number in a macrophyte species Potamogeton maackianus, and then disentangled the environmental and ontogenetic effects on these traits. Using a hierarchical nested design, we measured the four traits from 681 individuals across five ecological scales: lake, transect, depth stratus, quadrat and individual. A notable high trait variation (coefficient variation: 48–112%) was observed within species. These traits differed in the spatial structure, depending on environmental factors of different scales. Shoot height and branch length were most responsive to lake, transect and depth stratus scales, while root/shoot ratio and leaf number to quadrat and individual scales. The trait variations caused by environment are nearly three times higher than that caused by ontogeny, with ontogenetic variance ranging from 21% (leaf number) to 33% (branch length) of total variance. Remarkably, these traits showed non-negligible ontogenetic variation (0–60%) in each ecological scale, and significant shifts in allometric trajectories at lake and depth stratus scales. Our results highlight that environmental filtering processes can sort individuals within species with traits values adaptive to environmental changes and ontogenetic variation of functional traits was non-negligible across the five ecological scales. PMID:23626856

Zhong, Jiayou; Cao, Te; Ni, Leyi; Xie, Ping

2013-01-01

208

Ecological effects and environmental fate of solid rocket exhaust  

NASA Technical Reports Server (NTRS)

Specific target processes were classified as to the chemical, chemical-physical, and biological reactions and toxic effects of solid rocket emissions within selected ecosystems at Kennedy Space Center. Exposure of Citris seedlings, English peas, and bush beans to SRM exhaust under laboratory conditions demonstrated reduced growth rates, but at very high concentrations. Field studies of natural plant populations in three diverse ecosystems failed to reveal any structural damage at the concentration levels tested. Background information on elemental composition of selected woody plants from two terrestrial ecosystems is reported. LD sub 50 for a native mouse (peromysous gossypinus) exposed to SRM exhaust was determined to be 50 ppm/g body weight. Results strongly indicate that other components of the SRM exhaust act synergically to enhance the toxic effects of HCl gas when inhaled. A brief summary is given regarding the work on SRM exhaust and its possible impact on hatchability of incubating bird eggs.

Nimmo, B.; Stout, I. J.; Mickus, J.; Vickers, D.; Madsen, B.

1974-01-01

209

Combining social learning with agro-ecological research practice for more effective management of nitrate pollution  

Microsoft Academic Search

The path of research followed by a team of agro-ecologists who sought to address a complex environment issue by means of a social learning approach is described. Agro-ecological data from monitoring nitrates in surface and ground water and agricultural practices at micro-catchment scale provided the material for the process. The failure of scientists to deploy scientific data effectively in order

Marco Toderi; Neil Powell; Giovanna Seddaiu; Pier Paolo Roggero; David Gibbon

2007-01-01

210

EVALUATION OF METHODS FOR DETECTING ECOLOGICAL EFFECTS FROM GENETICALLY ENGINEERED MICROORGANISMS AND PEST CONTROL AGENTS IN TERRESTRIAL SYSTEMS  

EPA Science Inventory

This report summarizes and evaluates research from several laboratories that deals with the detection of ecological effects induced through exposure of microbes or plants to genetically engineered microorganisms (GEMS) and microbial pest control agents (MPCAS) . The development o...

211

Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida  

NASA Astrophysics Data System (ADS)

Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

2012-02-01

212

Estimating the Cumulative Ecological Effect of Local Scale Landscape Changes in South Florida  

USGS Publications Warehouse

Ecosystem restoration in south Florida is a state and national priority centered on the Everglades wetlands. However, urban development pressures affect the restoration potential and remaining habitat functions of the natural undeveloped areas. Land use (LU) planning often focuses at the local level, but a better understanding of the cumulative effects of small projects at the landscape level is needed to support ecosystem restoration and preservation. The South Florida Ecosystem Portfolio Model (SFL EPM) is a regional LU planning tool developed to help stakeholders visualize LU scenario evaluation and improve communication about regional effects of LU decisions. One component of the SFL EPM is ecological value (EV), which is evaluated through modeled ecological criteria related to ecosystem services using metrics for (1) biodiversity potential, (2) threatened and endangered species, (3) rare and unique habitats, (4) landscape pattern and fragmentation, (5) water quality buffer potential, and (6) ecological restoration potential. In this article, we demonstrate the calculation of EV using two case studies: (1) assessing altered EV in the Biscayne Gateway area by comparing 2004 LU to potential LU in 2025 and 2050, and (2) the cumulative impact of adding limestone mines south of Miami. Our analyses spatially convey changing regional EV resulting from conversion of local natural and agricultural areas to urban, industrial, or extractive use. Different simulated local LU scenarios may result in different alterations in calculated regional EV. These case studies demonstrate methods that may facilitate evaluation of potential future LU patterns and incorporate EV into decision making.

Hogan, Dianna M.; Labiosa, William; Pearlstine, Leonard; Hallac, David; Strong, David; Hearn, Paul; Bernknopf, Richard

2012-01-01

213

[Physiological and ecological effects of inter- and mixed cropping rape with milk vetch].  

PubMed

The investigation on the growth, yield and benefit of rape inter- and mixed cropped with milk vetch showed that comparing with sowing rape under zero tillage, the physiological and ecological characters of transplanted rape, including its height, leaf size, root diameter, opening degree and yield were obviously improved. Under zero tillage, mixed cropping had an obvious advantage than inter- and single cropping. After tillage, the yield of transplanted rape under mixed cropping was 11.9% more than that under single cropping with zero tillage. The benefit of transplanting rape under mixed cropping with tillage was the biggest, followed by single cropping rape with zero tillage. It could be concluded that the patterns of transplanting rape under mixed cropping after tillage and zero tillage had the best physiological and ecological effects, not only increasing rape yield and income, but also improving soil fertility. PMID:16262062

Zhou, Kejin; Xing, Jun; Bo, Yuhong; Sang, Yasong; Wu, Shelan; Song, Guoliang

2005-08-01

214

Additive genetic breeding values correlate with the load of partially deleterious mutations.  

PubMed

The mutation-selection-balance model predicts most additive genetic variation to arise from numerous mildly deleterious mutations of small effect. Correspondingly, "good genes" models of sexual selection and recent models for the evolution of sex are built on the assumption that mutational loads and breeding values for fitness-related traits are correlated. In support of this concept, inbreeding depression was negatively genetically correlated with breeding values for traits under natural and sexual selection in the weevil Callosobruchus maculatus. The correlations were stronger in males and strongest for condition. These results confirm the role of existing, partially recessive mutations in maintaining additive genetic variation in outbred populations, reveal the nature of good genes under sexual selection, and show how sexual selection can offset the cost of sex. PMID:20466931

Tomkins, Joseph L; Penrose, Marissa A; Greeff, Johan; LeBas, Natasha R

2010-05-14

215

Fire Ecology  

NSDL National Science Digital Library

Forest fires have become a regular summertime occurrence in North America, sparking debate about the proper role of fire on the land. The following websites examine fires and fire ecology in different ecosystems, regions, and time periods. The first site (1), from the USGS-Western Ecological Research Center shares information about fire ecology research in the California shrublands, Sierra Nevada forests, and Mohave and Sonoran deserts. The second site (2) features the Fire Ecology Center at Texas Tech University. The Fire Ecology Center focuses on the role of fire in grassland ecosystems and their website contains information on current research, publications, managing pastures, managing problem plants, and more. The third site (3), from the USGS-Northern Prairie Wildlife Research Center contains "an annotated bibliography on fire in North American wetland ecosystems and a subject index of all fire-related literature that has appeared in Wildlife Review." Hosted by Yellowstone National Park, the fourth site (4) addresses wildland fires in Yellowstone. The Park website presents brief sections on Fire Ecology, Fire Monitoring, Prescribed Fire, and Fire Effects -- to name a few. The fifth (5) site, from the Canadian Forest Service, provides information about forest fires in Canada including weekly fire statistics, fire research, daily fire maps, a fire database, and more. Part of a great site on the land use history of the Colorado Plateau from Northern Arizona University, the sixth site (6) offers a brief overview of wildfire history and ecology on the Plateau with links to information about ponderosa pine fire ecology, reintroduction of fire to forest ecosystems, and fire ecology research studies. The seventh site (7), from DiscoverySchool.com, contains a lesson plan on forest fire ecology for grade levels 9-12. The lesson spans two class periods and the site provides objectives, materials needed, discussion questions, academic standards, and more. The final (8) website, from the Why Files, "examines the role of fire in natural systems, and the role of science in understanding wildfires." The eleven-page website follows a kid-friendly narrative format and includes a bibliography and glossary.

216

ERTS-1 investigation of ecological effects of strip mining in eastern Ohio  

NASA Technical Reports Server (NTRS)

Evidence is presented of ERTS capability to detect, map and monitor the effects of strip mining. Both enlarge ERTS imagery and statistically processed outline maps and imagery of stripped earth and standing water are compared to aerial photos of a strip mine near Coshocton, Ohio. The outline maps and decision imagery are at present limited to forming a disruption map of recently mined and unreclaimed earth and the resultant standing water within the mined area. It is planned to prepare a map of the reclaimed areas (reclamation map) within the stripped area and to detect and identify ecological effects such as vegetation kills and stream sedimentation external to the stripped areas.

Chase, P. E.; Pettyjohn, W. A.

1973-01-01

217

Environmental monitoring and ecological risk assessment for pesticide contamination and effects in Lake Pamvotis, northwestern Greece.  

PubMed

Monitoring of pesticide residues in water and sediments was conducted as a basis for subsequent ecotoxicological risk assessment for the shallow eutrophic Lake Pamvotis, northwestern Greece. During a one-year study period, atrazine, desethylatrazine (DEA), simazine, diazinon, malathion, oxamyl, carbofuran, and ethion were detected in water and atrazine, desethylatrazine, diazinon, and s-ethyl dipropylthiocarbamate (EPTC) in sediments, all at ppb concentration level. Temporal variation in pesticide concentrations was observed. Highest residue levels for most pesticides in both water and sediment matrices occurred in the May to July period with the exception of atrazine and DEA, which show highest levels in water during the September to November period. The ecological risk associated with pesticide contamination was assessed using two different methods: The toxic unit method, which provides a first indication of the relative contribution of detected pesticides to the total toxicity and a probabilistic approach, and the inverse method of Van Straalen and Denneman, which is used to quantify the ecological risk. The maximum percentage of the ecological risk was 10.3 and 51.8% for water and 17.2 and 70.6% for sediment, based on acute and chronic level, respectively. These results show that pesticides exert a significant pressure on the aquatic system of Lake Pamvotis, especially for the chronic-effect level. Simple quotient methods should be coupled with higher-tier risk assessment, especially if restoration activities on lake ecosystems are to be undertaken for sustainable development. PMID:16117136

Hela, Dimitra G; Lambropoulou, Dimitra A; Konstantinou, Ioannis K; Albanis, Triantafyllos A

2005-06-01

218

Ecological effects of ocean acidification and habitat complexity on reef-associated macroinvertebrate communities  

PubMed Central

The ecological effects of ocean acidification (OA) from rising atmospheric carbon dioxide (CO2) on benthic marine communities are largely unknown. We investigated in situ the consequences of long-term exposure to high CO2 on coral-reef-associated macroinvertebrate communities around three shallow volcanic CO2 seeps in Papua New Guinea. The densities of many groups and the number of taxa (classes and phyla) of macroinvertebrates were significantly reduced at elevated CO2 (425–1100 µatm) compared with control sites. However, sensitivities of some groups, including decapod crustaceans, ascidians and several echinoderms, contrasted with predictions of their physiological CO2 tolerances derived from laboratory experiments. High CO2 reduced the availability of structurally complex corals that are essential refugia for many reef-associated macroinvertebrates. This loss of habitat complexity was also associated with losses in many macroinvertebrate groups, especially predation-prone mobile taxa, including crustaceans and crinoids. The transition from living to dead coral as substratum and habitat further altered macroinvertebrate communities, with far more taxa losing than gaining in numbers. Our study shows that indirect ecological effects of OA (reduced habitat complexity) will complement its direct physiological effects and together with the loss of coral cover through climate change will severely affect macroinvertebrate communities in coral reefs. PMID:24307670

Fabricius, K. E.; De'ath, G.; Noonan, S.; Uthicke, S.

2014-01-01

219

Carnivore repatriation and holarctic prey: narrowing the deficit in ecological effectiveness.  

PubMed

The continuing global decline of large carnivores has catalyzed great interest in reintroduction to restore populations and to reestablish ecologically functional relationships. I used variation in the distribution of four Holarctic prey species and their behavior as proxies to investigate the pace and intensity by which responses are lost or reinvigorated by carnivore repatriation. By simulating the presence of wolves (Canis lupus), tigers (Panthera tigris), and brown bears (Ursus arctos) at 19 transcontinental sites, I assayed three metrics of prey performance in areas with no large terrestrial carnivores (the polar islands of Greenland and Svalbard), extant native carnivores (Eastern Siberian Shield, boreal Canada, and Alaska); and repatriated carnivores (the Yellowstone region and Rocky Mountains). The loss and reestablishment of large carnivores changed the ecological effectiveness of systems by (1) dampening immediate group benefits, diminishing awareness, and diminishing flight reaction in caribou (Rangifer tarandus) where predation was eliminated and (2) reinstituting sensitivity to carnivores by elk (Cervus elaphus) and moose (Alces alces) in the Yellowstone region to levels observed in Asian elk when sympatric with Siberian tigers and wolves or in Alaskan moose sympatric with wolves. Behavioral compensation to reintroduced carnivores occurred within a single generation, but only the vigilance reaction of bison (Bison bison) in Yellowstone exceeded that of their wolf-exposed conspecifics from boreal Canada. Beyond these overt responses by prey, snow depth and distance to suitably vegetated habitat was related to heightened vigilance in moose and elk, respectively, but only at sites with carnivores. These findings are insufficient to determine whether similar patterns might apply to other species or in areas with alien predators, and they suggest that the presumed excessive vulnerability of naïve prey to repatriated carnivores may be ill-founded. Although behavior offers a proxy to evaluate ecological effectiveness, a continuing challenge will be to understand how naïve prey respond to novel or introduced predators. PMID:17650259

Berger, Joel

2007-08-01

220

Pleistocene and ecological effects on continental-scale genetic differentiation in the bobcat (Lynx rufus).  

PubMed

The potential for widespread, mobile species to exhibit genetic structure without clear geographic barriers is a topic of growing interest. Yet the patterns and mechanisms of structure--particularly over broad spatial scales--remain largely unexplored for these species. Bobcats occur across North America and possess many characteristics expected to promote gene flow. To test whether historical, topographic or ecological factors have influenced genetic differentiation in this species, we analysed 1 kb mtDNA sequence and 15 microsatellite loci from over 1700 samples collected across its range. The primary signature in both marker types involved a longitudinal cline with a sharp transition, or suture zone, occurring along the Great Plains. Thus, the data distinguished bobcats in the eastern USA from those in the western half, with no obvious physical barrier to gene flow. Demographic analyses supported a scenario of expansion from separate Pleistocene refugia, with the Great Plains representing a zone of secondary contact. Substructure within the two main lineages likely reflected founder effects, ecological factors, anthropogenic/topographic effects or a combination of these forces. Two prominent topographic features, the Mississippi River and Rocky Mountains, were not supported as significant genetic barriers. Ecological regions and environmental correlates explained a small but significant proportion of genetic variation. Overall, results implicate historical processes as the primary cause of broad-scale genetic differentiation, but contemporary forces seem to also play a role in promoting and maintaining structure. Despite the bobcat's mobility and broad niche, large-scale landscape changes have contributed to significant and complex patterns of genetic structure. PMID:22548482

Reding, Dawn M; Bronikowski, Anne M; Johnson, Warren E; Clark, William R

2012-06-01

221

SYNTHESIS Ecological impacts of invasive alien plants: a meta-analysis of their effects on species, communities and ecosystems  

E-print Network

on resident species, communities and ecosystems. Across studies, alien plants had a significant effect in 11-up effects, diversity, ecological complexity, ecosystem functioning, effect size, exotic species, island, N), and hence impact upon ecosystem services and human well-being (Pejchar & Mooney 2009). However, while

Kratochvíl, Lukas

222

Effect of Classification Procedure on the Performance of Numerically Defined Ecological Regions  

Microsoft Academic Search

Ecological regionalizations define geographic regions exhibiting relative homogeneity in ecological (i.e., environmental and\\u000a biotic) characteristics. Multivariate clustering methods have been used to define ecological regions based on subjectively\\u000a chosen environmental variables. We developed and tested three procedures for defining ecological regions based on spatial\\u000a modeling of a multivariate target pattern that is represented by compositional dissimilarities between locations (e.g., taxonomic

Ton Snelder; Anthony Lehmann; Nicolas Lamouroux; John Leathwick; Karin Allenbach

2010-01-01

223

Prediction of deleterious nonsynonymous single-nucleotide polymorphism for human diseases.  

PubMed

The identification of genetic variants that are responsible for human inherited diseases is a fundamental problem in human and medical genetics. As a typical type of genetic variation, nonsynonymous single-nucleotide polymorphisms (nsSNPs) occurring in protein coding regions may alter the encoded amino acid, potentially affect protein structure and function, and further result in human inherited diseases. Therefore, it is of great importance to develop computational approaches to facilitate the discrimination of deleterious nsSNPs from neutral ones. In this paper, we review databases that collect nsSNPs and summarize computational methods for the identification of deleterious nsSNPs. We classify the existing methods for characterizing nsSNPs into three categories (sequence based, structure based, and annotation based), and we introduce machine learning models for the prediction of deleterious nsSNPs. We further discuss methods for identifying deleterious nsSNPs in noncoding variants and those for dealing with rare variants. PMID:23431257

Wu, Jiaxin; Jiang, Rui

2013-01-01

224

Ecological effects of nitrogen and sulfur air pollution in the US: what do we know?  

USGS Publications Warehouse

Four decades after the passage of the US Clean Air Act, air-quality standards are set to protect ecosystems from damage caused by gas-phase nitrogen (N) and sulfur (S) compounds, but not from the deposition of these air pollutants to land and water. Here, we synthesize recent scientific literature on the ecological effects of N and S air pollution in the US. Deposition of N and S is the main driver of ecosystem acidification and contributes to nutrient enrichment in many natural systems. Although surface-water acidification has decreased in the US since 1990, it remains a problem in many regions. Perturbations to ecosystems caused by the nutrient effects of N deposition continue to emerge, although gas-phase concentrations are generally not high enough to cause phytotoxicity. In all, there is overwhelming evidence of a broad range of damaging effects to ecosystems in the US under current air quality conditions.

Greaver, Tara L.; Sullivan, Timothy J.; Herrick, Jeffrey D.; Barber, Mary C.; Baron, Jill S.; Cosby, Bernard J.; Deerhake, Marion E.; Dennis, Robin L.; Dubois, Jean-Jacque B.; Goodale, Christine L.; Herlihy, Alan T.; Lawrence, Gregory B.; Liu, Lingli; Lynch, Jason A.; Novak, Kristopher J.

2012-01-01

225

The Effect of an Ecological Imagery Program on Soccer Performance of Elite Players  

PubMed Central

Purpose Despite the acknowledged impact of imagery on performance, ecologically sound studies investigating imagery and its effects on performance subcomponents in real games are surprisingly limited. The aim of this study was to investigate the effects of imagery training on passing improvement in elite soccer players. Methods Sixty nine soccer players taking part in the national championship leagues in four age categories including U16, U19, U21 and over 21 were randomly assigned to the imagery and control groups. Interventional group participants completed an 8 week video-aided, cognitive imagery program on how to make a perfect soccer pass. Results Performance analysis through close video analysis showed that successful pass rate increased significantly in the intervention group compared to control (OR = 1.19, P=0.002, 95%CI = 1.06-1.33). Further analysis revealed that the results are statistically significant in U16 and U21 but not other categories. Conclusions We concluded that successful soccer passing through real competitions as a multidimensional and critical open skill could be enhanced by an ecologically sound method of mental imagery. PMID:22942993

Seif-Barghi, Tohid; Kordi, Ramin; Memari, Amir-Hossein; Mansournia, Mohammad-Ali; Jalali-Ghomi, Majid

2012-01-01

226

Effect of the ecological water conveyance project on environment in the Lower Tarim River, Xinjiang, China.  

PubMed

The dynamic response of groundwater level is examined in traverse and lengthways directions. Take the Yinsu section for an example, we have simulated groundwater levels before and after water-conveyance every time and calculated the incidence of groundwater on the both sides of the river. It is noted that the effect keeps growing with the water-delivery times increasing, from 570 m after the first times to 3,334 m after the eighth times. In addition, this paper involves the temporal response of the natural vegetation to water conveyance, vegetation coverage, planted-species number, dominant position and species diversity from 2002 to 2006. The findings indicate that the positive influence of ecological water conveyance project (EWCP) on the ecosystem in the Lower Tarim River is a long-term process. In this paper, we try to calculate water required for recovery of damaged ecosystem by using data available. This project is likely the base of research on water demand and the reference of measures for research on ecological water conveyance effect. PMID:18274873

Ye, Zhaoxia; Chen, Yaning; Li, Weihong; Yan, Yan

2009-02-01

227

[Ecological effect of different types land consolidation in Hubei Province of China].  

PubMed

A model for estimating the ecosystem services value under effects of land consolidation was built to quantitatively evaluate the ecological effects of three different types of land consolidation projects in Jianghan Plain, middle hilly region, and western mountainous area of Hubei Province. With the implementation of the projects, the total value of ecosystem services in Jianghan Plain was decreased by 0.3%, among which, the values of food production service and other three services increased but those of water conservation and other four services decreased. In hilly region, the total value of ecosystem services was decreased by 14.6%, with the value of food production service increased by 55.2% and those of other eight services all decreased. In mountainous area, the total value of ecosystem services was decreased by 19.9%, with the value of food production service increased by 24.9% while the values of other eight services all decreased. In the land consolidation in the middle hilly region and western mountainous area of Hubei Province, there was an obvious conversion process 'from ecology to production' in the ecosystem services value. PMID:23189708

Gu, Xiao-Kun

2012-08-01

228

Ecologically relevant geomorphic attributes of streams are impaired by even low levels of watershed effective imperviousness  

NASA Astrophysics Data System (ADS)

Urbanization almost inevitably results in changes to stream morphology. Understanding the mechanisms for such impacts is a prerequisite to minimizing stream degradation and achieving restoration goals. However, investigations of urban-induced changes to stream morphology typically use indicators of watershed urbanization that may not adequately represent degrading mechanisms and commonly focus on geomorphic attributes such as channel dimensions that may be of little significance to the ecological goals for restoration. We address these shortcomings by testing if a measure characterizing urban stormwater drainage system connections to streams (effective imperviousness, EI) is a better predictor of change to ecologically relevant geomorphic attributes than a more general measure of urban density (total imperviousness, TI). We test this for 17 sites in independent watersheds across a gradient of urbanization. We found that EI was a better predictor of all geomorphic variables tested than was TI. Bank instability was positively correlated with EI, while width/depth (a measure of channel incision), bedload sediment depth, and frequency of bars, benches, and large wood were negatively correlated. Large changes in all geomorphic variables were detected at very low levels of EI (< 2-3%). Excess urban stormwater runoff, as represented by EI, drives geomorphic change in urban streams, highlighting the dominant role of the stormwater drainage system in efficiently transferring stormwater runoff from impervious surfaces to the stream, as found for ecological indicators. It is likely that geomorphic condition of streams in urbanizing watersheds, particularly those attributes of ecological relevance, can only be maintained if excess urban stormwater flows are kept out of streams through retention and harvesting. The extent to which EI can be reduced within urban and urbanizing watersheds, through techniques such as distributed stormwater harvesting and infiltration, and the components of the hydrologic regime to be addressed, requires further investigation. Urbanization influences stream morphology more than any other land use (Douglas, 2011): it alters hydrology and sediment inputs leading to deepening and widening of streams (Chin, 2006). Concomitantly, urbanization often directly impairs stream morphology through channel and riparian zone interventions, e.g., culverts (Hawley et al., 2012), rock protection (Vietz et al., 2012b), and constricted floodplains (Gurnell et al., 2007). These changes to channel geomorphology in turn contribute to poor in-stream ecological condition (Morley and Karr, 2002; Walsh et al., 2005b; Gurnell et al., 2007; Elosegi et al., 2010).The common conception is that channels undergo gross morphologic alterations if > 10-20% of their watershed is covered by impervious surfaces (total imperviousness, TI; Bledsoe and Watson, 2001; Chin, 2006; Table 1). Many of these studies may, however, underestimate the influence of urbanization by using insensitive channel metrics and assessing streams in early stages of urbanization. Most importantly, TI, as a measure of urban density, may not adequately represent the way in which urbanization alters the master variables of flow and sediment within a watershed.Hydrologists have long recognized that, rather than the proportion of impervious cover within a watershed, it is the proportion that is directly connected to the stream through stormwater drainage systems that may be a better predictor of urban-induced hydrologic change (Leopold, 1968). Referred to as effective imperviousness (EI) the proportion of impervious cover directly connected to the stream through stormwater drainage systems may also be a better predictor of geomorphic response than is TI. Over the last decade a direct measure of EI has been found to be a better predictor of ecological response in urban streams (Walsh et al., 2012), but use of such a metric has not found its way into geomorphic studies even though TI has been found to be ineffective (e.g., Bledsoe et al.,

Vietz, Geoff J.; Sammonds, Michael J.; Walsh, Christopher J.; Fletcher, Tim D.; Rutherfurd, Ian D.; Stewardson, Michael J.

2014-02-01

229

Southeast Asian primate communities: the effects of ecology and Pleistocene refuges on species richness.  

PubMed

We examined historical and ecological factors affecting current primate biodiversity in Southeast Asia. In Africa, Madagascar and South America, but not Southeast Asia, primate species richness is positively associated with average rainfall and distance from the equator (latitude). We predicted that Southeast Asia's non-conformance may be due to the effect of dispersed Pleistocene refuges (locations of constricted tropical forests during glacial maxima which today are at least 305 m in altitude). Based on 45 forested sites (13 on large islands; 32 on the mainland) of at least 100 km(2) to minimize recent human impact, we determined correlations between extant primate species richness and rainfall, latitude and supplementary ecological variables, while controlling for refuges and islands. We found that refuge sites had significantly higher primate species richness than non-refuges (t = -2.76, P < 0.05), and distance from the nearest Pleistocene refuge was negatively correlated with species richness for non-refuge sites (r = -0.51, P < 0.05). There was no difference in species richness between sites on large islands and the mainland (t = -1.4, P = 0.16). The expected positive relationship between rainfall and species richness was not found (r = 0.17, P = 0.28). As predicted, primate species richness was negatively correlated with latitude (r = -0.39, P < 0.05) and positively correlated with mean temperature (r = 0.45, P < 0.05). General linear models indicated that a site's latitude (F1,38 = 6.18, P < 0.05) and Pleistocene refuge classification (F1,42 = 5.96, P < 0.05) were the best predictors of species richness. Both ecological and historical factors contribute to present day primate species richness in Southeast Asia, making its biodiversity less of an outlier than previously believed. PMID:24344966

Hassel-Finnegan, Heather; Borries, Carola; Zhao, Qing; Phiapalath, Phaivanh; Koenig, Andreas

2013-12-01

230

Literature Review on the Effects of Prescription Fire on theEcology of Site 300  

SciTech Connect

Lawrence Livermore National Laboratory has historically conducted prescription burns across approximately 2,000 acres of Site 300 on an annual basis to safeguard test facilities and operations from the risk of wildfire encroachment. Prescription burns began in 1960, and although fire frequency varies among the designated burn areas, all have been burned at least once. A patchwork of native perennial grassland communities and associated special-status plant and animal populations occur onsite in many areas that have been receiving these treatments. Because the size and locations of prescription burns may shift in coming years, an evaluation is warranted to determine how these shifts may affect listed biota, including rare plants, and the distinct ecological conditions present on the site. This report presents the results of a literature review conducted by ICF International (ICF) to collect basic information on native perennial grasslands in California, the influence of fire on these grasslands, and management tools for restoring and maintaining them. The objective of this study was to review the scientific literature on California native grasslands and summarize the current state of knowledge pertaining to the possible effects -- both beneficial and detrimental -- of prescribed fire on the ecology of Site 300. The results of this review are intended to inform future management practices that may be carried out at Site 300 to maintain the plant and wildlife communities and to ensure that the ecological conditions benefit the special-status species that inhabit the Site. This review is also intended to identify a study approach to investigate changes over the next 10 years in the burned areas and in areas where burning will be discontinued.

Preston, R

2011-03-14

231

Administrative Ecology  

ERIC Educational Resources Information Center

This article discusses how all four facets of administrative ecology help dispel the claims about the "impossibility" of the superintendency. These are personal ecology, professional ecology, organizational ecology, and community ecology. Using today's superintendency as an administrative platform, current literature describes a preponderance of…

McGarity, Augustus C., III; Maulding, Wanda

2007-01-01

232

Face Adaptation Effects Show Strong and Long-Lasting Transfer from Lab to More Ecological Contexts  

PubMed Central

A review on recent experiments on figural face aftereffects reveals that adaptation effects in famous faces can last for hours up to days. Such adaptations seem to be highly reliable regarding test–retest designs as well as regarding the generalizability of adaptation across different adaptation routines and adaptations toward different kinds of facial properties. However, in the studies conducted so far, adaptation and the subsequent test phase were carried out in typical laboratory environments. Under these circumstances, it cannot be ruled out that the observed effects are, in fact, episodic learn–test compatibility effects. To test for ecological validity in adaptation effects we used an adaptation paradigm including environmental and social properties that differed between adaptation and test phase. With matched samples (n1?=?n2?=?54) we found no main effects of experimental setting compatibility resulting from varying where the tests where conducted (environmental condition) nor any interaction with effects of stimulus compatibility resulting from varying stimulus similarity between adaptation and test phase using the same picture, different pictures of the same person, or different persons (transfer). This indicates that these adaptation effects are not artificial or merely lab-biased effects. Adaptation to face stimuli may document representational adaptations and tuning mechanisms that integrate new visual input in a very fast, reliable, and sustainable way. PMID:22291676

Carbon, Claus-Christian; Ditye, Thomas

2012-01-01

233

Cumulative ecological and socioeconomic effects of forest policies in coastal Oregon.  

PubMed

Forest biodiversity policies in multi-ownership landscapes are typically developed in an uncoordinated fashion with little consideration of their interactions or possible unintended cumulative effects. We conducted an assessment of some of the ecological and socioeconomic effects of recently enacted forest management policies in the 2.3-million-ha Coast Range Physiographic Province of Oregon. This mountainous area of conifer and hardwood forests includes a mosaic of landowners with a wide range of goals, from wilderness protection to high-yield timber production. We projected forest changes over 100 years in response to logging and development using models that integrate land use change and forest stand and landscape processes. We then assessed responses to those management activities using GIS models of stand structure and composition, landscape structure, habitat models for focal terrestrial and aquatic species, timber production, employment, and willingness to pay for biodiversity protection. Many of the potential outcomes of recently enacted policies are consistent with intended goals. For example, we project the area of structurally diverse older conifer forest and habitat for late successional wildlife species to strongly increase. 'Other outcomes might not be consistent with current policies: for example, hardwoods and vegetation diversity strongly decline within and across owners. Some elements of biodiversity, including streams with high potential habitat for coho salmon (Oncorhynchus kisutch) and sites of potential oak woodland, occur predominately outside federal lands and thus were not affected by the strongest biodiversity policies. Except for federal lands, biodiversity policies were not generally characterized in sufficient detail to provide clear benchmarks against which to measure the progress or success. We conclude that land management institutions and policies are not well configured to deal effectively with ecological issues that span broad spatial and temporal scales and that alternative policies could be constructed that more effectively provide for a mix of forest values from this region. PMID:17479831

Spies, Thomas A; Johnson, K Norman; Burnett, Kelly M; Ohmann, Janet L; McComb, Brenda C; Reeves, Gordon H; Bettinger, Pete; Kline, Jeffrey D; Garber-Yonts, Brian

2007-01-01

234

Human Ecology Human ecology Research  

E-print Network

Human Ecology Impact of Human ecology Research Bonus Issue FROM SCHOLARSHIP TO POLICY MAKING OF HUMAN ECOLOGY APRIL 2005/VOLUME 33, NUMBER 1 #12;Human Ecology Volume 33, Number 1 April 2005 The New York State College of Human Ecology at Cornell University Lisa Staiano-Coico, Ph.D. Rebecca Q

Wang, Z. Jane

235

A Daphnia magna feeding bioassay as a cost effective and ecological relevant sublethal toxicity test for Environmental Risk Assessment of toxic effluents  

Microsoft Academic Search

Environmental Risk Assessment of chemical products and effluents within EC countries require the use of cost effective standardized toxicity tests that in most cases are restricted to acute responses to high doses. Thus, subtle ecological effects are underestimated. Here we propose a short-term one day Daphnia magna feeding inhibition test as a cost effective and ecological relevant sublethal bioassay. The

C. Barata; P. Alañon; S. Gutierrez-Alonso; M. C. Riva; C. Fernández; J. V. Tarazona

2008-01-01

236

Analysis of ecological effects of geopressured-geothermal resource development. Geopressured-geothermal technical paper No. 4  

SciTech Connect

The activities involved in geopressured-geothermal resource production are identified and their ecological impacts are discussed. The analysis separates those activites that are unique to geopressured-geothermal development from those that also occur in oil and gas and other resource developments. Of the unique activities, those with the greatest potential for serious ecological effect are: (1) accidental brine discharge as a result of a blowout during well drilling; (2) subsidence; (3) fault activation and enhanced seismicity; and (4) subsurface contamination of water, hydrocarbon, and mineral reservoirs. Available methods to predict and control these effects are discussed.

Not Available

1979-07-01

237

Evaluating Ecological Effects in a Semi-arid Aquatic System Using Three Lines of Evidence  

NASA Astrophysics Data System (ADS)

One mission of Los Alamos National Laboratory has been to develop explosives, machine explosive charges, and test explosive components for the United States nuclear weapons program. Effluents containing high explosives and metals from machining and photographic facilities were discharged to Canon de Valle for forty years at rates up to ten million gallons per year, making up as much as half of the canyon's flow. Discharges to the canyon were discontinued in 1996. Canon de Valle has an interrupted stream that supports an herbaceous ground cover and a multi-layer canopy of conifers, oak and aspen. An ecological screening assessment and problem formulation identified barium, cadmium, copper, manganese and silver as metals of potential ecological concern for the aquatic system in the canyon. Additionally, potential impacts associated with high explosives in the aquatic system are unknown because aquatic community screening values are not available. Two field studies were designed and implemented to assess the adverse effects in the canyon's aquatic system. The first field study consisted of benthic macro-invertebrate surveys that were conducted in Canon de Valle and three reference streams. The survey was then repeated in Canon de Valle four years later to assess trends in the benthic macro-invertebrate community. The second field study consisted of toxicity testing with {it Chironomus tentans} using three locations in the Canon de Valle and one location in a reference canyon. Two rounds of toxicity testing were conducted. Each round was supported with sediment and water sampling at each location for contaminant analysis. The data from the contaminant analysis of water and sediments will be presented along with the results of the benthic macro-invertebrate surveys and the toxicity tests. An example of identifying the contaminants associated with reduced survival in a toxicity test will presented, the utility of benthic macro-invertebrate community metrics as indicators of adverse ecological effects will be discussed, and the relative importance of these three lines of evidence for assessing adverse effects in the canyon's aquatic system will be discussed.

Tardiff, M. F.; Ford-Schmid, R.; Hickmott, D. D.

2003-12-01

238

Ecological and biomedical effects of effluents from near-term electric vehicle storage battery cycles  

SciTech Connect

An assessment of the ecological and biomedical effects due to commercialization of storage batteries for electric and hybrid vehicles is given. It deals only with the near-term batteries, namely Pb/acid, Ni/Zn, and Ni/Fe, but the complete battery cycle is considered, i.e., mining and milling of raw materials, manufacture of the batteries, cases and covers; use of the batteries in electric vehicles, including the charge-discharge cycles; recycling of spent batteries; and disposal of nonrecyclable components. The gaseous, liquid, and solid emissions from various phases of the battery cycle are identified. The effluent dispersal in the environment is modeled and ecological effects are assessed in terms of biogeochemical cycles. The metabolic and toxic responses by humans and laboratory animals to constituents of the effluents are discussed. Pertinent environmental and health regulations related to the battery industry are summarized and regulatory implications for large-scale storage battery commercialization are discussed. Each of the seven sections were abstracted and indexed individually for EDB/ERA. Additional information is presented in the seven appendixes entitled; growth rate scenario for lead/acid battery development; changes in battery composition during discharge; dispersion of stack and fugitive emissions from battery-related operations; methodology for estimating population exposure to total suspended particulates and SO/sub 2/ resulting from central power station emissions for the daily battery charging demand of 10,000 electric vehicles; determination of As air emissions from Zn smelting; health effects: research related to EV battery technologies. (JGB)

Not Available

1980-05-01

239

Ecological effects of a major oil spill on Panamanian coastal marine communities  

SciTech Connect

In 1986 more than 8 million liters of crude oil spilled into a complex region of mangroves, seagrasses, and coral reefs just east of the Caribbean entrance to the Panama Canal. This was the largest recorded spill into coastal habitats in the tropical Americas. Many populations of plants and animals in both oiled and unoiled sites had been studied previously, thereby providing an unprecedented measure of ecological variation before the spill. Documentation of the spread of oil and its biological effects begun immediately. Intertidal mangroves, seagrasses, algae, and associated invertebrates were covered by oil and died soon after. More surprisingly, there was also extensive mortality of shallow subtidal reef corals and infauna of seagrass beds. After 1.5 years only some organisms in areas exposed to the open sea have recovered.

Jackson, J.B.C.; Cubit, J.D.; Keller, B.D.; Batista, V.; Burns, K.; Caffey, H.M.; Caldwell, R.L.; Garrity, S.D.; Getter, C.D.; Gonzalez, C.; Guzman, H.M.; Kaufmann, K.W.; Knap, A.H.; Levings, S.C.; Marshall, M.J.; Steger, R.; Thompson, R.C.; Weil, E. (Smithsonian Tropical Research Institute, Balboa (Panama))

1989-01-06

240

Inclusion of soil arsenic bioaccessibility in ecological risk assessment and comparison with biological effects.  

PubMed

The purpose of this study was to conduct an ecological risk assessment (ERA) for meadow voles (Microtus pennslvanicus) found at three arsenic contaminated sites in Nova Scotia, Canada (as well as two background locations) and to compare the numeric results to measured biomarkers of exposure and effect. The daily intake of arsenic by meadow voles was determined by three separate calculations: estimated daily intake (EDI), bioaccessible estimated daily intake (BEDI, with bioaccessibility of soil included), and actual daily intake (ADI, which is calculated with arsenic concentrations in the stomach contents). The median bioaccessibility of arsenic in soils from the contaminated locations was significantly greater than at background locations. The bioaccessible arsenic concentration in soil from all samples (both contaminated and background) was significantly less than the total concentration. Use of site-specific bioaccessibility (hazard quotients=38 at Upper Seal Harbour (USH); 60 at Lower Seal Harbour (LSH); and 120 at Montague tailings (MONT)) and stomach arsenic contents (hazard quotients=2.1 at USH; 7.9 at LSH; and 6.7 at MONT) in the ERA resulted in lower numeric risk than compared to risk calculated with 100% bioavailability (hazard quotient=180 at USH; 75 at LSH; and 680 at MONT). Further, the use of bioaccessibility on the calculation of risk was aligned with biomarker results (changes in glutathione and micronucleated erythrocytes) in voles captured at the sites. This study provides evidence that using site-specific bioaccessibility in ERAs may provide a more realistic level of conservatism, thereby enhancing the accuracy of predicting risk to wildlife receptors. Furthermore, when numeric risk assessments are combined with site-specific biological data (i.e., biomarkers of exposure and effect), both lines of evidence can be used to make informed decisions about ecological risk and site management. PMID:22078367

Saunders, Jared R; Knopper, Loren D; Koch, Iris; Reimer, Kenneth J

2011-12-15

241

Deleterious epistatic interactions between electron transport system protein-coding loci in the copepod Tigriopus californicus.  

PubMed

The nature of epistatic interactions between genes encoding interacting proteins in hybrid organisms can have important implications for the evolution of postzygotic reproductive isolation and speciation. At this point very little is known about the fitness differences caused by specific closely interacting but evolutionarily divergent proteins in hybrids between populations or species. The intertidal copepod Tigriopus californicus provides an excellent model in which to study such interactions because the species range includes numerous genetically divergent populations that are still capable of being crossed in the laboratory. Here, the effect on fitness due to the interactions of three complex III proteins of the electron transport system in F2 hybrid copepods resulting from crosses of a pair of divergent populations is examined. Significant deviations from Mendelian inheritance are observed for each of the three genes in F2 hybrid adults but not in nauplii (larvae). The two-way interactions between these genes also have a significant impact upon the viability of these hybrid copepods. Dominance appears to play an important role in mediating the interactions between these loci as deviations are caused by heterozygote/homozygote deleterious interactions. These results suggest that the fitness consequences of the interactions of these three complex III-associated genes could influence reproductive isolation in this system. PMID:16624922

Willett, Christopher S

2006-07-01

242

Detection of deleterious genotypes in multigenerational studies. I. Disruptions in individual Arabidopsis actin genes.  

PubMed Central

Plant actins are involved in numerous cytoskeletal processes effecting plant development, including cell division plane determination, cell elongation, and cell wall deposition. Arabidopsis thaliana has five ancient subclasses of actin with distinct patterns of spatial and temporal expression. To test their functional roles, we identified insertion mutants in three Arabidopsis actin genes, ACT2, ACT4, and ACT7, representing three subclasses. Adult plants homozygous for the act2-1, act4-1, and act7-1 mutant alleles appear to be robust, morphologically normal, and fully fertile. However, when grown as populations descended from a single heterozygous parent, all three mutant alleles were found at extremely low frequencies relative to the wild-type in the F2 generation. Thus, all three mutant alleles appear to be deleterious. The act2-1 mutant allele was found at normal frequencies in the F1, but at significantly lower frequencies than expected in the F2 and F3 generations. These data suggest that the homozygous act2-1/act2-1 mutant adult plants have a reduced fitness in the 2N sporophytic portion of the life cycle, consistent with the vegetative expression of ACT2. These data are interpreted in light of the extreme conservation of plant actin subclasses and genetic redundancy. PMID:9611186

Gilliland, L U; McKinney, E C; Asmussen, M A; Meagher, R B

1998-01-01

243

The role of deleterious mutations in the stability of hybridogenetic water frog complexes  

PubMed Central

Background Some species of water frogs originated from hybridization between different species. Such hybrid populations have a particular reproduction system called hybridogenesis. In this paper we consider the two species Pelophylax ridibundus and Pelophylax lessonae, and their hybrids Pelophylax esculentus. P. lessonae and P. esculentus form stable complexes (L-E complexes) in which P. esculentus are hemiclonal. In L-E complexes all the transmitted genomes by P. esculentus carry deleterious mutations which are lethal in homozygosity. Results We analyze, by means of an individual based computational model, L-E complexes. The results of simulations based on the model show that, by eliminating deleterious mutations, L-E complexes collapse. In addition, simulations show that particular female preferences can contribute to the diffusion of deleterious mutations among all P. esculentus frogs. Finally, simulations show how L-E complexes react to the introduction of translocated P. ridibundus. Conclusions The conclusions are the following: (i) deleterious mutations (combined with sexual preferences) strongly contribute to the stability of L-E complexes; (ii) female sexual choice can contribute to the diffusion of deleterious mutations; and (iii) the introduction of P. ridibundus can destabilize L-E complexes. PMID:24885008

2014-01-01

244

Ecological effects and animal risk assessment of radiation pollution in Russia and former USSR  

SciTech Connect

The ecological after-effects of long-term radiation pollution, animal biodiversity changes and life-cycle assessment of model species of soil invertebrates mammals, birds, reptiles have been studied in 1968-1994 in the former USSR (Russia, Ukraine, Kazachstan). There has been observed an initial reduction of animal biodiversity community structure in Kyshtym (south Ural) and Chernobyl polluted areas and a low return to the former ecosystems. The secondary changes and side-effects for the active migrants (insects, birds, mammals) have been registered. The most valid bioindicators and biomarkers of radioactive pollution may be stable populations of reptiles, birds, earthworms, centipede, microarthropods. The radioactive soil pollution exerts the greatest impact on the permanent soil dwelling animals. As direct effects it has been seen the appreciable reduction of population density disturbance of the breeding process, degradation of species diversity community structure. In fact a soil with high level {sup 90}Sr and a radiation 1--3 R/day containing 10-fold reduction of population soil inhabit millipedes earthworms, insect larvae, Enchytraeidae aranea. The accumulation of radionuclides by terrestrial and soil animals effects of trophic levels, zoogenical radionuclides migration have been studied in polluted ecosystems of South Ural and Chernobyl.

Krivolutsky, D. [Russian Academy of Sciences, Moscow (Russian Federation). Inst. of Ecology and Evolution Problems

1995-12-31

245

Risk assessment and ecological effects of transgenic Bacillus thuringiensis crops on non-target organisms.  

PubMed

The application of recombinant DNA technology has resulted in many insect-resistant varieties by genetic engineering (GE). Crops expressing Cry toxins derived from Bacillus thuringiensis (Bt) have been planted worldwide, and are an effective tool for pest control. However, one ecological concern regarding the potential effects of insect-resistant GE plants on non-target organisms (NTOs) has been continually debated. In the present study, we briefly summarize the data regarding the development and commercial use of transgenic Bt varieties, elaborate on the procedure and methods for assessing the non-target effects of insect-resistant GE plants, and synthetically analyze the related research results, mostly those published between 2005 and 2010. A mass of laboratory and field studies have shown that the currently available Bt crops have no direct detrimental effects on NTOs due to their narrow spectrum of activity, and Bt crops are increasing the abundance of some beneficial insects and improving the natural control of specific pests. The use of Bt crops, such as Bt maize and Bt cotton, results in significant reductions of insecticide application and clear benefits on the environment and farmer health. Consequently, Bt crops can be a useful component of integrated pest management systems to protect the crop from targeted pests. PMID:21564541

Yu, Hui-Lin; Li, Yun-He; Wu, Kong-Ming

2011-07-01

246

There Is Water Everywhere: How News Framing Amplifies the Effect of Ecological Worldviews on Preference for Flooding Protection Policy  

Microsoft Academic Search

The purpose of this study is to examine the interactive effect of worldviews and media frames on policy preference. Using flooding as a case study, we examine the interplay of ecological worldviews and news framed as either emphasizing harmony with nature or mastery over nature on individuals' preference for flood protection policy. A total of 255 undergraduate students participated in

Timothy K. F. Fung; Dominique Brossard; Isabella Ng

2011-01-01

247

The ecological effects of mining discharges on subtidal habitats dominated by macroalgae in northern Chile: population and community level studies  

Microsoft Academic Search

In 1996\\/97, a study was carried out to evaluate several variables related to the potential ecological effects of soluble copper and iron released as the result of direct dumping of mine tailing into the littoral zone of the Pacific Ocean off northern Chile. Variables studied included:

J. A. Vásquez; J. M. A. Vega; B. Matsuhiro; C. Urzüa

1999-01-01

248

POTENTIAL ECOLOGICAL AND NONTARGET EFFECTS OF TRANSGENIC PLANT GENE PRODUCTS ON AGRICULTURE, SILVICULTURE, AND NATURAL ECOSYSTEMS: GENERAL INTRODUCTION  

EPA Science Inventory

A symposium was held at the University of Maryland Nov. 30 - Dec. 2, 1992, to discuss transgenic plant risk assessment issues for measurement and identification of potential ecological and nontarget organism effects. he goal was to identify available scientific information and hi...

249

Lawrence Livermore National Laboratory interests and capabilities for research on the ecological effects of global climatic and atmospheric change  

SciTech Connect

The Lawrence Livermore National Laboratory (LLNL) has interests and capabilities in all three types of research that must be conducted in order to understand and predict effects of global atmospheric and climatic (i.e., environmental) changes on ecological systems and their functions (ecosystem function is perhaps most conveniently defined as mass and energy exchange and storage). These three types of research are: (1) manipulative experiments with plants and ecosystems; (2) monitoring of present ecosystem, landscape, and global exchanges and pools of energy, elements, and compounds that play important roles in ecosystem function or the physical climate system, and (3) mechanistic (i.e., hierarchic and explanatory) modeling of plant and ecosystem responses to global environmental change. Specific experimental programs, monitoring plans, and modeling activities related to evaluation of ecological effects of global environmental change that are of interest to, and that can be carried out by LLNL scientists are outlined. Several projects have the distinction of integrating modeling with empirical studies resulting in an Integrated Product (a model or set of models) that DOE or any federal policy maker could use to assess ecological effects. The authors note that any scheme for evaluating ecological effects of atmospheric and climatic change should take into account exceptional or sensitive species, in particular, rare, threatened, or endangered species.

Amthor, J.S.; Houpis, J.L.; Kercher, J.R.; Ledebuhr, A.; Miller, N.L.; Penner, J.E.; Robison, W.L.; Taylor, K.E.

1994-09-01

250

Unexpected Ecological Effects of Distributing the Exotic Weevil, Larinus planus (F.), for the Biological Control of Canada Thistle  

Microsoft Academic Search

Rhinocyllus conicus , a weevil introduced for biological control of exotic weeds, has had major non- target ecological effects on native thistles. Some practitioners have argued that this is an isolated case. We re- port, however, that another Eurasian weevil ( Larinus planus ), currently being distributed in North America for the control of Canada thistle ( Cirsium arvense ),

Svaa M. Louda; Charles W. O'Brien

2002-01-01

251

DEVELOPMENT OF PROTEIN PROFILE TECHNOLOGY TO EVALUATE ECOLOGICAL EFFECTS OF ENVIRONMENTAL CHEMICALS USING A SMALL FISH MODEL  

EPA Science Inventory

Hemmer, Michael J., Robert T. Hudson and Calvin C. Walker. In press. Development of Protein Profile Technology to Evaluate Ecological Effects of Environmental Chemicals Using a Small Fish Model (Abstract). To be presented at the EPA Science Forum: Healthy Communities and Ecosyste...

252

Testing the ecological stability of ectomycorrhizal symbiosis: effects of heat, ash and mycorrhizal colonization on Pinus muricata seedling performance  

Microsoft Academic Search

Understanding how abiotic conditions medi- atetheoutcomeofbioticinteractionsisakeyquestionin community ecology. This is particularly interesting in the case of mutualisms because changingenvironmental conditionsmaybeasourceofevolutionaryorecological instability in the relationship between symbiotic part- ners. For the mycorrhizal symbiosis, elevated nutrient levels may make the carbon cost to plants of supporting mycorrhizal fungi outweigh the benefits of mycorrhizal nutrient acquisition. In this study, we simulated the effects

Kabir G. Peay; Thomas D. Bruns; Matteo Garbelotto

2009-01-01

253

Anthropogenic effects on the biota: towards a new system of principles and criteria for analysis of ecological hazards.  

PubMed

The currently accepted system of criteria for evaluating environmental and ecological hazards of man-made chemicals (pollutants) is vulnerable to criticism. In this paper, a new concept of the system of approaches towards criteria for evaluating the ecological hazard from man-made impact is proposed. It is suggested to assess the man-made impacts (including effects of pollutants and xenobiotics) on the biota according to the following four levels of disturbance in biological and ecological systems: (1) the level of individual responses; (2) the level of aggregated responses of groups of organisms; (3) the level of stability and integrity of the ecosystem; (4) the level of contributions of the ecosystem to biospheric processes. On the basis of the author's experimental studies, an example is given of how to apply the proposed approach and the system of criteria to the analysis of concrete experimental data. To exemplify the efficiency of the proposed approach, it is shown how to use it to analyze new data on effects of a synthetic surfactant on water filtering by bivalves. It is concluded that the proposed approach will be helpful in better assessing environmental and ecological hazards from anthropogenic effects on biota, including effects of man-made chemicals polluting ecosystems. PMID:12852181

Ostroumov, Sergei A

2003-01-01

254

DESIGN AND PERFORMANCE OF A FIELD EXPOSURE SYSTEM FOR EVALUATION OF THE ECOLOGICAL EFFECTS OF SO2 ON NATIVE GRASSLAND  

EPA Science Inventory

The report describes the design and performance of two replicate field exposure systems for evaluating the ecological effects of chronic SO2 exposure on 0.5 ha plots of native Montana grassland. The SO2 was supplied at a constant rate to each plot through a network of 2.5-cm insi...

255

Lawrence Livermore National Laboratory interests and capabilities for research on the ecological effects of global climatic and atmospheric change  

Microsoft Academic Search

The Lawrence Livermore National Laboratory (LLNL) has interests and capabilities in all three types of research that must be conducted in order to understand and predict effects of global atmospheric and climatic (i.e., environmental) changes on ecological systems and their functions (ecosystem function is perhaps most conveniently defined as mass and energy exchange and storage). These three types of research

J. S. Amthor; J. L. Houpis; J. R. Kercher; A. Ledebuhr; N. L. Miller; J. E. Penner; W. L. Robison; K. E. Taylor

1994-01-01

256

Available online at www.sciencedirect.com Visual ecology of the fiddler crab, Uca tangeri: effects of sex,  

E-print Network

of the coloration of the eastern Atlantic fiddler crab, Uca tangeri, with particular attention to predator (eAvailable online at www.sciencedirect.com Visual ecology of the fiddler crab, Uca tangeri: effects to be more visible to crabs (mouthparts) than to avian predators from above. While conspicuousness varies

Cummings, Molly E.

257

Ecological effects of water retention in the River Rhine valley: a review assisting future retention basin classification  

Microsoft Academic Search

This review paper summarizes the ecological effects of the use of floodplains and flood retention basins to control river flow in the River Rhine (Rhein) valley. Early River Rhine regulation strategies including channel straightening are assessed. The subsequent disappearance of alluvial hardwood forests has been highlighted as the major disadvantage. The response of trees to more recent strategies such as

M. Scholz

2007-01-01

258

Two classes of deleterious recessive alleles in a natural population of zebrafish, Danio rerio.  

PubMed Central

Natural populations carry deleterious recessive alleles which cause inbreeding depression. We compared mortality and growth of inbred and outbred zebrafish, Danio rerio, between 6 and 48 days of age. Grandparents of the studied fish were caught in the wild. Inbred fish were generated by brother-sister mating. Mortality was 9% in outbred fish, and 42% in inbred fish, which implies at least 3.6 lethal equivalents of deleterious recessive alleles per zygote. There was no significant inbreeding depression in the growth, perhaps because the surviving inbred fish lived under less crowded conditions. In contrast to alleles that cause embryonic and early larval mortality in the same population, alleles responsible for late larval and early juvenile mortality did not result in any gross morphological abnormalities. Thus, deleterious recessive alleles that segregate in a wild zebrafish population belong to two sharply distinct classes: early-acting, morphologically overt, unconditional lethals; and later-acting, morphologically cryptic, and presumably milder alleles. PMID:15451692

McCune, Amy R.; Houle, David; McMillan, Kyle; Annable, Rebecca; Kondrashov, Alexey S.

2004-01-01

259

Environmental assessment for the satellite power system-concept development and evaluation program-microwave health and ecological effects  

NASA Technical Reports Server (NTRS)

Potential health and ecological effects of the microwave beam from the microwave power transmission system (MPTS) of the satellite power system (SPS) are discussed. A detailed critical review of selected scientific articles from the published literature on the biological effects of nonionizing electromagnetic radiation is provided followed by an assessment of the possible effects of the SPS, based on exposure values for the reference system.

1980-01-01

260

Environmental assessment for the satellite power system-concept development and evaluation program-microwave health and ecological effects  

SciTech Connect

This report is concerned with the potential health and ecological effects of the microwave beam from the microwave power transmission system (MPTS) of the satellite power system (SPS). The report is written in the form of a detailed critical review of selected scientific articles from the published literature on the biological effects of nonionizing electromagnetic radiation, followed by an assessment of the possible effects of the SPS, based on exposure values for the reference system (US DOE and NASA, 1978).

Not Available

1980-11-01

261

Ecology 2006 20, 10701079  

E-print Network

chemical defences, predation risk, seed depredation Functional Ecology (2006) 20, 1070­1079 doi: 10.1111/j Ecological Society Blackwell Publishing Ltd Foraging by fearful frugivores: combined effect of fruit ripening of herbivore foraging, though empirical studies have seldom measured the combined effects of these two factors

Herrera, Carlos M.

262

Ecological contingency in the effects of climatic warming on forest herb communities  

USGS Publications Warehouse

Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951–2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500–1.200 m above sea level) and primary upper montane to subalpine forests (1,500–2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects.

Harrison, Susan; Damschen, Ellen I.; Grace, James B.

2010-01-01

263

Ecological contingency in the effects of climatic warming on forest herb communities  

PubMed Central

Downscaling from the predictions of general climate models is critical to current strategies for mitigating species loss caused by climate change. A key impediment to this downscaling is that we lack a fully developed understanding of how variation in physical, biological, or land-use characteristics mediates the effects of climate change on ecological communities within regions. We analyzed change in understory herb communities over a 60-y period (1949/1951–2007/2009) in a complex montane landscape (the Siskiyou Mountains, Oregon) where mean temperatures have increased 2 °C since 1948, similar to projections for other terrestrial communities. Our 185 sites included primary and secondary-growth lower montane forests (500–1.200 m above sea level) and primary upper montane to subalpine forests (1,500–2,100 m above sea level). In lower montane forests, regardless of land-use history, we found multiple herb-community changes consistent with an effectively drier climate, including lower mean specific leaf area, lower relative cover by species of northern biogeographic affinity, and greater compositional resemblance to communities in southerly topographic positions. At higher elevations we found qualitatively different and more modest changes, including increases in herbs of northern biogeographic affinity and in forest canopy cover. Our results provide community-level validation of predicted nonlinearities in climate change effects. PMID:20974978

Harrison, Susan; Damschen, Ellen I.; Grace, James B.

2010-01-01

264

Probabilistic ecological hazard assessment: evaluating pharmaceutical effects on aquatic higher plants as an example.  

PubMed

The practicality of a probabilistic ecological hazard assessment (PEHA) methodology using intraspecies endpoint sensitivity distributions (IESDs) and chemical toxicity distributions (CTDs) was evaluated on data sets of pharmaceutical toxicity to aquatic macrophytes. A PEHA does not use an exposure distribution but rather uses a point estimate, which is useful for applications with sufficient effects data but lacking in comprehensive exposure data or when a criterion concentration is desired. The probability of finding an effect measure or potency value below a threshold can be calculated from the effects distribution. PEHA analyses using CTDs for both EC(10) and EC(25)Lemna gibba toxicity values indicated a <1% probability of encountering an antibiotic with toxicity below 1 microg/L. IESDs for microcosm mixture studies with eight pharmaceuticals (8PM) and four tetracyclines showed that the probability was nearly 20% for Myriophyllum sibiricum and 13% for L. gibba (8PM data). Hazard quotients calculated from the 1% and 5% distribution thresholds indicated potential risk only in certain cases. PMID:16225919

Brain, Richard A; Sanderson, Hans; Sibley, Paul K; Solomon, Keith R

2006-06-01

265

A review of fire effects on vegetation and soils in the Great Basin region: response and ecological site characteristics  

USGS Publications Warehouse

This review synthesizes the state of knowledge on fire effects on vegetation and soils in semi-arid ecosystems in the Great Basin Region, including the central and northern Great Basin and Range, Columbia River Basin, and the Snake River Plain. We summarize available literature related to: (1) the effects of environmental gradients, ecological site, and vegetation characteristics on resilience to disturbance and resistance to invasive species; (2) the effects of fire on individual plant species and communities, biological soil crusts, seed banks, soil nutrients, and hydrology; and (3) the role of fire severity, fire versus fire surrogate treatments, and post-fire grazing in determining ecosystem response. From this, we identify knowledge gaps and present a framework for predicting plant successional trajectories following wild and prescribed fires and fire surrogate treatments. Possibly the three most important ecological site characteristics that influence a site’s resilience (ability of the ecological site to recover from disturbance) and resistance to invasive species are soil temperature/moisture regimes and the composition and structure of vegetation on the ecological site just prior to the disturbance event.

Miller, Richard F.; Chambers, Jeanne C.; Pyke, David A.; Pierson, Fred B.; Williams, C. Jason

2013-01-01

266

Complex Deleterious Interactions Associated with Malic Enzyme May Contribute to Reproductive Isolation in the Copepod Tigriopus californicus  

PubMed Central

Dobzhansky-Muller incompatibilities can result from the interactions of more than a single pair of interacting genes and there are several different models of how such complex interactions can be structured. Previous empirical work has identified complex conspecific epistasis as a form of complex interaction that has contributed to postzygotic reproductive isolation between taxa, but other forms of complexity are also possible. Here, I probe the genetic basis of reproductive isolation in crosses of the intertidal copepod Tigriopus californicus by looking at the impact of markers in genes encoding metabolic enzymes in F2 hybrids. The region of the genome associated with the locus ME2 is shown to have strong, repeatable impacts on the fitness of hybrids in crosses and epistatic interactions with another chromosomal region marked by the GOT2 locus in one set of crosses. In a cross between one of these populations and a third population, these two regions do not appear to interact despite the continuation of a large effect of the ME2 region itself in both crosses. The combined results suggest that the ME2 chromosomal region is involved in incompatibilities with several unique partners. If these deleterious interactions all stem from the same factor in this region, that would suggest a different form of complexity from complex conspecific epistasis, namely, multiple independent deleterious interactions stemming from the same factor. Confirmation of this idea will require more fine-scale mapping of the interactions of the ME2 region of the genome. PMID:21731664

Willett, Christopher S.

2011-01-01

267

Complex deleterious interactions associated with malic enzyme may contribute to reproductive isolation in the copepod Tigriopus californicus.  

PubMed

Dobzhansky-Muller incompatibilities can result from the interactions of more than a single pair of interacting genes and there are several different models of how such complex interactions can be structured. Previous empirical work has identified complex conspecific epistasis as a form of complex interaction that has contributed to postzygotic reproductive isolation between taxa, but other forms of complexity are also possible. Here, I probe the genetic basis of reproductive isolation in crosses of the intertidal copepod Tigriopus californicus by looking at the impact of markers in genes encoding metabolic enzymes in F(2) hybrids. The region of the genome associated with the locus ME2 is shown to have strong, repeatable impacts on the fitness of hybrids in crosses and epistatic interactions with another chromosomal region marked by the GOT2 locus in one set of crosses. In a cross between one of these populations and a third population, these two regions do not appear to interact despite the continuation of a large effect of the ME2 region itself in both crosses. The combined results suggest that the ME2 chromosomal region is involved in incompatibilities with several unique partners. If these deleterious interactions all stem from the same factor in this region, that would suggest a different form of complexity from complex conspecific epistasis, namely, multiple independent deleterious interactions stemming from the same factor. Confirmation of this idea will require more fine-scale mapping of the interactions of the ME2 region of the genome. PMID:21731664

Willett, Christopher S

2011-01-01

268

[Effect of different tillage methods on rice growth and soil ecology].  

PubMed

Field experiments were conducted in double-cropping rice field in South China during 1998-1999 to study the effect of different tillage methods on rice growth and soil ecology. The results showed that with rice scattering planting, no-tillage method caused a reduction of rice tillering, effective panicle, and filled grains of rice. Grain yield under no-tillage was 13.40% lower than that under conventional tillage, and the economic benefits decreased by 10.9%. Soil analysis showed that in no-tillage fields, soil bulk density and hardness were increased, soil porosity and available P and K were decreased, the amount of actinomyces and fungi was reduced, while that of soil bacteria was increased, and the enzyme activity was promoted. Minimum tillage and conventional tillage had similar soil physical and chemical properties, soil microbial quantity and enzyme activity. Minimum tillage could produce a 2.1% higher grain yield than conventional tillage, and increase the economic benefits by 11.0%. PMID:11758381

Li, H; Lu, W; Liu, Y; Zhang, X

2001-08-01

269

Plant genetic variation mediates an indirect ecological effect between belowground earthworms and aboveground aphids  

PubMed Central

Background Interactions between aboveground and belowground terrestrial communities are often mediated by plants, with soil organisms interacting via the roots and aboveground organisms via the shoots and leaves. Many studies now show that plant genetics can drive changes in the structure of both above and belowground communities; however, the role of plant genetic variation in mediating aboveground-belowground interactions is still unclear. We used an earthworm-plant-aphid model system with two aphid species (Aphis fabae and Acyrthosiphon pisum) to test the effect of host-plant (Vicia faba) genetic variation on the indirect interaction between the belowground earthworms (Eisenia veneta) on the aboveground aphid populations. Results Our data shows that host-plant variety mediated an indirect ecological effect of earthworms on generalist black bean aphids (A. fabae), with earthworms increasing aphid growth rate in three plant varieties but decreasing it in another variety. We found no effect of earthworms on the second aphid species, the pea aphid (A. pisum), and no effect of competition between the aphid species. Plant biomass was increased when earthworms were present, and decreased when A. pisum was feeding on the plant (mediated by plant variety). Although A. fabae aphids were influenced by the plants and worms, they did not, in turn, alter plant biomass. Conclusions Previous work has shown inconsistent effects of earthworms on aphids, but we suggest these differences could be explained by plant genetic variation and variation among aphid species. This study demonstrates that the outcome of belowground-aboveground interactions can be mediated by genetic variation in the host-plant, but depends on the identity of the species involved. PMID:25331082

2014-01-01

270

Using observation-level random effects to model overdispersion in count data in ecology and evolution  

PubMed Central

Overdispersion is common in models of count data in ecology and evolutionary biology, and can occur due to missing covariates, non-independent (aggregated) data, or an excess frequency of zeroes (zero-inflation). Accounting for overdispersion in such models is vital, as failing to do so can lead to biased parameter estimates, and false conclusions regarding hypotheses of interest. Observation-level random effects (OLRE), where each data point receives a unique level of a random effect that models the extra-Poisson variation present in the data, are commonly employed to cope with overdispersion in count data. However studies investigating the efficacy of observation-level random effects as a means to deal with overdispersion are scarce. Here I use simulations to show that in cases where overdispersion is caused by random extra-Poisson noise, or aggregation in the count data, observation-level random effects yield more accurate parameter estimates compared to when overdispersion is simply ignored. Conversely, OLRE fail to reduce bias in zero-inflated data, and in some cases increase bias at high levels of overdispersion. There was a positive relationship between the magnitude of overdispersion and the degree of bias in parameter estimates. Critically, the simulations reveal that failing to account for overdispersion in mixed models can erroneously inflate measures of explained variance (r2), which may lead to researchers overestimating the predictive power of variables of interest. This work suggests use of observation-level random effects provides a simple and robust means to account for overdispersion in count data, but also that their ability to minimise bias is not uniform across all types of overdispersion and must be applied judiciously. PMID:25320683

2014-01-01

271

Parapoxvirus causes a deleterious disease in red squirrels associated with UK population declines.  

PubMed Central

The disease implications of novel pathogens need to be considered when investigating the ecological impact of species translocations on native fauna. Traditional explanations based on competition or predation may often not be the whole story. Evidence suggests that an emerging infectious disease, caused by a parapoxvirus, may be a significant component of the impact that the introduced grey squirrel has had on UK red squirrel populations. Here we validate the potential role of parapoxvirus by proving that the virus is highly pathogenic in the red squirrel while having no detectable effect on grey squirrel health. PMID:11886647

Tompkins, Daniel M; Sainsbury, A W; Nettleton, P; Buxton, D; Gurnell, J

2002-01-01

272

A Dietary Test of Putative Deleterious Sterols for the Aphid Myzus persicae  

E-print Network

A Dietary Test of Putative Deleterious Sterols for the Aphid Myzus persicae Sophie Bouvaine1, College Station, Texas, United States of America Abstract The aphid Myzus persicae displays high mortality on tobacco plants bearing a transgene which results in the accumulation of the ketosteroids cholestan-3-one

Behmer, Spencer T.

273

Hapten design for compound-selective antibodies: ELISAS for environmentally deleterious small molecules  

E-print Network

Hapten design for compound-selective antibodies: ELISAS for environmentally deleterious small molecules Marvin H. Goodrow* , Bruce D. Hammock Department of Entomology and Environmental Toxicology antibodies that exclude recognition of analytes larger than the target molecule. The use of this size

Hammock, Bruce D.

274

White Paper: Summary of the NOAA Workshop - Ecological Effect of Sea Level Rise in the Florida Panhandle and Coastal Alabama: Research and Modeling Needs  

EPA Science Inventory

The Center for Sponsored Coastal Ocean Research (CSCOR) is addressing current and future impacts to ecological systems due to the long term effect of sea level rise due to climate change and subsidence on coastal ecosystems through the peer-reviewed research program, the Ecologic...

275

Habitat differentiation and the ecological costs of hybridization: the effects of introduced mulberry (Morus alba) on a native congener (M. rubra)  

Microsoft Academic Search

Summary 1 The effects of hybridization on the abundance of parental taxa depends on their relative frequency, the viability of hybrid offspring and the degree of ecological differ- entiation among parental and hybrid taxa. Habitat overlap can facilitate competition for suitable sites and threaten the persistence of parental taxa, especially those in small populations. 2 Here we examine ecological differentiation

KEVIN S. BURGESS; BRIAN C. HUSBAND

2006-01-01

276

Macrophage Migration Inhibitory Factor Inhibition Is Deleterious for High-Fat Diet-Induced Cardiac Dysfunction  

PubMed Central

Aims Development of metabolic syndrome is associated with impaired cardiac performance, mitochondrial dysfunction and pro-inflammatory cytokine increase, such as the macrophage migration inhibitory factor MIF. Depending on conditions, MIF may exert both beneficial and deleterious effects on the myocardium. Therefore, we tested whether pharmacological inhibition of MIF prevented or worsened metabolic syndrome-induced myocardial dysfunction. Methods and Results C57BL/6J mice were fed for ten weeks with 60% fat-enriched diet (HFD) or normal diet (ND). MIF inhibition was obtained by injecting mice twice a week with ISO-1, for three consecutive weeks. Then, triglycerides, cholesterol, fat mass, glucose intolerance, insulin resistance, ex vivo cardiac contractility, animal energetic substrate utilization assessed by indirect calorimetry and mitochondrial respiration and biogenesis were evaluated. HFD led to fat mass increase, dyslipidemia, glucose intolerance and insulin resistance. ISO-1 did not alter these parameters. However, MIF inhibition was responsible for HFD-induced cardiac dysfunction worsening. Mouse capacity to increase oxygen consumption in response to exercise was reduced in HFD compared to ND, and further diminished in ISO-1-treated HFD group. Mitochondrial respiration was reduced in HFD mice, treated or not with ISO-1. Compared to ND, mitochondrial biogenesis signaling was upregulated in the HFD as demonstrated by mitochondrial DNA amount and PGC-1? expression. However, this increase in biogenesis was blocked by ISO-1 treatment. Conclusion MIF inhibition achieved by ISO-1 was responsible for a reduction in HFD-induced mitochondrial biogenesis signaling that could explain majored cardiac dysfunction observed in HFD mice treated with MIF inhibitor. PMID:23536817

Montaigne, David; Marechal, Xavier; Ballot, Caroline; Hassoun, Sidi Mohamed; Decoster, Brigitte; Neviere, Remi; Lancel, Steve

2013-01-01

277

The Ecological Road-Effect Zone of a Massachusetts (U.S.A.) Suburban Highway  

Microsoft Academic Search

Ecological flows and biological diversity trace broad patterns across the landscape, whereas trans- portation planning for human mobility traditionally focuses on a narrow strip close to a road or highway. To help close this gap we examined the \\

Richard T. T. Forman; Robert D. Deblinger

2000-01-01

278

DESIGN OF FIELD EXPERIMENTS TO DETERMINE THE ECOLOGICAL EFFECTS OF PETROLEUM IN INTERTIDAL ECOSYSTEMS  

EPA Science Inventory

Is it possible to design field experiments that will yield ecologically and statistically significant information about how oil affects intertidal ecosystems. What classes of experimental design and technical approach are most likely to generate optimal information on these effec...

279

Exploring the effects of local development regulations on ecological landscape structure  

E-print Network

were classified into forested and non-forested classes and the landscape structure was quantified with a number of landscape metrics related to fragmentation??an indicator of habitat degradation. Two factors, the ecological approach to landscape...

Kim, Jin Ki

2005-08-29

280

Handbook for Ecology Action.  

ERIC Educational Resources Information Center

This handbook has been compiled to aid concerned individuals and ecology groups more adequately define their goals, initiate good programs, and take effective action. It examines the ways a group of working individuals can become involved in action programs for ecological change. Part 1 deals with organization, preliminary organizing, structuring,…

Eber, Ronald

281

Significance and effect of ecological rehabilitation project in inland river basins in northwest China.  

PubMed

The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study. PMID:23716005

Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

2013-07-01

282

Significance and Effect of Ecological Rehabilitation Project in Inland River Basins in Northwest China  

NASA Astrophysics Data System (ADS)

The Ecological Water Transfer and Rehabilitation Project in the arid inland area of northwest China is an important measure in restoring a deteriorated ecosystem. However, the sustainability of the project is affected by many socio-economic factors. This article examines the attitudes of the local populace toward the project, its impact on the livelihood of the people, and the positive effects of water-efficient agricultural practices in Ejina County. Related data were collected through questionnaire surveys and group discussions. The results identified three critical issues that may influence the sustainability of the project in the study area. The first issue relates to the impact of the project on the livelihood of local herdsmen. The potential for the sustainability of the project is compromised because the livelihood of the herdsmen greatly depends on the compensation awarded by the project. The second issue is that the project did not raise the water resource utilization ratio, which may undermine its final purpose. Finally, the compensation provided by the project considers losses in agriculture, but neglects the externalities and public benefit of eco-water. Thus, appropriate compensation mechanisms should be established and adopted according to local economic, environmental, and social conditions. Some recommendations for improving the sustainability of the project are provided based on the results of this study.

Wang, Yu; Feng, Qi; Chen, Lijuan; Yu, Tengfei

2013-07-01

283

Proximal ecological effects of the 1980 eruptions of Mount St. Helens  

NASA Technical Reports Server (NTRS)

The diversity of ecosystems and volcanic processes involved in the 1980 eruptions of Mount St. Helens, southwest Washington, provide an excellent setting for examining effects of volcanic events on ecosystems. These eruptions included a lateral blast, debris avalanche, mudflows, pyroclastic flows, and airfall tephra. Affected ecosystems within 30 km of the vent were lakes, streams, upland and riparian forest, and meadows. Ecological disturbances imposed by the Mount St. Helens events were predominantly physical, rather than climatic or chemical which are the dominant classes of disturbances considered in analysis of global catastrophes. Analysis of ecosystem response to disturbance should be based on consideration of composition and structure of the predisturbance system in terms that represent potential survivability of organisms, mechanisms in the primary disturbance, initial survivors, secondary disturbances arising from the primary disturbance and the biological responses to secondary disturbances, invasion of the site by new propagules, interactions among secondary disturbance processes and surviving and invading organisms. Predicting ecosystem response to disturbance is enchanced by considering the mechanisms of disturbance rather than type of disturbance. In the 1980 Mount St. Helens events, the disturbance types, involved primarily the mechanisms of sedimentation, heating, and shear stress. Each disturbance type involved one or more mechanisms. Ecosystem response varied greatly across the landscape. Analysis of ecosystem response to disturbance, regardless of type, should include detailed consideration of the properties of individual species, primary and secondary disturbance mechanisms, and their distributions across landscapes.

Swanson, F. J.

1988-01-01

284

Self-monitoring effects of ecological momentary assessment on smokers' perceived risk and worry.  

PubMed

Using ecological momentary assessment (EMA), we sought to determine whether differences in reporting would exist for smokers who self-monitored their smoking-related negative thoughts five times daily in comparison to a non-EMA control group. One hundred seventeen smokers were randomly assigned to two conditions. Eighty-eight smokers carried personal digital assistants (PDAs) for 2 weeks and monitored negative thoughts each day, and 29 smokers did not self-monitor their negative thoughts. All smokers completed pretest and posttest assessments reporting their perceived risk and worry associated with smoking consequences. The data revealed evidence of self-monitoring effects, as smokers in the EMA condition reported less worry after 2 weeks of self-monitoring compared to smokers in the control condition. The two conditions did not differ in their reports of perceived risk of smoking consequences. These data suggest that EMA procedures asking respondents to self-monitor their thoughts about smoking may influence feelings about their smoking behavior. PMID:23244640

Magnan, Renee E; Köblitz, Amber R; McCaul, Kevin D; Dillard, Amanda J

2013-06-01

285

Open top culverts as an alternative drainage system to minimize ecological effects in earth roads.  

NASA Astrophysics Data System (ADS)

During the last fifteen years a research team from School of Forestry at the Technical University of Madrid (Spain) has developed several competitive research projects regarding forest roads and open top culverts. A first approach was established with a prototype of 7 meters length in a hydraulic channel at the laboratory determining main parameters of different open top culverts in relation to different sizes of gravels and the self washing properties relationship with different slopes up to 8 %. The curves obtained may help to properly install these drainage systems avoiding maintenance costs. In addition more targeted pilot studies were developed in different forest earth roads in center and north Spain. The construction of the stations under study was financed by the U.P.M and the R&D National Plan. The main outcomes relates the low variation of humidity in a 20 m. wide range at both sides of the open top culverts and several considerations relating the angle of installation, the spacing of such drainage systems and the benefits against rilling along the roads. Also the erosion produced downhill was established and some construction methods to avoid adverse ecological effects. The diffusion of results includes congresses and a small booklet with a great acceptance in forestry services. Also a patent (ES 2 262 437) of an advanced model has been registered.

García, Jose L.; Elorrieta, Jose; Robredo, Jose C.; García, Ricardo; García, Fernando; Gimenez, Martin C.

2013-04-01

286

[Ecological effects of intercrops in comprehensive management patterns of hilly area plum orchard].  

PubMed

The study on the ecological effects of intercrops in four cropping patterns showed that with the increase of multiple cropping, the annual increase of soil organic matter, total N, total P and total K was 5% - 20%, 7% - 40%, 8% - 70% and 15% - 80%, respectively. Potato-soybean had the best benefit in soil and water conservation, followed by cole-peanut, potato-watermelon, and wheat. Compared with control, the average soil erosion module and runoff amount of 4 patterns were decreased by 44.19%, 39.55%, 38.24% and 37.56%, and 22.40%, 9.28%, 24.11% and 21.16%, respectively. Cole-peanut had the highest biomass, being averaged 100 276 kg . hm(-2) annually, and the second was potato-watermelon, with an average of 73 692 kg x hm(-2). Potato-watermelon had the highest productivity, which averaged 37 565 kg x hm(-2) annually, and the second was potato-soybean, averaged 25 934 kg x hm(-2). The efficiency of energy input was in order of cole-peanut, potato-watermelon, potato-soybean, and wheat, and the value was 2.96, 2.08, 2.01 and 0.96, respectively. PMID:16180746

Zhang, Tie; Huang, Xianpeng; Yang, Bin

2005-06-01

287

Ecological effects of contaminants in McCoy Branch, 1991--1993  

SciTech Connect

The 1984 Hazardous and Solid Waste Amendments to the Resource Conservation and Recovery Act (RCRA) required assessment of all current and former solid waste management units. Following guidelines under RCRA and the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), a remedial investigation (RI) was required of the Y-12 Plant for their filled coal ash pond (FCAP) and associated areas on McCoy Branch. The RI process was initiated and assessments were presented. Because the disposal of coal ash in the ash pond, McCoy Branch, and Rogers Quarry was not consistent with the Tennessee Water Quality Act, several remediation steps were implemented between 1986 and 1994 for McCoy Branch to address disposal problems. The required ecological risk assessments of McCoy Branch watershed included provisions for biological monitoring of the watershed. The objectives of the biological monitoring were to (1) document changes in biological quality of McCoy Branch after completion of a pipeline bypassing upper McCoy Branch and further, after termination of all discharges to Rogers Quarry, (2) provide guidance on the need for additional remediation, and (3) evaluate the effectiveness of implemented remedial actions. The data from the biological monitoring program may also determine whether the goals of protection of human health and the environment of McCoy Branch are being accomplished.

Ryon, M.G. [ed.] [ed.

1996-09-01

288

Effects of the antibiotic enrofloxacin on the ecology of tropical eutrophic freshwater microcosms.  

PubMed

The main objective of the present study was to assess the ecological impacts of the fluoroquinolone antibiotic enrofloxacin on the structure and functioning of tropical freshwater ecosystems. Enrofloxacin was applied at a concentration of 1, 10, 100 and 1,000 ?g/L for 7 consecutive days in 600-L outdoor microcosms in Thailand. The ecosystem-level effects of enrofloxacin were monitored on five structural (macroinvertebrates, zooplankton, phytoplankton, periphyton and bacteria) and two functional (organic matter decomposition and nitrogen cycling) endpoint groups for 4 weeks after the last antibiotic application. Enrofloxacin was found to dissipate relatively fast from the water column (half-dissipation time: 11.7h), and about 11% of the applied dose was transformed into its main by-product ciprofloxacin after 24h. Consistent treatment-related effects on the invertebrate and primary producer communities and on organic matter decomposition could not be demonstrated. Enrofloxacin significantly affected the structure of leaf-associated bacterial communities at the highest treatment level, and reduced the abundance of ammonia-oxidizing bacteria and ammonia-oxidizing archaea in the sediments, with calculated NOECs of 10 and <1 ?g/L, respectively. The ammonia concentration in the microcosm water significantly increased in the highest treatment level, and nitrate production was decreased, indicating a potential impairment of the nitrification function at concentrations above 100 ?g/L. The results of this study suggest that environmentally relevant concentrations of enrofloxacin are not likely to result in direct or indirect toxic effects on the invertebrate and primary producer communities, nor on important microbially mediated functions such as nitrification. PMID:24380725

Rico, Andreu; Dimitrov, Mauricio R; Van Wijngaarden, René P A; Satapornvanit, Kriengkrai; Smidt, Hauke; Van den Brink, Paul J

2014-02-01

289

Ecological Footprint  

NSDL National Science Digital Library

Students explore their own Ecological Footprint in the context of how many Earths it would take if everyone used the same amount of resources they did. They compare this to the Ecological Footprint of individuals in other parts of the world and to the Ecological footprint of a family member when they were the student's age.

2007-01-01

290

GENERIC ECOLOGICAL ASSESSMENT ENDPOINTS (GEAE) FOR ECOLOGICAL RISK ASSESSMENT  

EPA Science Inventory

Ecological risk assessment is a process for evaluating the likelihood that adverse ecological effects may occur or are occurring as a result of exposure to one or more stressors. A critical early step in conducting an ecological risk assessment is to select assessment endpoints. ...

291

Incorporating ecologically relevant measures of pesticide effect for estimating the compatibility of pesticides and biocontrol agents.  

PubMed

The compatibility of biological control agents with pesticides is a central concern in integrated pest management programs. The most common assessments of compatibility consist of simple comparisons of acute toxicity among pest species and select biocontrol agents. A more sophisticated approach, developed by the International Organisation of Biological Control (IOBC), is based on a tiered hierarchy made up of threshold values for mortality and sublethal effects that is used to determine the compatibility of pesticides and biological control agents. However, this method is unable to capture longer term population dynamics, which is often critical to the success of biological control and pest suppression. In this article, we used the delay in population growth index, a measure of population recovery, to investigate the potential impacts that the threshold values for levels of lethal and sublethal effects developed by the IOBC had on three biocontrol agents: sevenspotted lady beetle, Coccinella septempunctata L.; the aphid parasitoid Diaeretiella rapae (M'Intosh), and Fopius arisanus (Sonan), a parasitoid of tephritid flies. Based on life histories of these economically important natural enemies, we established a delay of 1-generation time interval as sufficient to disrupt biological control success. We found that delays equivalent to 1-generation time interval were caused by mortality as low as 50% or reductions of offspring as low as 58%, both values in line with thresholds developed by the IOBC. However, combinations of mortality and reduction of offspring lower than these values (from 32 to 43% each) over a simulated 4-mo period caused significant population delays. Furthermore, the species used in these simulations reacted differently to the same levels of effect. The parasitoid D. rapae was the most susceptible species, followed by F. arisanus and C. septempunctata. Our results indicate that it is not possible to generalize about potential long-term impacts of pesticides on biocontrol agents because susceptibility is influenced by differences in life history variables. Additionally, populations of biocontrol agents may undergo significant damage when mortality approaches 50% or when there is mortality of -30% and a 30% reduction in offspring caused by a sublethal effect. Our results suggest that more ecologically relevant measures of effect such as delays in population growth may advance our knowledge of pesticide impacts on populations of beneficial species. PMID:17849847

Stark, John D; Vargas, Roger; Banks, John E

2007-08-01

292

Journal of Animal Ecology 2004  

E-print Network

Journal of Animal Ecology 2004 73, 342­352 © 2004 British Ecological Society Blackwell Publishing, Ltd. Year- and sex-dependent effects of experimental brood sex ratio manipulation on fledging, reproductive value, sex allocation, sex-dependent mortality, varia- ble environment. Journal of Animal Ecology

Laaksonen, Toni

293

[Venous ecology].  

PubMed

The purpose of venous ecology is to study the effect of the environment on the peripheral vessels. It is very extensive but still little explored subject in need of multidisciplinary study. The author reviews some of the major problems of ecophlebology: --pollution and harmful effects of urban life (atmospheric pollution, stress and influence of noise on the vessels); --the influence of habitat (furniture, ergonomics, urbanism, sociological studies and under-floor heating); --the cites new research on terrestrial electro-magnettism, meteoropathology, biological clocks and the influence of the mass media. In conclusion he hopes that ecophlebology will be the object of research which will permit a better understanding, and hence better control, of the pathological mechanisms resulting from the environment. PMID:928510

Reinharez, D

1977-01-01

294

Issues in Ecology, Issue 08: Effects of Aquaculture on World Fish Supply  

NSDL National Science Digital Library

This report discusses the negative and positive aspects of aquaculture as an alternative to harvesting wild stocks of fish. The report defines aquaculture and describes its recent growth, as well as its ecological impact. Practices to sustain aquaculture operations, such as habitat modification and the use of wild-caught seedstock are discussed. Changes to ocean food webs, the introduction of non-native fish and pathogens, and nutrient pollution from wastes are presented as negative consequences of aquaculture operations. The report discusses strategies to improve aquaculture, such as reducing fish meal and oil in fish feed, integrating production systems, and promoting sustainability within the industry. Issues in Ecology is an ongoing series of reports designed to present major ecological issues in an easy-to-read manner. This Issue summarizes the consensus of a panel of scientific experts based on the information that was current and available at the time of its publication in 2001.

Naylor, Rosamond

2010-02-16

295

Community metabolism of aquatic Closed Ecological Systems: Effects of nitrogen sources  

NASA Astrophysics Data System (ADS)

To investigate the effect of nitrogen sources on Closed Ecological Systems (CESs), three nitrogen sources (NaNO 3, sodium nitrate; NH 4Cl, ammonium chloride; and NH 4NO 3, ammonium nitrate) were each tested in freshwater CESs consisting of a chemically defined medium, three species of green algae ( Ankistrodesmus, S cenedesmus, and Selenastrum), the grazer Daphnia magna, and associated microbes, under 12 h light/12 h dark cycles. It had been hypothesized that the development of high pH in earlier CESs was the result of nitrate utilization, and that ammonium might result in acid conditions, while ammonium nitrate might result in more moderate pH. The three nitrogen sources supported similar densities of algae (estimated by in vivo fluorescence) and similar Daphnia populations. The experiments showed that pH levels rapidly increased when grazers were absent or at low abundances irrespective of the nitrogen source. Consequently, it is hypothesized that carbon cycles, rather than nitrogen sources, are responsible for the pH dynamics. Oxygen diurnal (light:dark) cycles tended to come into balance more quickly than pH. It may be more feasible to convert O 2 data to energy units (using "oxycalorific" values) than CO 2 data since CO 2 dynamics may include other chemical reactions than just photosynthesis and respiration. The feasibility of sustaining grazer populations for at least several weeks in small, simple CESs was demonstrated, along with the ability to monitor algae-grazer dynamics, and the recording of O 2 and pH measurements.

Taub, Frieda B.

2009-10-01

296

Calibrating biomonitors to ecological disturbance: a new technique for explaining metal effects in natural waters.  

PubMed

Bioaccumulated toxic metals in tolerant biomonitors are indicators of metal bioavailability and can be calibrated against metal-specific responses in sensitive species, thus creating a tool for defining dose-response for metals in a field setting. Dose-response curves that define metal toxicity in natural waters are rare. Demonstrating cause and effect under field conditions and integrated chemical measures of metal bioavailability from food and water is problematic. The total bioaccumulated metal concentration in any organism that is a net accumulator of the metal is informative about metal bioavailability summed across exposure routes. However, there is typically no one universal metal concentration that is indicative of toxicity, especially across species, largely because of interspecies differences in detoxification. Stressed organisms are also only present across a narrow range in the dose-response curve, limiting the use of singles species as both biomonitors and bioindicator of stress. Herein we show, in 3 field settings, that bioaccumulated Cu concentrations in a metal-tolerant, riverine biomonitor (species of the caddisfly genus Hydropsyche spp.) can be calibrated against metal-specific ecological responses across very wide ranges of contamination. Using the calibrated dose-response, we show that reduced abundance of species and individuals from particularly sensitive mayfly families (heptageniid mayflies) is more than 2-fold more sensitive to bioavailable Cu than other traditional measures of stress like EPT or total number of benthic macroinvertebrate species. We propose that this field dose-response curve be tested more widely for general application, and that calibrations against other stress responses be developed for biomonitors from lakes, estuaries, and coastal marine ecosystems. PMID:20821686

Luoma, Samuel N; Cain, Daniel J; Rainbow, Philip S

2010-04-01

297

DESIGNING PESTICIDE METABOLIC PATHWAY/DEGRADATE DATABASES FOR REGISTRANT SUBMITTED HEALTH EFFECTS/ECOLOGICAL EFFECTS DATA  

EPA Science Inventory

OPPTS requires information on the toxic effects of pesticide metabolites as well as the parent chemical. Currently, OPP receives metabolic maps with registrant study data submissions, but there is no efficient way to access previously submitted maps on similar chemicals to help w...

298

The road to rack and ruin: selecting deleterious mitochondrial DNA variants.  

PubMed

Mitochondria constitute the major energy-producing compartment of the eukaryotic cell. These organelles contain many molecules of DNA that contribute only a handful of proteins required for energy production. Mutations in the DNA of mitochondria were identified as a cause of human disease a quarter of a century ago, and they have subsequently been implicated in ageing. The process whereby deleterious variants come to dominate a cell, tissue or human is the subject of debate. It is likely to involve multiple, often competing, factors, as selection pressures on mitochondrial DNA can be both indirect and intermittent, and are subjected to rapid change. Here, we assess the different models and the prospects for preventing the accumulation of deleterious mitochondrial DNA variants with time. PMID:24864317

Holt, Ian J; Speijer, Dave; Kirkwood, Thomas B L

2014-07-01

299

Eco-genetic model to explore fishing-induced ecological and evolutionary effects on growth and maturation schedules  

PubMed Central

Eco-genetic individual-based models involve tracking the ecological dynamics of simulated individual organisms that are in part characterized by heritable parameters. We developed an eco-genetic individual-based model to explore ecological and evolutionary interactions of fish growth and maturation schedules. Our model is flexible and allows for exploration of the effects of heritable growth rates (based on von Bertalanffy and biphasic growth patterns), heritable maturation schedules (based on maturation reaction norm concepts), or both on individual- and population-level traits. In baseline simulations with rather simple ecological trade-offs and over a relatively short time period (<200 simulation years), simulated male and female fish evolve differential genetic growth and maturation. Further, resulting patterns of genetically determined growth and maturation are influenced by mortality rate and density-dependent processes, and maturation and growth parameters interact to mediate the evolution of one another. Subsequent to baseline simulations, we conducted experimental simulations to mimic fisheries harvest with two size-limits (targeting large or small fish), an array of fishing mortality rates, and assuming a deterministic or stochastic environment. Our results suggest that fishing with either size-limit may induce considerable changes in life-history trait expression (maturation schedules and growth rates), recruitment, and population abundance and structure. However, targeting large fish would cause more adverse genetic effects and may lead to a population less resilient to environmental stochasticity.

Wang, Hui-Yu; Höök, Tomas O

2009-01-01

300

Effects of ecological flooding on the temporal and spatial dynamics of carabid beetles (Coleoptera, Carabidae) and springtails (Collembola) in a polder habitat  

PubMed Central

Abstract Within the scope of the Integrated Rhine Program an ecological flood gate and channel was inserted into the polder “Ingelheim” to enhance animal and plant diversity. In 2008, carabid beetles and springtails were collected, using pitfall traps, to measure the effects of ecological flooding and a strong precipitation event at a flood-disturbed and a dry location in this area. At both localities, xerophilic and mesophilic carabid beetle species were dominant throughout the study period. The total number of individuals of hygrophilic species was comparatively constant, while species number increased, partly due to the changed moisture conditions caused by ecological flooding and strong precipitation. Carabid beetle diversity and evenness decreased marginally when ecological flooding was absent. Springtails represent a less mobile arthropod order, and as such the impact of ecological flooding was stronger. An increase in both numbers of species and individuals of hygrophilic and hygrotolerant species occurred in the flood-disturbed location after ecological flooding. After the sites at both locations had dried, the number of individuals belonging to these species declined rapidly. In contrast to carabid species, the strong precipitation event showed no influence on hygrophilic springtail species. Thus, collembolan diversity and evenness decreased markedly in the absence of flooding. We showed that ecological flooding has an influence on the spatial and temporal dynamics of different arthropod groups that inhabit the polder “Ingelheim”. These findings demonstrate the importance of using different arthropod groups as bioindicators in determining the ecological value of a particular polder design. PMID:21738425

Lessel, Tanja; Marx, Michael Thomas; Eisenbeis, Gerhard

2011-01-01

301

[Effect of temperature on proteinase activities of enteral microbiota and intestinal mucosa of fish of different ecological group].  

PubMed

Effect of temperature on proteinases activities of enteral microbiota and of intestinal mucosa was studied in five fish species (roach Rutilus rutilus, crucian carp Carassius carassius, common perch Perca fluviatilis, pike-perch Zander lucioperca, and pike Esox lucius) belonging by the nutrition type to different ecological groups. Essential differences of temperature characteristics of proteinases of intestinal mucosa and of enteral microbiota are revealed in fish belonging by the nutrition type to different ecologic groups. The character of the t0-function of proteinases of intestinal mucosa and enteral microbiota by casein and hemoglobin as a rule is different. The highest values of relative proteinases activities for casein in the zone of low temperatures (38 and 45.3 % of the maximal activity) are found at study of proteinases of enteral microbiota in common perch and crucian carp. The latter indicates a significant adaptability of the enteral microbiota proteinases of common perch and crucial carp to functioning at low temperatures. PMID:22645973

Kuz'mina, V V; Shalygin, M V; Skvortsova, E G

2012-01-01

302

corRna: a web server for predicting multiple-point deleterious mutations in structural RNAs.  

PubMed

RNA molecules can achieve a broad range of regulatory functions through specific structures that are in turn determined by their sequence. The prediction of mutations changing the structural properties of RNA sequences (a.k.a. deleterious mutations) is therefore useful for conducting mutagenesis experiments and synthetic biology applications. While brute force approaches can be used to analyze single-point mutations, this strategy does not scale well to multiple mutations. In this article, we present corRna a web server for predicting the multiple-point deleterious mutations in structural RNAs. corRna uses our RNAmutants framework to efficiently explore the RNA mutational landscape. It also enables users to apply search heuristics to improve the quality of the predictions. We show that corRna predictions correlate with mutagenesis experiments on the hepatitis C virus cis-acting replication element as well as match the accuracy of previous approaches on a large test-set in a much lower execution time. We illustrate these new perspectives offered by corRna by predicting five-point deleterious mutations--an insight that could not be achieved by previous methods. corRna is available at: http://corrna.cs.mcgill.ca. PMID:21596778

Lam, Edmund; Kam, Alfred; Waldispühl, Jérôme

2011-07-01

303

Somatic deleterious mutation rate in a woody plant: estimation from phenotypic data  

PubMed Central

We conducted controlled crosses in populations of the long-lived clonal shrub, Vaccinium angustifolium (lowbush blueberry) to estimate inbreeding depression and mutation parameters associated with somatic deleterious mutation. Inbreeding depression level was high, with many plants failing to set fruit after self-pollination. We also compared fruit set from autogamous pollinations (pollen collected from within the same inflorescence) with fruit set from geitonogamous pollinations (pollen collected from the same plant but from inflorescences separated by several meters of branch growth). The difference between geitonogamous versus autogamous fitness within single plants is referred to as ‘autogamy depression' (AD). AD can be caused by somatic deleterious mutation. AD was significantly different from zero for fruit set. We developed a maximum-likelihood procedure to estimate somatic mutation parameters from AD, and applied it to geitonogamous and autogamous fruit set data from this experiment. We infer that, on average, approximately three sublethal, partially dominant somatic mutations exist within the crowns of the plants studied. We conclude that somatic mutation in this woody plant results in an overall genomic deleterious mutation rate that exceeds the rate measured to date for annual plants. Some implications of this result for evolutionary biology and agriculture are discussed. PMID:23778990

Bobiwash, K; Schultz, S T; Schoen, D J

2013-01-01

304

ECOLOGICAL RISK ASSESSMENT WORKSHOP  

EPA Science Inventory

As ecological risk assessment evolves, it is moving beyond focus on single species toward addressing multiple species and their interactions, and from assessing effects of simple chemical toxicity to the cumulative impacts of multiple interacting chemical, physical, and biologica...

305

COMMUNITY AND ECOSYSTEM ECOLOGY Effects of Natural Forest Fragmentation on a  

E-print Network

for human uses. Therefore, understanding the ecological and evolutionary impli- cations of fragmentation of populations of forest specialists may alter gene Ã?ow patterns and selection pressures, thus inÃ?uencing the evolutionary trajectories of some organisms in fragmented landscapes (Lynam 1997, Bolger et al. 2000, Austen et

Gillespie, Rosemary

306

Vegetation Composition and Succession of Abandoned Farmland: Effects of Ecological, Historical and Spatial Factors  

Microsoft Academic Search

In North America, as well as in Europe, the mechanization and the modernization of the agricultural activities had strongly modified the agricultural landscapes. Originating from these transformations of the agricultural environment, abandoned farmlands remain poorly known environments. A holistic approach, including the analysis of ecological, historical and spatial factors, is used in order to understand the dynamics of these environments

Karyne Benjamin; Gérald Domon; André Bouchard

2005-01-01

307

ECOLOGICAL ENDPOINT MODELING FOR TMDLS: EFFECTS OF SEDIMENT ON FISH POPULATIONS  

EPA Science Inventory

Sediment is one of the primary stressors of concern for Total Maximum Daily Loads (TMDLs) for streams, and often it is a concern because of its impact on ecological endpoints. A modeling approach relating sediment to stream fish population dynamics is presented. Equations are d...

308

ECOLOGICAL AND NONHUMAN BIOLOGICAL EFFECTS OF SOLAR UV-B RADIATION  

EPA Science Inventory

Recent studies regarding the impact of UV-B radiation upon ecological and nonhuman biological systems is the subject of the report. For years scientists and laymen alike have causally noted the impact of solar ultraviolet radiation upon the non-human component of the biosphere. S...

309

Cascading effects of introduced Nile perch (Lates niloticus) on the foraging ecology of Nile tilapia  

E-print Network

- indigenous fish species in the Lake Victoria Basin of East Africa has been followed by dramatic ecological 2000; Pringle 2005). Although many fish stocks in Lake Victoria had declined prior to expansion followed that observed in Lake Victoria (Ogutu- Ohwayo 1993; Chapman et al. 1996a,b). Four non- indigenous

Chapman, Lauren J.

310

The Ecological and Population Validity of Reading Interventions for Adolescents: Can Effectiveness Be Generalized?  

ERIC Educational Resources Information Center

This article examined the ecological and population validity of research on reading interventions for adolescents in Grades 6 through 12. The 26 studies meeting selection criteria were analyzed to determine the characteristics of the students, interventionists, classroom structures, and school environments used, as well as whether there were…

Reed, Deborah K.; McCray Sorrells, Audrey; Cole, Heather A.; Takakawa, Nara N.

2013-01-01

311

General Ecology  

NSDL National Science Digital Library

This tutorial explains how environmental conditions and organism interactions determine animal and tree distribution and abundance. There are definitions of important ecological terms such as ecology, interactions, and abundance; descriptions of the environmental conditions needed for rainforests and how they provide habitat for many species; and an explanation of the spawning process. The tutorial also introduces food chain concepts and the unique ecology of riparian habitats. A quiz is also available.

312

Effects of Changes in Lugu Lake Water Quality on Schizothorax Yunnansis Ecological Habitat Based on HABITAT Model  

NASA Astrophysics Data System (ADS)

Schizothorax Yunnansis is an unique fish species only existing in Lugu Lake, which is located in the southwestern China. The simulation and research on Schizothorax Yunnansis habitat environment have a vital significance to protect this rare fish. With the development of the tourism industry, there bring more pressure on the environmental protection. The living environment of Schizothorax Yunnansis is destroyed seriously because the water quality is suffering the sustaining pollution of domestic sewage from the peripheral villages. This paper analyzes the relationship between water quality change and Schizothorax Yunnansis ecological habitat and evalutes Schizothorax Yunnansis's ecological habitat impact based on HABITAT model. The results show that when the TP concentration in Lugu Lake does not exceed Schizothorax Yunnansis's survival threshold, Schizothorax Yunnansis can get more nutrients and the suitable habitat area for itself is increased. Conversely, it can lead to TP toxicity in the Schizothorax Yunnansis and even death. Therefore, unsuitable habitat area for Schizothorax Yunnansis is increased. It can be seen from the results that HABITAT model can assist in ecological impact assessment studies by translating results of hydrological, water quality models into effects on the natural environment and human society.

Huang, Wei; Mynnet, Arthur

313

Effects of human activities on the ecological processes of river biofilms in a highly urbanized river  

NASA Astrophysics Data System (ADS)

Many anthropogenic disturbances and their effects of aquatic ecosystem are difficult to quantify in urbanized rivers. In past, specific taxa analysis of community structure was a common approach in river health monitoring studies. However, it is still difficult to understand stream ecosystem integrity without considering ecosystem processes. The complex species composition and metabolism of a river biofilm have the capacity to interact and/or modulate their surrounding environment. Because of their short life cycles, species richness, and worldwide distribution, structure and function of river biofilm communities are sensitive to change in environmental conditions. Therefore, biofilms are widely used as early warning systems of water pollution for water quality monitoring studies. In this study, we used river biofilms as a bioindicator by examining their extracellular enzyme activities and photosynthesis efficiency to understand human activities on the ecological processes of river ecosystem in a highly urbanized river. We sampled four sites along the Keelung River, Taiwan, based on different intensities of anthropogenic disturbances including water pollution index, population densities, land use types and types of stream habitats. Two study sites are heavily influenced by human activities and the others are not. The activities of extracellular enzymes within the biofilm play an important function for organic matter decomposition and nutrient cycling. We measured seven extracellular enzyme activities (?-d-glucosidase, phosphatase, leucine-aminopeptidase, sulfatase, peroxidase, polyphenol oxidase, and esterase) to examine specific enzyme activity changes at four study sites monthly. In addition, relative proportion of each extracellular enzyme activity on total enzyme activities was calculated in order to examine the relationship between functional biofilm profiles and different urban intensities. Among four study sites, leucine-aminopeptidase and esterase activities constituted nearly 50% of total enzyme activities. Peroxidase and polyphenol oxidase activities were about 30% of total enzyme activities. Some extracellular enzyme activities showed seasonal variation. For example, phosphatase, peroxidase, and polyphenol oxidase activities were higher in the summer than in the winter, whereas esterase activity was lower in the summer than in the winter. The algal and cyanobacterial assemblages of river biofilms provide the main site of primary productivity in river ecosystem. Through chlorophyll a fluorescence detection, we examined the efficiency of transformation energy in photosynthesis of river biofilms. Measurements of biofilm photosynthetic efficiency showed to be below the normal level of photosynthetic efficiency among four study sites. By combining these two aspects, we discussed how biofilms were affected by different anthropogenic disturbances and hope to contribute a better understanding of river ecosystem processes for river health monitoring program.

Hung, R.; Li, M.

2013-12-01

314

Adapting to climate change on Western public lands: addressing the ecological effects of domestic, wild, and feral ungulates.  

PubMed

Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production-the most widespread and long-running commercial use of public lands-can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates. PMID:23151970

Beschta, Robert L; Donahue, Debra L; DellaSala, Dominick A; Rhodes, Jonathan J; Karr, James R; O'Brien, Mary H; Fleischner, Thomas L; Deacon Williams, Cindy

2013-02-01

315

Adapting to Climate Change on Western Public Lands: Addressing the Ecological Effects of Domestic, Wild, and Feral Ungulates  

NASA Astrophysics Data System (ADS)

Climate change affects public land ecosystems and services throughout the American West and these effects are projected to intensify. Even if greenhouse gas emissions are reduced, adaptation strategies for public lands are needed to reduce anthropogenic stressors of terrestrial and aquatic ecosystems and to help native species and ecosystems survive in an altered environment. Historical and contemporary livestock production—the most widespread and long-running commercial use of public lands—can alter vegetation, soils, hydrology, and wildlife species composition and abundances in ways that exacerbate the effects of climate change on these resources. Excess abundance of native ungulates (e.g., deer or elk) and feral horses and burros add to these impacts. Although many of these consequences have been studied for decades, the ongoing and impending effects of ungulates in a changing climate require new management strategies for limiting their threats to the long-term supply of ecosystem services on public lands. Removing or reducing livestock across large areas of public land would alleviate a widely recognized and long-term stressor and make these lands less susceptible to the effects of climate change. Where livestock use continues, or where significant densities of wild or feral ungulates occur, management should carefully document the ecological, social, and economic consequences (both costs and benefits) to better ensure management that minimizes ungulate impacts to plant and animal communities, soils, and water resources. Reestablishing apex predators in large, contiguous areas of public land may help mitigate any adverse ecological effects of wild ungulates.

Beschta, Robert L.; Donahue, Debra L.; DellaSala, Dominick A.; Rhodes, Jonathan J.; Karr, James R.; O'Brien, Mary H.; Fleischner, Thomas L.; Deacon Williams, Cindy

2013-02-01

316

Behavioral Ecology doi:10.1093/beheco/arq172 Forum: Invited Review The fusion of behavioral ecology and ecology  

E-print Network

Behavioral ecology and ecology have projects in common. Community ecology can provide behavioral ecology with the tools to ask realistic questions about the current action of natural selection. Evolutionary ecology has moved beyond asking ‘‘Why does trait x contribute to reproductive success?’ ’ and on to ‘‘What are the conditions under which trait x contributes to reproductive success?’ ’ We need to bring this ecological perspective to the study of the evolution of behavior. Community ecologists have recognized that behavior influences ecological outcomes. For example, behavior contributes to the effect of history on community assembly, to indirect effects in predator– prey interactions, and to the responses of populations to human disturbance. More generally, behavior is often the source of context dependence; behavioral responses in different conditions lead to different ecological outcomes. As community ecology is broadening to include behavior, behavioral ecologists can begin to incorporate ecological perspectives in asking evolutionary questions. [Behav Ecol 22:225–230 (2011)] Behavioral ecology and ecology need each other. Behavior is linked to ecology at every level, from the population to the ecosystem, but here I will focus on the relation of behavior to population and community ecology. Behavioral ecology joins the study of animal behavior to evolutionary biology; its goal is to explain how behavior determines fitness. The goal of ecology is to explain the outcomes of interactions of organisms with their environments, including other organisms. Ecology, especially community ecology, can provide behavioral ecology with the tools to ask realistic questions about the evolution of behavior. In turn, the study of behavior can help ecology deal with questions about context dependence. ECOLOGY AND THE EVOLUTION OF BEHAVIOR In the first half of the 20th century, studies of behavior and of ecology were more intertwined than they are now. It was taken for granted that an animal’s behavior could be understood only in the context of its natural history. To pursue evolutionary questions about behavior, we now need to bring back analytical natural history.

Deborah M. Gordon

317

Effects of ground water exchange on the hydrology and ecology of surface water.  

PubMed

Ground water exchange affects the ecology of surface water by sustaining stream base flow and moderating water-level fluctuations of ground water-fed lakes. It also provides stable-temperature habitats and supplies nutrients and inorganic ions. Ground water input of nutrients can even determine the trophic status of lakes and the distribution of macrophytes. In streams the mixing of ground water and surface water in shallow channel and bankside sediments creates a unique environment called the hyporheic zone, an important component of the lotic ecosystem. Localized areas of high ground water discharge in streams provide thermal refugia for fish. Ground water also provides moisture to riparian vegetation, which in turn supplies organic matter to streams and enhances bank resistance to erosion. As hydrologists and ecologists interact to understand the impact of ground water on aquatic ecology, a new research field called "ecohydrology" is emerging. PMID:12019646

Hayashi, Masaki; Rosenberry, Donald O

2002-01-01

318

Ecologically-based rodent management: its effectiveness in cropping systems in South-East Asia  

Microsoft Academic Search

Ecologically-based rodent management (EBRM] has re-emerged as a paradigm for large scale rodent management campaigns. This concept has been tested in replicated, village-scale experiments over 4 years on rodent pests in lowland irrigated rice crops. In Indonesia, villages that practised EBRM had a mean increase in rice yield of 6%, whereas production levels were maintained in Vietnam but control costs

G. R. Singleton; P. R. Brown; J. Jacob

2004-01-01

319

Overview of the effects of the coal fuel cycle on hydrology, water quality and use, and aquatic ecology  

SciTech Connect

Literature is summarized for the effects of the coal fuel cycle (mining, mine-site processing, transportation, storage, onsite processing, combustion, and waste collection and disposal) on water resources. Aspects considered include surface- and ground-water hydrology, water quality and use, and aquatic ecology. Water use is discussed with regard to both availability and water quality constraints on use. Requirements of the recently enacted Surface Mining Control and Reclamation Act are introduced where appropriate. For the combustion step in the fuel cycle, only those effects which are specific to coal as a fuel are addressed. Effects not specific to coal use (such as thermal effects, impingement, and entrainment resulting from cooling water withdrawal and use) are not considered. Reference is made to more exhaustive studies of the topics reviewed. A summary of the major environmental effects of the coal fuel cycle is given below.

Cushman, R.M.; Gough, S.B.; Moran, M.S.

1980-05-01

320

Soil Ecology  

NASA Astrophysics Data System (ADS)

Soil Ecology is designed to meet the increasing challenge faced by today's environmental scientists, ecologists, agriculturalists, and biotechnologists for an integrated approach to soil ecology. It emphasizes the interrelations among plants, animals, and microbes, by first establishing the fundamental physical and chemical properties of the soil habitat and then functionally characterizing the major components of the soil biota and some of their most important interactions. The fundamental principles underpinning soil ecology are established and this then enables an integrated approach to explore and understand the processes of soil nutrient (carbon, nitrogen, and phosphorus) cycling and the ecology of extreme soil conditions such as soil-water stress. Two of the most topical aspects of applied soil ecology are then selected. First, the ecology of soil pollution is examined, focusing on acid deposition and radionuclide pollution. Second, manipulation of soil ecology through biotechnology is discussed, illustrating the use of pesticides and microbial inocula in soils and pointing toward the future by considering the impact of genetically modified inocula on soil ecology.

Killham, Ken

1994-04-01

321

Geomorphic and ecological effects of Hurricanes Katrina and Rita on coastal Louisiana marsh communities  

USGS Publications Warehouse

Hurricanes Katrina and Rita made landfall in 2005, subjecting the coastal marsh communities of Louisiana to various degrees of exposure. We collected data after the storms at 30 sites within fresh (12), brackish/intermediate (12), and saline (6) marshes to document the effects of saltwater storm surge and sedimentation on marsh community dynamics. The 30 sites were comprised of 15 pairs. Most pairs contained one site where data collection occurred historically (that is, prestorms) and one Coastwide Reference Monitoring System site. Data were collected from spring 2006 to fall 2007 on vegetative species composition, percentage of vegetation cover, aboveground and belowground biomass, and canopy reflectance, along with discrete porewater salinity, hourly surface-water salinity, and water level. Where available, historical data acquired before Hurricanes Katrina and Rita were used to compare conditions and changes in ecological trajectories before and after the hurricanes. Sites experiencing direct and indirect hurricane influences (referred to in this report as levels of influence) were also identified, and the effects of hurricane influence were tested on vegetation and porewater data. Within fresh marshes, porewater salinity was greater in directly impacted areas, and this heightened salinity was reflected in decreased aboveground and belowground biomass and increased cover of disturbance species in the directly impacted sites. At the brackish/intermediate marsh sites, vegetation variables and porewater salinity were similar in directly and indirectly impacted areas, but porewater salinity was higher than expected throughout the study. Interestingly, directly impacted saline marsh sites had lower porewater salinity than indirectly impacted sites, but aboveground biomass was greater at the directly impacted sites. Because of the variable and site-specific nature of hurricane influences, we present case studies to help define postdisturbance baseline conditions in fresh, brackish/ intermediate, and saline marshes. In fresh marshes, the mechanism of hurricane influence varied across the landscape. In the western region, saltwater storm surge inundated freshwater marshes and remained for weeks, effectively causing damage that reset the vegetation community. This is in contrast to the direct physical disturbance of the storm surge in the eastern region, which flipped and relocated marsh mats, thereby stressing the vegetation communities and providing an opportunity for disturbance species to colonize. In the brackish/intermediate marsh, disturbance species took advantage of the opportunity provided by shifting species composition caused by physical and saltwater-induced perturbations, although this shift is likely to be short lived. Saline marsh sites were not negatively impacted to a severe degree by the hurricanes. Species composition of vegetation in saline marshes was not affected, and sediment deposition appeared to increase vegetative productivity. The coastal landscape of Louisiana is experiencing high rates of land loss resulting from natural and anthropogenic causes and is experiencing subsidence rates greater than 10.0 millimeters per year (mm yr-1); therefore, it is important to understand how hurricanes influence sedimentation and soil properties. We document long-term vertical accretion rates and accumulation rates of organic matter, bulk density, carbon and nitrogen. Analyses using caesium-137 to calculate long-term vertical accretion rates suggest that accretion under impounded conditions is less than in nonimpounded conditions in the brackish marsh of the chenier plain. Our data also support previous studies indicating that accumulation rates of organic matter explain much of the variability associated with vertical accretion in brackish/intermediate and saline marshes. In fresh marshes, more of the variability associated with vertical accretion was explained by mineral accumulation than in the other mars

Piazza, Sarai C.; Steyer, Gregory D.; Cretini, Kari F.; Sasser, Charles E.; Visser, Jenneke M.; Holm, Guerry O.; Sharp, Leigh Anne; Evers, D. Elaine; Meriwether, John R.

2011-01-01

322

The Effect of Social and Classroom Ecological Factors on Promoting Self-Determination in Elementary School  

PubMed Central

Promoting the self-determination of students with disabilities as a means to access the general curriculum has been the subject of research in recent years, as has the importance of efforts to promote self-determination during elementary years. To examine the status of such efforts in the field, 203 elementary special educators were surveyed in 23 states to determine how (a) classroom instructional practices or strategies, (b) classroom ecological or setting variables, and (c) self-reported barriers to promoting self-determination affected their perceptions of the importance of teaching self-determination and the frequency with which they did so. Results indicated that special educators’ perceived importance of teaching self-determination was not impacted by classroom instructional factors, but was affected by classroom ecological factors. Classroom ecological factors were not, however, significant in the frequency with which teachers provided instruction on self-determination, but classroom instructional practices were. Limitations and implications are discussed, and suggestions for future research are offered. PMID:25067895

Cho, Hyunjeong; Wehmeyer, Michael; Kingston, Neil

2014-01-01

323

The Effect of Inappropriate Calibration: Three Case Studies in Molecular Ecology  

PubMed Central

Time-scales estimated from sequence data play an important role in molecular ecology. They can be used to draw correlations between evolutionary and palaeoclimatic events, to measure the tempo of speciation, and to study the demographic history of an endangered species. In all of these studies, it is paramount to have accurate estimates of time-scales and substitution rates. Molecular ecological studies typically focus on intraspecific data that have evolved on genealogical scales, but often these studies inappropriately employ deep fossil calibrations or canonical substitution rates (e.g., 1% per million years for birds and mammals) for calibrating estimates of divergence times. These approaches can yield misleading estimates of molecular time-scales, with significant impacts on subsequent evolutionary and ecological inferences. We illustrate this calibration problem using three case studies: avian speciation in the late Pleistocene, the demographic history of bowhead whales, and the Pleistocene biogeography of brown bears. For each data set, we compare the date estimates that are obtained using internal and external calibration points. In all three cases, the conclusions are significantly altered by the application of revised, internally-calibrated substitution rates. Collectively, the results emphasise the importance of judicious selection of calibrations for analyses of recent evolutionary events. PMID:18286172

Ho, Simon Y. W.; Saarma, Urmas; Barnett, Ross; Haile, James; Shapiro, Beth

2008-01-01

324

Rare deleterious mutations of the gene EFR3A in autism spectrum disorders  

PubMed Central

Background Whole-exome sequencing studies in autism spectrum disorder (ASD) have identified de novo mutations in novel candidate genes, including the synaptic gene Eighty-five Requiring 3A (EFR3A). EFR3A is a critical component of a protein complex required for the synthesis of the phosphoinositide PtdIns4P, which has a variety of functions at the neural synapse. We hypothesized that deleterious mutations in EFR3A would be significantly associated with ASD. Methods We conducted a large case/control association study by deep resequencing and analysis of whole-exome data for coding and splice site variants in EFR3A. We determined the potential impact of these variants on protein structure and function by a variety of conservation measures and analysis of the Saccharomyces cerevisiae Efr3 crystal structure. We also analyzed the expression pattern of EFR3A in human brain tissue. Results Rare nonsynonymous mutations in EFR3A were more common among cases (16 / 2,196?=?0.73%) than matched controls (12 / 3,389?=?0.35%) and were statistically more common at conserved nucleotides based on an experiment-wide significance threshold (P?=?0.0077, permutation test). Crystal structure analysis revealed that mutations likely to be deleterious were also statistically more common in cases than controls (P?=?0.017, Fisher exact test). Furthermore, EFR3A is expressed in cortical neurons, including pyramidal neurons, during human fetal brain development in a pattern consistent with ASD-related genes, and it is strongly co-expressed (P?deleterious mutations in EFR3A were found to be associated with ASD using an experiment-wide significance threshold. Synaptic phosphoinositide metabolism has been strongly implicated in syndromic forms of ASD. These data for EFR3A strengthen the evidence for the involvement of this pathway in idiopathic autism. PMID:24860643

2014-01-01

325

Ecological effects on streams from forest fertilization; literature review and conceptual framework for future study in the western Cascades  

USGS Publications Warehouse

Fertilization of forests with urea-nitrogen has been studied numerous times for its effects on water quality. Stream nitrogen concentrations following fertilization are typically elevated during winter, including peaks in the tens-of-thousands of parts per billion range, with summer concentrations often returning to background or near-background levels. Despite these increases, water-quality criteria for nitrogen have rarely been exceeded. However, such criteria are targeted at fish toxicity or human health and are not relevant to concentrations that could cause ecological disturbances.Studies of the responses of stream biota to fertilization have been rare and have targeted either immediate, toxicity-based responses or used methods insensitive to ongoing ecological processes. This report reviews water-quality studies following forest fertilizations, emphasizing Cascade streams in the Pacific Northwest and documented biological responses in those streams. A conceptual model predicting potential ecological response to fertilization, which includes effects on algal growth and primary production, is presented. In this model, applied fertilizer nitrogen reaching streams is mostly exported during winter. However, some nitrogen retained in soils or stream and riparian areas may become available to aquatic biota during spring and summer. Biological responses may be minimal in small streams nearest to application because of light limitation, but may be elevated downstream where light is sufficient to allow algal growth. Ultimately, algal response could be greatest in downstream reaches, although ambient nutrient concentrations remain low due to uptake and benthic nutrient recycling. Ground-water flow paths and hyporheic processing could be critical in determining the fate of applied nitrogen. A framework is provided for testing this response in the Little River watershed, a tributary to the North Umpqua River, Oregon, at basic and intensive levels of investigation.

Anderson, C.W.

2002-01-01

326

Seasonality and midscale spatial effects on Cichla ecology and fish species diversity in a neotropical floodplain river  

E-print Network

The influence of seasonal fluctuations in water levels on tropical fish species from fluvial environments was evaluated by comparing the ecology of resident piscivores and habitat use of prey fish within a floodplain river. Ecological data were...

Jepsen, David Brice

2012-06-07

327

Cumulative effects of restoration efforts on ecological characteristics of an open water area within the Upper Mississippi River  

USGS Publications Warehouse

Ecological restoration efforts in large rivers generally aim to ameliorate ecological effects associated with large-scale modification of those rivers. This study examined whether the effects of restoration efforts-specifically those of island construction-within a largely open water restoration area of the Upper Mississippi River (UMR) might be seen at the spatial scale of that 3476ha area. The cumulative effects of island construction, when observed over multiple years, were postulated to have made the restoration area increasingly similar to a positive reference area (a proximate area comprising contiguous backwater areas) and increasingly different from two negative reference areas. The negative reference areas represented the Mississippi River main channel in an area proximate to the restoration area and an open water area in a related Mississippi River reach that has seen relatively little restoration effort. Inferences on the effects of restoration were made by comparing constrained and unconstrained models of summer chlorophyll a (CHL), summer inorganic suspended solids (ISS) and counts of benthic mayfly larvae. Constrained models forced trends in means or in both means and sampling variances to become, over time, increasingly similar to those in the positive reference area and increasingly dissimilar to those in the negative reference areas. Trends were estimated over 12- (mayflies) or 14-year sampling periods, and were evaluated using model information criteria. Based on these methods, restoration effects were observed for CHL and mayflies while evidence in favour of restoration effects on ISS was equivocal. These findings suggest that the cumulative effects of island building at relatively large spatial scales within large rivers may be estimated using data from large-scale surveillance monitoring programs. Published in 2010 by John Wiley & Sons, Ltd.

Gray, B.R.; Shi, W.; Houser, J.N.; Rogala, J.T.; Guan, Z.; Cochran-Biederman, J. L.

2011-01-01

328

Ecological Footprints  

NSDL National Science Digital Library

Ever wondered what sort of impact your everyday existence has on the planet? The University of Texas at Austin offers this information as part of their training in Natural Resource Management. An ecological footprint is defined here as "the area on the surface of Earth that each person appropriates in order to live," including many kinds of ecological services -- from food, air, water, and living space, to the recycling of wastes. This site offers an introduction to the concept of Ecological Footprints, including links to spreadsheets for calculation, national footprints, and related scientific articles.

329

The effect of ecological parameters on the distribution of snail vectors of schistosomiasis.  

PubMed

The infestation of the water courses showed 32.5% for Biomphalaria alexandrina and 8.75% for Bulinus truncatus. Ecological parameters, showed non significant variations in the water courses harbouring snail vectors and those free from snails except for conductivity in the habitats harbouring B. truncatus. This variation was more highly significant (p<0.001). Of the examined sites, 11.25% were harbouring B. alexandrina and Lymnaea natalenesis living together and 5% of the sites were harbouring B. truncatus and Physa acuta snails. Snail vectors were distributed with different degrees with aquatic plants reflecting the degree of species preference plants for snails' life. PMID:12557938

Kader, A A

2001-04-01

330

Sexual selection accelerates the elimination of a deleterious mutant in Drosophila melanogaster.  

PubMed

Although theory indicates that indirect genetic benefits through mate choice should be widespread, empirical work has often either failed to detect the operation of such benefits or shown a net cost to the presence of sexual selection. We tested whether sexual selection can increase the speed with which a conditionally deleterious allele is removed from a laboratory population of Drosophila melanogaster. The alcohol dehydrogenase null allele (Adh-) confers slightly lower viability than wild-type alleles in the absence of ethanol but is lethal in homozygotes when ethanol comprises 6% of the medium. We tracked the frequency of this allele in artificially constructed populations reared at three different levels of ethanol (0%, 2%, and 4%) that either experienced sexual selection or did not. Loss of the deleterious Adh- allele was more rapid when sexual selection was allowed to act, especially in the presence of ethanol. We also quantified the strength of both nonsexual and sexual selection against the Adh- allele using maximum-likelihood estimation. In contrast to recent experiments employing monogamy/polygamy designs, our results demonstrate a fitness benefit to sexual selection. This is consistent with the operation of good-genes female choice. PMID:19154371

Hollis, Brian; Fierst, Janna L; Houle, David

2009-02-01

331

Clonal Deleterious Mutations in the I?b? Gene in the Malignant Cells in Hodgkin's Lymphoma  

PubMed Central

Members of the nuclear factor (NF)-?B family of transcription factors play a crucial role in cellular activation, immune responses, and oncogenesis. In most cells, they are kept inactive in the cytosol by complex formation with members of the inhibitor of NF-?B (I?B) family, whose degradation activates NF-?B in response to diverse stimuli. In Hodgkin's lymphoma (HL), high constitutive nuclear activity of NF-?B is characteristic of the malignant Hodgkin and Reed-Sternberg (H/RS) cells, which occur at low number in a background of nonneoplastic inflammatory cells. In single H/RS cells micromanipulated from histological sections of HL, we detect clonal deleterious somatic mutations in the I?B? gene in two of three Epstein-Barr virus (EBV)-negative cases but not in two EBV-positive cases (in which a viral oncogene may account for NF-?B activation). There was no evidence for I?B? mutations in two non-HL entities or in normal germinal center B cells. This study establishes deleterious I?B? mutations as the first recurrent genetic defect found in H/RS cells, indicating a role of I?B? defects in the pathogenesis of HL and implying that I?B? is a tumor suppressor gene. PMID:10637284

Jungnickel, Berit; Staratschek-Jox, Andrea; Bräuninger, Andreas; Spieker, Tilmann; Wolf, Jürgen; Diehl, Volker; Hansmann, Martin-Leo; Rajewsky, Klaus; Küppers, Ralf

2000-01-01

332

Ecological risk as a tool for evaluating the effects of offshore wind farm construction in the North Sea  

Microsoft Academic Search

Offshore wind power generation represents a chance to supply energy in a more sustainable way; however, the ecological risks\\u000a associated with the construction and operation of offshore wind farms are still largely unknown. This paper uses the concept\\u000a of ecological risk for analysing ecological changes during construction of offshore wind farms. “Ecological risk” is defined\\u000a as the potentially reduced ability

Corinna Nunneri; Hermann J. Lenhart; Benjamin Burkhard; Wilhelm Windhorst

2008-01-01

333

A synthesis of the ecological effects of air pollution from nitrogen and sulfur in the U.S  

USGS Publications Warehouse

Four decades after the passage of the US Clean Air Act, air-quality standards are set to protect ecosystems from damage caused by gas-phase nitrogen (N) and sulfur (S) compounds, but not from the deposition of these air pollutants to land and water. Here, we synthesize recent scientific literature on the ecological effects of N and S air pollution in the US. Deposition of N and S is the main driver of ecosystem acidification and contributes to nutrient enrichment in many natural systems. Although surface-water acidification has decreased in the US since 1990, it remains a problem in many regions. Perturbations to ecosystems caused by the nutrient effects of N deposition continue to emerge, although gas-phase concentrations are generally not high enough to cause phytotoxicity. In all, there is overwhelming evidence of a broad range of damaging effects to ecosystems in the US under current air quality conditions.

Greaver, T.L.; Sullivan, T.; Herrick, J.D.; Barber, M.; Baron, J.; Cosby, B.; Deerharke, M.; Dennis, R.; Dubois, J.J.D.; Goodale, C.; Herlihy, A.; Lawrence, G.; Liu, L.; Lynch, J.; Novak, K.

2012-01-01

334

Migration intensity has no effect on peak HIV prevalence: an ecological study  

PubMed Central

Background Correctly identifying the determinants of generalized HIV epidemics is crucial to bringing down ongoing high HIV incidence in these countries. High rates of migration are believed to be an important determinant of HIV prevalence. This study has two aims. Firstly, it evaluates the ecological association between levels of internal and international migration and national peak HIV prevalence using thirteen variables from a variety of sources to capture various aspects of internal and international migration intensity. Secondly, it examines the relationship between circular migration and HIV at an individual and population-level in South Africa. Methods Linear regression was used to analyze the association between the various measures of migration intensity and peak national HIV prevalence for 141 countries and HIV prevalence by province and ethnic group in South Africa. Results No evidence of a positive ecological association between national migration intensity and HIV prevalence was found. This remained the case when the analyses were limited to the countries of sub-Saharan Africa. On the whole, countries with generalized HIV epidemics had lower rates of internal and external migration. Likewise, no association was found between migration and HIV positivity at an individual or group-level in South Africa. Conclusion These results do not support the thesis that migration measured at the country level plays a significant role in determining peak HIV prevalence. PMID:24961725

2014-01-01

335

Urban Ecology  

NSDL National Science Digital Library

When people think about the concept and idea of ecology, they may not immediately picture a bustling urban street or a network of interconnected bike paths. Since 1975, a group of architects and activists have been thinking about exactly those things in terms of urban ecology (and a good deal more to boot), coupling it with a conviction that urban ecology can draw on ecology, public participation and urban planning "to help design and build healthier cities." Given these ideas, it seems logical that this organization has its roots in the Bay Area, and continues to offer up interesting plans and proposals, many of which can be found on the website. One such document is the Walkable Streets Toolkit, which is designed for use by communities that seek to make their streets more pedestrian friendly. Additionally, visitors will want to look at current and past editions of The Urban Ecologist, which is the group's quarterly newsletter.

336

Phytoplankton Ecology  

NSDL National Science Digital Library

This site describes phytoplankton ecology research by marine ecologists at Mote Marine Laboratory (MML), an independent, nonprofit research organization based in Sarasota, Florida. The emphasis of MML's phytoplankton ecology research is the photophysiology of marine algae -- with recent emphasis on the ability to predict and possibly mitigate blooms of the toxic marine dinoflagellate, Gymnodinium breve. The no-frills phytoplankton ecology homepage describes research and offers data (maps, figures, tables) from 1998 and 1999 projects on Red Tide transects, Nutrient and chlorophyll concentrations, and Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) transect data, among several others. The site also offers general information on Red Tides, Red Tide conditions in Southwest Florida, a chronology of historic Red Tide events, and links to related resources.

337

Conservation Ecology  

NSDL National Science Digital Library

Conservation Ecology is a new, exclusively electronic, peer-reviewed scientific journal of the Resilience Alliance, with content ranging from the applied to the theoretical. Topics covered by the journal include: "the conservation of ecosystems, landscapes, species, populations, and genetic diversity; the restoration of ecosystems and habitats; and the management of resources." This site includes the full text version of the articles (including past issues), as well as instructions on how to submit papers and how to subscribe. Subscriptions to Conservation Ecology are free of charge and all materials are available for browsing without cost. Edited by ecosystem ecology expert, Dr. C. S. Holling, Conservation Ecology breaks new ground in an important, emerging science.

1997-01-01

338

Aquatic Ecology Aquatic ecology group studies ecological interactions  

E-print Network

Aquatic Ecology Aquatic ecology group studies ecological interactions between biota and their environment in freshwater and marine ecosystems. The group focuses particularly on the ecological interactions and their underlying ecological processes necessary to sustain ecosystem structure and function in their natural state

339

Evolution- and Structure-Based Computational Strategy Reveals the Impact of Deleterious Missense Mutations on MODY 2 (Maturity-Onset Diabetes of the Young, Type 2)  

PubMed Central

Heterozygous mutations in the central glycolytic enzyme glucokinase (GCK) can result in an autosomal dominant inherited disease, namely maturity-onset diabetes of the young, type 2 (MODY 2). MODY 2 is characterised by early onset: it usually appears before 25 years of age and presents as a mild form of hyperglycaemia. In recent years, the number of known GCK mutations has markedly increased. As a result, interpreting which mutations cause a disease or confer susceptibility to a disease and characterising these deleterious mutations can be a difficult task in large-scale analyses and may be impossible when using a structural perspective. The laborious and time-consuming nature of the experimental analysis led us to attempt to develop a cost-effective computational pipeline for diabetic research that is based on the fundamentals of protein biophysics and that facilitates our understanding of the relationship between phenotypic effects and evolutionary processes. In this study, we investigate missense mutations in the GCK gene by using a wide array of evolution- and structure-based computational methods, such as SIFT, PolyPhen2, PhD-SNP, SNAP, SNPs&GO, fathmm, and Align GVGD. Based on the computational prediction scores obtained using these methods, three mutations, namely E70K, A188T, and W257R, were identified as highly deleterious on the basis of their effects on protein structure and function. Using the evolutionary conservation predictors Consurf and Scorecons, we further demonstrated that most of the predicted deleterious mutations, including E70K, A188T, and W257R, occur in highly conserved regions of GCK. The effects of the mutations on protein stability were computed using PoPMusic 2.1, I-mutant 3.0, and Dmutant. We also conducted molecular dynamics (MD) simulation analysis through in silico modelling to investigate the conformational differences between the native and the mutant proteins and found that the identified deleterious mutations alter the stability, flexibility, and solvent-accessible surface area of the protein. Furthermore, the functional role of each SNP in GCK was identified and characterised using SNPeffect 4.0, F-SNP, and FASTSNP. We hope that the observed results aid in the identification of disease-associated mutations that affect protein structure and function. Our in silico findings provide a new perspective on the role of GCK mutations in MODY2 from an evolution-based structure-centric point of view. The computational architecture described in this paper can be used to predict the most appropriate disease phenotypes for large-genome sequencing projects and to provide individualised drug therapy for complex diseases such as diabetes. PMID:24578721

George, Doss C. Priya; Chakraborty, Chiranjib; Haneef, SA Syed; NagaSundaram, Nagarajan; Chen, Luonan; Zhu, Hailong

2014-01-01

340

Evolution- and structure-based computational strategy reveals the impact of deleterious missense mutations on MODY 2 (maturity-onset diabetes of the young, type 2).  

PubMed

Heterozygous mutations in the central glycolytic enzyme glucokinase (GCK) can result in an autosomal dominant inherited disease, namely maturity-onset diabetes of the young, type 2 (MODY 2). MODY 2 is characterised by early onset: it usually appears before 25 years of age and presents as a mild form of hyperglycaemia. In recent years, the number of known GCK mutations has markedly increased. As a result, interpreting which mutations cause a disease or confer susceptibility to a disease and characterising these deleterious mutations can be a difficult task in large-scale analyses and may be impossible when using a structural perspective. The laborious and time-consuming nature of the experimental analysis led us to attempt to develop a cost-effective computational pipeline for diabetic research that is based on the fundamentals of protein biophysics and that facilitates our understanding of the relationship between phenotypic effects and evolutionary processes. In this study, we investigate missense mutations in the GCK gene by using a wide array of evolution- and structure-based computational methods, such as SIFT, PolyPhen2, PhD-SNP, SNAP, SNPs&GO, fathmm, and Align GVGD. Based on the computational prediction scores obtained using these methods, three mutations, namely E70K, A188T, and W257R, were identified as highly deleterious on the basis of their effects on protein structure and function. Using the evolutionary conservation predictors Consurf and Scorecons, we further demonstrated that most of the predicted deleterious mutations, including E70K, A188T, and W257R, occur in highly conserved regions of GCK. The effects of the mutations on protein stability were computed using PoPMusic 2.1, I-mutant 3.0, and Dmutant. We also conducted molecular dynamics (MD) simulation analysis through in silico modelling to investigate the conformational differences between the native and the mutant proteins and found that the identified deleterious mutations alter the stability, flexibility, and solvent-accessible surface area of the protein. Furthermore, the functional role of each SNP in GCK was identified and characterised using SNPeffect 4.0, F-SNP, and FASTSNP. We hope that the observed results aid in the identification of disease-associated mutations that affect protein structure and function. Our in silico findings provide a new perspective on the role of GCK mutations in MODY2 from an evolution-based structure-centric point of view. The computational architecture described in this paper can be used to predict the most appropriate disease phenotypes for large-genome sequencing projects and to provide individualised drug therapy for complex diseases such as diabetes. PMID:24578721

George, Doss C Priya; Chakraborty, Chiranjib; Haneef, S A Syed; Nagasundaram, Nagarajan; Chen, Luonan; Zhu, Hailong

2014-01-01

341

Quantifying the effect of ecological restoration on soil erosion in China's Loess Plateau region: an application of the MMF approach.  

PubMed

Land degradation due to erosion is one of the most serious environmental problems in China. To reduce land degradation, the government has taken a number of conservation and restoration measures, including the Sloping Land Conversion Program (SLCP), which was launched in 1999. A logical question is whether these measures have reduced soil erosion at the regional level. The objective of this article is to answer this question by assessing soil erosion dynamics in the Zuli River basin in the Loess Plateau of China from 1999 to 2006. The MMF (Morgan, Morgan and Finney) model was used to simulate changes in runoff and soil erosion over the period of time during which ecological restoration projects were implemented. Some model variables were derived from remotely sensed images to provide improved land surface representation. With an overall accuracy rate of 0.67, our simulations show that increased ground vegetation cover, especially in forestlands and grasslands, has reduced soil erosion by 38.8% on average from 1999 to 2006. During the same time period, however, the change in rainfall pattern has caused a 13.1% +/- 4.3% increase in soil erosion, resulting in a net 25.7% +/- 8.5% reduction in soil erosion. This suggests that China's various ecological restoration efforts have been effective in reducing soil loss. PMID:19756858

Li, Changbin; Qi, Jiaguo; Feng, Zhaodong; Yin, Runsheng; Guo, Biyun; Zhang, Feng; Zou, Songbing

2010-03-01

342

Ecological Impacts of Climate Change  

NSDL National Science Digital Library

This 28-page downloadable booklet is based on Ecological Impacts of Climate Change (2009), a report by an independent panel of experts convened by the National Research Council. It explains general themes about the ecological consequences of climate change and identifies examples of ecological changes across the United States. Also available are powerpoints on current effects of climate changes. Each example is of a specific species. The powerpoints are tailored for different parts of the country.

2009-03-10

343

Workshop on Closed System Ecology  

NASA Technical Reports Server (NTRS)

Self maintaining laboratory scale ecological systems completely isolated from exchanges of matter with external systems were demonstrated. These research tools are discussed in terms of their anticipated value in understanding (1) global ecological material and energy balances, (2) the dynamics of stability and instability in ecosystems, (3) the effects of man-made substances and structures on ecosystems, and (4) the precise requirements for dynamic control of controlled ecology life support systems (CELSS).

1982-01-01

344

Disease effects on lobster fisheries, ecology, and culture: overview of DAO Special 6.  

PubMed

Lobsters are prized by commercial and recreational fishermen worldwide, and their populations are therefore buffeted by fishery practices. But lobsters also remain integral members of their benthic communities where predator-prey relationships, competitive interactions, and host-pathogen dynamics push and pull at their population dynamics. Although lobsters have few reported pathogens and parasites relative to other decapod crustaceans, the rise of diseases with consequences for lobster fisheries and aquaculture has spotlighted the importance of disease for lobster biology, population dynamics and ecology. Researchers, managers, and fishers thus increasingly recognize the need to understand lobster pathogens and parasites so they can be managed proactively and their impacts minimized where possible. At the 2011 International Conference and Workshop on Lobster Biology and Management a special session on lobster diseases was convened and this special issue of Diseases of Aquatic Organisms highlights those proceedings with a suite of articles focused on diseases discussed during that session. PMID:23186696

Behringer, Donald C; Butler, Mark J; Stentiford, Grant D

2012-08-27

345

Ecology 2001 15, 669675  

E-print Network

. A different degree of seed coat scarification caused by differences in gut retention time, chemical and effect on the seeds of each plant consumed. Key-words: Frugivory, Mediterranean shrubs, seed ingestion by birds, seed traits Functional Ecology (2001) 15, 669­675 Introduction The effect that the ingestion

Traveset, Anna

346

Maintenance of sex-linked deleterious alleles by selfing and group selection in metapopulations of the phytopathogenic fungus Microbotryum violaceum.  

PubMed

Microbotryum violaceum is a fungus that causes the sterilizing anther smut disease in many Caryophyllaceae. Its diploid teliospores are heterozygous at the mating-type locus, normally producing equal proportions of haploid sporidia of the two mating types. However, natural populations contain high frequencies of individuals producing sporidia of only one mating type. This mating-type ratio bias is caused by the presence of deleterious alleles at haploid phase ("haplo-lethals") linked to the mating-type locus. These haplo-lethals can be transmitted if there is conjugation among the products of meiosis (intratetrad selfing). Haplo-lethals still suffer from selective disadvantages, through reducing the infection probability of strains that carry them, and thus cannot persist in a panmictic population. We develop a realistic model of a metapopulation of M. violaceum on its host Silene latifolia. Simulations show that if intratetrad selfing rate is high, haplo-lethals can be maintained under a metapopulation structure because of founder effects and selection at the population level. Populations founded only by strains carrying haplo-lethals experience a lower extinction rate precisely because of their lower infection ability; they spread more slowly and sterilize fewer plants, thereby allowing their host population to grow more rapidly and therefore to be less prone to extinction. PMID:15795854

Tellier, Aurelien; Villaréal, Lorys M M A; Giraud, Tatiana

2005-05-01

347

Ecological risk assessment. Book chapter  

SciTech Connect

Risk assessment has been suggested as a tool to help manage ecological problems. Ecological risk assessment is usually defined as the process that evaluates the likelihood that adverse ecological effects are occurring, or may occur, as a result of exposure to one or more stressors. The basic concept, while straightforward, is difficult to apply to any but the simplest ecological problems. A formidable problem in many risk assessments, and especially for complex questions such as addressing the challenge of ecological sustainability, is selecting what ecological component or system is to be considered at risk. This selection is entirely social and political, but estimating the actual risk is technical and scientific. The question of what is at risk must be answered within the political decision-making framework or the results of the risk assessment will be of limited utility.

Lackey, R.T.

1996-03-01

348

Post-Doctoral Fellow Landscape Ecology / Movement Ecology  

E-print Network

Post-Doctoral Fellow Landscape Ecology / Movement Ecology The Corridor Research Group Job to hire a Post-Doctoral Fellow to lead a large-scale experiment examining the effects of fragmentation Site, near Aiken, South Carolina. The Post-Doctoral Fellow will coordinate this collaborative research

Haddad, Nick

349

A social ecology of hyperactive boys: medication effects in structured classroom environments.  

PubMed Central

Hyperactive boys on methylphenidate (Ritalin), hyperactive boys on placebo, and comparison boys were observed in quasi-naturalistic classroom settings. Ambient stimulation (quiet versus noisy conditions) and source of regulation (self-paced versus other-paced activities) were varied in a 2 x 2 design. Compared to their peers, hyperactive boys on placebo showed lower rates of task attention and higher rates of gross motor movement, regular and negative verbalization, noise-making, physical contact, social initiation, disruption, and acts that were perceived as energetic, inappropriate, or unexpected. Self-paced activities resulted in increased rates of verbalization, social initiation, and high-energy episodes. High ambient noise levels reduced task attention and increased the rates of many other behaviors including verbalization, physical contact, gross motor movement, and high-energy acts. Medication-by-situation interactions emerged for both classroom dimensions, with hyperactive boys on placebo being readily distinguishable from their peers under some classroom conditions and indistinguishable under other conditions. Moderate relationships were found between teacher ratings and many individual behavior categories. Discussion focused on (a) the merits and limitations of a social ecological research perspective, and (b) the implications of these findings for the design of intervention strategies. PMID:468749

Whalen, C K; Henker, B; Collins, B E; Finck, D; Dotemoto, S

1979-01-01

350

Effective coordination and cooperation between ecological risk assessments and natural resource damage assessments: a new synthesis.  

PubMed

Although ecological risk assessments (ERAs) and natural resource damage assessments (NRDAs) are performed under different statutory and regulatory authorities, primarily the Comprehensive Environmental Response, Compensation and Liability Act (CERCLA), as currently practiced, the activities typically overlap. ERAs performed as part of the response process (typically by the US Environmental Protection Agency [USEPA]) should be closely coordinated with the natural resource trustees' (trustees') NRDAs. Trustees should actively participate in the early stages of the remedial investigation (RI) and work with USEPA, including the potentially responsible parties (PRPs), when appropriate, to coordinate NRDA data needs with those of the RI. Close coordination can present opportunities to avoid inefficiencies, such as unnecessary resampling or duplicate data gathering, and provide the opportunity to fulfill both process requirements with a few well-designed investigations. Early identification of opportunities for practical combined assessment can save money and time as the restoration process proceeds and facilitate a cooperative resolution of the entire site's CERCLA liability. The Society of Environmental Toxicology and Chemistry (SETAC) convened an invited workshop (August 2008) to address coordination between ERA and NRDA efforts. This paper presents the findings and conclusions of the Framework Work Group, which considered technical issues common to each process, while mindful of the current legal and policy landscape, and developed recommendations for future practice. PMID:19545190

Gouguet, Ronald G; Charters, David W; Champagne, Larry F; Davis, Mark; Desvouges, William; Durda, Judi L; Hyatt, William H; Jacobson, Rachel; Kapustka, Larry; Longoria, Rose M

2009-10-01

351

The Ecological Impact of Biofuels  

E-print Network

The Ecological Impact of Biofuels Joseph E. Fargione,1 Richard J. Plevin,2 and Jason D. Hill3 1 land-use change Abstract The ecological impact of biofuels is mediated through their effects on land, air, and water. In 2008, about 33.3 million ha were used to produce food- based biofuels

Kammen, Daniel M.

352

Journal of Animal Ecology 2004  

E-print Network

Journal of Animal Ecology 2004 73, 925­934 © 2004 British Ecological Society Time to extinction Curie, Bat. A, 177, quai St Bernard, Case 237, F-75252 Paris Cedex 5, France; ¶Department of Animal consider the effects on the estimated time to extinction and whether density regulation acts only

Engen, Steinar

353

Journal of Animal Ecology 2007  

E-print Network

Journal of Animal Ecology 2007 76, 1045­1052 © 2007 The Authors. Journal compilation © 2007 British-words: density effect, Ficedula hypoleuca, long-term trend, Parus major, timing of breeding. Journal of Animal, Journal of Animal Ecology, 76,

Laaksonen, Toni

354

Designing for ecology : the ecological park  

E-print Network

This thesis aims to define a) what an ecological park is, and b) whether it is a new model in park design. Reference to the literature on landscape ecology is used to analyze the natural ecological merit of these parks, ...

Power, Andres M

2006-01-01

355

Quantifying rare, deleterious variation in 12 human cytochrome P450 drug-metabolism genes in a large-scale exome dataset.  

PubMed

The study of genetic influences on drug response and efficacy ('pharmacogenetics') has existed for over 50 years. Yet, we still lack a complete picture of how genetic variation, both common and rare, affects each individual's responses to medications. Exome sequencing is a promising alternative method for pharmacogenetic discovery as it provides information on both common and rare variation in large numbers of individuals. Using exome data from 2203 AA and 4300 Caucasian individuals through the NHLBI Exome Sequencing Project, we conducted a survey of coding variation within 12 Cytochrome P450 (CYP) genes that are collectively responsible for catalyzing nearly 75% of all known Phase I drug oxidation reactions. In addition to identifying many polymorphisms with known pharmacogenetic effects, we discovered over 730 novel nonsynonymous alleles across the 12 CYP genes of interest. These alleles include many with diverse functional effects such as premature stop codons, aberrant splicesites and mutations at conserved active site residues. Our analysis considering both novel, predicted functional alleles as well as known, actionable CYP alleles reveals that rare, deleterious variation contributes markedly to the overall burden of pharmacogenetic alleles within the populations considered, and that the contribution of rare variation to this burden is over three times greater in AA individuals as compared with Caucasians. While most of these impactful alleles are individually rare, 7.6-11.7% of individuals interrogated in the study carry at least one newly described potentially deleterious alleles in a major drug-metabolizing CYP. PMID:24282029

Gordon, Adam S; Tabor, Holly K; Johnson, Andrew D; Snively, Beverly M; Assimes, Themistocles L; Auer, Paul L; Ioannidis, John P A; Peters, Ulrike; Robinson, Jennifer G; Sucheston, Lara E; Wang, Danxin; Sotoodehnia, Nona; Rotter, Jerome I; Psaty, Bruce M; Jackson, Rebecca D; Herrington, David M; O'Donnell, Christopher J; Reiner, Alexander P; Rich, Stephen S; Rieder, Mark J; Bamshad, Michael J; Nickerson, Deborah A

2014-04-15

356

Deleterious effect of soil?applied metalaxyl and mancozeb on the mycoparasite Pythium oligandrum  

Microsoft Academic Search

Pythium oligandrum was recovered, identified and quantified from air?dried soil plated on 1.5% water agar containing 0.1% glucose. Isolations of P. oligandrum over 2 years from soils treated with single applications of metalaxyl plus mancozeb were consistently lower than those from untreated soil from the same fields. In three fields in the first year P. oligandrum was reduced from a

J. G. White; A. J. Wakeham; G. M. Petch

1992-01-01

357

Does long-term swimming participation have a deleterious effect on the adult female skeleton?  

PubMed

Swimming is a popular activity for Australian women with proven cardiovascular benefits yet lacks the features thought necessary to stimulate positive adaptive changes in bone. Given that peak bone mass is attained close to the end of the second decade, we asked whether swimming was negatively associated with bone mineral density in premenopausal women beyond this age. Bone mass and retrospective physical activity data were gathered from 43 female swimmers and 44 controls (mean ages 40.4 and 43.8 years, respectively). Swimmers were recruited from the Australian Union of Senior Swimmers International while controls were healthy community dwellers with similar lean mass, fat mass, height, weight and body mass index. None of the participants had a history of medical complaints nor use of medications known to affect bone. Dual energy X-ray absorptiometry was used to determine areal bone mineral density at total body, lumbar spine, proximal femur, distal radius and tibia while self-administered questionnaires were used to approximate historical and recent physical activity and calcium intake. Swimmers had averaged over 2 hours of swimming per week for the past 5 years and 1.45 h/week over lifetime with no systematic swimming exposure for controls. Lifetime exposure to weight bearing and impact exercise were similar. There were no intergroup differences for bone mass at any site though controls had higher incidence of low bone mass/osteoporosis. No differences in bone mass were detected between swimmers in the upper and lower quartiles for swim participation for any period. Long-term swim participation did not compromise areal bone mineral density. PMID:22230920

Greenway, Kate Gwendoline; Walkley, Jeff Whenan; Rich, Peter Adrian

2012-09-01

358

Guard crabs alleviate deleterious effects of vermetid snails on a branching coral  

Microsoft Academic Search

Stony corals provide important structural habitat for microbes, invertebrates, and fishes, which in some cases has led to\\u000a the evolution of beneficial interactions that may protect corals from environmental factors such as thermal stress, nutrient\\u000a limitation, competitors, or predators. For example, guard crabs (Trapezia spp.) protect corals (Pocillopora sp.) from attacks by crown-of-thorn seastar and sedimentation. Here, a field experiment

A. C. Stier; C. S. McKeon; C. W. Osenberg; J. S. Shima

2010-01-01

359

Deleterious effects by mosquitofish ( Gambusia affinis ) on the endangered fire salamander ( Salamandra infraimmaculata )  

Microsoft Academic Search

Invasive fishes, via competition and predation, may be an important factor in endangering populations of amphibians and other aquatic fauna. The mosquito- fish, Gambusia affinis, commonly stocked into amphibian breeding sites for mosquito control worldwide, has recently been found in some breeding sites of the endangered fire salamander Salamandra infraimmaculata in northern Israel. A comparison of Salamandra larvae in natural

O. Segev; M. Mangel; L. Blaustein

2009-01-01

360

Trimetazidine Reverses Deleterious Effects of Ischemia-Reperfusion in the Isolated Perfused Pig Kidney Model  

Microsoft Academic Search

Background: Delayed graft function has remained an important complication after renal transplantation. Methods: The purpose of this study was to evaluate Euro-Collins (EC) plus trimetazidine (TMZ) in comparison with standard EC solution after 24- or 48-hour cold storage. The normothermic isolated perfused pig kidney technique combined with proton nuclear magnetic spectroscopy was used. Results: The study verified that TMZ plus

Thierry Hauet; Denis Mothes; Jean-Michel Goujon; Thierry Germonville; Jean Claude Caritez; Michel Carretier; Michel Eugene; Jean-Paul Tillement

1998-01-01

361

Consistent deleterious effects of vermetid gastropods on coral performance Jeffrey S. Shima a,  

E-print Network

with other sessile or- ganisms (Box and Mumby, 2007; Mumby et al., 2007), and predation (e.g., by crown-of-thorns starfish: Done, 1992). Here, we focus on a newly identified strong interaction between vermetid gastropods

Shima, Jeff

362

The mushroom ribosome-inactivating protein lyophyllin exerts deleterious effects on mouse embryonic development in vitro.  

PubMed

Earlier investigations disclose that some plant ribosome-inactivating proteins (RIPs) adversely affect mouse embryonic development. In the present study, a mushroom RIP, namely lyophyllin from Lyophyllum shimeji, was isolated, partially sequenced, and its translation inhibitory activity determined. Its teratogenicity was studied by using a technique entailing microinjection and postimplantation whole-embryo culture. It was found that embryonic abnormalities during the period of organogenesis from E8.5 to E9.5 were induced by lyophyllin at a concentration as low as 50 microg/ml, and when the lyophyllin concentration was raised, the number of abnormal embryos increased, the final somite number decreased, and the abnormalities increased in severity. The affected embryonic structures included the cranial neural tube, forelimb buds, branchial arches, and body axis, while optic and otic placodes were more resistant. Lyophyllin at a concentration higher than 500 microg/ml also induced forebrain blisters within the cranial mesenchyme. When the abnormal embryos were examined histologically, an increase of cell death was found to be associated with abnormal structures, indicating that cell death may be one of the underlying causes of teratogenicity of the mushroom RIP. This constitutes the first report on the teratogenicity of a mushroom RIP. PMID:19568748

Chan, W Y; Ng, T B; Lam, Joyce S Y; Wong, Jack H; Chu, K T; Ngai, P H K; Lam, S K; Wang, H X

2010-01-01

363

Relative Effectiveness of Mating Success and Sperm Competition at Eliminating Deleterious Mutations in  

E-print Network

to a standard competitor male. This process was repeated for males subjected to a diet quality manipulation result obtained for our diet manipulation points to an interesting discrepancy between environmental: Stephen R. Proulx, UC Santa Barbara, United States of America Received June 14, 2011; Accepted April 19

Sokolowski, Marla

364

Deleterious Effect of Hyperoxia at Birth on White Matter Damage in the Newborn Rat  

Microsoft Academic Search

White matter damage (WMD) remains the leading cause of cerebral palsy in children born prematurely. The release of an excessive amount of reactive oxygen species is recognized as a risk factor for WMD. We hypothesize that free radical injury during reoxygenation at birth may be harmful to the immature white matter and may underlie, at least in part, the pathogenesis

Gaelle Vottier; Hoa Pham; Julien Pansiot; Valérie Biran; Pierre Gressens; Christiane Charriaut-Marlangue; Olivier Baud

2011-01-01

365

Upper limit of the rate and per generation effects of deleterious genomic mutations  

E-print Network

of Orthopedic Surgery and Basic Medical Sciences, University of Missouri ­ Kansas City, Kansas City, MO 64108- nation depends on a U>1.0 (Kondrashov, 1988). * Corresponding author. Departments of Orthopedic Surgery

Pfrender, Michael

366

Highly deleterious role of small amounts of carbon on the giant magnetoresistance effect  

E-print Network

://jap.aip.org/authors Downloaded 02 Mar 2012 to 128.205.23.46. Redistribution subject to AIP license or copyright; see http is a common contaminant in high and ultra-high-vacuum systems, and easily gets incorporated in films during and magnetic properties of ``giant'' magnetoresistance GMR spin valves. Controlled incorporation of 1­3 at

Chopra, Harsh Deep

367

Methylcobalamin corrects the deleterious in vitro effect of nitrous oxide on thymidylate synthetase  

Microsoft Academic Search

Summary  In this study, cobalamin deficiency was produced in vitro by the use of nitrous oxide, known to inactivate the vitamin. In 14 sets of experiments, normal human lymphocytes stimulated\\u000a with phytohemagglutinin on day 0 were exposed to nitrous oxide and oxygen on day 2. McCbl was delivered later to half of the\\u000a cells. Untreated cells served as a control. On

Farid I. Haurani; Young S. Kauh; Elias M. Abboud

1985-01-01

368

Nigella sativa relieves the deleterious effects of ischemia reperfusion injury on liver  

PubMed Central

AIM: To determine whether Nigella sativa prevents hepatic ischemia-reperfusion injury to the liver. METHODS: Thirty rats were divided into three groups as sham (Group 1), control (Group 2), and Nigella sativa (NS) treatment group (Group 3). All rats underwent hepatic ischemia for 45 min followed by 60 min period of reperfusion. Rats were intraperitoneally infused with only 0.9% saline solution in group 2. Rats in group 3 received NS (0.2 mL/kg) intraperitoneally, before ischemia and before reperfusion. Blood samples and liver tissues were harvested from the rats, and then the rats were sacrificed. Serum aspartate aminotransferase (AST), alanine aminotransferase (ALT), and lactate dehydrogenase (LDH) levels were determined. Total antioxidant capacity (TAC), catalase (CAT), total oxidative status (TOS), oxidative stress index (OSI) and myeloperoxidase (MPO) in hepatic tissue were measured. Also liver tissue histopathology was evaluated by light microscopy. RESULTS: The levels of liver enzymes in group 3 were significantly lower than those in the group 2. TAC in liver tissue was significantly higher in group 3 than in group 2. TOS, OSI and MPO in hepatic tissue were significantly lower in group 3 than the group 2. Histological tissue damage was milder in the NS treatment group than that in the control group. CONCLUSION: Our results suggest that Nigella sativa treatment protects the rat liver against to hepatic ischemia-reperfusion injury. PMID:18777598

Yildiz, Fahrettin; Coban, Sacit; Terzi, Alpaslan; Ates, Mustafa; Aksoy, Nurten; Cakir, Hale; Ocak, Ali Riza; Bitiren, Muharrem

2008-01-01

369

Deleterious Effects of Molting on the Morpho-physiology of Japanese Quail Layers (Coturnix japonica)  

PubMed Central

Molting is a natural physiological phenomenon involving the periodic replacement of old feathers with new ones in the avian species. During mid-November an extensive loss of feathers in Japanese quail was observed in our breeding colony. The cause of molting could not be established, however, lower ambient temperatures may have played a major role and the decrease in day length could not be ruled out as a contributing factor. This study was conducted to correlate some aspects of the molting process using various physiological and morphometric parameters. Forty healthy 125-days old layers, hatch-mates, of approximately similar body weights (130.0±3.9 g) and in peak production were used for cohort evaluation of the molting process. Most of the birds lost feathers extensively from the cervical, thorax and dorsum areas, while some did not molt and continued laying eggs as usual, serving as a premolting control group. The molting birds drastically lost body weight weighing on average 117.5 g compared to 130.0 g in the control group and ceased egg production completely. There was a significant increase in blood glucose (293.03 mg/dL vs. 222.11 mg/dL), an increase in PCV values (47.14% vs. 41.43%) and a decrease in total plasma proteins (3.5 g/dl vs. 5.56 g/dl) and oviducts (1.55 g vs. 5.78 g, a decrease of 73.2%). Ovarian follicles underwent atresia and resorption. Birds that recovered from the molt resumed egg production and regained their body weights showing similar morpho-physiological measures of the control values, which changed during the molting phase. Scientists working with Japanese quail should be fully aware of the physiology of the molting process and its impact on on-going studies involving growth, physiology, endocrinology, nutrition, reproduction and toxicology.

Arora, Kashmiri L.; Vatsalya, Vatsalya

2014-01-01

370

Deleterious effects of fungi isolated from paddy soils on seminal root of rice  

Microsoft Academic Search

Soil samples were collected from rice paddies at 22 locations in northeastern Honshu, Japan. In 20 of the samples, seedling growth of rice was improved by soil pasteurization (aerated steaming at 60°C for 30?min), although no typical disease symptoms were observed in the seedlings grown in the untreated soil samples. In most locations, rice seedlings grew better in a potting

Hiromitsu Furuya; Keisuke Tubaki; Tsutomu Matsumoto; Shin-ichi Fuji; Hideki Naito

2005-01-01

371

Functional Molecular Ecological Networks  

PubMed Central

Biodiversity and its responses to environmental changes are central issues in ecology and for society. Almost all microbial biodiversity research focuses on “species” richness and abundance but not on their interactions. Although a network approach is powerful in describing ecological interactions among species, defining the network structure in a microbial community is a great challenge. Also, although the stimulating effects of elevated CO2 (eCO2) on plant growth and primary productivity are well established, its influences on belowground microbial communities, especially microbial interactions, are poorly understood. Here, a random matrix theory (RMT)-based conceptual framework for identifying functional molecular ecological networks was developed with the high-throughput functional gene array hybridization data of soil microbial communities in a long-term grassland FACE (free air, CO2 enrichment) experiment. Our results indicate that RMT is powerful in identifying functional molecular ecological networks in microbial communities. Both functional molecular ecological networks under eCO2 and ambient CO2 (aCO2) possessed the general characteristics of complex systems such as scale free, small world, modular, and hierarchical. However, the topological structures of the functional molecular ecological networks are distinctly different between eCO2 and aCO2, at the levels of the entire communities, individual functional gene categories/groups, and functional genes/sequences, suggesting that eCO2 dramatically altered the network interactions among different microbial functional genes/populations. Such a shift in network structure is also significantly correlated with soil geochemical variables. In short, elucidating network interactions in microbial communities and their responses to environmental changes is fundamentally important for research in microbial ecology, systems microbiology, and global change. PMID:20941329

Zhou, Jizhong; Deng, Ye; Luo, Feng; He, Zhili; Tu, Qichao; Zhi, Xiaoyang

2010-01-01

372

Are large-scale manipulations of streamflow for ecological outcomes effective either as experiments or management actions? (Invited)  

NASA Astrophysics Data System (ADS)

Dams impose a host of impacts on freshwater and estuary ecosystems. In recent decades, dam releases for ecological outcomes have been increasingly implemented to mitigate for these impacts and are gaining global scope. Many are designed and conducted using an experimental framework. A recent review of large-scale flow experiments (FE) evaluates their effectiveness and identifies ways to enhance their scientific and management value. At least 113 large-scale flow experiments affecting 98 river systems globally have been documented over the last 50 years. These experiments span a range of flow manipulations from single pulse events to comprehensive changes in flow regime across all seasons and different water year types. Clear articulation of experimental objectives, while not universally practiced, was crucial for achieving management outcomes and changing dam operating policies. We found a strong disparity between the recognized ecological importance of a multi faceted flow regimes and discrete flow events that characterized 80% of FEs. Over three quarters of FEs documented both abiotic and biotic outcomes, but only one third examined multiple trophic groups, thus limiting how this information informs future dam management. Large-scale flow experiments represent a unique opportunity for integrated biophysical investigations for advancing ecosystem science. Nonetheless, they must remain responsive to site-specific issues regarding water management, evolving societal values and changing environmental conditions and, in particular, can characterize the incremental benefits from and necessary conditions for changing dam operations to improve ecological outcomes. This type of information is essential for understanding the full context of value based trade-offs in benefits and costs from different dam operations that can serve as an empirical basis for societal decisions regarding water and ecosystem management. FE may be the best approach available to managers for resolving critical uncertainties that impede decision making in adaptive settings, for example, when we lack sufficient understanding to model biophysical responses to alternative operations. Integrated long term monitoring of biotic abiotic responses and defining clear management based objectives highlight ways for improving the efficiency and value of FEs.

Konrad, C. P.; Olden, J.

2013-12-01

373

Parapoxvirus causes a deleterious disease in red squirrels associated with UK population declines  

Microsoft Academic Search

The disease implications of novel pathogens need to be considered when investigating the ecological impact of species translocations on native fauna. Traditional explanations based on competition or pre- dation may often not be the whole story. Evidence suggests that an emerging infectious disease, caused by a parapoxvirus, may be a significant component of the impact that the introduced grey squirrel

D. M. Tompkinsl; A. W. Sainsbury; P. Nettleton; D. Buxton; J. Gurnell

2002-01-01

374

Restoration Ecology  

NSDL National Science Digital Library

While not a panacea, the emerging field of restoration ecology provides an important tool for environmental conservation and contributes greatly to our understanding of ecology.The first Web site is the home page of the Society for Ecological Restoration, offering a good starting point for exploring this relatively new discipline (1). The next site (2) provides an overview of the University of Wisconsin's Center for Restoration Ecology, "the first comprehensive, interdisciplinary research team assembled to advance the science and technology of ecosystem restoration." The National Oceanic and Atmospheric Administration outlines its plans for coastal and estuarine restoration in this Web site (3). The Fermi National Accelerator Laboratory in Illinois has implemented one of the largest tallgrass prairie restorations to date (4). The Kissimmee River Restoration Web site (5) provides a detailed look at this incredibly ambitious dam removal and wetland restoration project in Florida. The next Web site (6) offers a visually-attractive introduction to the restoration efforts of the nonprofit organization RESTORE, focusing on the forests of Maine. The Wildlands Project, another restoration-oriented nonprofit organization, describes its vision of ecosystem conservation in this Web site, which includes a personal brief from distinguished biologist E. O. Wilson. (7). The Wildwood project of the Scottish organization Carrifran offers an interesting contrast to restoration efforts in the US, as much of Scotland has been denuded of its original forests for thousands of years (8).

Sohmer, Rachel.

2002-01-01

375

Landscape ecology  

Microsoft Academic Search

In this paper the authors outline an approach to landscape study that employs a hierarchical paradigm of pattern and behavior. Although emphasis is on forested landscapes, we can generalize a theory of landscape ecology. Attention is focused on the wide range of phenomena in a natural terrestrial landscape by considering the apparent complexity of landscape dynamics and illustrating how a

Dean L. Urban; R. V. ONeill; Herman H. Shugart

1987-01-01

376

Trash Ecology  

ERIC Educational Resources Information Center

A hands on activity involving density, frequency and biomass using transects, quadrats and a local good deed by cleaning up the neighborhood while practicing important techniques in ecology is detailed. The activity is designed for KCC-STEP, whose primary goal is to expand the scientific knowledge and research experiences of their students, who…

Lind, Georgia J.

2004-01-01

377

Evaluation of the Effect of Ecologic on Root Knot Nematode, Meloidogyne incognita, and Tomato Plant, Lycopersicon esculenum  

PubMed Central

Nonchemical methods and strategies for nematode management including cultural methods and engineered measures have been recommended as an alternative to methyl bromide (a major soil fumigant), due to its role in the depletion of the ozone layer. Hence, an international agreement has recently been reached calling for its reduced consumption and complete phasing out. This present research evaluates the potential of Ecologic, a biological, marine shell meal chitin material, as a soil amendment management agent for root knot nematode, Meloidogyne incognita, control, and its effect on the growth of Floradel tomato plant, Lycopersicon esculentum. To accomplish this goal, studies were conducted during which, experimental pots were set up in greenhouse environments using sterilized soil inoculated with 5,000 root-knot eggs per 1500 g soil. There were 4 treatments and 5 replications. Treatments were: No chitin; 50 g chitin; 100 g chitin; and 200 g chitin. A two-week wait period following Ecologic amendment preceded Floradel tomato planting to allow breakdown of the chitin material into the soil. Fresh and dry weights of shoot and root materials were taken as growth end-points. A statistically significant difference (p ? 0.05) was obtained with regard to the growth rate of L. esculentum at 100 g chitin treatment compared to the control with no chitin. Mean fresh weights of Floradel tomato were 78.0 ± 22.3g, 81.0 ± 20.3g, 109.0 ± 25.4g and 102.0 ± 33.3g at 0, 50, 100 and 200g chitin, respectively. The analysis of root knot nematode concentrations indicated a substantial effect on reproduction rate associated with chitin amendment. Study results showed a significant decrease in both root knot nematode eggs and juveniles (J2) at 100g and 200g Ecologic chitin levels, however, an increase in nematode concentrations was recorded at the 50g Ecologic chitin level (p ? 0.05). The mean amounts of J2 population, as expressed per 1500cm3 soil, were 49,933 ± 38,819, 86,050 ± 25248, 103 ± 133 and 103 ± 133 for 0, 50, 100 and 200g chitin, respectively. Similarly, the mean numbers of root knot nematode eggs (per 1500cm3 of soil) were 40,759 ± 36,712, 66,048 ± 39,730, 9,904 ± 16,591 and 9,257 ± 17,204. Root gall rating was also significantly lower (p ? 0.05) at the 100g and 200g chitin levels compared to the control. Percent gall ratings were 3.3 ± 1.0%, 3.2 ± 1.0%, 1.0 ± 0.5%, and 1.0% ± 0.6% for amendment levels of 0, 50, 100, and 200g chitin, respectively. PMID:18678924

Ladner, Debora C.; Tchounwou, Paul B.; Lawrence, Gary W.

2008-01-01

378

An Ecological Risk Assessment Framework for Effects of Onsite Wastewater Treatment Systems and Other Localized Sources of Nutrients on Aquatic Ecosystems  

Microsoft Academic Search

An ecological risk assessment framework for onsite wastewater treatment systems and other localized sources of nutrients is presented, including problem formulation, characterization of exposure, characterization of effects, and risk characterization. The framework is most pertinent to the spatial scale of residential treatment systems located adjacent to small ponds, streams, or lagoons and some parts of shallow estuaries. Freshwater and estuarine

Rebecca A. Efroymson; Daniel S. Jones; Arthur J. Gold

2007-01-01

379

The Effects of Ecology-Based Summer Nature Education Program on Primary School Students' Environmental Knowledge, Environmental Affect and Responsible Environmental Behavior  

ERIC Educational Resources Information Center

The purpose of the study was to assess the effects of ecology-based nature education program on elementary school students' environmental knowledge, environmental affect, and responsible environmental behavior. A total number of 64 elementary school students including 26 females and 38 males who participated in summer natural education organized…

Erdogan, Mehmet

2011-01-01

380

Direct and indirect effects of light environment generate ecological trade-offs in herbivore performance and parasitism.  

PubMed

A variety of ecological factors influence host use by parasitoids, including both abiotic and biotic factors. Light environment is one important abiotic parameter that differs among habitats and influences a suite of plant nutritional and resistance traits that in turn affect herbivore performance. However, the extent to which these bottom-up effects "cascade up" to affect higher trophic levels and the relative importance of direct and indirect effects of sunlight on tritrophic interactions are unclear. The objective of this study was to test how light environment (light gap vs. shaded forest understory) and leaf type (sun vs. shade leaves) affect the performance and incidence of parasitism of two species of moth larvae, Euclea delphinii and Acharia stimulea (Limacodidae). We manipulated the leaf phenotype of potted white oak saplings by growing them in either full sun or full shade throughout leaf expansion to produce sun and shade leaves, respectively. These saplings were then placed in light gap and adjacent shaded understory habitats in the forest in a full-factorial design, and stocked with sentinel larvae that were exposed to parasitism ("exposed" experiments). We reared additional larvae in sleeve cages (protected from parasitism) to isolate light environment and leaf phenotype treatment effects on larval performance in the absence of enemies ("bagged" experiments). In the exposed experiments, light environment strongly affected the likelihood of parasitism, while leaf phenotype did not. Euclea delphinii larvae were up to 6.6 times more likely to be parasitized in light gaps than in shaded understory habitats. This pattern was consistent for both tachinid fly and wasp parasitoids across two separate experiments. However, the larval performance of both species in the bagged experiments was maximized in the shade-habitat/sun-leaf treatment, a habitat/leaf-type combination that occurs infrequently in nature. Taken together, our results suggest that the direct effects of light environment on the incidence of parasitism supersede any indirect effects resulting from altered leaf quality and reveal inherent ecological trade-offs for herbivores confronted with choosing between sunny (high leaf quality, harsh environment, high parasitism) and shaded (reduced leaf quality less harsh environment, reduced parasitism) habitats. PMID:24358715

Stoepler, Teresa M; Lill, John T

2013-10-01

381

[Ecology and health].  

PubMed

The World Health Organization (WHO) has proclaimed 1990 as the year of human environment protection. A tight bond between ecology as a science, and preventive medicine has been observed. The paper presents the basic facts about ground, water and air pollution, as well as the effects of ecological disorders on human health. Noted are the basic pointers for the improvement of the conditions in our environment and the role that society and the individual, especially a physician has to carry. Everybody should act accordingly with the proclaimed slogan: Think global--Act local. PMID:2233546

Prvulovi?, M

1990-01-01

382

Global change ecology.  

PubMed

Ecology has expanded from its traditional focus on organisms to include studies of the Earth as an integrated ecosystem. Aided by satellite technologies and computer models of the climate of the Earth, global change ecology now records basic parameters of our planet, including its net primary productivity, biogeochemical cycling and effects of humans on it. As I discuss here, this new perspective shows us what must be done to transform human behaviors to enable the persistence of life on Earth under human stewardship. PMID:16769436

Schlesinger, William H

2006-06-01

383

Compliance to a Cell Phone-Based Ecological Momentary Assessment Study: The Effect of Time and Personality Characteristics  

ERIC Educational Resources Information Center

Ecological momentary assessment (EMA) is a method that is now widely used to study behavior and mood in the settings in which they naturally occur. It maximizes ecological validity and avoids the limitations of retrospective self-reports. Compliance patterns across time have not been studied. Consistent compliance patterns could lead to data not…

Courvoisier, Delphine S.; Eid, Michael; Lischetzke, Tanja

2012-01-01

384

Plant Ecology An Introduction  

E-print Network

1 Plant Ecology An Introduction Ecology as a Science Study of the relationships between living and causes of the abundance and distribution of organisms Ecology as a Science We'll use the perspective of terrestrial plants Basic ecology - ecological principles Applied ecology - application of principles

Cochran-Stafira, D. Liane

385

Physiological and behavioural effects of imidacloprid on two ecologically relevant earthworm species (Lumbricus terrestris and Aporrectodea caliginosa).  

PubMed

Earthworms play key roles in soils and sub-lethal effects of environmental toxicants on these organisms should be taken seriously, since they might have detrimental effects on higher ecological levels. In laboratory experiments we have assessed sub-lethal effects (body mass change and cast production) of imidacloprid on two earthworm species commonly found in different agricultural soils (Lumbricus terrestris and Aporrectodea caliginosa). After 7 days of exposure in contaminated soil, a significant loss of body mass was found in both species exposed to imidacloprid concentrations as low as 0.66 mg kg(-1) dry soil. These losses ranged from 18.3 to 39% for A. caliginosa and from 7.4 to 32.4% for L. terrestris, respectively. Changes in cast production, a new biomarker previously validated using L. terrestris, was assessed by soil sieving using the recommended mesh size (5.6 mm) for L. terrestris and three different mesh sizes for A. caliginosa (5.6, 4 and 3.15 mm). The 4 mm mesh size proved to be the most suitable sieve size for A. caliginosa. Cast production increased by 26.2% in A. caliginosa and by 28.1% in L. terrestris at the lowest imidacloprid concentration tested (0.2 mg kg(-1) dry soil), but significantly decreased at higher concentrations (equal to and above 0.66 mg kg(-1) dry soil) in both earthworm species after the 7 days exposure experiment. These decreases in cast production ranged from 44.5 to 96.9% in A. caliginosa and from 42.4 to 95.7% in L. terrestris. The EC(50) for cast production were 0.84 (L. terrestris) and 0.76 mg kg(-1) dry soil (A. caliginosa), respectively. The detected sub-lethal effects were found close to the predicted environmental concentration (PEC) of imidacloprid, which is in the range of 0.33-0.66 mg kg(-1) dry soil. The biomarkers used in the present study, body mass change and changes in cast production, may be of ecological relevance and have shown high sensitivity for imidacloprid exposure of earthworms. The measurement of changes in cast production should be considered for inclusion in current standard tests. PMID:20821048

Dittbrenner, Nils; Triebskorn, Rita; Moser, Isabelle; Capowiez, Yvan

2010-11-01

386

Computational Screening and Molecular Dynamic Simulation of Breast Cancer Associated Deleterious Non-Synonymous Single Nucleotide Polymorphisms in TP53 Gene  

PubMed Central

Breast cancer is one of the most common cancers among the women around the world. Several genes are known to be responsible for conferring the susceptibility to breast cancer. Among them, TP53 is one of the major genetic risk factor which is known to be mutated in many of the breast tumor types. TP53 mutations in breast cancer are known to be related to a poor prognosis and chemo resistance. This renders them as a promising molecular target for the treatment of breast cancer. In this study, we present a computational based screening and molecular dynamic simulation of breast cancer associated deleterious non-synonymous single nucleotide polymorphisms in TP53. We have predicted three deleterious coding non-synonymous single nucleotide polymorphisms rs11540654 (R110P), rs17849781 (P278A) and rs28934874 (P151T) in TP53 with a phenotype in breast tumors using computational tools SIFT, Polyphen-2 and MutDB. We have performed molecular dynamics simulations to study the structural and dynamic effects of these TP53 mutations in comparison to the wild-type protein. Results from our simulations revealed a detailed consequence of the mutations on the p53 DNA-binding core domain that may provide insight for therapeutic approaches in breast cancer. PMID:25105660

Chitrala, Kumaraswamy Naidu; Yeguvapalli, Suneetha

2014-01-01

387

[Ecological and radio-ecological effects from long-term use of the lake Kyzyl-Tash as a cooling reservoir by the nuclear fuel cycle facility].  

PubMed

This review introduces long-term study findings on ecological and radiation induced regime of the water reservoir - lake Kyzyl-Tash (R-2) - used as a heat sink of nuclear-power reactors in the Southern Urals from 1948 through 2008. It was exhibited that water reservoir exploitation by the nuclear fuel cycle facility "Mayak" PA resulted in hydrological, thermal, hydrochemical and radiological ecosystem regimes changes. The central radioactive substances depot in the water reservoir was determined to be the upper 20-30 cm bed silt layers, contamination density of which in 1980-1990s amounted on average approximately 0.2 PBq/km2 (about 5 kKu/km2). Some regularities of radionuclide distribution in bed sediments and biota were ascertained. Dose estimates from ionizing exposure to fish inhabited the water reservoir were experimentally made. Dose contribution was mainly due to incorporated beta-emitters amounted up to 2-3 Gy/y in 1980s. The leading role in the reservoir life belonged to phytoplankton with its algal nuisance periodicity constituting 5-6 years for blue-green and diatomic algae, and 2-3 years for green algae. During periods of the highest development pressure phytoplankton productive capacity in the reservoir was by an order of magnitude greater compared to control water reservoirs of the region. Combined long-term impact of radiological and chemical factors did not cause irreversible changes either in fish populations or ecological system in general. It can be proved by the fact that during 1970-1980s the water reservoir R-2 was inhabited by such cleanness indicators as crawfish (Astacus leptodactylus) and shellfish (Anodonta cygnea L.). On reducing of thermal and chemical pressure in the end of 1980s some processes observed gave evidence of ecosystem restoration in the lake Kyzyl-Tash. At the present moment the situation of the water reservoir exploiting as a heat sink is stabilized with preserved self-cleaning capacity. PMID:20968056

Smagin, A I

2010-01-01

388

Effectiveness of post-fire seeding at the Fitzner-Eberhardt Arid Land Ecology Reserve, Washington  

USGS Publications Warehouse

In August 2007, the Milepost 17 and Wautoma fires burned a combined total of 77,349 acres (31,302 hectares) of the Fitzner-Eberhardt Arid Land Ecology Reserve (ALE), part of the Hanford Reach National Monument administered by the U.S. Fish and Wildlife Service (USFWS) Mid-Columbia National Wildlife Refuge. In 2009, the USFWS implemented a series of seeding and herbicide treatments to mitigate potential negative consequences of these fires, including mortality of native vegetation, invasion of Bromus tectorum (cheatgrass), and soil erosion. Treatments included combinations of seeding (drill and aerial), herbicides, and one of six different mixtures of species. Artemisia tridentata ssp. wyomingensis (Wyoming big sagebrush) also was planted by hand in a small area in the southern end of the fire perimeter. Due to differences in plant communities prior to the fire and the multiple treatments applied, treatments were grouped into five treatment associations including mid-elevation aerial seedings, low-elevation aerial seedings, low-elevation drill seedings, high-elevation drill seeding, and no seeding treatments. Data collected at the mid-elevation aerial seedings indicate that the seeding did not appear to increase the density of seedlings compared to the non-seeded area in 2010. At the low-elevation aerial seedings, there were significantly more seedlings at seeded areas as compared to non-seeded areas. Low densities of existing perennial plants probably fostered a low-competition environment enabling seeds to germinate and emerge in 2010 during adequate moisture. Low-elevation drill seedings resulted in significant emergence of seeded grasses in 2009 and 2010 and forbs in 2010. This was likely due to adequate precipitation and that the drill seeding assured soil-to-seed contact. At the high-elevation drill seeding, which was implemented in 2009, there were a high number of seedlings in 2010. Transplanting of A. tridentata following the fires resulted in variable survival rates that warrant further testing; however, transplants located closer to washes tended to have the highest survival rates. Overall, the low-elevation aerial and drill seedings, and the high-elevation drill seedings resulted in significant numbers of seedlings. Further research is needed on methods that provide land managers with critical information about whether or not to seed post-fire areas including status of pre-fire vegetation and estimates of plant mortality due to fire.

Wirth, Troy A.; Pyke, David A.

2011-01-01

389

Reduction of Lysyl Hydroxylase 3 Causes Deleterious Changes in the Deposition and Organization of Extracellular Matrix*  

PubMed Central

Lysyl hydroxylase 3 (LH3) is a multifunctional enzyme possessing lysyl hydroxylase, collagen galactosyltransferase, and glucosyltransferase (GGT) activities. We report here an important role for LH3 in the organization of the extracellular matrix (ECM) and cytoskeleton. Deposition of ECM was affected in heterozygous LH3 knock-out mouse embryonic fibroblasts (MEF+/?) and in skin fibroblasts collected from a member of a Finnish epidermolysis bullosa simplex (EBS) family known to be deficient in GGT activity. We show the GGT deficiency to be due to a transcriptional defect in one LH3 allele. The ECM abnormalities also lead to defects in the arrangement of the cytoskeleton in both cell lines. Ultrastructural abnormalities were observed in the skin of heterozygous LH3 knock-out mice indicating that even a moderate decrease in LH3 has deleterious consequences in vivo. The LH3 null allele in the EBS family member and the resulting abnormalities in the organization of the extracellular matrix, similar to those found in MEF+/?, may explain the correlation between the severity of the phenotype and the decrease in GGT activity reported in this family. PMID:19696018

Risteli, Maija; Ruotsalainen, Heli; Salo, Antti M.; Sormunen, Raija; Sipila, Laura; Baker, Naomi L.; Lamande, Shireen R.; Vimpari-Kauppinen, Leena; Myllyla, Raili

2009-01-01

390

Increased mitochondrial mutation frequency after an island colonization: positive selection or accumulation of slightly deleterious mutations?  

PubMed Central

Island colonizations are excellent models for studying early processes of evolution. We found in a previous study on mice that had colonized the sub-Antarctic Kerguelen Archipelago about 200 years ago that they were derived from a single founder lineage and that this showed an unexpectedly large number of new mutations in the mitochondrial D-loop. To assess whether positive selection has played a role in the emergence of these variants, we have obtained 16 full mitochondrial genome sequences from these mice. For comparison, we have compiled 57 mitochondrial genome sequences from laboratory inbred lines that became established about 100 years ago, also starting from a single founder lineage. We find that the island mice and the laboratory lines show very similar mutation frequencies and patterns. None of the patterns in the Kerguelen mice provides evidence for positive selection. We conclude that nearly neutral evolutionary processes that assume the presence of slightly deleterious variants can fully explain the patterns. This supports the notion of time-dependency of molecular evolution and provides a new calibration point. Based on the observed mutation frequency, we calculate an average evolutionary rate of 0.23 substitutions per site per Myr for the earliest time frame of divergence, which is about six times higher than the long-term rate of 0.037 substitutions per site per Myr. PMID:23389667

Hardouin, Emilie A.; Tautz, Diethard

2013-01-01

391

Partition dataset according to amino acid type improves the prediction of deleterious non-synonymous SNPs  

SciTech Connect

Highlights: Black-Right-Pointing-Pointer Proper dataset partition can improve the prediction of deleterious nsSNPs. Black-Right-Pointing-Pointer Partition according to original residue type at nsSNP is a good criterion. Black-Right-Pointing-Pointer Similar strategy is supposed promising in other machine learning problems. -- Abstract: Many non-synonymous SNPs (nsSNPs) are associated with diseases, and numerous machine learning methods have been applied to train classifiers for sorting disease-associated nsSNPs from neutral ones. The continuously accumulated nsSNP data allows us to further explore better prediction approaches. In this work, we partitioned the training data into 20 subsets according to either original or substituted amino acid type at the nsSNP site. Using support vector machine (SVM), training classification models on each subset resulted in an overall accuracy of 76.3% or 74.9% depending on the two different partition criteria, while training on the whole dataset obtained an accuracy of only 72.6%. Moreover, the dataset was also randomly divided into 20 subsets, but the corresponding accuracy was only 73.2%. Our results demonstrated that partitioning the whole training dataset into subsets properly, i.e., according to the residue type at the nsSNP site, will improve the performance of the trained classifiers significantly, which should be valuable in developing better tools for predicting the disease-association of nsSNPs.

Yang, Jing; Li, Yuan-Yuan [School of Biotechnology, East China University of Science and Technology, Shanghai 200237 (China) [School of Biotechnology, East China University of Science and Technology, Shanghai 200237 (China); Shanghai Center for Bioinformation Technology, Shanghai 200235 (China); Li, Yi-Xue, E-mail: yxli@sibs.ac.cn [School of Biotechnology, East China University of Science and Technology, Shanghai 200237 (China) [School of Biotechnology, East China University of Science and Technology, Shanghai 200237 (China); Shanghai Center for Bioinformation Technology, Shanghai 200235 (China); Ye, Zhi-Qiang, E-mail: yezq@pkusz.edu.cn [Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055 (China) [Laboratory of Chemical Genomics, School of Chemical Biology and Biotechnology, Peking University Shenzhen Graduate School, Shenzhen 518055 (China); Key Laboratory of Systems Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai 200031 (China)

2012-03-02

392

A meta-analysis on the ecological effects of aquaculture on the water column: dissolved nutrients.  

PubMed

Environmental effects of aquaculture loadings have often been reviewed descriptively, and thus have not provided quantitative estimates of the overall response in the water column. Meta-analytical reviewing techniques allow the contextualisation of quantitative effects in the domain of current literature. In the present paper, more than 50 peer-reviewed articles were analysed and about 425 study cases used to test whether worldwide cultivations have a differential effect on dissolved nutrient levels. Meta-analysis feasibility depends on obtaining an estimate of the effect size from every study and the most common measure of effect size (Hedges' d) is the difference between means of controls and impacts standardised by dividing by the pooled standard deviation. Across all study cases, irrespective of cultivation and organism type, the cumulative effect size was large and significant (d>0.8) for ammonium, nitrite and nitrate, medium (0.8>d>0.5) for dissolved phosphorus, and not significant (d<0.2) for silicates. Effects were mainly correlated with the degree of openness in water bodies, and ammonium and the other nitrogen forms were the most highly informative descriptors of effects in the area surrounding farms, even though weakness in statistical approach was highlighted. The results partially contradict the common view that effects of aquaculture and associated environmental patterns are well defined throughout the current literature. PMID:17166578

Sarà, G

2007-05-01

393

Animal Ecology  

NSDL National Science Digital Library

This tutorial introduces students to the concept of animal ecology. The first section explains the different ways animals use camouflage. There is also a discussion of how the process of decay breaks organic matter down into nutrients, and how simple aquatic organisms (algae, zooplankton) provide a food source for larger organisms. The concept of food chains is introduced, and land-based and aquatic examples are described. A quiz and glossary are included.

394

The Mozart Effect: Musical Phenomenon or Musical Preference? A More Ecologically Valid Reconsideration  

ERIC Educational Resources Information Center

The "Mozart effect" is the reported phenomenon of increased spatial abilities after listening to that composer's music. However, subsequent research suggests that the Mozart effect may be an artifactual consequence of heightened arousal and mood rather than the music of Mozart per se (e.g., Thompson, Schellenberg, & Husain, 2001). The present…

Cassity, Hope Daniels; Henley, Tracy B.; Markley, Robert P.

2007-01-01

395

The ecology of infectious disease: Effects of host diversity and community composition  

E-print Network

prevalence of ticks by diluting the effects of the ubiquitous white-footed mouse (Peromyscus leucopus by diluting the effects of the most competent disease reservoir, the ubiquitous white-footed mouse (Peromyscus leucopus). As habitats are degraded by frag- mentation or other anthropogenic forces, some members

396

The environmental consequences of nuclear war (SCOPE 28), Vol. 2: Ecological, agricultural, and human effects  

Microsoft Academic Search

Offerred in this book is an appraisal of the possible environmental consequences of nuclear war. It presents a consensus among leading scientists of the effects on climate, ecosystems, and food supply. Volume 2 reviews ecosystems structure and function relevant to nuclear war effects, plant and animal responses and recovery, agricultural productivity, vulnerability of world food production and storage, estimated population

M. A. Harwell; T. C. Hutchinson

1986-01-01

397

Reproductive isolation driven by the combined effects of ecological adaptation and reinforcement  

Microsoft Academic Search

Recent years have seen a resurgence of interest in the process of speciation but few studies have elucidated the mechanisms either driving or constraining the evolution of reproductive isolation. In theory, the direct effects of reinforcing selection for increased mating discrimination where interbreeding produces hybrid offspring with low fitness and the indirect effects of adaptation to different environments can both

P. Nosil; B. J. Crespi; C. P. Sandoval

2003-01-01

398

Ecological effects and environmental fate of solid rocket exhaust. Annual report  

Microsoft Academic Search

Studies on the chemical, chemical-physical, and biological reactions and the toxic effects of solid rocket emissions within selected ecosystems at Kennedy Space Center cover laboratory conditions of exhaust and field studies of natural plant populations in three diverse ecosystems. The latter failed to reveal any structural damage at the concentration levels tested (5 to 100 ppM HCl). The effect, if

B. Nimmo; J. Stout; J. Mickus; D. Vickers; B. Madsen

1974-01-01

399

Ecological effects of feral biofuel crops in constructed oak savannah communities - June 2012  

EPA Science Inventory

The effects of elevated temperatures and drought on constructed oak savannahs were studied to determine the interactive effects of potentially invasive feral biofuel species and climate change on native grassland communities. A total of 12 sunlit mesocosm were used. Each mesoco...

400

Chemical Modulation of Mutant mGlu1 Receptors Derived from Deleterious GRM1 Mutations Found in Schizophrenics.  

PubMed

Schizophrenia is a complex and highly heterogeneous psychiatric disorder whose precise etiology remains elusive. While genome-wide association studies (GWAS) have identified risk genes, they have failed to determine if rare coding single nucleotide polymorphisms (nsSNPs) contribute in schizophrenia. Recently, two independent studies identified 12 rare, deleterious nsSNPS in the GRM1 gene, which encodes the metabotropic glutamate receptor subtype 1 (mGlu1), in schizophrenic patients. Here, we generated stable cell lines expressing the mGlu1 mutant receptors and assessed their pharmacology. Using both the endogenous agonist glutamate and the synthetic agonist DHPG, we found that several of the mutant mGlu1 receptors displayed a loss of function that was not due to a loss in plasma membrane expression. Due to a lack of mGlu1 positive allosteric modulators (PAM) tool compounds active at human mGlu1, we optimized a known mGlu4 PAM/mGlu1 NAM chemotype into a series of potent and selective mGlu1 PAMs by virtue of a double "molecular switch". Employing mGlu1 PAMs from multiple chemotypes, we demonstrate that the mutant receptors can be potentiated by small molecules and in some cases efficacy restored to that comparable to wild type mGlu1 receptors, suggesting deficits in patients with schizophrenia due to these mutations may be amenable to intervention with an mGlu1 PAM. However, in wild type animals, mGlu1 negative allosteric modulators (NAMs) are efficacious in classic models predictive of antipsychotic activity, whereas we show that mGlu1 PAMs have no effect to slight potentiation in these models. These data further highlight the heterogeneity of schizophrenia and the critical role of patient selection strategies in psychiatric clinical trials to match genotype with therapeutic mechanism. PMID:25137254

Cho, Hyekyung P; Garcia-Barrantes, Pedro M; Brogan, John T; Hopkins, Corey R; Niswender, Colleen M; Rodriguez, Alice L; Venable, Daryl F; Morrison, Ryan D; Bubser, Michael; Daniels, J Scott; Jones, Carrie K; Conn, P Jeffrey; Lindsley, Craig W

2014-10-17

401

Chemical Modulation of Mutant mGlu1 Receptors Derived from Deleterious GRM1 Mutations Found in Schizophrenics  

PubMed Central

Schizophrenia is a complex and highly heterogeneous psychiatric disorder whose precise etiology remains elusive. While genome-wide association studies (GWAS) have identified risk genes, they have failed to determine if rare coding single nucleotide polymorphisms (nsSNPs) contribute in schizophrenia. Recently, two independent studies identified 12 rare, deleterious nsSNPS in the GRM1 gene, which encodes the metabotropic glutamate receptor subtype 1 (mGlu1), in schizophrenic patients. Here, we generated stable cell lines expressing the mGlu1 mutant receptors and assessed their pharmacology. Using both the endogenous agonist glutamate and the synthetic agonist DHPG, we found that several of the mutant mGlu1 receptors displayed a loss of function that was not due to a loss in plasma membrane expression. Due to a lack of mGlu1 positive allosteric modulators (PAM) tool compounds active at human mGlu1, we optimized a known mGlu4 PAM/mGlu1 NAM chemotype into a series of potent and selective mGlu1 PAMs by virtue of a double “molecular switch”. Employing mGlu1 PAMs from multiple chemotypes, we demonstrate that the mutant receptors can be potentiated by small molecules and in some cases efficacy restored to that comparable to wild type mGlu1 receptors, suggesting deficits in patients with schizophrenia due to these mutations may be amenable to intervention with an mGlu1 PAM. However, in wild type animals, mGlu1 negative allosteric modulators (NAMs) are efficacious in classic models predictive of antipsychotic activity, whereas we show that mGlu1 PAMs have no effect to slight potentiation in these models. These data further highlight the heterogeneity of schizophrenia and the critical role of patient selection strategies in psychiatric clinical trials to match genotype with therapeutic mechanism. PMID:25137254

2014-01-01

402

Towards a synthesis of frameworks in nutritional ecology: interacting effects of protein, carbohydrate and phosphorus on field cricket fitness.  

PubMed

Phosphorus has been identified as an important determinant of nutrition-related biological variation. The macronutrients protein (P) and carbohydrates (C), both alone and interactively, are known to affect animal performance. No study, however, has investigated the importance of phosphorus relative to dietary protein or carbohydrates, or the interactive effects of phosphorus with these macronutrients, on fitness-related traits in animals. We used a nutritional geometry framework to address this question in adult field crickets (Gryllus veletis). Our results showed that lifespan, weight gain, acoustic mate signalling and egg production were maximized on diets with different P : C ratios, that phosphorus did not positively affect any of these fitness traits, and that males and females had different optimal macronutrient intake ratios for reproductive performance. When given a choice, crickets selected diets that maximized both lifespan and reproductive performance by preferentially eating diets with low P : C ratios, and females selected diets with a higher P : C ratio than males. Conversely, phosphorus intake was not regulated. Overall, our findings highlight the importance of disentangling the influences of different nutrients, and of quantifying both their individual and interactive effects, on animal fitness traits, so as to gain a more integrative understanding of their nutritional ecology. PMID:25143029

Harrison, Sarah J; Raubenheimer, David; Simpson, Stephen J; Godin, Jean-Guy J; Bertram, Susan M

2014-10-01

403

Geographical Distribution of Adolescent Body Height with Respect to Effective Day Length in Japan: An Ecological Analysis  

PubMed Central

The height of Japanese youth raised in the northern region tends to be greater than that of youth raised in the southern region; therefore, a geographical gradient in youth body height exists. Although this gradient has existed for about 100 years, the reasons for it remain unclear. Consideration of the nutritional improvement, economic growth, and intense migration that has occurred in this period indicates that it is probably the result of environmental rather than nutritional or genetic factors. To identify possible environmental factors, ecological analysis of prefecture-level data on the body size of 8- to 17-year-old youth averaged over a 13-year period (1996 to 2008) and Japanese mesh climatic data on the climatic variables of temperature, solar radiation, and effective day length (duration of photoperiod exceeding the threshold of light intensity) was performed. The geographical distribution of the standardized height of Japanese adolescents was found to be inversely correlated to a great extent with the distribution of effective day length at a light intensity greater than 4000 lx. The results of multiple regression analysis of effective day length, temperature, and weight (as an index of food intake) indicated that a combination of effective day length and weight was statistically significant as predictors of height in early adolescence; however, only effective day length was statistically significant as a predictor of height in late adolescence. Day length may affect height by affecting the secretion of melatonin, a hormone that inhibits sexual and skeletal maturation, which in turn induces increases in height. By affecting melatonin production, regional differences in the duration of the photoperiod may lead to regional differences in height. Exposure to light intensity greater than 4000 lx appears to be the threshold at which light intensity begins to affect the melatonin secretion of humans who spend much of their time indoors. PMID:23227226

Yokoya, Masana; Shimizu, Hideyasu; Higuchi, Yukito

2012-01-01

404

Review article. Studying climate effects on ecology through the use of climate indices: the North Atlantic Oscillation, El Ni?o Southern Oscillation and beyond.  

PubMed Central

Whereas the El Niño Southern Oscillation (ENSO) affects weather and climate variability worldwide, the North Atlantic Oscillation (NAO) represents the dominant climate pattern in the North Atlantic region. Both climate systems have been demonstrated to considerably influence ecological processes. Several other large-scale climate patterns also exist. Although less well known outside the field of climatology, these patterns are also likely to be of ecological interest. We provide an overview of these climate patterns within the context of the ecological effects of climate variability. The application of climate indices by definition reduces complex space and time variability into simple measures, 'packages of weather'. The disadvantages of using global climate indices are all related to the fact that another level of problems are added to the ecology-climate interface, namely the link between global climate indices and local climate. We identify issues related to: (i) spatial variation; (ii) seasonality; (iii) non-stationarity; (iv) nonlinearity; and (v) lack of correlation in the relationship between global and local climate. The main advantages of using global climate indices are: (i) biological effects may be related more strongly to global indices than to any single local climate variable; (ii) it helps to avoid problems of model selection; (iii) it opens the possibility for ecologists to make predictions; and (iv) they are typically readily available on Internet. PMID:14561270

Stenseth, Nils Chr; Ottersen, Geir; Hurrell, James W; Mysterud, Atle; Lima, Mauricio; Chan, Kung-Sik; Yoccoz, Nigel G; Adlandsvik, Bj?rn

2003-01-01

405

Ecological Applications, 15(2), 2005, pp. 377404 2005 by the Ecological Society of America  

E-print Network

or inadvertent releases of GEOs into the environment could have negative ecological effects under certain Report GENETICALLY ENGINEERED ORGANISMS AND THE ENVIRONMENT: CURRENT STATUS AND RECOMMENDATIONS1 A. A 68182-0040 USA Abstract. The Ecological Society of America has evaluated the ecological effects

Snow, Allison A.

406

Effects of stream topology on ecological community results from neutral models  

EPA Science Inventory

While neutral theory and models have stimulated considerable literature, less well investigated is the effect of topology on neutral metacommunity model simulations. We implemented a neutral metacommunity model using two different stream network topologies, a widely branched netw...

407

The effects of exposure to environmental factors on Heart Rate Variability: an ecological perspective.  

PubMed

The impact of human exposure to environmental factors on Heart Rate Variability (HRV) was examined in the urban space of Tel-Aviv-Jaffa. Four environmental factors were investigated: thermal and social loads; CO concentrations and noise. Levels of HRV are explained mainly by subjective social stresses, noise and CO. The most interesting result is the fact that while subjective social stress and noise increase HRV, low levels of CO are reducing HRV to some extent moderating the impact of subjective social stress and noise. Beyond the poisoning effect of CO and the fact that extremely low levels of HRV associated with high dozes of CO increase risk for life, low levels of CO may have a narcotic effect, as it is measured by HRV. The effects of thermal loads on HRV are negligible probably due to the use of behavioral means in order to neutralize heat and cold effects. PMID:23477780

Schnell, Izhak; Potchter, Oded; Epstein, Yoram; Yaakov, Yaron; Hermesh, Hagai; Brenner, Shmuel; Tirosh, Emanuel

2013-12-01

408

Hydrologic and Ecological Effects of Watershed Urbanization: Implication for Watershed Management in Hillslope Regions  

E-print Network

In this study, I examined the effect of watershed urbanization on the invasion of alien woody species in riparian forests. This study was conducted in three major steps: 1) estimating the degree of watershed urbanization using impervious surface...

Sung, Chan Yong

2011-08-08

409

Ecological Effects of Spring and Late Summer Applications of Lambda-Cyhalothrin on Freshwater Microcosms  

Microsoft Academic Search

The aim of the study was to compare the effects of the pyrethroid insecticide lambda-cyhalothrin (treated at 10, 25, 50, 100,\\u000a 250 ng active ingredient a.i.\\/L) on a drainage ditch ecosystem in spring and late summer. Microcosms (water volume approximately\\u000a 430 L) were established using enclosures in a 50-cm–deep experimental ditch system containing communities typical of macrophyte-dominated\\u000a freshwater ecosystems. Effects

R. P. A. Van Wijngaarden; T. C. M. Brock; P. J. van den Brink; R. Gylstra; S. J. Maund

2006-01-01

410

Effects of organic matter removal on the soil food web: Forestry practices meet ecological theory  

Microsoft Academic Search

We examine the long-term effects of removing forest harvesting residues (above-ground whole-tree harvesting; WTH) in the soil food web, using data from two different experiments on slash removal and addition in Sweden. Removal of harvesting residues had negative effects on the abundances of animals at higher trophic positions and on more mobile animals. Predators such as gamasid mites, spiders and

Jan Bengtsson; Heléne Lundkvist; Peter Saetre; Björn Sohlenius; Berit Solbreck

1998-01-01

411

Community ecology of invasions: direct and indirect effects of multiple invasive species on aquatic communities.  

PubMed

With many ecosystems now supporting multiple nonnative species from different trophic levels, it can be challenging to disentangle the net effects of invaders within a community context. Here, we combined wetland surveys with a mesocosm experiment to examine the individual and combined effects of nonnative fish predators and nonnative bullfrogs on aquatic communities. Among 139 wetlands, nonnative fish (bass, sunfish, and mosquitofish) negatively influenced the probability of occupancy of Pacific treefrogs (Pseudacris regilla), but neither invader correlated strongly with occupancy by California newts (Taricha torosa), western toads (Anaxyrus boreas), or California red-legged frogs (Rana draytonii). In mesocosms, mosquitofish dramatically reduced the abundance of zooplankton and palatable amphibian larvae (P. regilla and T. torosa), leading to increases in nutrient concentrations and phytoplankton (through loss of zooplankton), and rapid growth of unpalatable toad larvae (through competitive release). Bullfrog larvae reduced the growth of native anurans but had no effect on survival. Despite strong effects on natives, invaders did not negatively influence one another, and their combined effects were additive. Our results highlight how the net effects of multiple nonnative species depend on the trophic level of each invader, the form and magnitude of invader interactions, and the traits of native community members. PMID:22834365

Preston, Daniel L; Henderson, Jeremy S; Johnson, Pieter T J

2012-06-01

412

Potential effects of large linear pipeline construction on soil and vegetation in ecologically fragile regions.  

PubMed

Long-distance pipeline construction results in marked human disturbance of the regional ecosystem and brings into question the safety of pipeline construction with respect to the environment. Thus, the direct environmental impact and proper handling of such large projects have received much attention. The potential environmental effects, however, have not been fully addressed, particularly for large linear pipeline projects, and the threshold of such effects is unclear. In this study, two typical eco-fragile areas in western China, where large linear construction projects have been conducted, were chosen as the case study areas. Soil quality indices (SQI) and vegetation indices (VI), representing the most important potential effects, were used to analyze the scope of the effect of large pipeline construction on the surrounding environment. These two indices in different buffer zones along the pipeline were compared against the background values. The analysis resulted in three main findings. First, pipeline construction continues to influence the nearby eco-environment even after a 4-year recovery period. During this period, the effect on vegetation due to pipeline construction reaches 300 m beyond the working area, and is much larger in distance than the effect on soil, which is mainly confined to within 30 m either side of the pipeline, indicating that vegetation is more sensitive than soil to this type of human disturbance. However, the effect may not reach beyond 500 m from the pipeline. Second, the scope of the effect in terms of distance on vegetation may also be determined by the frequency of disturbance and the intensity of the pipeline construction. The greater the number of pipelines in an area, the higher the construction intensity and the more frequent the disturbance. Frequent disturbance may expand the effect on vegetation on both sides of the pipeline, but not on soil quality. Third, the construction may eliminate the stable, resident plant community. During the recovery period, the plant community in the work area of the pipeline is replaced by some species that are rare or uncommon in the resident plant community because of human disturbance, thereby increasing the plant diversity in the work area. In terms of plant succession, the duration of the recovery period has a direct effect on the composition and structure of the plant community. The findings provide a theoretical basis and scientific foundation for improving the environmental impact assessment (EIA) of oil and gas pipeline construction as it pertains to the desert steppe ecosystem, and provide a reference point for recovery and management of the eco-environment during the pipeline construction period. PMID:25112841

Xiao, Jun; Wang, Ya-Feng; Shi, Peng; Yang, Lei; Chen, Li-Ding

2014-11-01

413

Acidity, nutrients, and minerals in atmospheric precipitation over Florida: deposition patterns, mechanisms and ecological effects  

SciTech Connect

A monitoring network of 21 bulk and 4 wet/dry collectors located throughout Florida measured spatial and temporal trends during a one-year period from May 1978 to April 1979. The project summary notes that statewide deposition rates of nitrogen and phosphorus were below the loading rates associated with eutrophication, although nutrient concentrations were higher during the summer. Overall, pH appears to have relatively small effects (in the range 4.7-6.8) on community structure in soft-water Florida lakes. More dramatic effects could occur under more acidic conditions in the future. 4 references, 5 figures, 1 table.

Brezonik, P.L.; Hendry, C.D. Jr.; Edgerton, E.S.; Schulze, R.L.; Crisman, T.L.

1983-06-01

414

Testing the ecological stability of ectomycorrhizal symbiosis: effects of heat, ash and mycorrhizal colonization on Pinus muricata seedling performance  

Microsoft Academic Search

Understanding how abiotic conditions mediate the outcome of biotic interactions is a key question in community ecology. This\\u000a is particularly interesting in the case of mutualisms because changing environmental conditions may be a source of evolutionary\\u000a or ecological instability in the relationship between symbiotic partners. For the mycorrhizal symbiosis, elevated nutrient\\u000a levels may make the carbon cost to plants of

Kabir G. Peay; Thomas D. Bruns; Matteo Garbelotto

2010-01-01

415

RESEARCH AT THE GULF ECOLOGY DIVISION ON THE EFFECTS OF LOW DISSOLVED OXYGEN ON ESTUARINE ANIMALS  

EPA Science Inventory

Concerns about hypoxia and its effects on saltwater organisms are increasing as environmental conditions in the inshore and nearshore marine environments are better understood. Along the Gulf of Mexico coast, periods of very low dissolved oxygen (D.O.) concentrations have been re...

416

Ecological Entomology (1994) 19, 111-120 The effects of host plant phenology on the demography  

E-print Network

on Quercus alba and Q.macrocarpu. 2. We monitored and manipulated the timing of foliation on field and potted and manipulated the timing of leaf fall on Q.alba and Q.macrocarpa trees in the field and observed its effects, Camerariahamadryadella, host-plant phenology, survival, mortality, population dynamics, Quercus, demography. * Present

Connor, Edward F.

417

Effects of terrestrial runoff on the ecology of corals and coral reefs: review and synthesis  

Microsoft Academic Search

This paper reviews and evaluates the current state of knowledge on the direct effects of terrestrial runoff on (1) the growth and survival of hard coral colonies, (2) coral reproduction and recruitment, and (3) organisms that interact with coral populations (coralline algae, bioeroders, macroalgae and heterotrophic filter feeders as space competitors, pathogens, and coral predators). The responses of each of

Katharina E. Fabricius

2005-01-01

418

CLIMATE AND LAND USE CHANGE EFFECTS ON ECOLOGICAL RESOURCES IN THREE WATERSHEDS: A SYNTHESIS REPORT  

EPA Science Inventory

This report is a synthesis of three watershed case-study assessments conducted by GCRP to advance the capability of management decisions. The report compares and contrasts methods and processes employed by the three case study teams to learn effective analytic, project managemen...

419

Fire and grazing in a shrub-invaded arid grassland community: independent or interactive ecological effects?  

Microsoft Academic Search

This study examined the response of summer and winter annuals and perennials in a shrub-invaded arid plant community to combinations of fire and grazing by cattle to determine their effects on individual abundances, species richness and diversity. Thirteen species differed significantly in abundance across the burn treatment while nine differed significantly across the grazing treatment. Summer and winter annual plants

Thomas J. Valone; Douglas A. Kelt

1999-01-01

420

Adverse Outcome Pathways and Ecological Risk Assessment: Bridging to Population Level Effects, Journal Article  

EPA Science Inventory

The viability of populations of plants and animals is a key focus for environmental regulation. Population-level responses integrate the cumulative effects of chemical stressors on individuals as those individuals interact with and are affected by their con-specifics, competitor...

421

Adverse Outcome Pathways and Ecological Risk Assessment: Bridging to Population Level Effects  

EPA Science Inventory

The viability of populations of plants and animals is a key focus for environmental regulation. Population-level responses integrate the cumulative effects of chemical stressors on individuals as those individuals interact with and are affected by their con-specifics, competitor...

422

Effects of wastewater treatment plant effluent on bat foraging ecology in an urban stream system  

Microsoft Academic Search

Wastewater treatment plant (WWTP) effluent in the Cape Fear River Basin headwaters in North Carolina, USA, has influenced stream water quality and aquatic components of the stream food web. To examine effects of WWTP effluent on terrestrial predators in this system we determined prey availability, bat community structure, and bat foraging and commuting behavior at sites above and below WWTPs.

M. C. Kalcounis-Rueppell; V. H. Payne; S. R. Huff; A. L. Boyko

2007-01-01

423

Ecological Effects of Metals in Streams on a Defense Materials Processing Site in South Carolina, USA  

Microsoft Academic Search

The Savannah River Site (SRS) is a 780 km U.S. Department of Energy facility near Aiken, South Carolina, established in 1950 to produce nuclear materials. SRS streams are “integrators” that potentially receive water transportable contaminants from all sources within their drainage basins, necessitating a watershed approach to organize contaminant distribution data and characterize the effects of multiple contaminants on aquatic

Michael H. Paller; Susan A. Dyer

2010-01-01

424

COMMUNITY ECOLOGY -ORIGINAL PAPER The effects of topdown versus bottomup control on benthic  

E-print Network

and herbivores are important drivers of reef community struc- ture. When herbivores were removed, fleshy algae domi- nated, while crustose coralline algae (CCA) and coral were more abundant when herbivores were present. The effects of fertilization varied depending on herbivore treatment; without herbivores fleshy

Smith, Jennifer E.

425

Ecological effects of aerosol drift from a saltwater cooling system. Final report  

Microsoft Academic Search

The local terrestrial effects of salt aerosol drift from powered spray modules and a mechanical draft cooling tower at Turkey Point, Florida were evaluated through field and controlled exposure studies. Indigenous vegetation, soil and fresh water were sampled over a year long period to acquire pre-activation baseline data and to provide for the assessment of possible environmental impact of salt

I. J. Hindawi; L. C. Raniere; J. A. Rea

1976-01-01

426

Sustainability Evaluation of the Grain for Green Project: From Local People's Responses to Ecological Effectiveness in Wolong Nature Reserve  

NASA Astrophysics Data System (ADS)

This article examines the sustainability of the Grain for Green Project in the Wolong Nature Reserve. Pertinent data were collected through a questionnaire survey and a spatial analysis of reforested lands. The study results identified four critical issues that may influence the sustainability of the project in the study area. The first issue is concerned with the project’s impacts on local sustenance. Because local grain consumption depends greatly on compensation awarded by the project, the potential for sustainability of the project is compromised. The second issue is that the project causes negative effects on local incomes in the Wolong Nature Reserve, which may undermine local economic prospects. The third issue is that the project failed to deliver suitable habitat for the giant panda, although two of the suitability requirements that deal with landform features were met. Lastly, the project neglects great differences among geographical areas in the country, providing the same compensation and length of compensation period to all participants. Appropriate compensation mechanisms should be established and adapted to local economic, environmental, and social conditions. In managing nature reserves and moving toward sustainability, ensuring all aspects of local socioeconomic and ecological/environmental issues are properly addressed is a real challenge. Based on our study, some recommendations for improving sustainability of the project are given.

Xu, Jian-Ying; Chen, Li-Ding; Lu, Yi-He; Fu, Bo-Jie

2007-07-01

427

Sustainability evaluation of the Grain for Green Project: from local people's responses to ecological effectiveness in Wolong Nature Reserve.  

PubMed

This article examines the sustainability of the Grain for Green Project in the Wolong Nature Reserve. Pertinent data were collected through a questionnaire survey and a spatial analysis of reforested lands. The study results identified four critical issues that may influence the sustainability of the project in the study area. The first issue is concerned with the project's impacts on local sustenance. Because local grain consumption depends greatly on compensation awarded by the project, the potential for sustainability of the project is compromised. The second issue is that the project causes negative effects on local incomes in the Wolong Nature Reserve, which may undermine local economic prospects. The third issue is that the project failed to deliver suitable habitat for the giant panda, although two of the suitability requirements that deal with landform features were met. Lastly, the project neglects great differences among geographical areas in the country, providing the same compensation and length of compensation period to all participants. Appropriate compensation mechanisms should be established and adapted to local economic, environmental, and social conditions. In managing nature reserves and moving toward sustainability, ensuring all aspects of local socioeconomic and ecological/environmental issues are properly addressed is a real challenge. Based on our study, some recommendations for improving sustainability of the project are given. PMID:17503146

Xu, Jian-Ying; Chen, Li-Ding; Lu, Yi-He; Fu, Bo-Jie

2007-07-01

428

Ecological effects of pipeline construction through deciduous forested wetlands, Midland County, Michigan. Topical report, October 1990--August 1992  

SciTech Connect

This study is designed to record vegetational changes induced by the construction of a large-diameter gas pipeline through deciduous forested wetlands. Two second-growth wetland sites mapped Lenawee soils were selected in Midland County, Michigan: Site 1, a younger stand subjected to recent selective logging, and Site 2, a more mature stand. The collection of ecological data to analyze plant succession on the right-of-way (ROW) and the effects of the developing ROW plant communities on adjacent forest communities was initiated in 1989. Cover class estimates were made for understory and ROW plant species on the basis of 1 {times} 1{minus}m quadrats. Individual stem diameters and species counts were recorded for overstory plants in 10{minus}m quadrats. Although long-term studies have not been completed, firm baseline data were established for comparative analyses with future sampling. Current data indicate that vegetation became well-established on the ROW within one year and subsequently increased in coverage. About 65% of the species were wetland indicators, and the dominants included seeded and natural invading species; nevertheless, some elements of the original flora regenerated and persist. The plants of the ecotone understories of both sites changed from their original composition as a result of the installation of the gas pipeline. Although some forest species persist at both sites, the ecotone of Site I was influenced more by the seeded species, whereas the natural invaders were more important at Site 2.

Rastorfer, J.R. [Chicago State Univ., IL (United States). Dept. of Biological Sciences; Van Dyke, G.D.; Zellmer, S.D.; Wilkey, P.L. [Argonne National Lab., IL (United States)

1995-04-01

429

Ecological effects of cell-level processes: genome size, functional traits and regional abundance of herbaceous plant species  

PubMed Central

Background and Aims Genome size is known to be correlated with a number of phenotypic traits associated with cell sizes and cell-division rates. Genome size was therefore used as a proxy for them in order to assess how common plant traits such as height, specific leaf area and seed size/number predict species regional abundance. In this study it is hypothesized that if there is residual correlation between genome size and abundance after these traits are partialled out, there must be additional ecological effects of cell size and/or cell-division rate. Methods Variation in genome size, plant traits and regional abundance were examined in 436 herbaceous species of central European flora, and relationships were sought for among these variables by correlation and path analysis. Key Results Species regional abundance was weakly but significantly correlated with genome size; the relationship was stronger for annuals (R2 = 0·145) than for perennials (R2 = 0·027). In annuals, genome size was linked to abundance via its effect on seed size, which constrains seed number and hence population growth rate. In perennials, it weakly affected (via height and specific leaf area) competitive ability. These relationships did not change qualitatively after phylogenetic correction. In both annuals and perennials there was an unresolved effect of genome size on abundance. Conclusions The findings indicate that additional predictors of regional abundance should be sought among variables that are linked to cell size and cell-division rate. Signals of these cell-level processes remain identifiable even at the landscape scale, and show deep differences between perennials and annuals. Plant population biology could thus possibly benefit from more systematic use of indicators of cell-level processes. PMID:22628380

Herben, Tomas; Suda, Jan; Klimesova, Jitka; Mihulka, Stanislav; Riha, Pavel; Simova, Irena

2012-01-01

430

Migration Ecology  

NSDL National Science Digital Library

This site from the University of Lund, Sweden, introduces various research studies in the field of Migration Ecology including research information on "Orientation and navigation," "Flight," "Migration patterns," and "Energetics." The mission of the group is "to forward, by research and teaching, the understanding of adaptive values and evolutionary possibilities and limitations in animal migration, -flight, -orientation and energetics." Many of the group's publications are available for free as PDFs, and the site offers a simple search mechanism to help visitors find the publications they are