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1

Cell-mediated immune response and IL2 production in white-tailed deer experimentally infected with hemorrhagic disease viruses  

Microsoft Academic Search

Hemorrhagic disease, caused by various serotypes of two closely related orbivirus serogroups, the epizootic hemorrhagic disease viruses (EHDV) and the bluetongue viruses (BTV), is a major cause of morbidity and mortality in white-tailed deer (WTD) in the United States. Despite the importance of hemorrhagic disease in WTD, little is known about host defense mechanisms triggered by infection with either causative

C. F. Quist; E. W. Howerth; D. I. Bounous; D. E. Stallknecht

1997-01-01

2

Macrobrachium rosenbergii nodavirus infection in M. rosenbergii (de Man) with white tail disease cultured in Taiwan  

Microsoft Academic Search

White tail disease (WTD) is a serious problem in Macrobrachium rosenbergii hatcheries and nursery ponds in Asia. The causative agents have been identified as M. rosenbergii nodavirus (MrNV) and its associated extra small virus. This is the first re- port demonstrating MrNV virus in M. rosenbergii displaying WTD signs in Taiwan by reverse tran- scriptase-polymerase chain reaction (RT-PCR). Amplified fragments

C S Wang; J S Chang; C M Wen; H H Shih; S N Chen

2008-01-01

3

Detection and phylogenetic profiling of nodavirus associated with white tail disease in Malaysian Macrobrachium rosenbergii de Man.  

PubMed

White tail disease (WTD) is a serious viral disease in the hatcheries and nursery ponds of Macrobrachium rosenbergii in many parts of the world. A new disease similar to WTD was observed in larvae and post larvae of M. rosenbergii cultured in Malaysia. In the present study, RT-PCR assay was used to detect the causative agents of WTD, M. rosenbergii nodavirus (MrNV) and extra small virus (XSV) using specific primers for MrNV RNA2 and XSV. The results showed the presence of MrNV in the samples with or without signs of WTD. However, XSV was only detected in some of the MrNV-positive samples. Phylogenetic analysis showed that the RNA2 of our Malaysian isolates were significantly different from the other isolates. Histopathological studies revealed myofiber degeneration of the tail muscles and liquefactive myopathy in the infected prawns. This was the first report on the occurrence of MrNV in the Malaysian freshwater prawn. PMID:22223294

Saedi, Tayebeh Azam; Moeini, Hassan; Tan, Wen Siang; Yusoff, Khatijah; Daud, Hassan Mohd; Chu, Kua Beng; Tan, Soon Guan; Bhassu, Subha

2012-05-01

4

A Nonluminescent and Highly Virulent Vibrio harveyi Strain Is Associated with "Bacterial White Tail Disease" of Litopenaeus vannamei Shrimp  

PubMed Central

Recurrent outbreaks of a disease in pond-cultured juvenile and subadult Litopenaeus vannamei shrimp in several districts in China remain an important problem in recent years. The disease was characterized by “white tail” and generally accompanied by mass mortalities. Based on data from the microscopical analyses, PCR detection and 16S rRNA sequencing, a new Vibrio harveyi strain (designated as strain HLB0905) was identified as the etiologic pathogen. The bacterial isolation and challenge tests demonstrated that the HLB0905 strain was nonluminescent but highly virulent. It could cause mass mortality in affected shrimp during a short time period with a low dose of infection. Meanwhile, the histopathological and electron microscopical analysis both showed that the HLB0905 strain could cause severe fiber cell damages and striated muscle necrosis by accumulating in the tail muscle of L. vannamei shrimp, which led the affected shrimp to exhibit white or opaque lesions in the tail. The typical sign was closely similar to that caused by infectious myonecrosis (IMN), white tail disease (WTD) or penaeid white tail disease (PWTD). To differentiate from such diseases as with a sign of “white tail” but of non-bacterial origin, the present disease was named as “bacterial white tail disease (BWTD)”. Present study revealed that, just like IMN and WTD, BWTD could also cause mass mortalities in pond-cultured shrimp. These results suggested that some bacterial strains are changing themselves from secondary to primary pathogens by enhancing their virulence in current shrimp aquaculture system.

Zhou, Junfang; Fang, Wenhong; Yang, Xianle; Zhou, Shuai; Hu, Linlin; Li, Xincang; Qi, Xinyong; Su, Hang; Xie, Layue

2012-01-01

5

White-tailed deer (Odocoileus virginianus) as a potential sentinel for human Lyme disease in Indiana.  

PubMed

We assessed the potential of white-tailed deer (WTD) (Odocoileus virginianus) to be a sentinel for human cases of Lyme disease (LD) in Indiana using location data from a 3-year survey of approximately 3400 hunted deer with associated tick Ixodes scapularis and Borrelia burgdorferi (Bb) data. Data on human LD cases at the county level were obtained from the Indiana Department of Health. All data were assigned to county centroids to match the resolution of the LD data before creating optimized trend surfaces for LD incidence, hunted deer count, Ixodes scapularis and Bb prevalence. To determine whether LD was spatially associated with the areas of high densities of deer, deer with Ixodes scapularis and deer with ticks infected with Bb, we used spatial analysis with distance indices (SADIE). The SADIE analysis found significant spatial association between LD and the distribution of three organismal predictor variables, that is, WTD, Ixodes ticks and Bb. Lyme disease incident rate varied between 0.08 cases per 10,000 habitants (Johnson county) and 5.9 cases per 10,000 habitants (Warren county). In conclusion, WTD can be used as an accurate and cost-effective sentinel for human LD. This method will permit public health workers to identify potentially endemic areas independently of human case reports. PMID:22776734

Raizman, E A; Holland, J D; Shukle, J T

2013-05-01

6

Susceptibility of white-tailed deer (Odocoileus virginianus) to experimental infection with epizootic hemorrhagic disease virus serotype 7.  

PubMed

During the fall of 2006, in Israel, epizootic hemorrhagic disease virus (EHDV) serotype 7 caused an intense and widespread epizootic in domestic cattle that resulted in significant economic losses for the dairy industry. The susceptibility of potential North American vector and ruminant hosts to infection with EHDV-7 is not known but is essential to understanding the potential for establishment of this exotic orbivirus in North America if it were introduced. Our primary objective was to determine whether white-tailed deer (WTD; Odocoileus virginianus) are susceptible to infection with EHDV-7. Six, 8-mo-old WTD were experimentally infected with EHDV-7, and all became infected and exhibited varying degrees of clinical disease. Clinical signs, clinicopathologic abnormalities, and postmortem findings were consistent with previous reports of orbiviral hemorrhagic disease (HD) in this species. Four of six animals died or were euthanized because of the severity of disease, one on postinoculation day (PID) 5 and the remaining WTD on PID 7. All deer had detectable viremia on PID 3, which peaked on PID 5 or 6 and persisted for as long as PID 46 in one animal. Deer surviving the acute phase of the disease seroconverted by PID 10. Based on the 67% mortality rate we observed, this strain of EHDV-7 is virulent in WTD, reaffirming their role as a sentinel species for the detection of endemic and nonendemic EHDV. Further, the observed disease was indistinguishable from previous reports of disease caused by North American EHDV and bluetongue virus serotypes, highlighting the importance of serotype-specific diagnostics during suspected HD outbreaks. PMID:22740533

Ruder, Mark G; Allison, Andrew B; Stallknecht, David E; Mead, Daniel G; McGraw, Sabrina M; Carter, Deborah L; Kubiski, Steven V; Batten, Carrie A; Klement, Eyal; Howerth, Elizabeth W

2012-07-01

7

Vector competence of Culicoides sonorensis (Diptera: Ceratopogonidae) to epizootic hemorrhagic disease virus serotype 7  

PubMed Central

Background Culicoides sonorensis (Diptera: Ceratopogonidae) is a vector of epizootic hemorrhagic disease virus (EHDV) serotypes 1 and 2 in North America, where these viruses are well-known pathogens of white-tailed deer (WTD) and other wild ruminants. Although historically rare, reports of clinical EHDV infection in cattle have increased in some parts of the world over the past decade. In 2006, an EHDV-7 epizootic in cattle resulted in economic loss for the Israeli dairy industry. White-tailed deer are susceptible to EHDV-7 infection and disease; however, this serotype is exotic to the US and the susceptibility of C. sonorensis to this cattle-virulent EHDV is not known. The objective of the study was to determine if C. sonorensis is susceptible to EHDV-7 infection and is a competent vector. Methods To evaluate the susceptibility of C. sonorensis, midges were fed on EHDV-7 infected WTD, held at 22 ± 1°C, and processed individually for virus isolation and titration on 4–16 days post feeding (dpf). Midges with a virus titer of ?102.7 median tissue culture infective doses (TCID50)/midge were considered potentially competent. To determine if infected C. sonorensis were capable of transmitting EHDV-7 to a host, a susceptible WTD was then fed on by a group of 14–16 dpf midges. Results From 4–16 dpf, 45% (156/350) of midges that fed on WTD with high titer viremia (>107 TCID50/ml) were virus isolation-positive, and starting from 10–16 dpf, 32% (35/109) of these virus isolation-positive midges were potentially competent (?102.7 TCID50/midge). Midges that fed on infected deer transmitted the virus to a susceptible WTD at 14–16 dpf. The WTD developed viremia and severe clinical disease. Conclusion This study demonstrates that C. sonorensis is susceptible to EHDV-7 infection and can transmit the virus to susceptible WTD, thus, C. sonorensis should be considered a potential vector of EHDV-7. Together with previous work, this study demonstrates that North America has a susceptible ruminant and vector host for this exotic, cattle-virulent strain of EHDV-7.

2012-01-01

8

Disease Limits Populations: Plague and Black-Tailed Prairie Dogs  

PubMed Central

Abstract Plague is an exotic vector-borne disease caused by the bacterium Yersinia pestis that causes mortality rates approaching 100% in black-tailed prairie dogs (Cynomys ludovicianus). We mapped the perimeter of the active portions of black-tailed prairie dog colonies annually between 1999 and 2005 at four prairie dog colony complexes in areas with a history of plague, as well as at two complexes that were located outside the distribution of plague at the time of mapping and had therefore never been affected by the disease. We hypothesized that the presence of plague would significantly reduce overall black-tailed prairie dog colony area, reduce the sizes of colonies on these landscapes, and increase nearest-neighbor distances between colonies. Within the region historically affected by plague, individual colonies were smaller, nearest-neighbor distances were greater, and the proportion of potential habitat occupied by active prairie dog colonies was smaller than at plague-free sites. Populations that endured plague were composed of fewer large colonies (>100 ha) than populations that were historically plague free. We suggest that these differences among sites in colony size and isolation may slow recolonization after extirpation. At the same time, greater intercolony distances may also reduce intercolony transmission of pathogens. Reduced transmission among smaller and more distant colonies may ultimately enhance long-term prairie dog population persistence in areas where plague is present.

Johnson, Tammi L.; Collinge, Sharon K.; Ray, Chris

2010-01-01

9

Experimental adenovirus hemorrhagic disease in yearling black-tailed deer.  

PubMed

An apparently novel adenovirus was associated with an epizootic of hemorrhagic disease that is believed to have killed thousands of mule deer (Odocoileus hemionus) in California (USA) during 1993-1994. A systemic vasculitis with pulmonary edema and hemorrhagic enteropathy or a localized vasculitis associated with necrotizing stomatitis/pharyngitis/glossitis or osteomyelitis of the jaw were common necropsy findings in animals that died during this epizootic. Six black-tailed yearling deer (O. hemionus columbianus) were inoculated with purified adenovirus isolated from a black-tailed fawn that died of acute adenovirus hemorrhagic disease during the epizootic. Three of six inoculated deer also received intramuscular injections of dexamethasone sodium phosphate every 3 days during the study. Eight days post-inoculation, one deer (without dexamethasone) developed bloody diarrhea and died. Necropsy and histopathologic findings were identical to lesions in free-ranging animals that died of the natural disease. Hemorrhagic enteropathy and pulmonary edema were the significant necropsy findings and there was microscopic vascular damage and endothelial intranuclear inclusion bodies in the vessels of the intestines and lungs. Adenovirus was identified in necrotic endothelial cells in the lungs by fluorescent antibody staining, immunohistochemistry and by transmission electron microscopy. Adenovirus was reisolated from tissues of the animal that died of experimental adenovirus hemorrhagic disease. Similar gross and microscopic lesions were absent in four of six adenovirus-inoculated deer and in the negative control animal which were necropsied at variable intervals during the 14 wk study. One deer was inoculated with purified adenovirus a second time, 12 wk after the first inoculation. Fifteen days after the second inoculation, this deer developed severe ulceration of the tongue, pharynx and rumen and necrotizing osteomyelitis of the mandible which was associated with vasculitis and thrombosis of adjacent large vessels and endothelial intranuclear inclusions. Transmission electron microscopy demonstrated adenovirus within the nuclei of vascular cells and immunohistochemistry demonstrated adenovirus antigen within tonsilar epithelium and in rare vessels. PMID:9391965

Woods, L W; Hanley, R S; Chiu, P H; Burd, M; Nordhausen, R W; Stillian, M H; Swift, P K

1997-10-01

10

Chronic wasting disease in free-ranging Wisconsin white-tailed deer  

USGS Publications Warehouse

Three White-tailed Deer shot within 5 km during the 2001 hunting season in Wisconsin tested positive for chronic wasting disease, a prion disease of cervids. Subsequent sampling within 18 km showed a 3% prevalence (n=476). This discovery represents an important range extension for chronic wasting disease into the eastern United States.

Joly, D. O.; Ribic, C. A.; Langenberg, J. A.; Beheler, K.; Batha, C. A.; Dhuey, B. J.; Rolley, R. E.; Bartelt, G.; VanDeelen, T. R.; Samuel, M. D.

2003-01-01

11

PARASITES, DISEASES, AND HEALTH STATUS OF SYMPATRIC POPULATIONS OF FALLOW DEER AND WHITE-TAILED DEER IN KENTUCKY1  

Microsoft Academic Search

In August 1983, a study on parasites, diseases, and health status was conducted on sympatric populations of fallow deer (Darna dama) and white-tailed deer (Odocolleus virgini- anus) from Land Between The Lakes, Lyon and Trigg counties, Kentucky. Five adult deer of each species were studied. White-tailed deer had antibodies to epizootic hemorrhagic disease (EHD) virus and Leptospira interogans serovariety icterohemorrhagiae,

William R. Davidson; James M. Crum; Jack L. Blue; Dennis W. Sharp; John H. Phillips

1985-01-01

12

EPIZOOTIC HEMORRHAGIC DISEASE VIRUS AND BLUETONGUE VIRUS SEROTYPE DISTRIBUTION IN WHITE-TAILED DEER IN GEORGIA  

Microsoft Academic Search

Serum samples collected from 1,396 white-tailed deer (Odocoileu.s virginianus) in five areas of Georgia (USA) from 1989 to 1991 were tested for precipitating and serum neutralizing (SN) antibodies to the enzootic North American epizootic hemorrhagic disease virus (EHDV) and bluetongue virus (BTV) serotypes. Precipitating antibodies to the EHDV or BTV serogroups, as detected by agar gel immunodiffusion (ACID) tests, were

David E. Stallknecht; Victor F. Nettles; Edward A. Rollor; Elizabeth W. Howerth

1995-01-01

13

Modeling the Impact of Climate and Landscape on the Efficacy of White Tailed Deer Vaccination for Cattle Tick Control in Northeastern Mexico  

PubMed Central

Cattle ticks are distributed worldwide and affect animal health and livestock production. White tailed deer (WTD) sustain and spread cattle tick populations. The aim of this study was to model the efficacy of anti-tick vaccination of WTD to control tick infestations in the absence of cattle vaccination in a territory where both host species coexist and sustain cattle tick populations. Agent-based models that included land cover/landscape properties (patch size, distances to patches) and climatic conditions were built in a GIS environment to simulate WTD vaccine effectiveness under conditions where unvaccinated cattle shared the landscape. Published and validated information on tick life cycle was used to build models describing tick mortality and developmental rates. Data from simulations were applied to a large territory in northeastern Mexico where cattle ticks are endemic and WTD and cattle share substantial portions of the habitat. WTD movements were simulated together with tick population dynamics considering the actual landscape and climatic features. The size of the vegetation patches and the distance between patches were critical for the successful control of tick infestations after WTD vaccination. The presence of well-connected, large vegetation patches proved essential for tick control, since the tick could persist in areas of highly fragmented habitat. The continued application of one yearly vaccination on days 1-70 for three years reduced tick abundance/animal/patch by a factor of 40 and 60 for R. annulatus and R. microplus, respectively when compared to non-vaccinated controls. The study showed that vaccination of WTD alone during three consecutive years could result in the reduction of cattle tick populations in northeastern Mexico. Furthermore, the results of the simulations suggested the possibility of using vaccines to prevent the spread and thus the re-introduction of cattle ticks into tick-free areas.

Estrada-Pena, Agustin; Carreon, Diana; Almazan, Consuelo; de la Fuente, Jose

2014-01-01

14

A universal carrier test for the long tail of Mendelian disease.  

PubMed

Mendelian disorders are individually rare but collectively common, forming a 'long tail' of genetic disease. A single highly accurate assay for this long tail would allow the scaling up of the Jewish community's successful campaign of population screening for Tay-Sachs disease to the general population, thereby improving millions of lives, greatly benefiting minority health and saving billions of dollars. This need has been addressed by designing a universal carrier test: a non-invasive, saliva-based assay for more than 100 Mendelian diseases across all major population groups. The test has been exhaustively validated with a median of 147 positive and 525 negative samples per variant, demonstrating a multiplex assay whose performance compares favourably with the previous standard of care, namely blood-based single-gene carrier tests. Because the test represents a dramatic reduction in the cost and complexity of large-scale population screening, an end to many preventable genetic diseases is now in sight. Moreover, given that the assay is inexpensive and requires only a saliva sample, it is now increasingly feasible to make carrier testing a routine part of preconception care. PMID:20729146

Srinivasan, Balaji S; Evans, Eric A; Flannick, Jason; Patterson, A Scott; Chang, Christopher C; Pham, Tuan; Young, Sharon; Kaushal, Amit; Lee, James; Jacobson, Jessica L; Patrizio, Pasquale

2010-10-01

15

Prion sequence polymorphisms and chronic wasting disease resistance in Illinois white-tailed deer (Odocoileus virginianus)  

PubMed Central

Nucleic acid sequences of the prion gene (PRNP) were examined and genotypes compiled for 76 white-tailed deer from northern Illinois, which previously tested positive for chronic wasting disease (CWD), and 120 negative animals selected to control for geographic location and age. Nine nucleotide polymorphisms, seven silent and two coding, were found in the sampled population. All observed polymorphisms except two of very low frequency were observed in both negative and positive animals, although five polymorphic loci had significantly different distributions of alleles between infected and non-infected individuals. Nucleotide base changes 60C/T, 285A/C, 286G/A and 555C/T were observed with higher than expected frequencies in CWD negative animals suggesting disease resistance, while 153C/T was observed more than expected in positive animals, suggesting susceptibility. The two coding polymorphisms, 285A/C (Q95H) and 286G/A (G96S), have been described in white-tailed deer populations sampled in Colorado and Wisconsin. Frequency distributions of coding polymorphisms in Wisconsin and Illinois deer populations were different, an unexpected result considering the sampled areas are less than 150 km apart. The total number of polymorphisms per animal, silent or coding, was negatively correlated to disease status. The potential importance of silent polymorphisms (60C/T, 153C/T, 555C/T), either individually or cumulatively, in CWD disease status has not been previously reported.

Kelly, Amy C; Mateus-Pinilla, Nohra E; Diffendorfer, Jay; Jewell, Emily; Ruiz, Marilyn O; Killefer, John; Shelton, Paul; Beissel, Tom

2008-01-01

16

Prion protein polymorphisms in white-tailed deer influence susceptibility to chronic wasting disease.  

PubMed

The primary sequence of the prion protein affects susceptibility to transmissible spongiform encephalopathies, or prion diseases, in mice, sheep and humans. The Prnp gene sequence of free-ranging, Wisconsin white-tailed deer was determined and the Prnp genotypes of chronic wasting disease (CWD)-positive and CWD-negative deer were compared. Six amino acid changes were identified, two of which were located in pseudogenes. Two alleles, a Q-->K polymorphism at codon 226 and a single octapeptide repeat insertion into the pseudogene, have not been reported previously. The predominant alleles--wild-type (Q95, G96 and Q226) and a G96S polymorphism--comprised almost 98% of the Prnp alleles in the Wisconsin white-tailed deer population. Comparison of the allelic frequencies in the CWD-positive and CWD-negative deer suggested that G96S and a Q95H polymorphism were linked to a reduced susceptibility to CWD. The G96S allele did not, however, provide complete resistance, as a CWD-positive G96S/G96S deer was identified. The G96S allele was also linked to slower progression of the disease in CWD-positive deer based on the deposition of PrP(CWD) in the obex region of the medulla oblongata. Although the reduced susceptibility of deer with at least one copy of the Q95H or G96S allele is insufficient to serve as a genetic barrier, the presence of these alleles may modulate the impact of CWD on white-tailed deer populations. PMID:16760415

Johnson, Chad; Johnson, Jody; Vanderloo, Joshua P; Keane, Delwyn; Aiken, Judd M; McKenzie, Debbie

2006-07-01

17

Anaplasma odocoilei sp. nov. (family Anaplasmataceae) from white-tailed deer (Odocoileus virginianus).  

PubMed

Recently, an undescribed Anaplasma sp. (also called Ehrlichia-like sp. or WTD agent) was isolated in ISE6 tick cells from captive white-tailed deer. The goal of the current study was to characterize this organism using a combination of experimental infection, morphologic, serologic, and molecular studies. Each of 6 experimentally inoculated white-tailed deer fawns (Odocoileus virginianus) became chronically infected (100+ days) with the Anaplasma sp. by inoculation of either infected whole blood or culture. None of the deer showed evidence of clinical disease, but 3 of the 6 deer evaluated had multiple episodes of transient thrombocytopenia. Light microscopy of Giemsa-stained, thin blood smears revealed tiny, dark, spherical structures in platelets of acutely infected deer. Anaplasma sp. was detected in platelets of inoculated deer by polymerase chain reaction, transmission electron microscopy, immunohistochemistry, and in situ hybridization. Five of 6 deer developed antibodies reactive to Anaplasma sp. antigen, as detected by indirect fluorescent antibody testing. Phylogenetic analyses of 16S rRNA, groESL, and gltA sequences confirmed the Anaplasma sp. is related to A. platys. Two attempts to transmit the Anaplasma sp. between deer by feeding Amblyomma americanum, a suspected tick vector, were unsuccessful. Based on its biologic, antigenic, and genetic characteristics, this organism is considered a novel species of Anaplasma, and the name Anaplasma odocoilei sp. nov. is proposed with UMUM76(T) (=CSUR-A1) as the type strain. PMID:23276749

Tate, Cynthia M; Howerth, Elizabeth W; Mead, Daniel G; Dugan, Vivien G; Luttrell, M Page; Sahora, Alexandra I; Munderloh, Ulrike G; Davidson, William R; Yabsley, Michael J

2013-02-01

18

A VERSATILE MODEL OF DISEASE TRANSMISSION APPLIED TO FORECASTING BOVINE TUBERCULOSIS DYNAMICS IN WHITE-TAILED DEER POPULATIONS  

Microsoft Academic Search

A model was derived for disease transmission in dynamic host populations and its application was demonstrated in forecasting possible outcomes of a bovine tuberculosis (Myco- bacterium boris) epidemic in a white-tailed deer (Odocoileus virginianus) population. The ap- proach was mechanistic, based disease transmission on the probability of each susceptible indi- vidual becoming infected per unit time, and afforded the flexibility

C. W. McCarty; M. W. Miller

1998-01-01

19

AN EPIZOOTIC OF HEMORRHAGIC DISEASE IN WHITE-TAILED DEER (000COILEUS VIRGINIANUS) IN MISSOURI: NECROPSY FINDINGS AND POPULATION IMPACT  

Microsoft Academic Search

An epizootic occurred among white-tailed deer (Odocolleus virginlanus) from July through October 1988 mnMissouri (USA). From late July through September, nine necropsied deer had lesions of the peracute or acute forms of hemorrhagic disease (HD) or no apparent lesions, whereas two deer necropsied in October had lesions of the chronic form of HD. Epizootic hem- orrhagic disease virus was isolated

John R. Fischer; Lonnie P. Hansen; James R. Turk; Margaret A. Miller; Harvey S. Gosser

20

Transmission of Chronic Wasting Disease in Wisconsin White-Tailed Deer: Implications for Disease Spread and Management  

PubMed Central

Few studies have evaluated the rate of infection or mode of transmission for wildlife diseases, and the implications of alternative management strategies. We used hunter harvest data from 2002 to 2013 to investigate chronic wasting disease (CWD) infection rate and transmission modes, and address how alternative management approaches affect disease dynamics in a Wisconsin white-tailed deer population. Uncertainty regarding demographic impacts of CWD on cervid populations, human and domestic animal health concerns, and potential economic consequences underscore the need for strategies to control CWD distribution and prevalence. Using maximum-likelihood methods to evaluate alternative multi-state deterministic models of CWD transmission, harvest data strongly supports a frequency-dependent transmission structure with sex-specific infection rates that are two times higher in males than females. As transmissible spongiform encephalopathies are an important and difficult-to-study class of diseases with major economic and ecological implications, our work supports the hypothesis of frequency-dependent transmission in wild deer at a broad spatial scale and indicates that effective harvest management can be implemented to control CWD prevalence. Specifically, we show that harvest focused on the greater-affected sex (males) can result in stable population dynamics and control of CWD within the next 50 years, given the constraints of the model. We also provide a quantitative estimate of geographic disease spread in southern Wisconsin, validating qualitative assessments that CWD spreads relatively slowly. Given increased discovery and distribution of CWD throughout North America, insights from our study are valuable to management agencies and to the general public concerned about the impacts of CWD on white-tailed deer populations.

Jennelle, Christopher S.; Henaux, Viviane; Wasserberg, Gideon; Thiagarajan, Bala; Rolley, Robert E.; Samuel, Michael D.

2014-01-01

21

Disease risk surface for Coxiella burnetii seroprevalence in white-tailed deer.  

PubMed

Coxiella burnetii is considered a re-emerging zoonosis in many countries. The bacterium is enzootic in livestock and wildlife in the United States, and environmental contamination is widespread. Despite the potential for exposure, the estimated prevalence of Q fever in humans and animals is not well elucidated, and reported human infections in the United States are relatively rare. Zoonotic transmission of the bacterium is usually associated with abortions in domestic ruminants, but other modes of transmission, such as contact with infected blood and/or milk during field dressing of infected wildlife, have not been thoroughly investigated. Studies of zoonotic pathogen transmission between animal reservoir hosts and humans are usually established in response to documented emergence or re-emergence of a zoonosis in a particular locale, and, as such, the prevalence of infection in wildlife is largely unknown for many zoonotic pathogens, including C. burnetii. The objective of this study was to create a disease risk surface for C. burnetii seroprevalence in wild white-tailed deer (Odocoileus virginianus) in New York State. Blood samples were collected from hunter-harvested deer from across New York State in 2009 and 2010. The samples were processed and tested for the presence of anti-C. burnetii antibodies via indirect microimmunofluorescence assays using phase II C. burnetii strain RSA439. Overall, 14.50% of the tested white-tailed deer were C. burnetii phase II seropositive. The dual Kernel density estimation method was used to create a smoothed disease risk surface, which revealed variation in seroprevalence ranging from 0% to 32.0%. Areas of higher seroprevalence were detected in four discrete areas of Central New York and in one additional area in the southwest corner of the northern part of the state. This suggests certain locales where humans may be at increased risk for exposure to the bacterium secondary to contact with potentially infected deer. PMID:23176671

Kirchgessner, M S; Dubovi, E J; Whipps, C M

2013-11-01

22

Demographic patterns and harvest vulnerability of chronic wasting disease infected white-tailed deer in Wisconsin  

USGS Publications Warehouse

Chronic wasting disease (CWD) is a fatal disease of white-tailed deer (Odocoileus virginianus) caused by transmissible protease-resistant prions. Since the discovery of CWD in southern Wisconsin in 2001, more than 20,000 deer have been removed from a >2,500-km2 disease eradication zone surrounding the three initial cases. Nearly all deer removed were tested for CWD infection and sex, age, and harvest location were recorded. Our analysis used data from a 310-km2 core study area where disease prevalence was higher than surrounding areas. We found no difference in harvest rates between CWD infected and noninfected deer. Our results show that the probability of infection increased with age and that adult males were more likely to be infected than adult females. Six fawns tested positive for CWD, five fawns from the core study area, including the youngest (5 months) free-ranging cervid to test positive. The increase in male prevalence with age is nearly twice the increase found in females. We concluded that CWD is not randomly distributed among deer and that differential transmission among sex and age classes is likely driving the observed patterns in disease prevalence. We discuss alternative hypotheses for CWD transmission and spread and, in addition, discuss several possible nonlinear relationships between prevalence and age. Understanding CWD transmission in free-ranging cervid populations will be essential to the development of strategies to manage this disease in areas where CWD is found, as well as for surveillance strategies in areas where CWD threatens to spread.

Grear, D. A.; Samuel, M. D.; Langenberg, J. A.; Keane, D.

2006-01-01

23

Spatial epidemiology of chronic wasting disease in Wisconsin white-tailed deer  

USGS Publications Warehouse

Chronic wasting disease (CWD) is a fatal, emerging disease of cervids associated with transmissible protease-resistant prion proteins. The potential for CWD to cause dramatic declines in deer and elk populations and perceived human health risks associated with consuming CWD-contaminated venison have led wildlife agencies to embark on extensive CWD control programs, typically involving culling to reduce deer populations. We characterized the spatial distribution of CWD in white-tailed deer (Odocoileus virginianus) in Wisconsin to facilitate CWD management. We found that CWD prevalence declined with distance from a central location, was locally correlated at a scale of 3.6 km, and was correlated with deer habitat abundance. The latter result is consistent with patterns expected for a positive relationship between density and prevalence of CWD. We recommend management activities focused on culling in geographic areas with high prevalence to have the greatest probability of removing infected individuals. Further research is needed to elucidate the factors in envolved in CWD spread and infection rates, especially the role of density-dependent transmission. ?? Wildlife Disease Association 2006.

Joly, D. O.; Samuel, M. D.; Langenberg, J. A.; Blanchong, J. A.; Batha, C. A.; Rolley, R. E.; Keane, D. P.; Ribic, C. A.

2006-01-01

24

ANTIBODIES TO SPIROCHETES IN WHITE-TAILED DEER AND PREVALENCE OF INFECTED TICKS FROM FOCI OF LYME DISEASE IN CONNECTICUT  

Microsoft Academic Search

White-tailed deer (Odocoileus virginianus) were examined for the tick, Ixodes dam- mini, and sera were analyzed for antibodies to spirochetes during 1982. Of the 323 animals inspected in four areas endemic for Lyme disease, 188 (58%) had adult ticks; parasitism ranged from 43% at Haddam to 82% at East Lyme. Direct and indirect fluorescent antibody tests detected spirochetes in 18

Louis A. Magnarelli; John F. Anderson; W. Adrian Chappell

25

Antibodies to Bluetongue and Epizootic Hemorrhagic Disease Viruses in a Barrier Island White-tailed Deer Population  

Microsoft Academic Search

From 1981 through 1989, serum samples from 855 white-tailed deer (Odocoileus virginianus) from Ossabaw Island, Georgia (USA), were tested for antibodies to bluetongue virus (BTV) and epizootic hemorrhagic disease virus (EHDV). During this period, prevalence of precipitating antibodies to BTV and EHDV as determined by agar gel immunodiffusion (AGID) tests decreased from 74% to 3% and from 34% to 1%,

David E. Stallknecht; M. Lisa Kellogg; J. L. Blue; J. E. Pearson

1991-01-01

26

Chronic wasting disease in a Wisconsin white-tailed deer farm  

USGS Publications Warehouse

In September 2002, chronic wasting disease (CWD), a prion disorder of captive and wild cervids, was diagnosed in a white-tailed deer (Odocoileus virginianus) from a captive farm in Wisconsin. The facility was subsequently quarantined, and in January 2006 the remaining 76 deer were depopulated. Sixty animals (79%) were found to be positive by immunohistochemical staining for the abnormal prion protein (PrPCWD) in at least one tissue; the prevalence of positive staining was high even in young deer. Although none of the deer displayed clinical signs suggestive of CWD at depopulation, 49 deer had considerable accumulation of the abnormal prion in the medulla at the level of the obex. Extraneural accumulation of the abnormal protein was observed in 59 deer, with accumulation in the retropharyngeal lymph node in 58 of 59 (98%), in the tonsil in 56 of 59 (95%), and in the rectal mucosal lymphoid tissue in 48 of 58 (83%). The retina was positive in 4 deer, all with marked accumulation of prion in the obex. One deer was considered positive for PrPCWD in the brain but not in the extraneural tissue, a novel observation in white-tailed deer. The infection rate in captive deer was 20-fold higher than in wild deer. Although weakly related to infection rates in extraneural tissues, prion genotype was strongly linked to progression of prion accumulation in the obex. Antemortem testing by biopsy of rectoanal mucosal-associated lymphoid tissue (or other peripheral lymphoid tissue) may be a useful adjunct to tonsil biopsy for surveillance in captive herds at risk for CWD infection.

Keane, D. P.; Barr, D. J.; Bochsler, P. N.; Hall, S. M.; Gidlewski, T.; O'Rourke, K. I.; Spraker, T. R.; Samuel, M. D.

2008-01-01

27

PRION PROTEIN GENE HETEROGENEITY IN FREE-RANGING WHITE-TAILED DEER WITHIN THE CHRONIC WASTING DISEASE AFFECTED REGION OF WISCONSIN  

Microsoft Academic Search

Chronic wasting disease (CWD) was first identified in Wisconsin (USA) in white- tailed deer (Odocoileus virginianus) in February 2002. To determine if prion protein gene (Prnp) allelic variability was associated with CWD in white-tailed deer from Wisconsin, we sequenced Prnp from 26 CWD-positive and 100 CWD-negative deer. Sequence analysis of Prnp suggests that at least 86-96% of the white-tailed deer

Chad Johnson; Jody Johnson; Murray Clayton; Debbie McKenzie; Judd Aiken

28

Molecular characterization of Trypanosoma (Megatrypanum) spp. infecting cattle (Bos taurus), white-tailed deer (Odocoileus virginianus), and elk (Cervus elaphus canadensis) in the United States.  

PubMed

In the United States, the generally non-pathogenic trypanosome of cattle is designated Trypanosoma (Megatrypanum) theileri and is distinguished morphologically from Trypanosoma (M.) cervi, a trypanosome originally described in mule deer and elk. Phylogenetic studies of the Megatrypanum trypanosomes using various molecular markers reveal two lineages, designated TthI and TthII, with several genotypes within each. However, to date there is very limited genetic data for T. theileri, and none for the Megatrypanum trypanosomes found in wild ungulates, in the U.S. In this study U.S. isolates from cattle (Bos taurus), white-tailed deer (Odocoileus virginianus) (WTD), and elk (Cervus elaphus canadensis) were compared by ribosomal DNA (rDNA) sequence analysis and their incidence in cattle and WTD in south Texas counties was investigated. Phylogenetic analyses showed clear separation of the bovine and cervine trypanosomes. Both lineages I and II were represented in the U.S. cattle and WTD parasites. Lineage I cattle isolates were of a previously described genotype, whereas WTD and elk isolates were of two new genotypes distinct from the cattle trypanosomes. The cattle isolate of lineage II was of a previously reported genotype and was divergent from the WTD isolate, which was of a new genotype. In La Salle, Starr, Webb, and Zapata counties in south Texas a total of 51.8% of white-tailed deer were positive for trypanosomes by 18S rDNA PCR. Of the cattle screened in Webb County, 35.4% were positive. Drought conditions prevailing in south Texas when the animals were screened suggest the possibility of a vector for Trypanosoma other than the ked (Lipoptena mazamae) and tabanid flies (Tabanus spp. and Haematopota spp.). PMID:23683651

Fisher, Amanda C; Schuster, Greta; Cobb, W Jacob; James, Andrea M; Cooper, Susan M; Peréz de León, Adalberto A; Holman, Patricia J

2013-10-18

29

Host culling as an adaptive management tool for chronic wasting disease in white-tailed deer: a modelling study  

PubMed Central

Emerging wildlife diseases pose a significant threat to natural and human systems. Because of real or perceived risks of delayed actions, disease management strategies such as culling are often implemented before thorough scientific knowledge of disease dynamics is available. Adaptive management is a valuable approach in addressing the uncertainty and complexity associated with wildlife disease problems and can be facilitated by using a formal model. We developed a multi-state computer simulation model using age, sex, infection-stage, and seasonality as a tool for scientific learning and managing chronic wasting disease (CWD) in white-tailed deer Odocoileus virginianus. Our matrix model used disease transmission parameters based on data collected through disease management activities. We used this model to evaluate management issues on density- (DD) and frequency-dependent (FD) transmission, time since disease introduction, and deer culling on the demographics, epizootiology, and management of CWD. Both DD and FD models fit the Wisconsin data for a harvested white-tailed deer population, but FD was slightly better. Time since disease introduction was estimated as 36 (95% CI, 24–50) and 188 (41–>200) years for DD and FD transmission, respectively. Deer harvest using intermediate to high non-selective rates can be used to reduce uncertainty between DD and FD transmission and improve our prediction of long-term epidemic patterns and host population impacts. A higher harvest rate allows earlier detection of these differences, but substantially reduces deer abundance. Results showed that CWD has spread slowly within Wisconsin deer populations, and therefore, epidemics and disease management are expected to last for decades. Non-hunted deer populations can develop and sustain a high level of infection, generating a substantial risk of disease spread. In contrast, CWD prevalence remains lower in hunted deer populations, but at a higher prevalence the disease competes with recreational hunting to reduce deer abundance. Synthesis and applications. Uncertainty about density- or frequency-dependent transmission hinders predictions about the long-term impacts of chronic wasting disease on cervid populations and the development of appropriate management strategies. An adaptive management strategy using computer modelling coupled with experimental management and monitoring can be used to test model predictions, identify the likely mode of disease transmission, and evaluate the risks of alternative management responses.

Wasserberg, Gideon; Osnas, Erik E; Rolley, Robert E; Samuel, Michael D

2009-01-01

30

Host culling as an adaptive management tool for chronic wasting disease in white-tailed deer: a modelling study.  

PubMed

Emerging wildlife diseases pose a significant threat to natural and human systems. Because of real or perceived risks of delayed actions, disease management strategies such as culling are often implemented before thorough scientific knowledge of disease dynamics is available. Adaptive management is a valuable approach in addressing the uncertainty and complexity associated with wildlife disease problems and can be facilitated by using a formal model.We developed a multi-state computer simulation model using age, sex, infection-stage, and seasonality as a tool for scientific learning and managing chronic wasting disease (CWD) in white-tailed deer Odocoileus virginianus. Our matrix model used disease transmission parameters based on data collected through disease management activities. We used this model to evaluate management issues on density- (DD) and frequency-dependent (FD) transmission, time since disease introduction, and deer culling on the demographics, epizootiology, and management of CWD.Both DD and FD models fit the Wisconsin data for a harvested white-tailed deer population, but FD was slightly better. Time since disease introduction was estimated as 36 (95% CI, 24-50) and 188 (41->200) years for DD and FD transmission, respectively. Deer harvest using intermediate to high non-selective rates can be used to reduce uncertainty between DD and FD transmission and improve our prediction of long-term epidemic patterns and host population impacts. A higher harvest rate allows earlier detection of these differences, but substantially reduces deer abundance.Results showed that CWD has spread slowly within Wisconsin deer populations, and therefore, epidemics and disease management are expected to last for decades. Non-hunted deer populations can develop and sustain a high level of infection, generating a substantial risk of disease spread. In contrast, CWD prevalence remains lower in hunted deer populations, but at a higher prevalence the disease competes with recreational hunting to reduce deer abundance.Synthesis and applications. Uncertainty about density- or frequency-dependent transmission hinders predictions about the long-term impacts of chronic wasting disease on cervid populations and the development of appropriate management strategies. An adaptive management strategy using computer modelling coupled with experimental management and monitoring can be used to test model predictions, identify the likely mode of disease transmission, and evaluate the risks of alternative management responses. PMID:19536340

Wasserberg, Gideon; Osnas, Erik E; Rolley, Robert E; Samuel, Michael D

2009-04-01

31

Preclinical diagnosis of chronic wasting disease in captive mule deer (Odocoileus hemionus) and white-tailed deer (Odocoileus virginianus) using tonsillar biopsy  

Microsoft Academic Search

The usefulness of tonsillar biopsy on live deer for preclinical diagnosis of the transmissible spongiform encephalopathy chronic wasting disease (CWD) was evaluated. Disease was tracked in a CWD-endemic herd using serial tonsillar biopsies collected at 6 to 9 month intervals from 34 captive mule deer (Odocoileus hemionus) and five white-tailed deer (O. virginianus). Tonsillar biopsies were examined for accumulation of

Margaret A. Wild; Terry R. Spraker; Christina J. Sigurdson; Katherine I. O'Rourke; Michael W. Miller

32

The importance of localized culling in stabilizing chronic wasting disease prevalence in white-tailed deer populations.  

PubMed

Strategies to contain the spread of disease often are developed with incomplete knowledge of the possible outcomes but are intended to minimize the risks associated with delaying control. Culling of game species by government agencies is one approach to control disease in wild populations but is unpopular with hunters and wildlife enthusiasts, politically unpalatable, and erodes public support for agencies responsible for wildlife management. We addressed the functional differences between hunting and government culling programs for managing chronic wasting disease (CWD) in white-tailed deer by comparing prevalence over a 10-year period in Illinois and Wisconsin. When both Illinois and Wisconsin were actively culling from 2003 - 2007, there were no statistical differences between state CWD prevalence estimates. Wisconsin government culling concluded in 2007 and average prevalence over the next five years was 3.09 ± 1.13% with an average annual increase of 0.63%. During that same time period, Illinois continued government culling and there was no change in prevalence throughout Illinois. Despite its unpopularity among hunters, localized culling is a disease management strategy that can maintain low disease prevalence while minimizing impacts on recreational deer harvest. PMID:24128754

Manjerovic, Mary Beth; Green, Michelle L; Mateus-Pinilla, Nohra; Novakofski, Jan

2014-01-01

33

Evaluating Spatial Overlap and Relatedness of White-tailed Deer in a Chronic Wasting Disease Management Zone  

PubMed Central

Wildlife disease transmission, at a local scale, can occur from interactions between infected and susceptible conspecifics or from a contaminated environment. Thus, the degree of spatial overlap and rate of contact among deer is likely to impact both direct and indirect transmission of infectious diseases such chronic wasting disease (CWD) or bovine tuberculosis. We identified a strong relationship between degree of spatial overlap (volume of intersection) and genetic relatedness for female white-tailed deer in Wisconsin’s area of highest CWD prevalence. We used volume of intersection as a surrogate for contact rates between deer and concluded that related deer are more likely to have contact, which may drive disease transmission dynamics. In addition, we found that age of deer influences overlap, with fawns exhibiting the highest degree of overlap with other deer. Our results further support the finding that female social groups have higher contact among related deer which can result in transmission of infectious diseases. We suggest that control of large social groups comprised of closely related deer may be an effective strategy in slowing the transmission of infectious pathogens, and CWD in particular.

Magle, Seth B.; Samuel, Michael D.; Van Deelen, Timothy R.; Robinson, Stacie J.; Mathews, Nancy E.

2013-01-01

34

Epidemiology of toxoplasmosis in white tailed deer (Odocoileus virginianus): Occurrence, congenital transmission, correlates of infection, isolation, and genetic characterization of Toxoplasma gondii.  

PubMed

The prevalence of Toxoplasma gondii in white tailed deer (WTD) in the USA is high but little is known of the epidemiology of toxoplasmosis in this host. In the present study, we compared T. gondii seroprevalence from 749 WTD collected in 2012 and 2013 from a Metropolitan Park in Ohio and 487 WTD deer shot in Minnesota during 2008, 2009, and 2010. Serum samples were tested for antibodies to T. gondii by the modified agglutination test (cut-off titer, 25). Additionally myocardial samples from 123 seropositive WTD from Ohio were digested in pepsin and the digests were bioassayed for the isolation of T. gondii. Furthermore, to estimate transplacental rate of transmission, brains from 155 fetuses (included twins) from 148 deer from Minnesota were bioassayed in mice for the isolation of viable T. gondii. Seroprevalence of T. gondii varied with the year of collection, geography, and the age of deer. Of the Ohio deer sampled in 2012 and 2013 seroprevalences for the two years were similar (73.4% and 75.7%, respectively); remarkably 150 (66.1%) of 227 deer of <1 year of age were seropositive. Of the Minnesota deer, seroprevalence was lowest for the year 2008 (14.8%, 26/175) versus 2009 (27.7%, 59/213), and 2010 (25.2%, 25/99), thought to be related to environmental temperatures. Viable T. gondii was isolated in mice from the myocardium of four WTD from Ohio, and brain of one WTD fetus from Minnesota. Tachyzoites from infected mouse tissues were further propagated in cell culture. The DNA isolated from culture-derived tachyzoites of these five T. gondii isolates was characterized using 11 PCR-RFLP markers (SAG1, 5'- and 3'-SAG2, alt.SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, L358, PK1 and Apico). Four genotypes were found, including ToxoDB genotype no. 1 (Type II), no. 2 (Type III), no. 3 (Type II variant) and no. 146. Results indicate fluctuating seroprevalence, probably related to weather and warrant further epidemiological studies. PMID:24582734

Dubey, J P; Dennis, P M; Verma, S K; Choudhary, S; Ferreira, L R; Oliveira, S; Kwok, O C H; Butler, E; Carstensen, M; Su, C

2014-05-28

35

Demodectic Mange, Dermatophilosis, and Other Parasitic and Bacterial Dermatologic Diseases in Free-Ranging White-tailed Deer (Odocoileus virginianus) in the United States From 1975 to 2012.  

PubMed

The white-tailed deer (Odocoileus virginianus) is a common and widespread North American game species. To evaluate the incidence, clinical manifestations, demography, and pathology of bacterial and parasitic dermatologic diseases in white-tailed deer in the southeastern United States, we retrospectively evaluated white-tailed deer cases submitted to the Southeastern Cooperative Wildlife Disease Study from 1975 to 2012. Among 2569 deer examined, bacterial or parasitic dermatologic disease was diagnosed in 88 (3.4%) individuals, with Demodex spp (n = 37; 42.0%) and Dermatophilus congolensis (n = 19; 21.6%) as the most common causes. Demodicosis was significantly more common in deer older than 2 years and was most often detected in the fall; no statistically significant sex predilection was identified. Affected animals had patchy to generalized alopecia, often distributed over the head, neck, limbs, and trunk; microscopic lesions included epidermal crusts and cutaneous nodules with mild perifollicular, lymphoplasmacytic inflammation. Dermatophilosis was most common in males younger than 1 year that were often found dead. Crusting, erythema, and alopecia occurred on the face, ears, and distal extremities. Less commonly, infectious dermatologic diseases were associated with other bacteria (n = 13; 14.8%), fungi (n = 5; 5.7%), ectoparasites (chiggers, lice, mites, and ticks; n = 11; 12.5%), and larval nematodes (n = 7; 8.0%). Population-level effects of these diseases in white-tailed deer are likely minimal; however, due to their dramatic presentation, demodicosis, dermatophilosis, and other infectious skin diseases can be of concern to hunters and, in some cases, may have zoonotic potential. PMID:23912715

Nemeth, N M; Ruder, M G; Gerhold, R W; Brown, J D; Munk, B A; Oesterle, P T; Kubiski, S V; Keel, M K

2014-05-01

36

Polymorphisms in the prion precursor functional gene but not the pseudogene are associated with susceptibility to chronic wasting disease in white-tailed deer  

Microsoft Academic Search

Chronic wasting disease (CWD) status and PrP genotypes were determined for a group of 133 wild white-tailed deer in a 780 acre enclosure in western Nebraska, USA. Approximately half of the deer tested showed evidence of PrPd in the brainstem or lymphoid tissues. Four PRNP alleles encoding amino acid substitutions were identified, with substitutions at residues 95 (QRH), 96 (GRS)

Katherine I. O'Rourke; Terry R. Spraker; Linda K. Hamburg; Thomas E. Besser; Kelly A. Brayton; Donald P. Knowles

2004-01-01

37

Animal Tails  

NSDL National Science Digital Library

Call it tail envy. With only a vestigial nub to show for ourselves, perhaps it's no wonder that animal tails capture our attention. The following Web sites present some of the more interesting tails to be found in the animal kingdom. The first Web site contains a recent article from Discovery News describing new findings that at least one species of scorpion produces two distinct types of tail venom, which have completely different effects on their victims (1). The next site from Singapore Zoological Gardens introduces the cebids (our New World monkey cousins), some of which have amazing prehensile tails that are used like a fifth limb (2). The rattlesnake is another famously-tailed creature, highlighted in the following site from the Arizona-Sonora Desert Museum (3). The site covers the main aspects of rattlesnake natural history, including a section on how the rattle forms. The Great Plains Nature Center in Wichita, Kansas, offers a Web page devoted to the beaver, including tail trivia and an audio clip of a resident beaver surprised in his den at the Kansas Wildlife Exhibit (4). Anyone who has witnessed the freakishly fascinating spectacle of a gecko leaving its tail behind to distract a would-be predator will appreciate this brief bio of the Tokay gecko, presented by ReptileCenter.com, the Herpetologist's Portal (5). Stacy's Wag'N'Train -- offering dog-training classes in San Jose, California -- provides this online guide to dog body language, which would have a very limited vocabulary without the tail (6). So, how did the peacock get its tail? It's a simple question that has driven zoologists crazy for over a century. The next Web site (7) contains an in-depth article on the subject from the Independent (London), offered through National Geographic News. And finally, the bizarre gulper eel -- able to tie its tail in several knots -- gets is own Web page on Pangea, the Web server for the Department of Educational Leadership and Technology at Southeastern Louisiana University (8). This deep-sea curiosity uses its bioluminescent tail tip to lure hapless prey into its impossibly gigantic mouth.

Sohmer, Rachel.

2003-01-01

38

Broad and fine-scale genetic analysis of white-tailed deer populations: estimating the relative risk of chronic wasting disease spread  

PubMed Central

Chronic wasting disease is a transmissible spongiform encephalopathy of cervids, similar to sheep scrapie that has only recently been detected in wild populations of white-tailed deer (Odocoileus virginianus) and mule deer (Odocoileus hemionus hemionus) in western Canada. Relatively little is known about local transmission dynamics of the disease or the potential for long-distance spread. We analysed the population genetic structure of over 2000 white-tailed deer sampled from Alberta, British Columbia, and Saskatchewan using microsatellite profiles and mtDNA sequencing to assess the relative risk of disease spread. There was very little differentiation among subpopulations and a weak trend of increasing differentiation with geographic distance. This suggests that the potential for long-distance disease spread through the dispersal of infected individuals is possible, yet the risk of spread should gradually diminish with distance from infection foci. Within subpopulations, females were more related than expected by chance (R > 0) within a radius of approximately 500 m. Sex-biased philopatry and social interactions among related females may facilitate local disease transmission within social groups. Local herd reduction may therefore be an effective tool for reducing the disease prevalence when implemented at the appropriate spatial scale.

Cullingham, Catherine I; Merrill, Evelyn H; Pybus, Margo J; Bollinger, Trent K; Wilson, Gregory A; Coltman, David W

2011-01-01

39

Tail planes  

NASA Technical Reports Server (NTRS)

This report presents methods by which the cells of large commercial airplanes may be reduced. The tail of large airplanes represent an area where considerable improvement in weight and size reduction can be attained.

Constantin, L

1926-01-01

40

Tail Buffeting  

NASA Technical Reports Server (NTRS)

An approximate theory of buffeting is here presented, based on the assumption of harmonic disturbing forces. Two cases of buffeting are considered: namely, for a tail angle of attack greater and less than the stalling angle, respectively. On the basis of the tests conducted and the results of foreign investigators, a general analysis is given of the nature of the forced vibrations the possible load limits on the tail, and the methods of elimination of buffeting.

Abdrashitov, G.

1943-01-01

41

Diagnostic detection methods for Mycobacterium avium subsp. paratuberculosis in white-tailed deer  

PubMed Central

This study compares the results and suitability of serological testing, microscopic examination, deoxyribonucleic acid (DNA) detection, and bacterial culture for detecting Mycobacterium avium subsp. paratuberculosis (Map) infection in asymptomatic farmed white-tailed deer (WTD) (Odocoileus virginianus). Deer were classified as infected if culture slants from their feces, lymph nodes, or ileum were positive, or if a polymerase chain reaction (PCR) assay detected Map DNA in any of its tissues. Deer identified as positive by agar gel immunodiffusion (AGID) testing or enzyme-linked immunosorbent assay (ELISA) but not by bacterial culture, Ziehl-Neelsen staining, or PCR assay were classified as suspect. Culture of tissues classified 10/16 (62.5%), histopathologic examination 1/16 (6.3%), tissue smears 4/16 (25%), culture slant (CS)-PCR on feces 12/15 (80%), CS-PCR on tissue 13/16 (81.3%), and direct PCR on uncultured tissues 5/16 (31.3%) deer as infected. The ELISA classified 2/15 (13.3%) deer as positive and therefore suspect. The AGID test was negative for all deer. Fifteen of 16 deer were positive by 1 or more tests; only 1 deer was negative on all 11 assays. The CS-PCR gave superior results on antemortem fecal testing as well as postmortem tissue testing and can be recommended for improving the detection of Map in WTD at every stage of infection.

Woodbury, Murray R.; Chirino-Trejo, Manuel; Mihajlovic, Biljana

2008-01-01

42

The Effects of Short Glass Fibre (SGF) Loading and a Silane Coupling Agent on Properties of Polypropylene\\/Waste Tyre Dust\\/Short Glass Fibre (PP\\/WTD\\/SGF) Composites  

Microsoft Academic Search

The properties of polypropylene\\/waste tyre dust\\/short glass fibre (PP\\/WTD\\/SGF) composites at 0 to 20 php SGF loading, with and without a silane coupling agent, ?-aminopropyltrimethoxysilane (?-APS) were studied. The results reveal that the equilibrium torque and Young's modulus increased while tensile strength and elongation at break decreased as SGF loading increased. SEM micrographs show poor adhesion of SGF-PP\\/WTD while FTIR analysis

Z. Zainal; H. Ismail

2011-01-01

43

Diversity and distribution of white-tailed deer mtdna lineages in chronic wasting disease (cwd) outbreak areas in southern wisconsin, USA  

USGS Publications Warehouse

Chronic wasting disease (CWD) is a transmissible spongiform encephalopathy affecting North American cervids. Because it is uniformly fatal, the disease is a major concern in the management of white-tailed deer populations. Management programs to control CWD require improved knowledge of deer interaction, movement, and population connectivity that could influence disease transmission and spread. Genetic methods were employed to evaluate connectivity among populations in the CWD management zone of southern Wisconsin. A 576-base-pair region of the mitochondrial DNA of 359 white-tailed deer from 12 sample populations was analyzed. Fifty-eight variable sites were detected within the sequence, defining 43 haplotypes. While most sample populations displayed similar levels of haplotype diversity, individual haplotypes were clustered on the landscape. Spatial clusters of different haplotypes were apparent in distinct ecoregions surrounding CWD outbreak areas. The spatial distribution of mtDNA haplotypes suggests that clustering of the deer matrilineal groups and population connectivity are associated with broad-scale geographic landscape features. These landscape characteristics may also influence the contact rates between groups and therefore the potential spread of CWD; this may be especially true of local disease spread between female social groups. Our results suggest that optimal CWD management needs to be tailored to fit gender-specific dispersal behaviors and regional differences in deer population connectivity. This information will help wildlife managers design surveillance and monitoring efforts based on population interactions and potential deer movement among CWD-affected and unaffected areas. Copyright ?? Taylor & Francis Group, LLC.

Rogers, K. G.; Robinson, S. J.; Samuel, M. D.; Grear, D. A.

2011-01-01

44

Evaluation of a wild white-tailed deer population management program for controlling chronic wasting disease in Illinois, 2003-2008.  

PubMed

We evaluated population management programs for controlling chronic wasting disease (CWD) in wild white-tailed deer in Illinois between November 2002 and March 2008. The intervention consisted of measures of deer removal from three deer population control programs: Illinois Department of Natural Resources culling, deer population control permits and nuisance deer removal permits. We included in the analysis a total of 14,650 white-tailed deer CWD test results. These data also included location and demographic data collected from both deer harvested in the interventions as well as deer from hunter harvests and deer vehicle collisions. We quantified intervention pressures as the number of years of intervention, the total number of deer removed and the average number of deer removed per year. We accounted for temporal and spatial variations of intervention by using mixed logistic regression to model the association between intervention pressures and CWD prevalence change. The results showed that deer population management intervention as practiced in Illinois during the study period was negatively associated with CWD prevalence and the strength of association varied depending on age of deer and the measure of intervention pressure. The population management programs showed a more consistent association with reduced CWD prevalence in fawn and yearling white-tailed deer than in adult deer. Our results also suggested that frequent and continuing intervention events with at least moderate intensity of culling were needed to reduce CWD prevalence. A longer study period, however, is needed to make a more definite conclusion about the effectiveness of similar population management programs for controlling CWD in wild white-tailed deer. PMID:23558033

Mateus-Pinilla, Nohra; Weng, Hsin-Yi; Ruiz, Marilyn O; Shelton, Paul; Novakofski, Jan

2013-07-01

45

Genetic susceptibility to chronic wasting disease in free-ranging white-tailed deer: Complement component C1q and Prnp polymorphisms  

USGS Publications Warehouse

The genetic basis of susceptibility to chronic wasting disease (CWD) in free-ranging cervids is of great interest. Association studies of disease susceptibility in free-ranging populations, however, face considerable challenges including: the need for large sample sizes when disease is rare, animals of unknown pedigree create a risk of spurious results due to population admixture, and the inability to control disease exposure or dose. We used an innovative matched case-control design and conditional logistic regression to evaluate associations between polymorphisms of complement C1q and prion protein (Prnp) genes and CWD infection in white-tailed deer from the CWD endemic area in south-central Wisconsin. To reduce problems due to admixture or disease-risk confounding, we used neutral genetic (microsatellite) data to identify closely related CWD-positive (n = 68) and CWD-negative (n = 91) female deer to serve as matched cases and controls. Cases and controls were also matched on factors (sex, location, age) previously demonstrated to affect CWD infection risk. For Prnp, deer with at least one Serine (S) at amino acid 96 were significantly less likely to be CWD-positive relative to deer homozygous for Glycine (G). This is the first characterization of genes associated with the complement system in white-tailed deer. No tests for association between any C1q polymorphism and CWD infection were significant at p < 0.05. After controlling for Prnp, we found weak support for an elevated risk of CWD infection in deer with at least one Glycine (G) at amino acid 56 of the C1qC gene. While we documented numerous amino acid polymorphisms in C1q genes none appear to be strongly associated with CWD susceptibility. ?? 2009 Elsevier B.V.

Blanchong, J. A.; Heisey, D. M.; Scribner, K. T.; Libants, S. V.; Johnson, C.; Aiken, J. M.; Langenberg, J. A.; Samuel, M. D.

2009-01-01

46

Safety of Tailings Dams  

NSDL National Science Digital Library

Contains information on different aspects of tailings dams; tailings dam properties, disasters, failure modes, slurry waves, stability analysis, and safe tailings disposal. Also includes a slope stability calculator and a tailings flow slide calculator.

2008-08-25

47

Evaluation of Serodiagnostic Assays for Mycobacterium bovis Infection in Elk, White-Tailed Deer, and Reindeer in the United States  

PubMed Central

In 2011, the United States Department of Agriculture conducted a project in which elk (Cervus elaphus spp.), white-tailed deer (WTD) (Odocoileus virginianus), and reindeer (Rangifer tarandus) were evaluated by the single cervical tuberculin test (SCT), comparative cervical tuberculin test (CCT), and serologic tests. The rapid antibody detection tests evaluated were the CervidTB Stat-Pak (Stat-Pak), and the Dual Path Platform VetTB (DPP). Blood was collected from presumably uninfected animals prior to tuberculin injection for the SCT. A total of 1,783 animals were enrolled in the project. Of these, 1,752 (98.3%) were classified as presumably uninfected, based on originating from a captive cervid herd with no history of exposure to TB. Stat-Pak specificity estimates were 92.4% in reindeer, 96.7% in WTD, and 98.3% in elk and were not significantly different from SCT specificity estimates. Using the DPP in series on Stat-Pak antibody-positive samples improved specificity in the three species. Thirty one animals were classified as confirmed infected, based on necropsy and laboratory results, and 27/31 were antibody positive on Stat-Pak for an estimated sensitivity of 87.1%. The study findings indicate that rapid serologic tests used in series are comparable to the SCT and CCT and may have a greater ability to detect TB-infected cervids.

Nelson, Jeffrey T.; Orloski, Kathleen A.; Lloyd, Audra L.; Camacho, Mark; Schoenbaum, Mark A.; Robbe-Austerman, Suelee; Thomsen, Bruce V.; Hall, S. Mark

2012-01-01

48

Serologic surveillance for the Lyme disease spirochete, Borrelia burgdorferi, in Minnesota by using white-tailed deer as sentinel animals.  

PubMed Central

To determine the effectiveness of white-tailed deer as sentinel animals in serologic surveillance programs for Borrelia burgdorferi, we performed enzyme-linked immunosorbent assay (ELISA) and Western immunoblotting analyses on 467 deer serum samples. The seropositivity rate in the ELISA was 5% for the 150 samples collected at the three sites in which the tick Ixodes scapularis was absent. The three sites with established I. scapularis populations had a seropositivity rate of 80% for 317 samples. Results were similar for two closely situated sites, one with an established I. scapularis population and one without; these sites were only 15 km apart. Rates of seropositivity were significantly higher in yearling and adult deer than in fawns. The mean numbers of bands seen on Western immunoblots were 3.0 for samples negative in the ELISA and 13.8 for samples positive in the ELISA; all of these samples were collected from sites in which I. scapularis was established. At sites in which I. scapularis was absent, the mean numbers of bands seen were 1.6 for samples negative in the ELISA and 8.2 for samples positive in the ELISA. There were 14 different B. burgdorferi antigens that reacted with more than 50% of the ELISA-positive samples from areas with I. scapularis. A 19.5-kDa antigen reacted with 94% of the ELISA-positive samples. Reactivity against OspA and OspB was weak a infrequent (2%). Serologic analysis of white-tailed deer sera appears to be an accurate and sensitive surveillance method for determining whether B. burgdorferi is present in specific geographic locations. Images

Gill, J S; McLean, R G; Shriner, R B; Johnson, R C

1994-01-01

49

Black-Tailed Prairie Dog  

USGS Multimedia Gallery

Black-tailed prairie dogs are quite susceptible to sylvatic plague, but a new plague vaccine put in their food shows significant promise in the laboratory. The prairie dogs transmit the disease to endangered black-footed ferrets, who eat the prairie dogs and are also quite susceptible to the disease...

2009-08-03

50

Chronic wasting disease infection patterns in female white-tailed deer related to demographics, genetic relationships, and spatial proximity of infected deer in southern Wisconsin  

USGS Publications Warehouse

Chronic wasting disease (CWD) is a fatal disease of white-tailed deer (Odocoileus virginianus) caused by transmissible protease resistant prions. Since the discovery of CWD in southern Wisconsin in 2001, more than 20,000 deer have been removed from a >2,500 km2 disease eradication zone surrounding the three initial cases. Nearly all deer removed were tested for CWD infection and sex, age, and harvest location were recorded. Our analysis used data from a 310 kin2 core study area where disease prevalence was higher than surrounding areas. We found no difference in harvest rates between CWD infected and non-infected deer. Ow results show that the probability of infection increased with age and that adult males were more likely to be infected than adult females. Six fawns tested positive for CWD, five fawns from the core study area, including the youngest (5 months) kee-ranging cervid to test positive. The increase in male prevalence with age is nearly twice the increase found in females. We concluded that CWD is not randomly distributed among deer and that differential transmission among sex and age classes is likely driving the observed patterns in disease prevalence. We discuss alternative hypotheses for CWD transmission and spread and, in addition, discuss several possible non-linear relationships between prevalence and age. Understanding CWD transmission in free-ranging cervid populations will be essential to the development of strategies to manage this disease in areas where CWD is found as well as for surveillance strategies in areas where CWD threatens to spread.

Grear, Daniel A.

2006-01-01

51

Consolidation of Tailings.  

National Technical Information Service (NTIS)

The integrity of cover systems placed on tailings impoundments will be affected by the potential for differential settlement of the tailings surface. This report reviews the phenomenon of consolidation for saturated and unsaturated tailings. The effect of...

J. D. Nelson R. E. Wardell S. R. Abt W. P. Staub

1983-01-01

52

Spatial and spatial-temporal clustering analysis of hemorrhagic disease in white-tailed deer in the southeastern USA: 1980-2003.  

PubMed

We used the space-time K function and Kulldorff's scan statistic to analyze the spatial and spatial-temporal clustering of hemorrhagic disease (HD) in white-tailed deer in Alabama, Georgia, South Carolina, North Carolina, and Tennessee. The HD occurrence data were binary presence/absence data acquired annually on a county basis from 1980 to 2003. Space-time K function was employed to globally examine the existence of spatial-temporal clustering in the HD data. Three approaches of Kulldorff's scan statistic, i.e., spatial clustering analysis for the entire period, spatial-temporal clustering analysis, and spatial clustering analysis by individual years, were applied to detect potential HD clusters. Statistically significant spatial clusters and spatial-temporal clusters were detected in the five southeastern states during the 24-year study period. Some clusters were observed in multiple years. Clusters were most evident in west Alabama, south Alabama, central South Carolina, and along the border between South Carolina and North Carolina. The identification of HD clusters may provide a means to better understand the causal factors related to the HD outbreaks. Results also have potential application in improving or designing effective surveillance programs for this disease. PMID:22554813

Xu, Bo; Madden, Marguerite; Stallknecht, David E; Hodler, Thomas W; Parker, Kathleen C

2012-10-01

53

Loss of a Tyrosine-Dependent Trafficking Motif in the Simian Immunodeficiency Virus Envelope Cytoplasmic Tail Spares Mucosal CD4 Cells but Does Not Prevent Disease Progression  

PubMed Central

A hallmark of pathogenic simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) infections is the rapid and near-complete depletion of mucosal CD4+ T lymphocytes from the gastrointestinal tract. Loss of these cells and disruption of epithelial barrier function are associated with microbial translocation, which has been proposed to drive chronic systemic immune activation and disease progression. Here, we evaluate in rhesus macaques a novel attenuated variant of pathogenic SIVmac239, termed ?GY, which contains a deletion of a Tyr and a proximal Gly from a highly conserved YxxØ trafficking motif in the envelope cytoplasmic tail. Compared to SIVmac239, ?GY established a comparable acute peak of viremia but only transiently infected lamina propria and caused little or no acute depletion of mucosal CD4+ T cells and no detectable microbial translocation. Nonetheless, these animals developed T-cell activation and declining peripheral blood CD4+ T cells and ultimately progressed with clinical or pathological features of AIDS. ?GY-infected animals also showed no infection of macrophages or central nervous system tissues even in late-stage disease. Although the ?GY mutation persisted, novel mutations evolved, including the formation of new YxxØ motifs in two of four animals. These findings indicate that disruption of this trafficking motif by the ?GY mutation leads to a striking alteration in anatomic distribution of virus with sparing of lamina propria and a lack of microbial translocation. Because these animals exhibited wild-type levels of acute viremia and immune activation, our findings indicate that these pathological events are dissociable and that immune activation unrelated to gut damage can be sufficient for the development of AIDS.

Breed, Matthew W.; Jordan, Andrea P. O.; Aye, Pyone P.; Lichtveld, Cornelis F.; Midkiff, Cecily C.; Schiro, Faith R.; Haggarty, Beth S.; Sugimoto, Chie; Alvarez, Xavier; Sandler, Netanya G.; Douek, Daniel C.; Kuroda, Marcelo J.; Pahar, Bapi; Piatak, Michael; Lifson, Jeffrey D.; Keele, Brandon F.; Hoxie, James A.

2013-01-01

54

Loss of a tyrosine-dependent trafficking motif in the simian immunodeficiency virus envelope cytoplasmic tail spares mucosal CD4 cells but does not prevent disease progression.  

PubMed

A hallmark of pathogenic simian immunodeficiency virus (SIV) and human immunodeficiency virus (HIV) infections is the rapid and near-complete depletion of mucosal CD4(+) T lymphocytes from the gastrointestinal tract. Loss of these cells and disruption of epithelial barrier function are associated with microbial translocation, which has been proposed to drive chronic systemic immune activation and disease progression. Here, we evaluate in rhesus macaques a novel attenuated variant of pathogenic SIVmac239, termed ?GY, which contains a deletion of a Tyr and a proximal Gly from a highly conserved YxxØ trafficking motif in the envelope cytoplasmic tail. Compared to SIVmac239, ?GY established a comparable acute peak of viremia but only transiently infected lamina propria and caused little or no acute depletion of mucosal CD4(+) T cells and no detectable microbial translocation. Nonetheless, these animals developed T-cell activation and declining peripheral blood CD4(+) T cells and ultimately progressed with clinical or pathological features of AIDS. ?GY-infected animals also showed no infection of macrophages or central nervous system tissues even in late-stage disease. Although the ?GY mutation persisted, novel mutations evolved, including the formation of new YxxØ motifs in two of four animals. These findings indicate that disruption of this trafficking motif by the ?GY mutation leads to a striking alteration in anatomic distribution of virus with sparing of lamina propria and a lack of microbial translocation. Because these animals exhibited wild-type levels of acute viremia and immune activation, our findings indicate that these pathological events are dissociable and that immune activation unrelated to gut damage can be sufficient for the development of AIDS. PMID:23152518

Breed, Matthew W; Jordan, Andrea P O; Aye, Pyone P; Lichtveld, Cornelis F; Midkiff, Cecily C; Schiro, Faith R; Haggarty, Beth S; Sugimoto, Chie; Alvarez, Xavier; Sandler, Netanya G; Douek, Daniel C; Kuroda, Marcelo J; Pahar, Bapi; Piatak, Michael; Lifson, Jeffrey D; Keele, Brandon F; Hoxie, James A; Lackner, Andrew A

2013-02-01

55

Uranium Mill Tailings Management  

SciTech Connect

This book presents the papers given at the Fifth Symposium on Uranium Mill Tailings Management. Advances made with regard to uranium mill tailings management, environmental effects, regulations, and reclamation are reviewed. Topics considered include tailings management and design (e.g., the Uranium Mill Tailings Remedial Action Project, environmental standards for uranium mill tailings disposal), surface stabilization (e.g., the long-term stability of tailings, long-term rock durability), radiological aspects (e.g. the radioactive composition of airborne particulates), contaminant migration (e.g., chemical transport beneath a uranium mill tailings pile, the interaction of acidic leachate with soils), radon control and covers (e.g., radon emanation characteristics, designing surface covers for inactive uranium mill tailings), and seepage and liners (e.g., hydrologic observations, liner requirements).

Nelson, J.D.

1982-01-01

56

Temporal and spatial dynamics of trypanosomes infecting the brush-tailed bettong (Bettongia penicillata): a cautionary note of disease-induced population decline  

PubMed Central

Background The brush-tailed bettong or woylie (Bettongia penicillata) is on the brink of extinction. Its numbers have declined by 90% since 1999, with their current distribution occupying less than 1% of their former Australian range. Woylies are known to be infected with three different trypanosomes (Trypanosoma vegrandis, Trypanosoma copemani and Trypanosoma sp. H25) and two different strains of T. copemani that vary in virulence. However, the role that these haemoparasites have played during the recent decline of their host is unclear and is part of ongoing investigation. Methods Woylies were sampled from five locations in southern Western Australia, including two neighbouring indigenous populations, two enclosed (fenced) populations and a captive colony. PCR was used to individually identify the three different trypanosomes from blood and tissues of the host, and to investigate the temporal and spatial dynamics of trypanosome infections. Results The spatial pattern of trypanosome infection varied among the five study sites, with a greater proportion of woylies from the Perup indigenous population being infected with T. copemani than from the neighbouring Kingston indigenous population. For an established infection, T. copemani detection was temporally inconsistent. The more virulent strain of T. copemani appeared to regress at a faster rate than the less virulent strain, with the infection possibly transitioning from the acute to chronic phase. Interspecific competition may also exist between T. copemani and T. vegrandis, where an existing T. vegrandis infection may moderate the sequential establishment of the more virulent T. copemani. Conclusion In this study, we provide a possible temporal connection implicating T. copemani as the disease agent linked with the recent decline of the Kingston indigenous woylie population within the Upper Warren region of Western Australia. The chronic association of trypanosomes with the internal organs of its host may be potentially pathogenic and adversely affect their long term fitness and coordination, making the woylie more susceptible to predation.

2014-01-01

57

Child with a Tail  

PubMed Central

Spina Bifida occulta usually presents with some cutaneous stigmata e.g. hair patch, sinus, lipoma, hyperpigmented skin and very rarely a congenital tail. A congenital tail may and may not be associated with spina bifida occulta and tethered cord. A four month old male child presented with congenital tail which was associated with spinal dysraphism and caused tethering of the cord itself. The tail and tethering lesion were excised successfully.

Sandhu, Asif Iqbal; Khan, Feeroz Alam; Ehmed, Ejaz; Dar, Sajid Hameed

2013-01-01

58

Length of Magnetospheric Tail  

Microsoft Academic Search

It is shown that hydromagnetic waves, through the action of radiation pressure, can prevent the tail of the magnetosphere from closing near the earth. It is argued that the tail of the magnetosphere may be 20 to 50 AU long. The tail can close at such heliocentric distances in the charge-exchange boundary shell where the solar wind is terminated and

A. J. Dessler

1964-01-01

59

Detailing the human tail.  

PubMed

There have been 23 true vestigial tails reported in the literature since 1884. A new case is described, and its magnetic resonance imaging and pathological features are presented. A review of the literature and analysis of the pathological characteristics reveal that the vestigial human tail may be associated with other abnormalities. Vestigial tails contain adipose and connective tissue, blood vessels, and nerves and are covered by skin. Bone, cartilage, notochord, and spinal cord elements are lacking. Tails are easily removed surgically without residual effects. Since 29% (7 of 24) of the reported tails have been associated with other malformations, careful clinical evaluation of these patients is recommended. PMID:3284435

Dubrow, T J; Wackym, P A; Lesavoy, M A

1988-04-01

60

Tails of Bacterial Motility  

NASA Astrophysics Data System (ADS)

The cytoplasm of living cells provides a complex fluid environment in which intracellular bacteria live and move. By analyzing the easily visible curved actin ``comet-tail'' of polymerization-based-motility bacteria such as Listeria monocytogenes, we can learn about sub-micron structure and dynamics of the tail and of the bacterial surface enzyme that catalyzes tail formation. By characterizing the motility, we can transform such motile systems into probes of the cytoplasmic environment.

Rutenberg, Andrew; Grant, Martin

2001-03-01

61

PREVALENCE OF THE LYME DISEASE SPIROCHETE, BORRELIA BURGDORFERI, IN DEER TICKS (IXODES DAMMINI) COLLECTED FROM WHITE-TAILED DEER (ODOCOILEUS WRGINIANUS) IN SAINT CROIX STATE PARK, MINNESOTA  

Microsoft Academic Search

During a special two-day hunt (11, 12 November 1989) in Saint Croix State Park, Minnesota (USA), one side of the neck for each of 146 white-tailed deer (Odocoileus virginianus) was examined for ticks. Of the 5,442 ticks collected, 90% (4,893) were the winter tick, Dermacentor albipictus, and 10% (549) were thedeer tick, Ixodes dammini, the primary vector of the causative

James S. Gill; Russell C. Johnson; Myra K. Sinclair; A. R. Weisbrod

62

Human tails and pseudotails.  

PubMed

A case of a tail in a 2-week-old infant is reported, and findings from a review of 33 previously reported cases of true tails and pseudotails are summarized. The true, or persistent, vestigial tail of humans arises from the most distal remnant of the embryonic tail. It contains adipose and connective tissue, central bundles of striated muscle, blood vessels, and nerves and is covered by skin. Bone, cartilage, notochord, and spinal cord are lacking. The true tail arises by retention of structures found normally in fetal development. It may be as long as 13 cm, can move and contract, and occurs twice as often in males as in females. A true tail is easily removed surgically, without residual effects. It is rarely familial. Pseudotails are varied lesions having in common a lumbosacral protrusion and a superficial resemblance to persistent vestigial tails. The most frequent cause of a pseudotail in a series of ten cases obtained from the literature was an anomalous prolongation of the coccygeal vertebrae. Additional lesions included two lipomas, and one each of teratoma, chondromegaly , glioma, and a thin, elongated parasitic fetus. PMID:6373560

Dao, A H; Netsky, M G

1984-05-01

63

Estimating tail probabilities  

SciTech Connect

This paper investigates procedures for univariate nonparametric estimation of tail probabilities. Extrapolated values for tail probabilities beyond the data are also obtained based on the shape of the density in the tail. Several estimators which use exponential weighting are described. These are compared in a Monte Carlo study to nonweighted estimators, to the empirical cdf, to an integrated kernel, to a Fourier series estimate, to a penalized likelihood estimate and a maximum likelihood estimate. Selected weighted estimators are shown to compare favorably to many of these standard estimators for the sampling distributions investigated.

Carr, D.B.; Tolley, H.D.

1982-12-01

64

Modelling Cometary Sodium Tails  

NASA Astrophysics Data System (ADS)

Neutral sodium is readily observed in cometary spectra and can be seen to form its own distinct tail around high activity comets. We present a brief overview of neutral sodium tail observations to date and discuss the importance of theoretical modelling in understanding these data. We have developed a new, 3D Monte-Carlo model of cometary sodium that incorporates several advancements over previous models. It includes weightings due to solar flux variation with heliocentric distance, and comprehensive handling of the Swings and Greenstein effects on the neutral sodium tail, which can have particularly dramatic effects in near-Sun comets. Some preliminary results from this model are presented, including predictions of the structure of the eagerly anticipated neutral sodium tail at Comet C/2012 S1 (ISON).

Birkett, K. S.; Jones, G. H.; Coates, A. J.

2013-09-01

65

Wagging tail vibration absorber  

NASA Technical Reports Server (NTRS)

A 750-foot cantilever length of extendible-tape boom (very low stiffness) was considered as the main system to be damped. A number of tail lengths were tried from 20 feet to 80 feet after which 40 feet was investigated further as a desirable compromise between performance and practical lengths. A 40-foot damping tail produced a damping effect on the main boom for the first mode equivalent in decay rate to 3.1 percent of critical damping. In this case the spring-hinge and tail were tuned to the main boom first mode frequency and the hinge damping was set at 30 percent of critical based on the tail properties. With this same setting, damping of the second mode was .4 percent and the third mode .1 percent.

Barclay, R. G.; Humphrey, P. W.

1969-01-01

66

Uranium Mill Tailings.  

National Technical Information Service (NTIS)

This bibliography contains information on uranium mill tailings included in the Department of Energy's Energy Data Base from January 1981 through October 1982. The abstracts are grouped by subject category as shown in the table of contents. Entries in the...

L. H. McLaren

1982-01-01

67

Combination of lung ultrasound (a comet-tail sign) and N-terminal pro-brain natriuretic peptide in differentiating acute heart failure from chronic obstructive pulmonary disease and asthma as cause of acute dyspnea in prehospital emergency setting  

PubMed Central

Introduction We studied the diagnostic accuracy of bedside lung ultrasound (the presence of a comet-tail sign), N-terminal pro-brain natriuretic peptide (NT-proBNP) and clinical assessment (according to the modified Boston criteria) in differentiating heart failure (HF)-related acute dyspnea from pulmonary (chronic obstructive pulmonary disease (COPD)/asthma)-related acute dyspnea in the prehospital setting. Methods Our prospective study was performed at the Center for Emergency Medicine, Maribor, Slovenia, between July 2007 and April 2010. Two groups of patients were compared: a HF-related acute dyspnea group (n = 129) and a pulmonary (asthma/COPD)-related acute dyspnea group (n = 89). All patients underwent lung ultrasound examinations, along with basic laboratory testing, rapid NT-proBNP testing and chest X-rays. Results The ultrasound comet-tail sign has 100% sensitivity, 95% specificity, 100% negative predictive value (NPV) and 96% positive predictive value (PPV) for the diagnosis of HF. NT-proBNP (cutoff point 1,000 pg/mL) has 92% sensitivity, 89% specificity, 86% NPV and 90% PPV. The Boston modified criteria have 85% sensitivity, 86% specificity, 80% NPV and 90% PPV. In comparing the three methods, we found significant differences between ultrasound sign and (1) NT-proBNP (P < 0.05) and (2) Boston modified criteria (P < 0.05). The combination of ultrasound sign and NT-proBNP has 100% sensitivity, 100% specificity, 100% NPV and 100% PPV. With the use of ultrasound, we can exclude HF in patients with pulmonary-related dyspnea who have positive NT-proBNP (> 1,000 pg/mL) and a history of HF. Conclusions An ultrasound comet-tail sign alone or in combination with NT-proBNP has high diagnostic accuracy in differentiating acute HF-related from COPD/asthma-related causes of acute dyspnea in the prehospital emergency setting. Trial registration ClinicalTrials.gov NCT01235182.

2011-01-01

68

The Tail Suspension Test  

PubMed Central

The tail-suspension test is a mouse behavioral test useful in the screening of potential antidepressant drugs, and assessing of other manipulations that are expected to affect depression related behaviors. Mice are suspended by their tails with tape, in such a position that it cannot escape or hold on to nearby surfaces. During this test, typically six minutes in duration, the resulting escape oriented behaviors are quantified. The tail-suspension test is a valuable tool in drug discovery for high-throughput screening of prospective antidepressant compounds. Here, we describe the details required for implementation of this test with additional emphasis on potential problems that may occur and how to avoid them. We also offer a solution to the tail climbing behavior, a common problem that renders this test useless in some mouse strains, such as the widely used C57BL/6. Specifically, we prevent tail climbing behaviors by passing mouse tails through a small plastic cylinder prior to suspension. Finally, we detail how to manually score the behaviors that are manifested in this test.

Terrillion, Chantelle E.; Piantadosi, Sean C.; Bhat, Shambhu; Gould, Todd D.

2012-01-01

69

Human tail: nature's aberration.  

PubMed

Human tail refers to a congenital cutaneous appendix protruding from the lumbosacral region. It is usually associated with an underlying spina bifida occulta, a form of spinal dysraphism. A contiguous fibrolipoma can sometimes be seen extending from the subcutaneous portion of the tail into the inferior spinal cord, resulting in tethered cord syndrome. Management of such lesions includes complete neurologic examination and magnetic resonance imaging. Early diagnosis and microsurgical intervention can prevent development or progression of severe neurologic defects in later life. PMID:22241711

Kumar, Dipti; Kapoor, Akshay

2012-07-01

70

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK ...  

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

REAR PROFILE OF TAIL FROM SECOND LEVEL OF TAIL DOCK STAND, SHOWING AIRCRAFT NUMBER (319), HORIZONTAL STABILIZER, TAIL CONE AND COOLING CTS FOR THE AUXILIARY POWER UNIT (APU), MECHANIC PAUL RIDEOUT IS LOWERING THE BALANCE PANELS ON THE STABILIZERS FOR LUBRICATION AND INSPECTION. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

71

Faun tail nevus  

PubMed Central

Faun tail nevus is a posterior midline cutaneous lesion of importance to dermatologists as it could be a cutaneous marker for its underlying spine and spinal cord anomaly. We report a 13-year-old girl with excessive hair growth over the lumbosacral region since birth. There was associated spinal anomaly with no neurological manifestation affecting the lower spinal cord. The diagnosis was made on clinical basis. The patient reported for cosmetic disability. This case is reported for its clinical importance.

Yamini, M.; Sridevi, K. S.; Babu, N. Prasanna; Chetty, Nanjappa G.

2011-01-01

72

Modelling Cometary Sodium Tails  

NASA Astrophysics Data System (ADS)

Neutral sodium is readily observed in cometary spectra and can be seen to form its own distinct tail at high activity comets. Solar radiation pressure accelerates the sodium atoms antisunward and, as strong sodium absorption lines are present in the solar spectrum, the magnitude of this force is dependent upon the Doppler shift of the incident solar radiation. Therefore the heliocentric velocity of the sodium atom directly determines its acceleration. This can produce unique effects, such as a stagnation region. Sodium is relatively easy to detect and so can potentially be used to trace mechanisms in the coma that are otherwise difficult to observe. The source of neutral sodium in the tail currently remains unknown. We have therefore developed a new, three dimensional Monte-Carlo model of neutral cometary sodium in order to facilitate testing of different source production functions. It includes weightings due to neutral sodium lifetime, variation of cometary sodium emission due to Fraunhofer absorption lines and solar flux variation with heliocentric distance. The Swings and Greenstein effects, which can have particularly dramatic effects in near-Sun comets, are also considered comprehensively. Preliminary results from this model are presented, focusing on a comparison of predictions of the neutral sodium tail of Comet C/2012 S1 (ISON) with initial observations.

Birkett, K. S.; Jones, G. H.; Coates, A. J.

2013-12-01

73

The tail plane  

NASA Technical Reports Server (NTRS)

This report deals with the calculation of the equilibrium, statistical stability, and damping of the tail plane. The author has simplified the present theory of longitudinal stability for the particular purpose of obtaining one definite coefficient characteristics of the effect of the tail plane. This coefficient is obtained by substituting certain aerodynamic characteristics and some dimensions of the airplane in a comparatively simple mathematical expression. Care has been taken to confine all aerodynamical information necessary for the calculation of the coefficient to the well-known curves representing the qualities of the wing section. This is done by making use of the present results of modern aerodynamics. All formulas and relations necessary for the calculation are contained in the paper. They give in some cases only an approximation of the real values. An example of calculation is added in order to illustrate the application of the method. The coefficient indicates not only whether the effect of the tail plane is great enough, but also whether it is not too great. It appears that the designer has to avoid a certain critical length of the fuselage, which inevitably gives rise to periodical oscillations of the airplane. The discussion also shows the way and in what direction to carry out experimental work.

Munk, Max M

1923-01-01

74

Preventive Effect of Pine Bark Extract (Flavangenol) on Metabolic Disease in Western Diet-Loaded Tsumura Suzuki Obese Diabetes Mice  

PubMed Central

It is known that the metabolic syndrome has a multi-factorial basis involving both genetic and environmental risk factors. In this study, Tsumura Suzuki Obese Diabetes (TSOD) mice, a mouse model of multi-factorial, hereditary, obese type II diabetes, were given a Western diet (WTD) as an environmental factor to prepare a disease model (TSOD-WTD) and to investigate the preventive effects of Pine bark extract (Flavangenol) against obesity and various features of metabolic disease appearing in this animal model. In contrast to control Tsumura Suzuki Non-obesity (TSNO) mice, TSOD mice were obese and suffered from other metabolic complications. WTD-fed TSOD mice developed additional features such as hyperinsulinemia, abnormal glucose/lipid metabolism and fatty liver. The treatment with Flavangenol had a suppressive effect on increase in body weight and accumulation of visceral and subcutaneous fat, and also showed preventive effects on symptoms related to insulin resistance, abnormal glucose/lipid metabolism and hypertension. Flavangenol also increased the plasma concentration of adiponectin and decreased the plasma concentration of TNF-?. We next investigated the effect of Flavangenol on absorption of meal-derived lipids. Flavangenol suppressed absorption of neutral fat in an olive-oil-loading test (in vivo) and showed an inhibitory effect on pancreatic lipase (in vitro). The above results suggest that Flavangenol has a preventive effect on severe metabolic disease due to multiple causes that involve both genetic and environmental risk factors. The mechanism of action might involve a partial suppressive effect of meal-derived lipids on absorption.

Shimada, Tsutomu; Kosugi, Mitsutaka; Tokuhara, Daisuke; Tsubata, Masahito; Kamiya, Tomoyasu; Sameshima, Mayu; Nagamine, Rika; Takagaki, Kinya; Miyamoto, Ken-ichi; Aburada, Masaki

2011-01-01

75

The geomagnetic tail  

SciTech Connect

A review is presented of the plasma sheet and lobe regions of the magnetotail, focusing principally on large-scale processes or microprocesses with some large-scale effects. Consideration is given to quiet and average structures, not necessarily related to activity phases, with quasi-steady convection aspects, and with the characteristics of dynamic phases including acceleration mechanisms and single particle aspects. Attention is given to various activity models, average and quiet time properties, properties and effects of magnetospheric convection, dynamics of the magnetotail, and the near tail, substorm current wedge.

Birn, J. (USAF, Geophysics Laboratory, Hanscom AFB, MA (United States))

1991-01-01

76

Surveillance for transmissible spongiform encephalopathy in scavengers of white-tailed deer carcasses in the chronic wasting disease area of wisconsin  

USGS Publications Warehouse

Chronic wasting disease (CWD), a class of neurodegenerative transmissible spongiform encephalopathies (TSE) occurring in cervids, is found in a number of states and provinces across North America. Misfolded prions, the infectious agents of CWD, are deposited in the environment via carcass remains and excreta, and pose a threat of cross-species transmission. In this study tissues were tested from 812 representative mammalian scavengers, collected in the CWD-affected area of Wisconsin, for TSE infection using the IDEXX HerdChek enzyme-linked immunosorbent assay (ELISA). Only four of the collected mammals tested positive using the ELISA, but these were negative when tested by Western blot. While our sample sizes permitted high probabilities of detecting TSE assuming 1% population prevalence in several common scavengers (93%, 87%, and 87% for raccoons, opossums, and coyotes, respectively), insufficient sample sizes for other species precluded similar conclusions. One cannot rule out successful cross-species TSE transmission to scavengers, but the results suggest that such transmission is not frequent in the CWD-affected area of Wisconsin. The need for further surveillance of scavenger species, especially those known to be susceptible to TSE (e.g., cat, American mink, raccoon), is highlighted in both a field and laboratory setting.

Jennelle, C. S.; Samuel, M. D.; Nolden, C. A.; Keane, D. P.; Barr, D. J.; Johnson, C.; Vanderloo, J. P.; Aiken, J. M.; Hamir, A. N.; Hoover, E. A.

2009-01-01

77

Helicopter Tail-Boom Strakes  

NASA Technical Reports Server (NTRS)

Yaw control and overall efficiency increased at hover and low speeds. Wind-tunnel investigation showed strake located on left side of tail boom has potential to reduce high adverse side loads on tail boom in hover and in sideward flight. Test demonstrated addition of single long strake to left side of tail boom most effective configuration for reducing left pedal requirements in right sideward flight.

Kelley, H. L.; Phelps, A. E., III; Wilson, J. C.

1986-01-01

78

Uranium mill tailings and radon  

SciTech Connect

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Hanchey, L A

1981-01-01

79

Uranium mill tailings and radon  

SciTech Connect

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the United States may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100.

Hanchey, L A

1981-04-01

80

3. VIEW OF WEST TAILING DAM, LARGE TANK, AND TAILING, ...  

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

3. VIEW OF WEST TAILING DAM, LARGE TANK, AND TAILING, LOOKING NORTHEAST. A SIX-FOOT SCALE IS LOCATED AGAINST WALL ON LEFT. PURPOSE OF TANK IS UNKNOWN, BUT APPEARS TO HAVE FALLEN FROM ITS ORIGINAL LOCATION AT THE MILL SITE, UP AND TO THE RIGHT OF THIS VIEW. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

81

Teratoma in Human Tail Lipoma  

Microsoft Academic Search

We report a case of a rare congenital teratoma that developed in a lipoma attached to a remnant human tail. A male newborn baby presented with a large, 3-cm mass with an open margin, which pedunculated from a tail attached to the midline skin of the coccygeal area. Magnetic resonance images demonstrated multiple sacral spinal bifida without cord tethering, and

Se-Hyuck Park; Jee Soon Huh; Ki Hong Cho; Yong Sam Shin; Se Hyck Kim; Young Hwan Ahn; Kyung Gi Cho; Soo Han Yoon

2005-01-01

82

Helicopter Tail Rotor Noise Analyses.  

National Technical Information Service (NTIS)

A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infini...

A. R. George S. T. Chou

1986-01-01

83

On Tail Biting Convolutional Codes  

Microsoft Academic Search

In this paper, we introduce generalized tail biting encoding as a means to ameliorate the rate deficiency caused by zero-tail convolutional encoding. This technique provides an important link between quasi-cyclic block and convolutional codes. Optimum and suboptimum decoding algorithms for these codes are described and their performance determined by analytical and simulation techniques.

H. H. Ma; J. Wolf

1986-01-01

84

Uranium Mill Tailings and Radon.  

National Technical Information Service (NTIS)

The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is e...

L. A. Hanchey

1981-01-01

85

Human tail with spina bifida.  

PubMed

A true human tail is a rare occurrence and is defined as a caudal, vestigial, midline protrusion with skin covering connective tissue, muscle, vessels and nerves. We report a case of true human tail in a child, which is a very rare happening in humans. PMID:19922280

Chauhan, S P S; Gopal, N N; Jain, Mohit; Gupta, Anurag

2009-12-01

86

Runaway tails in magnetized plasmas  

NASA Technical Reports Server (NTRS)

The evolution of a runaway tail driven by a dc electric field in a magnetized plasma is analyzed. Depending on the strength of the electric field and the ratio of plasma to gyrofrequency, there are three different regimes in the evolution of the tail. The tail can be (1) stable with electrons accelerated to large parallel velocities, (2) unstable to Cerenkov resonance because of the depletion of the bulk and the formation of a positive slope, (3) unstable to the anomalous Doppler resonance instability driven by the large velocity anisotropy in the tail. Once an instability is triggered (Cerenkov or anomalous Doppler resonance) the tail relaxes into an isotropic distribution. The role of a convection type loss term is also discussed.

Moghaddam-Taaheri, E.; Vlahos, L.; Rowland, H. L.; Papadopoulos, K.

1985-01-01

87

Recovery of Potash Feldspar from Molybdenite Tailings.  

National Technical Information Service (NTIS)

The Bureau of Mines used several laboratory batch flotation schemes combined with magnetic separation to investigate the feasibility of recovering potash feldspar and glass sands from molybdenite tailings. Four molybdenite tailings or prospective tailings...

W. H. Eddy G. V. Sullivan

1980-01-01

88

[Tail Plane Icing  

NASA Technical Reports Server (NTRS)

The Aviation Safety Program initiated by NASA in 1997 has put greater emphasis in safety related research activities. Ice-contaminated-tailplane stall (ICTS) has been identified by the NASA Lewis Icing Technology Branch as an important activity for aircraft safety related research. The ICTS phenomenon is characterized as a sudden, often uncontrollable aircraft nose- down pitching moment, which occurs due to increased angle-of-attack of the horizontal tailplane resulting in tailplane stall. Typically, this phenomenon occurs when lowering the flaps during final approach while operating in or recently departing from icing conditions. Ice formation on the tailplane leading edge can reduce tailplane angle-of-attack range and cause flow separation resulting in a significant reduction or complete loss of aircraft pitch control. In 1993, the Federal Aviation Authority (FAA) and NASA embarked upon a four-year research program to address the problem of tailplane stall and to quantify the effect of tailplane ice accretion on aircraft performance and handling characteristics. The goals of this program, which was completed in March 1998, were to collect aerodynamic data for an aircraft tail with and without ice contamination and to develop analytical methods for predicting the effects of tailplane ice contamination. Extensive dry air and icing tunnel tests which resulted in a database of the aerodynamic effects associated with tailplane ice contamination. Although the FAA/NASA tailplane icing program generated some answers regarding ice-contaminated-tailplane stall (ICTS) phenomena, NASA researchers have found many open questions that warrant further investigation into ICTS. In addition, several aircraft manufacturers have expressed interest in a second research program to expand the database to other tail configurations and to develop experimental and computational methodologies for evaluating the ICTS phenomenon. In 1998, the icing branch at NASA Lewis initiated a second multi-phase research program for tailplane icing (TIP II) to develop test methodologies and tailplane performance and handling qualities evaluation tools. The main objectives of this new NASA/Industry/Academia collaborative research programs were: (1) define and evaluate a sub-scale wind tunnel test methodology for determining tailplane performance degradation due to icing. (2) develop an experimental database of tailplane aerodynamic performance with and without ice contamination for a range of tailplane configurations. Wind tunnel tests were planned with representative general aviation aircraft, i.e., the Learjet 45, and a twin engine low speed aircraft. This report summarizes the research performed during the first year of the study, and outlines the work tasks for the second year.

1997-01-01

89

Helicopter tail rotor noise analyses  

NASA Technical Reports Server (NTRS)

A study was made of helicopter tail rotor noise, particularly that due to interactions with the main rotor tip vortices, and with the fuselage separation mean wake. The tail rotor blade-main rotor tip vortex interaction is modelled as an airfoil of infinite span cutting through a moving vortex. The vortex and the geometry information required by the analyses are obtained through a free wake geometry analysis of the main rotor. The acoustic pressure-time histories for the tail rotor blade-vortex interactions are then calculated. These acoustic results are compared to tail rotor loading and thickness noise, and are found to be significant to the overall tail rotor noise generation. Under most helicopter operating conditions, large acoustic pressure fluctuations can be generated due to a series of skewed main rotor tip vortices passing through the tail rotor disk. The noise generation depends strongly upon the helicopter operating conditions and the location of the tail rotor relative to the main rotor.

George, A. R.; Chou, S. T.

1986-01-01

90

Mercury's Dynamic Magnetic Tail  

NASA Technical Reports Server (NTRS)

The Mariner 10 and MESSENGER flybys of Mercury have revealed a magnetosphere that is likely the most responsive to upstream interplanetary conditions of any in the solar system. The source of the great dynamic variability observed during these brief passages is due to Mercury's proximity to the Sun and the inverse proportionality between reconnection rate and solar wind Alfven Mach number. However, this planet's lack of an ionosphere and its small physical dimensions also contribute to Mercury's very brief Dungey cycle, approx. 2 min, which governs the time scale for internal plasma circulation. Current observations and understanding of the structure and dynamics of Mercury's magnetotail are summarized and discussed. Special emphasis will be placed upon such questions as: 1) How much access does the solar wind have to this small magnetosphere as a function of upstream conditions? 2) What roles do heavy planetary ions play? 3) Do Earth-like substorms take place at Mercury? 4) How does Mercury's tail respond to extreme solar wind events such coronal mass ejections? Prospects for progress due to advances in the global magnetohydrodynamic and hybrid simulation modeling and the measurements to be taken by MESSENGER after it enters Mercury orbit on March 18, 2011 will be discussed.

Slavin, James A.

2010-01-01

91

Active Alu Element "A-Tails": Size Does Matter  

PubMed Central

Long and short interspersed elements (LINEs and SINEs) are retroelements that make up almost half of the human genome. L1 and Alu represent the most prolific human LINE and SINE families, respectively. Only a few Alu elements are able to retropose, and the factors determining their retroposition capacity are poorly understood. The data presented in this paper indicate that the length of Alu “A-tails” is one of the principal factors in determining the retropositional capability of an Alu element. The A stretches of the Alu subfamilies analyzed, both old (Alu S and J) and young (Ya5), had a Poisson distribution of A-tail lengths with a mean size of 21 and 26, respectively. In contrast, the A-tails of very recent Alu insertions (disease causing) were all between 40 and 97 bp in length. The L1 elements analyzed displayed a similar tendency, in which the “disease”-associated elements have much longer A-tails (mean of 77) than do the elements even from the young Ta subfamily (mean of 41). Analysis of the draft sequence of the human genome showed that only about 1000 of the over one million Alu elements have tails of 40 or more adenosine residues in length. The presence of these long A stretches shows a strong bias toward the actively amplifying subfamilies, consistent with their playing a major role in the amplification process. Evaluation of the 19 Alu elements retrieved from the draft sequence of the human genome that are identical to the Alu Ya5a2 insert in the NF1 gene showed that only five have tails with 40 or more adenosine residues. Sequence analysis of the loci with the Alu elements containing the longest A-tails (7 of the 19) from the genomes of the NF1 patient and the father revealed that there are at least two loci with A-tails long enough to serve as source elements within our model. Analysis of the A-tail lengths of 12 Ya5a2 elements in diverse human population groups showed substantial variability in both the Alu A-tail length and sequence homogeneity. On the basis of these observations, a model is presented for the role of A-tail length in determining which Alu elements are active. [The sequence data from this study have been submitted to GenBank under accession nos. AF504933–AF505511.

Roy-Engel, Astrid M.; Salem, Abdel-Halim; Oyeniran, Oluwatosin O.; Deininger, Lisa; Hedges, Dale J.; Kilroy, Gail E.; Batzer, Mark A.; Deininger, Prescott L.

2002-01-01

92

Bearing capacity of desiccated tailings  

SciTech Connect

The development of matric suctions in soils contributes to their shear strength, resulting in an enhanced factor of safety against bearing-capacity failure. In this paper, matric suction profiles of desiccated mine tailings are predicted from a steady-state solution for evaporative conditions, and from an isothermal mathematical model that simulates liquid and vapor water flow through soils. The shear-strength envelope with respect to matric suction is established by testing reconstituted tailings samples in a modified triaxial cell, in which matric suction can be controlled. The contribution of matric suction to the shear strength is interpreted as an additional apparent cohesion for use in bearing-capacity calculations. Because of the nonlinearity of the shear-strength profile, a numerical method of analysis is adopted to predict the ultimate bearing capacity of the desiccated tailings. A subsequent decrease in bearing capacity following 2D water infiltration into a partially capped tailings deposit and accompanying suction loss is investigated.

Rassam, D.W.; Williams, D.J. [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Civil Engineering] [Univ. of Queensland, Brisbane, Queensland (Australia). Dept. of Civil Engineering

1999-07-01

93

Theseus Tail Being Unloaded  

NASA Technical Reports Server (NTRS)

The tail of the Theseus prototype research aircraft is seen here being unloaded at NASA's Dryden Flight Research Center, Edwards, California, in May of 1996. The Theseus aircraft, built and operated by Aurora Flight Sciences Corporation, Manassas, Virginia, was a unique aircraft flown at NASA's Dryden Flight Research Center, Edwards, California, under a cooperative agreement between NASA and Aurora. Dryden hosted the Theseus program, providing hangar space and range safety for flight testing. Aurora Flight Sciences was responsible for the actual flight testing, vehicle flight safety, and operation of the aircraft. The Theseus remotely piloted aircraft flew its maiden flight on May 24, 1996, at Dryden. During its sixth flight on November 12, 1996, Theseus experienced an in-flight structural failure that resulted in the loss of the aircraft. As of the beginning of the year 2000, Aurora had not rebuilt the aircraft. Theseus was built for NASA under an innovative, $4.9 million fixed-price contract by Aurora Flight Sciences Corporation and its partners, West Virginia University, Morgantown, West Virginia, and Fairmont State College, Fairmont, West Virginia. The twin-engine, unpiloted vehicle had a 140-foot wingspan, and was constructed largely of composite materials. Powered by two 80-horsepower, turbocharged piston engines that drove twin 9-foot-diameter propellers, Theseus was designed to fly autonomously at high altitudes, with takeoff and landing under the active control of a ground-based pilot in a ground control station 'cockpit.' With the potential ability to carry 700 pounds of science instruments to altitudes above 60,000 feet for durations of greater than 24 hours, Theseus was intended to support research in areas such as stratospheric ozone depletion and the atmospheric effects of future high-speed civil transport aircraft engines. Instruments carried aboard Theseus also would be able to validate satellite-based global environmental change measurements. Dryden's Project Manager was John Del Frate.

1996-01-01

94

The structure of comet tails  

NASA Technical Reports Server (NTRS)

Present models of the plasma tails of comets are described. The interaction of the solar wind with ions from the cometary atmosphere is discussed, and the phenomenon of magnetic reconnection observed in plasma tails is explained. The accomplishments of the ICE mission to the Comet Giacobini-Zinner are summarized, and the tasks and expected contributions from upcoming Soviet, European, and Japanese missions to Comet Halley are addressed.

Brandt, J. C.; Niedner, M. B., Jr.

1986-01-01

95

Financial Risk and Heavy Tails  

Microsoft Academic Search

It is of great importance for those in charge of managing risk to understand how financial asset returns are distributed. Practitioners often assume for convenience that the distribution is normal. Since the 1960s, however, empirical evidence has led many to reject this assumption in favor of various heavy-tailed alternatives. In a heavy-tailed distribution the likelihood that one encounters significant deviations

Brendan O. Bradley; Murad S. Taqqu

2001-01-01

96

Sirenomelia apus with vestigial tail.  

PubMed

Sirenomelia is an exceptionally rare congenital malformation characterized by complete or near complete fusion of lower limbs. A newborn with clinical features of sirenomelia including fused lower limbs in medial position, absent fibula, anal atresia, complete absence of urogenital system (bilateral renal agenesis, absent ureters, urinary bladder, absent internal and external genitalia), a single umbilical artery and a vestigial tail is reported. Association of vestigial tail with sirenomelia is not described in the literature. PMID:15876775

Parikh, Tushar B; Nanavati, Ruchi N; Udani, Rekha H

2005-04-01

97

Morphogenesis of the T4 tail and tail fibers  

PubMed Central

Remarkable progress has been made during the past ten years in elucidating the structure of the bacteriophage T4 tail by a combination of three-dimensional image reconstruction from electron micrographs and X-ray crystallography of the components. Partial and complete structures of nine out of twenty tail structural proteins have been determined by X-ray crystallography and have been fitted into the 3D-reconstituted structure of the "extended" tail. The 3D structure of the "contracted" tail was also determined and interpreted in terms of component proteins. Given the pseudo-atomic tail structures both before and after contraction, it is now possible to understand the gross conformational change of the baseplate in terms of the change in the relative positions of the subunit proteins. These studies have explained how the conformational change of the baseplate and contraction of the tail are related to the tail's host cell recognition and membrane penetration function. On the other hand, the baseplate assembly process has been recently reexamined in detail in a precise system involving recombinant proteins (unlike the earlier studies with phage mutants). These experiments showed that the sequential association of the subunits of the baseplate wedge is based on the induced-fit upon association of each subunit. It was also found that, upon association of gp53 (gene product 53), the penultimate subunit of the wedge, six of the wedge intermediates spontaneously associate to form a baseplate-like structure in the absence of the central hub. Structure determination of the rest of the subunits and intermediate complexes and the assembly of the hub still require further study.

2010-01-01

98

SUBAQUEOUS DISPOSAL OF MILL TAILINGS  

SciTech Connect

A study of mill tailings and sulfide minerals was carried out in order to understand their behavior under subaqueous conditions. A series of electrochemical experiments, namely, cyclic voltammetry, electrochemical impedance spectroscopy and galvanic coupling tests were carried out in artificial seawater and in pH 6.8 buffer solutions with chloride and ferric salts. Two mill tailings samples, one from the Kensington Mine, Alaska, and the other from the Holden Mine, Washington, were studied along with pyrite, galena, chalcopyrite and copper-activated sphalerite. SEM analysis of mill tailings revealed absence of sulfide minerals from the Kensington Mine mill tailings, whereas the Holden Mine mill tailings contained approximately 8% pyrite and 1% sphalerite. In order to conduct electrochemical tests, carbon matrix composite (CMC) electrodes of mill tailings, pyrite and galena were prepared and their feasibility was established by conducting a series of cyclic voltammetry tests. The cyclic voltammetry experiments carried out in artificial seawater and pH 6.8 buffer with chloride salts showed that chloride ions play an important role in the redox processes of sulfide minerals. For pyrite and galena, peaks were observed for the formation of chloride complexes, whereas pitting behavior was observed for the CMC electrodes of the Kensington Mine mill tailings. The electrochemical impedance spectroscopy conducted in artificial seawater provided with the Nyquist plots of pyrite and galena. The Nyquist plots of pyrite and galena exhibited an inert range of potential indicating a slower rate of leaching of sulfide minerals in marine environments. The galvanic coupling experiments were carried out to study the oxidation of sulfide minerals in the absence of oxygen. It was shown that in the absence of oxygen, ferric (Fe3+) ions might oxidize the sulfide minerals, thereby releasing undesirable oxidation products in the marine environment. The source of Fe{sup 3{minus}} ions may be attributed to iron-bearing sulfide (and oxide) minerals present in the mill tailings. However, the concentration of available Fe{sup 3{minus}} ions can be reduced by the precipitation of insoluble ferric hydroxides (Fe(OH ){sub 3}) by seawater due to its near neutral pH. In such case, the oxidation of a sulfide mineral is inhibited due to the absence of an oxidizing agent (viz. oxygen and/or Fe{sup 3+} ions). The experiments carried out in this study provided a better understanding of behavior of sulfide minerals and mill tailings in subaqueous conditions and may be useful for further investigation of sulfide minerals and mill tailings in other environments.

Neeraj K. Mendiratta; Roe-Hoan Yoon; Paul Richardson

1999-09-03

99

Development of a Model of Natural Infection with Mycobacterium bovis in White-Tailed Deer  

Microsoft Academic Search

The objective of this study was to develop a suitable experimental model of natural Mycobacterium bovis infection in white-tailed deer (Odocoileus virginianus), describe the distribution and character of tuberculous lesions, and to examine possible routes of disease transmission. In October 1997, 10 mature female white-tailed deer were inoculated by intratonsilar instillation of 2 3 103 (low dose) or 2 3

Mitchell V. Palmer; Diana L. Whipple; Steven C. Olsen

1999-01-01

100

Does climate have heavy tails?  

NASA Astrophysics Data System (ADS)

When we speak about a distribution with heavy tails, we are referring to the probability of the existence of extreme values will be relatively large. Several heavy-tail models are constructed from Poisson processes, which are the most tractable models. Among such processes, one of the most important are the Lévy processes, which are those process with independent, stationary increments and stochastic continuity. If the random component of a climate process that generates the data exhibits a heavy-tail distribution, and if that fact is ignored by assuming a finite-variance distribution, then there would be serious consequences (in the form, e.g., of bias) for the analysis of extreme values. Yet, it appears that it is an open question to what extent and degree climate data exhibit heavy-tail phenomena. We present a study about the statistical inference in the presence of heavy-tail distribution. In particular, we explore (1) the estimation of tail index of the marginal distribution using several estimation techniques (e.g., Hill estimator, Pickands estimator) and (2) the power of hypothesis tests. The performance of the different methods are compared using artificial time-series by means of Monte Carlo experiments. We systematically apply the heavy tail inference to observed climate data, in particular we focus on time series data. We study several proxy and directly observed climate variables from the instrumental period, the Holocene and the Pleistocene. This work receives financial support from the European Commission (Marie Curie Initial Training Network LINC, No. 289447, within the 7th Framework Programme).

Bermejo, Miguel; Mudelsee, Manfred

2013-04-01

101

Uranium-mill-tailings conditioning technology  

Microsoft Academic Search

Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is sntering tailings at high temperatures (1100 to 1200°C) to radically alter the structure of tailings. This thermal stabilization at 1200°C reduced radon emanation power for tailings sands

D. R. Dreesen; E. J. Cokal; P. D. OBrien; E. F. Thode; L. E. Wangen; J. M. Williams

1982-01-01

102

Magnetohydrodynamics of Mira's cometary tail  

NASA Astrophysics Data System (ADS)

Aims: The asymptotic giant-branch, long-period variable star Mira exhibits a 4 parsec long cometary tail in the far-ultraviolet. We address the issue of the origin of this structure and its emission process by simulating the transition of this star from the interstellar medium to the Local Bubble, which is a tenuous, high-pressure medium. Methods: We use the hydrodynamic and the magnetohydrodynamic modules of the PLUTO astrophysical code to carry out our simulations. We study the system without a cooling function, with a simplified exponential cooling function, and with a simplified nonequilibrium cooling function. Results: We find evidence that magnetohydrodynamics constrain the shape of the cometary tail and explain features of its far-ultraviolet emission. We suggest an emission process that involves C0 excitation through inelastic electron collisions and a two-photon continuum to explain the luminosity of Mira's tail.

Gómez, E. A.

2013-10-01

103

Magnetospheric Substorms and Tail Dynamics  

NASA Technical Reports Server (NTRS)

This grant funded several studies of magnetospheric substorms and their effect on the dynamics of the earth's geomagnetic tail. We completed an extensive study of plasmoids, plasma/magnetic field structures that travel rapidly down the tail, using data from the ISEE 3 and IMP 8 spacecraft. This study formed the PhD thesis of Mark Moldwin. We found that magnetically plasmoids are better described as flux-ropes (twisted magnetic flux tubes) rather than plasma bubbles, as had been generally regarded up to that point (Moldwin and Hughes, 1990; 1991). We published several examples of plasmoids observed first in the near tail by IMP 8 and later in the distant tail by ISEE 3, confirming their velocities down tail. We showed how the passage of plasmoids distorts the plasma sheet. We completed the first extensive statistical survey of plasmoids that showed how plasmoids evolve as they move down tail from their formation around 30 RE to ISEE 3 apogee at 240 RE. We established a one-to-one correspondence between the observation of plasmoids in the distant tail and substorm onsets at earth or in the near tail. And we showed that there is a class of plasmoid-like structures that move slowly earthward, especially following weak substorms during northward IMF. Collectively this work constituted the most extensive study of plasmoids prior to the work that has now been done with the GEOTAIL spacecraft. Following our work on plasmoids, we turned our attention to signatures of substorm onset observed in the inner magnetosphere near geosynchronous orbit, especially signatures observed by the CRRES satellite. Using data from the magnetometer, electric field probe, plasma wave instrument, and low energy plasma instrument on CRRES we were able to better document substorm onsets in the inner magnetosphere than had been possible previously. Detailed calculation of the Poynting flux showed energy exchange between the magnetosphere and ionosphere, and a short burst of tailward convective flow just prior to onset, suggesting the active role of the ionosphere in the onset process, and adding credibility to the ballooning instability theory of substorm onset. This grant also supported a number of other substorm studies and reviews. These are represented by the list of publications and meeting presentations resulting out of this grant.

Hughes, W. Jeffrey

1998-01-01

104

Estimating Tails of Probability Distributions  

Microsoft Academic Search

We study the asymptotic properties of estimators of the tail of a distribution based on the excesses over a threshold. A key idea is the use of Pickands' generalised Pareto distribution and its fitting, in most cases, by the method of maximum likelihood. The results cover all three limiting types of extreme value theory. We propose a new estimator for

Richard L. Smith

1987-01-01

105

Uranium-Mill-Tailings Conditioning Technology.  

National Technical Information Service (NTIS)

Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is ...

D. R. Dreesen E. J. Cokal P. D. O'Brien E. F. Thode L. E. Wangen

1982-01-01

106

Uranium Mill Tailings Remedial Action Technology.  

National Technical Information Service (NTIS)

The uranium milling process involves the hydrometallurgical extraction of uranium from ores and the resultant generation of large quantities of waste referred to as tailings. Uranium mill tailings have been identified as requiring remediation because they...

J. N. Hartley G. W. Gee

1984-01-01

107

Turbo decoding with tail-biting trellises  

Microsoft Academic Search

Tail-biting codes are considered as component codes for parallel concatenated block codes. Based on the two-dimensional weight distribution of tail-biting codes, we calculate the minimum distance of the parallel concatenated code and give guidelines on how to choose good tail-biting component codes. We show how to encode tail-biting codes using systematic feedback encoders, which is an important design criterion. The

C. Weiss; Christian Bettstetter; Sven Riedel

1998-01-01

108

Colonization of mine tailings by marine invertebrates  

Microsoft Academic Search

An experiment was conducted to determine if a tailings substrate would inhibit recolonization of benthic macrofauna upon closure of a submarine tailings disposal (STD) operation. Trays of defaunated marine sediment, serving as a reference, and trays of tailings from a proposed gold mine were placed at 21 m depth on the ocean floor to allow colonization via settlement from the

E. R Kline; M. S Stekoll

2001-01-01

109

Tail Dependence for Heavy-Tailed Scale Mixtures of Multivariate Distributions  

Microsoft Academic Search

The tail dependence of multivariate distributions is frequently studied via the tool of copulas. This paper develops a general method, which is based on multivariate regular variation, to evaluate the tail dependence of heavy-tailed scale mixtures of multivariate distributions, whose copulas are not explicitly accessible. Tractable formulas for tail dependence parameters are derived, and a sucient condition under which the

Haijun Li; Yannan Grace Sun

110

Spatial and Temporal Analysis of Contact Rates in Female White-Tailed Deer  

Microsoft Academic Search

White-tailed deer (Odocoileus virginianus) are important game mammals and potential reservoirs of diseases of domestic livestock; thus, diseases of deer are of great concern to wildlife managers. Contact, either direct or indirect, is necessary for disease transmission, but we know little about the ecological contexts that promote intrasexual contact among deer. Using pair-wise direct contacts estimated from Global Positioning System

Lene J. Kjær; Eric M. Schauber; Clayton K. Nielsen

2008-01-01

111

Environmentally safe design of tailing dams for the management of iron ore tailings in Indian context.  

PubMed

The need for the disposal of iron ore tailings in an enviornmentally firiendly manner is of great concern. This paper investigates the soil engineering properties for the construction of iron ore tailing dam, its foundation, construction materials and design data used for the construction analysis of the tailing dam. Geophysical investigations were carried out to establish the bedrock below the spillway. A computer programme taking into account the Swedish Slip Circle Method of analysis was used in the stability analysis of dam. It also focuses on the charactierstics of the tailings reponsible for the determination of optimum size of tailing pond for the containment of the tailings. The studies on the settling characteristics of tailings indicate much less area in comparison to the area provided in the existing tailing ponds in India. In the proposed scheme, it is suggested to provide an additional unit of sedimentation tank before the disposal of tailings to the tailing pond. PMID:17051916

Ghose, Mrinal K; Sen, P K

2005-10-01

112

Uranium mill tailings quarterly report, January-March 1982  

Microsoft Academic Search

Progress is reported on: radon barrier systems for uranium mill tailings; liner evaluation for uranium mill tailings; revegetation\\/rock cover for stabilization of inactive U-tailings sites; and application of long-term chemical biobarriers for uranium tailings.

Latkovich

1982-01-01

113

Extracting aluminum from dross tailings  

NASA Astrophysics Data System (ADS)

Aluminum dross tailings, an industrial waste, from the Egyptian Aluminium Company (Egyptalum) was used to produce two types of alums: aluminum-sulfate alum [itAl2(SO4)3.12H2O] and ammonium-aluminum alum [ (NH 4)2SO4AL2(SO4)3.24H2O]. This was carried out in two processes. The first process is leaching the impurities using diluted H2SO4 with different solid/liquid ratios at different temperatures to dissolve the impurities present in the starting material in the form of solute sulfates. The second process is the extraction of aluminum (as aluminum sulfate) from the purifi ed aluminum dross tailings thus produced. The effects of temperature, time of reaction, and acid concentration on leaching and extraction processes were studied. The product alums were analyzed using x-ray diffraction and thermal analysis techniques.

Amer, A. M.

2002-11-01

114

Bearing capacity of desiccated tailings  

Microsoft Academic Search

The development of matric suctions in soils contributes to their shear strength, resulting in an enhanced factor of safety against bearing-capacity failure. In this paper, matric suction profiles of desiccated mine tailings are predicted from a steady-state solution for evaporative conditions, and from an isothermal mathematical model that simulates liquid and vapor water flow through soils. The shear-strength envelope with

Daud W. Rassam; David J. Williams

1999-01-01

115

Tadpole tail regeneration in Xenopus.  

PubMed

Some organisms have a remarkable ability to heal wounds without scars and to regenerate complex tissues following injury. By gaining a more complete understanding of the biological mechanisms that promote scar-free healing and tissue regeneration, it is hoped that novel treatments that can enhance the healing and regenerative capacity of human patients can be found. In the present article, we briefly examine the genetic, molecular and cellular mechanisms underlying the regeneration of the Xenopus tadpole tail. PMID:24849228

Chen, Yaoyao; Love, Nick R; Amaya, Enrique

2014-06-01

116

Chapter 17 Placing soil covers on soft mine tailings  

Microsoft Academic Search

Mine tailings are typically silt-sized materials derived from mineral processing, which are conventionally pumped as an aqueous slurry, thickened tailings or tailings paste to a tailings storage facility, usually a surface impoundment. On discharge, an aqueous tailings slurry forms a delta, on which the tailings particles undergo hydraulic sorting, sedimentation and self-weight consolidation, and desiccation on exposure to evaporation. Their

David John Williams

2005-01-01

117

The hydrogeology of a tailings impoundment formed by central discharge of thickened tailings: implications for tailings management  

NASA Astrophysics Data System (ADS)

The Kidd Creek Cu-Zn sulfide mine is located near Timmins, Ontario. Mill tailings are thickened and deposited as a slurry in a circular impoundment with an area of approximately 1200 ha. Deposition of tailings as a thickened slurry from a central discharge ramp results in a conical-shaped tailings deposit with low perimeter dykes, a uniform grain-size distribution, uniform and low hydraulic conductivity, and a tension-saturated zone above the water table up to 5 to 6 m thick. These characteristics provide benefits over conventionally disposed tailings with respect to tailings management. The thick tension-saturated zone within the tailings limits the thickness of unsaturated tailings that are susceptible to rapid sulfide oxidation. The conical shape of the deposit results in the formation of a recharge area near the centre of the impoundment and discharge in the peripheral areas. In contrast, the elevated nature of many conventional, unthickened tailings impoundments results in recharge over most of the surface of the impoundment, with discharge occurring outside the impoundment through large containment dykes. Three-dimensional pore water flow modelling suggests that approximately 90% of the total discharge from the thickened tailings occurs within the tailings impoundment. When discharge is confined within the impoundment, there is improved control over low-quality effluent, and an opportunity to design passive control measures to reduce treatment costs and minimize environmental impacts.

Al, Tom A.; Blowes, David W.

1999-06-01

118

Suppression of epidemic outbreaks with heavy-tailed contact dynamics  

NASA Astrophysics Data System (ADS)

We study the epidemic spreading process following contact dynamics with heavy-tailed waiting time distributions. We show both analytically and numerically that the temporal heterogeneity of contact dynamics can significantly suppress the disease's transmissibility, hence the size of epidemic outbreak, obstructing the spreading process. Furthermore, when the temporal heterogeneity is strong enough, one obtains the vanishing transmissibility for any finite recovery time and regardless of the underlying structure of contacts, the condition of which was derived.

Min, Byungjoon; Goh, K.-I.; Kim, I.-M.

2013-09-01

119

Enhancing the safety of tailings management facilities  

SciTech Connect

Unsafe tailings management facilities (TMFs) have caused serious accidents in Europe threatening human health/life and the environment. While advanced design, construction and management procedures are available, their implementation requires greater emphasis. An integrated research project funded by the European Union was carried out between 2002 and 2005 with the overall goal of improving the safety of TMFs (Sustainable Improvement in Safety of Tailings Facilities - TAILSAFE, http://www.tailsafe.com/). The objective of TAILSAFE was to develop and apply methods of parameter evaluation and measurement for the assessment and improvement of the safety state of tailings facilities, with particular attention to the stability of tailings dams and slurries, the special risks inherent when such materials include toxic or hazardous wastes, and authorization and management procedures for tailings facilities. Aspects of tailings facilities design, water management and slurry transport, non-destructive and minimally intrusive testing methods, monitoring and the application of sensors, intervention and remediation options were considered in TAILSAFE. A risk reduction framework (the TAILSAFE Parameter Framework) was established to contribute to the avoidance of catastrophic accidents and hazards from tailings facilities. Tailings from the mining and primary processing of metals, minerals and coal were included within the scope of TAILSAFE. The project focused on the avoidance of hazards by developing procedures and methods for investigating and improving the stability of tailings dams and tailings bodies.

Meggyes, T.; Niederleithinger, E.; Witt, K.J.; Csovari, M.; Kreft-Burman, K.; Engels, J.; McDonald, C.; Roehl, K.E. [BAM, Berlin (Germany). Federal Institute for Material Research & Testing

2008-07-01

120

Gelsolin: the tail of a molecular gymnast.  

PubMed

Gelsolin superfamily members are Ca(2+) -dependent, multidomain regulators of the actin cytoskeleton. Calcium binding activates gelsolin by inducing molecular gymnastics (large-scale conformational changes) that expose actin interaction surfaces by releasing a series of latches. A specialized tail latch has distinguished gelsolin within the superfamily. Active gelsolin exhibits actin filament severing and capping, and actin monomer sequestering activities. Here, we analyze a combination of sequence, structural, biophysical and biochemical data to assess whether the molecular plasticity, regulation and actin-related properties of gelsolin are also present in other superfamily members. We conclude that all members of the superfamily will be able to transition between a compact conformation and a more open form, and that most of these open forms will interact with actin. Supervillin, which lacks the severing domain 1 and the F-actin binding-site on domain 2, is the clear exception. Eight calcium-binding sites are absolutely conserved in gelsolin, adseverin, advillin and villin, and compromised to increasing degrees in CapG, villin-like protein, supervillin and flightless I. Advillin, villin and supervillin each contain a potential tail latch, which is absent from CapG, adseverin and flightless I, and ambiguous in villin-like protein. Thus, calcium regulation will vary across the superfamily. Potential novel isoforms of the superfamily suggest complex regulation at the gene, transcript and protein levels. We review animal, clinical and cellular data that illuminate how the regulation of molecular flexibility in gelsolin-like proteins permits cells to exploit the force generated from actin polymerization to drive processes such as cell movement in health and disease. PMID:23749648

Nag, Shalini; Larsson, Mårten; Robinson, Robert C; Burtnick, Leslie D

2013-07-01

121

CAUSES OF MORTALITY IN WHITE-TAILED SEA EAGLES FROM GERMANY  

Microsoft Academic Search

White-tailed Sea Eagles Haliaeetus albicilla found moribund or dead in the field were submitted for necropsy to the Institute for Zoo and Wildlife Research (IZW) and to the Institute for Food, Drugs and Animal Diseases (ILAT), Berlin, Germany. The moribund eagles had died in rehabilitation stations or were euthanized. Onehundred-twenty White-tailed Sea Eagles were examined between 1990 and 2000, comprising

Oliver Krone; Torsten Langgemach; Paul Sömmer; Norbert Kenntner

122

Thermal stabilization of uranium mill tailings  

Microsoft Academic Search

The treatment of uranium mill tailings by high-temperature sintering (>1050°C) has been investigated as a means of controlling the release of ²²²Rn and leachable contaminants. Thermal stabilization in laboratory trials at 1200°C reduced the radon emanation of various tailings by factors ranging from 37 to 1400 depending on the mineralogy of the tailings. The leachability of most contaminants (e.g., Al,

David R. Dreesen; Edward J. Cokal; Lawrence E. Wangen; Joel M. Williams; Edward F. Thode

1984-01-01

123

Active tails enhance arboreal acrobatics in geckos.  

PubMed

Geckos are nature's elite climbers. Their remarkable climbing feats have been attributed to specialized feet with hairy toes that uncurl and peel in milliseconds. Here, we report that the secret to the gecko's arboreal acrobatics includes an active tail. We examine the tail's role during rapid climbing, aerial descent, and gliding. We show that a gecko's tail functions as an emergency fifth leg to prevent falling during rapid climbing. A response initiated by slipping causes the tail tip to push against the vertical surface, thereby preventing pitch-back of the head and upper body. When pitch-back cannot be prevented, geckos avoid falling by placing their tail in a posture similar to a bicycle's kickstand. Should a gecko fall with its back to the ground, a swing of its tail induces the most rapid, zero-angular momentum air-righting response yet measured. Once righted to a sprawled gliding posture, circular tail movements control yaw and pitch as the gecko descends. Our results suggest that large, active tails can function as effective control appendages. These results have provided biological inspiration for the design of an active tail on a climbing robot, and we anticipate their use in small, unmanned gliding vehicles and multisegment spacecraft. PMID:18347344

Jusufi, Ardian; Goldman, Daniel I; Revzen, Shai; Full, Robert J

2008-03-18

124

The human tail and spinal dysraphism.  

PubMed

Recent publications have endeavoured to differentiate between the true, or vestigial tail, and the pseudotail by clinical and pathological examination, and have indicated the benign nature of the true tail. The true tail arises from the most distal remnant of the embryonic tail, contains adipose, connective, muscle, and nerve tissue, and is covered by skin. Pseudotails represent a variety of lesions having in common a lumbosacral protrusion and a superficial resemblance to vestigial tails. A review of the case reports indicates spina bifida to be the most frequent coexisting anomaly with both. A review of occult spinal dysraphism shows it to be associated with cutaneous signs in more than 50% of instances. Three cases of spinal dysraphism with tail-like cutaneous structures are described and their radiological, operative, and pathological findings presented. The classification of each of the appendages into true tail or pseudotail remains obscure. Although the finding of these three tails was the subject of much curiosity, surgical treatment was clearly designed to adequately deal with the associated dysraphic state. The presence of a tail-like appendage in the lumbosacral region should alert the clinician to the possibility of underlying spinal dysraphism. Preoperative assessment must include a complete neurological history and examination as well as computed tomographic or magnetic resonance imaging. PMID:1779337

Belzberg, A J; Myles, S T; Trevenen, C L

1991-10-01

125

TNF is required for the induction but not the maintenance of compression-induced BME signals in murine tail vertebrae: limitations of anti-TNF therapy for degenerative disc disease.  

PubMed

While bone marrow edema (BME) is diagnostic of spondyloarthropathy, its nature remains poorly understood. In contrast, BME in ankylosing spondylitis is caused by tumor necrosis factor (TNF)-induced vascular and cellular changes. To investigate the relationship between chronic compression and TNF signaling in compression-induced BME we utilized a tail vertebrae compression model with WT, TNF-Tg, and TNFR1&2-/- mice to evaluate: (i) healing following release of chronic compression, (ii) induction of BME in the absence of TNFR, and (iii) efficacy of anti-TNF therapy. Compression-induced normalized marrow contrast enhancement (NMCE) in WT was significantly decreased threefold (p?

Papuga, M Owen; Kwok, Edmund; You, Zhigang; Rubery, Paul T; Dougherty, Paul E; Pryhuber, Gloria; Beck, Christopher A; Hilton, Matthew J; Awad, Hani A; Schwarz, Edward M

2011-09-01

126

TNF is required for the induction but not the maintenance of compression-induced BME signals in murine tail vertebrae: limitations of anti-TNF therapy for degenerative disc disease  

PubMed Central

While bone marrow edema (BME) is diagnostic of spondyloarthropathy, its nature remains poorly understood. In contrast, BME in ankylosing spondylitis is caused by TNF-induced vascular and cellular changes. To investigate the relationship between chronic compression and TNF signaling in compression induced BME we utilized a tail vertebrae compression model with WT, TNF-Tg and TNFR1&2?/? mice to evaluate: 1) healing following release of chronic compression, 2) induction of BME in the absence of TNFR, and 3) efficacy of anti-TNF therapy. Compression-induced normalized marrow contrast enhancement (NMCE) in WT was significantly decreased 3-fold (p<0.01) within 2 weeks of release, while the NMCE values in TNF-Tg vertebrae remained elevated, but had a significant decrease (p<0.05) by 6 weeks after the release of compression. TNFR1&2?/? mice were resistant to compression-induced BME. Anti-TNF therapy did not affect NMCE vs. placebo. Histological examination revealed that NMCE values significantly correlated with marrow vascularity and cellularity (p<0.05), which account for 76% of the variability of NMCE. Collectively, these data demonstrate a critical role for TNF in the induction of chronic compression-induced BME, but not in its maintenance. Amelioration of BME is achieved through biomechanical stability, but is not affected by anti-TNF therapy.

Papuga, M. Owen; Kwok, Edmund; You, Zhigang; Rubery, Paul T.; Dougherty, Paul E.; Pryhuber, Gloria; Beck, Christopher A.; Hilton, Matthew J.; Awad, Hani A.; Schwarz, Edward M.

2011-01-01

127

Plakophilins, desmogleins, and pemphigus: the tail wagging the dog.  

PubMed

The importance of desmosomal cell adhesion to human health is evidenced by the autoimmune disease pemphigus vulgaris (PV), in which autoantibodies against the extracellular domain of the desmosomal cadherin desmoglein 3 cause potentially fatal blistering of the skin and mucous membranes. Tucker et al. describe how enhanced expression of a desmosomal cytoplasmic plaque protein, plakophilin-1, protects keratinocytes from PV IgG-induced loss of cell adhesion by inducing calcium-independent hyperadhesive desmosomes. This study beautifully demonstrates that desmosomal adhesion can be modulated by the molecular interactions of the desmoglein tail and suggests that these novel regulatory pathways may possibly be exploited in treating human disease. PMID:24646797

Ellebrecht, Christoph T; Payne, Aimee S

2014-04-01

128

Comet tail formation: Giotto observations  

SciTech Connect

The process of mass loading of the solar wind by cometary ions, which forms comet tails, has been observed throughout the coma of comet Halley. Three distinct regimes were found where the nature of the energy and momentum coupling between solar wind and cometary ions is different. Outside the bow shock, where there is little angular scattering of the freshly ionized particles, the coupling is described by the simple pickup trajectory and the energy is controlled by the angle between the flow and the magnetic field. Just inside the bow shock, there is considerable scattering accompanied by another acceleration process which raises some particle energies well above the straightforward pickup value. Finally, closer to the nucleus, the amount of scattering decreases and the coupling is once more controlled by the magnetic field direction. 4 refs., 3 figs.

Wilken, B.; Jockers, K.; Johnstone, A.; Coates, A.; Heath, J.; Formisano, V.; Amata, E.; Winningham, J.D.; Thomsen, M.; Bryant, D.A.

1986-01-01

129

Stability properties of a cometary plasma tail  

Microsoft Academic Search

The linear stability of the plasma tail of a comet is numerically investigated. Effects both of finite resistivity and of velocity shear are taken into account. The tail appears to be unstable against Kelvin-Helmholtz-like modes in which a certain amount of reconnection occurs. Because of the velocity flow shear the perturbation extends far beyond the singular layer and affects in

Francesco Malara; Giorgio Einaudi; Andre Mangeney

1989-01-01

130

CISLUNAR GEOMAGNETIC TAIL GRADIENT IN 1967  

Microsoft Academic Search

In this letter, the geomagnetic tail field gradient during the summers of 1966 and 1967 is examined for secular change. We use data from Ames magnetometers on Explorers 33 and 35. The 1967 data are compared with the earlier published 1966. Explorer 33 results [Mihalo. v et al., 1968]. Secular change of the tail field magnitude gradient is not found

J. D. Mihalov; C. P. Sonett

1968-01-01

131

Tale of tails: Parallelism and prehensility  

Microsoft Academic Search

The occurrence of prehensile tails among only five platyrrhine genera-Cebus, Alouatta, Lagothrix, Ateles, and Bmchyteles-might be inter- preted as evidence that these are a closely related, possibly monophyletic group. In the absence of behavioral data, it is impossible to test whether all possess equivalent biological roles; such would lend credence to the idea that their tails evolved from an homologous,

Alfred L. Rosenberger

1983-01-01

132

Unified Approach to Estimating Tail Behavior.  

National Technical Information Service (NTIS)

Tail estimators are proposed which make minimal assumptions and let the data dictate the form of the probability model. These estimators use only the observations in the tail and are based on a unifying density-quantile model. The fundamental result in th...

S. D. Grimshaw

1989-01-01

133

Factors influencing radon attenuation by tailing covers  

Microsoft Academic Search

The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi\\/m² s by application of covering layers of soils and clays. These covers present a radon diffusion barrier, which sufficiently increases the time required for radon passage from the tailings to the

W. B. Silker; V. C. Rogers

1981-01-01

134

Groundwater pollution due to a tailings dam  

Microsoft Academic Search

In 1982, the Oman Mining Company (OMC) commenced copper mining and smelting operations in the area of Sohar (Wadi Suq), Sultanate of Oman. Seawater was used for mining operations until 1993. During this period, 11 million tonnes of tailings had been deposited behind an unlined tailings dam. This has resulted in a major groundwater pollution problem.This paper presents results from

R. S Sharma; T. S Al-Busaidi

2001-01-01

135

EXPERIMENTAL RESEARCH ON HELICOPTER TAIL SHAKE PHENOMENON  

Microsoft Academic Search

Helicopter tail shake phenomenon is still remained as a long dragged issue that adversely affected the overall performance, occupants' comfort and handling qualities of helicopter. The objective of this research is to improve basic understanding of the viscous unsteady flow phenomenon observed behind the helicopter tail part. For this, a wind tunnel test had been conducted with a rigid 14%

Iskandar Shah Ishak; Shuhaimi Mansor; Tholudin Mat Lazim

136

Efficient Algorithms for Computing Sommerfeld Integral Tails  

Microsoft Academic Search

Sommerfeld-integrals (SIs) are ubiquitous in the analysis of problems involving antennas and scatterers embedded in planar multilayered media. It is well known that the oscillating and slowly decaying nature of their integrands makes the numerical evaluation of the SI real-axis tail segment a very time consuming and computationally expensive task. Therefore, SI tails have to be specially treated. In this

Ruzica Golubovic; Athanasios G. Polimeridis; Juan R. Mosig

2012-01-01

137

The histone tails of the nucleosome  

Microsoft Academic Search

Reversible acetylation of core histone tails plays an important role in the regulation of eukaryotic transcription, in the formation of repressive chromatin complexes, and in the inactivation of whole chromosomes. The high-resolution X-ray structure of the nucleosome core particle, as well as earlier evidence, suggests that the histone tails are largely responsible for the assembly of nucleosomes into chromatin fibers

Karolin Luger; Timothy J Richmond

1998-01-01

138

CONFIGURATION AND RECONNECTION OF THE GEOMAGNETIC TAIL  

Microsoft Academic Search

A description of certain aspects of the geomagnetic tail is made using data from the Ames magnetometer on the Explorer 33 satellite. The general shape corresponds with eaxlier findings of Ness and co-workers. The tail is found regular to distances greater than 82 R. The field values for Kp _ 2-]- vary from a low of about 4 gammas to

J. D. Mihalov; D. S. Colburn; R. G. Currie; C. P. Sonett

1968-01-01

139

The QQ-Estimator And Heavy Tails  

Microsoft Academic Search

. A common visual technique for assessing goodness of fit and estimating location and scale is theqq--plot. We apply this technique to data from a Pareto distribution and more generally to data generated bya distribution with a heavy tail. A procedure for assessing the presence of heavy tails and for estimating theparameter of regular variation is discussed which can supplement

Marie F. Kratz; Sidney I. Resnick

1995-01-01

140

The Dust Tail of Asteroid (3200) Phaethon  

NASA Astrophysics Data System (ADS)

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears gsim350'' (2.5 × 108 m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius ~1 ?m and a combined mass ~3 × 105 kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high surface temperatures (~1000 K) experienced by Phaethon at perihelion. The existence of the tail confirms earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active.

Jewitt, David; Li, Jing; Agarwal, Jessica

2013-07-01

141

Tail loss compromises immunity in the many-lined skink, Eutropis multifasciata  

NASA Astrophysics Data System (ADS)

Tail autotomy incurs energetic costs, and thus, a trade-off in resource allocation may lead to compromised immunity in lizards. We tested the hypothesis that tailless lizards will favor constitutive innate immunity responses over an energetically costly inflammatory response. The influence of fasting and colorful ornamentation was also investigated. We experimentally induced tail autotomy in the lizard Eutropis multifasciata and found that inflammation was suppressed by tail loss, but not further affected by fasting; the suppressive effect of colorful ornamentation was manifested only in males, but not in females. Constitutive innate immunity was not affected by any of these factors. As expected, only costly inflammation was compromised, and a less expensive constitutive innate immunity might be favored as a competent first-line defense during energetically demanding periods. After considering conventional trade-offs among tail regeneration and reproduction, further extending these studies to incorporate disease risk and how this influences escape responses to predators and future reproduction would make worthwhile studies.

Kuo, Chi-Chien; Yao, Chiou-Ju; Lin, Te-En; Liu, Hsu-Che; Hsu, Yu-Cheng; Hsieh, Ming-Kun; Huang, Wen-San

2013-04-01

142

14 CFR 23.481 - Tail down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 false Tail down landing conditions. ...AIRPLANES Structure Ground Loads § 23.481 Tail down landing conditions. (a) For a tail down landing, the airplane...before the maximum vertical load is...

2010-01-01

143

14 CFR 23.481 - Tail down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 false Tail down landing conditions. ...AIRPLANES Structure Ground Loads § 23.481 Tail down landing conditions. (a) For a tail down landing, the airplane...before the maximum vertical load is...

2009-01-01

144

Shake a tail feather: the evolution of the theropod tail into a stiff aerodynamic surface.  

PubMed

Theropod dinosaurs show striking morphological and functional tail variation; e.g., a long, robust, basal theropod tail used for counterbalance, or a short, modern avian tail used as an aerodynamic surface. We used a quantitative morphological and functional analysis to reconstruct intervertebral joint stiffness in the tail along the theropod lineage to extant birds. This provides new details of the tail's morphological transformation, and for the first time quantitatively evaluates its biomechanical consequences. We observe that both dorsoventral and lateral joint stiffness decreased along the non-avian theropod lineage (between nodes Theropoda and Paraves). Our results show how the tail structure of non-avian theropods was mechanically appropriate for holding itself up against gravity and maintaining passive balance. However, as dorsoventral and lateral joint stiffness decreased, the tail may have become more effective for dynamically maintaining balance. This supports our hypothesis of a reduction of dorsoventral and lateral joint stiffness in shorter tails. Along the avian theropod lineage (Avialae to crown group birds), dorsoventral and lateral joint stiffness increased overall, which appears to contradict our null expectation. We infer that this departure in joint stiffness is specific to the tail's aerodynamic role and the functional constraints imposed by it. Increased dorsoventral and lateral joint stiffness may have facilitated a gradually improved capacity to lift, depress, and swing the tail. The associated morphological changes should have resulted in a tail capable of producing larger muscular forces to utilise larger lift forces in flight. Improved joint mobility in neornithine birds potentially permitted an increase in the range of lift force vector orientations, which might have improved flight proficiency and manoeuvrability. The tail morphology of modern birds with tail fanning capabilities originated in early ornithuromorph birds. Hence, these capabilities should have been present in the early Cretaceous, with incipient tail-fanning capacity in the earliest pygostylian birds. PMID:23690987

Pittman, Michael; Gatesy, Stephen M; Upchurch, Paul; Goswami, Anjali; Hutchinson, John R

2013-01-01

145

Artificial inoculation-perspectives in tailings phytostabilization.  

PubMed

Intensive mining and processing activities worldwide resulted in the generation of huge amounts of waste (tailings), generally characterized as toxic, radioactive, and/or hazardous. The exposure potential and, hence, the risk posed by such wastes is enhanced by a general lack of vegetation. Phytostabilization has proven to be efficient in reducing this risk. However, establishing vegetation on tailing dumps may be expensive due to the intensive use of amendments and chemical fertilizers. In this article, investigations on artificial inoculation of mine tailings with bacterial strains as a means to improve the development of vegetative covers and reduce application cost by eliminating chemical fertilization are presented and discussed. The development of plants and microbial communities from tailings, as well as the impact of inoculation on metal uptake in plants, were studied. Experiments were carried out in greenhouse using two types of mine tailings (phosphogypsum and sulphidic tailings) from the Romanian Black Sea coast. Indigenous herbaceous plants were cultivated on tailings with the addition of chemical fertilizers versus bacterial inoculation. After a 6-month experimental period, excellent plant growth, which is associated with a rich microbial community, was observed in all inoculated treatments, in contrast with poor plant growth and microbiota from the chemical fertilization treatments alone. Additionally, artificial inoculation improved plant resistance to heavy metals by reducing the uptake of some toxic metals. Once a rich microbial community is established, inoculation may be discontinued. Based on these results, efficient and cost-effective phytostabilization schemes can be proposed. PMID:15224772

Petrisor, Ioana G; Dobrota, Smaranda; Komnitsas, Kostas; Lazar, Ioan; Kuperberg, J Michael; Serban, Mihai

2004-01-01

146

Strengthening of solidified dilute tailings slurry  

SciTech Connect

Tailings produced during mineral processing contain up to 75% or more water and are pumped into settling ponds for disposal. They often become a pollution source due to acid generation. While tailings have been used in underground backfill, the use is very limited at present. This paper presents research results on direct solidification and strengthening of the dilute tailings slurry without dewatering. Two types of tailings were tested at water/binder ratios of up to 4.5 using a special high-water binder. Adequate strength was achieved by solidifying the tailings as is. To further improve the strength, sands and fly ash were used as reinforcement materials or partial replacement of the binder. For oil sands tailings, the 3-day strength was increased by up to 114% with 10--15% additives. For hard rock tailings, up to 30% strength gain was achieved with 15% fly ash addition, and the strength was increased by up to 36% at 10% binder replacement and no strength reduction was observed at 20--25% replacement. These results indicate that higher strength can be achieved with the proper amount of additives and that the backfill process can be simplified and the operation cost reduced.

Zou, D.H.; Li, L.P. [Dalhousie Univ., Halifax, NS (Canada). Dept. Mining and Metallurgical Engineering] [Dalhousie Univ., Halifax, NS (Canada). Dept. Mining and Metallurgical Engineering

1999-01-01

147

Engineering assessment of inactive uranium mill tailings  

SciTech Connect

The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive.

Not Available

1981-07-01

148

A review on dural tail sign  

PubMed Central

“Dural tail sign” (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected.

Sotoudeh, Houman; Yazdi, Hadi Rokni

2010-01-01

149

A review on dural tail sign.  

PubMed

"Dural tail sign" (DTS) which is a thickening of the dura adjacent to an intracranial pathology on contrast-enhanced T1 MR Images, was first thought to be pathognomonic of meningioma, however, many subsequent studies demonstrated this sign adjacent to various intra- and extra-cranial pathologies and in spinal lesions. In this paper we outline the history, accompanying pathologies and the differentiation and probable pathophysiology of DTS. We also discuss whether we can predict tumoral involvement of the dural tail before surgery and whether the dural tail adjacent to a tumor should be resected. PMID:21161034

Sotoudeh, Houman; Yazdi, Hadi Rokni

2010-05-28

150

Vibrations of the earth's magnetic tail  

NASA Technical Reports Server (NTRS)

The natural vibration period of the tail (regarded as bundle of magnetic line-of-force strings) and the characteristic time of recurrence of magnetospheric substorms are of the same order, suggesting the possibility of a relation between these phenomena. A model of the tail in the form of a plasma cylinder whose free boundary is immersed in the interplanetary plasma is examined. The nature of the natural oscillations of the tail excited by variations of the solar wind pressure is studied in this model. These vibrations have a total energy of approximately 10 to the 22nd power erg, which is sufficient to generate magnetospheric substorms.

Yershkovich, A. I.; Nusinov, A. A.

1974-01-01

151

Sexual performance of rams sequentially exposed to short-tailed and fat-tailed ewes.  

PubMed

The objective of the study was to compare sexual performance of pure and crossbred rams, and to evaluate whether prior exposure of rams to short-tailed females would enhance their mating ability when later exposed to fat-tailed females. Twenty-two virgin, yearling Awassi (A; n = 7), F(1) Charollais x Awassi (CA; n = 7) and F(1) Romanov x Awassi (RA; n = 8) rams were subjected to sexual performance tests on six 20-min occasions. Each ram was individually exposed to two short-tailed oestrous ewes for three 20-min occasions on three consecutive days. Following 1 day of rest, the same 3-day procedure was repeated for each ram with fat-tailed ewes. Leg kicking bout frequency increased in CA and RA rams and decreased in A rams, when they were exposed to fat-tailed compared with short-tailed ewes. No differences in anogenital sniffing were observed among rams exposed to either short-tailed or fat-tailed ewes. However, greater (p < 0.001) anogenital sniffing bouts were recorded, when rams were exposed to short-tailed females. Upon exposure to fat-tailed ewes, CA and RA rams experienced a marked increase in mounting frequency compared with a slight increase in mounting of A rams (p < 0.001). The ability of Awassi rams to raise the fat tail of Awassi ewes was greater (p < 0.001) than CA and RA rams. Mating was improved in A while declining in CA and RA, when they were exposed to fat-tailed compared with short-tailed ewes (p < 0.001). Based on the results of the current study, it seems that all yearling rams were capable of mating with short-tailed ewes, whereas only Awassi rams managed to mate with fat-tailed ewes. It appears that brief exposures of yearling crossbred rams to short-tailed ewes do not improve their mating ability when later exposed to fat-tailed ewes. PMID:18363610

Kridli, R T; Abdullah, A Y; Shaker, M Momani; Mahmoud, K Z

2008-08-01

152

Approximation of Pearson Type IV Tail Probabilities.  

National Technical Information Service (NTIS)

Simple approximating functions for tail probabilities of the Pearson Type IV distribution are obtained by using the B sub n transformations and by truncating the continued fraction expansion. The behavior of these approximations is then investigated for v...

W. A. Woodward

1975-01-01

153

Horizontal tail loads in maneuvering flight  

NASA Technical Reports Server (NTRS)

A method is given for determining the horizontal tail loads in maneuvering flight. The method is based upon the assignment of a load-factor variation with time and the determination of a minimum time to reach peak load factor. The tail load is separated into various components. Examination of these components indicated that one of the components was so small that it could be neglected for most conventional airplanes; therefore, the number of aerodynamic parameters needed in this computation of tail loads was reduced to a minimum. In order to illustrate the method, as well as to show the effect of the main variables, a number of examples are given. Some discussion is given regarding the determination of maximum tail loads, maximum pitching accelerations, and maximum pitching velocities obtainable.

Pearson, Henry A; Mcgowan, William A; Donegan, James J

1951-01-01

154

Engineering Assessment of Inactive Uranium Mill Tailings.  

National Technical Information Service (NTIS)

The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included...

1981-01-01

155

Tree Growth Studies on Uranium Mill Tailings.  

National Technical Information Service (NTIS)

Coniferous trees planted in 1974 and deciduous species, that have volunteered since 1970 on uranium mill tailings that had been stabilized to varying degrees using limestone and vegetation, were evaluated. Their survival and growth rates were compared wit...

D. R. Murray M. Turcotte

1982-01-01

156

Cost of Decommissioning Uranium Mill Tailings.  

National Technical Information Service (NTIS)

This report identifies several key operations that are commonly carried out during decommissioning of tailings areas in the Canadian environment. These operations are unit costed for a generic site to provide a base reference case. The unit costs have als...

D. L. Lush C. Lendrum C. Hostovsky W. Eedy A. Ashbrook

1986-01-01

157

ATS Claus tail gas cleanup at Table Rock Tail Gas Plant. [Ammonium thiosulfate  

SciTech Connect

This paper describes the Table Rock Processing Plant which consists of four major parts: the treating plant, the dew point control plant, a sulfur plant, and the tail gas plant. The tail gas plant uses the ammonium thiosulfate process to convert about 4 tons per day of sulfur to 60 tons per day of ATS. The brief discussion is presented under headings: the tail gas process; chemistry (chemical reaction and equipment); plant performance. 7 refs.

White, S.P.

1981-01-01

158

Asbestos tailings as aggregates for asphalt mixture  

Microsoft Academic Search

To use many asbestos tailings collected in Ya-Lu highway, and to explore the feasibility of using asbestos tailings as aggregates\\u000a in common asphalt mixtures, and properties of some asphalt mixtures were evaluated as well. X-ray diffraction (XRD), X-ray\\u000a fluorescent (XRF), and atomic absorption spectrophotometry (AAS) were employed to determine the solid waste content of copper,\\u000a zinc, lead, and cadmium. Volume

Xiaoming Liu; Linrong Xu

2011-01-01

159

Radial tail resolution in the SELEX RICH  

Microsoft Academic Search

We use a seven million event data sample of 600GeV\\/c single-track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. We build the RICH ring radius histogram distribution and count the tail events that fall outside 5?, giving a fraction of 4×10-5 events outside the Gaussian tails. This control of events establishes the ability

A. Morelos; J. Mata; P. S. Cooper; J. Engelfried; J. L. Aguilera-Servin

2005-01-01

160

Head-tail instability at Tevatron  

SciTech Connect

Tevatron performance suffers from a coherent transverse instability. Experimental studies and theoretical examination allow identifying the instability as a weak head-tail, driven by the short-range wake fields in presence of the space charge. Growth rates and coherent tune shifts are measured at injection of single high-intensity proton bunches using a fast strip-line pickup. Landau damping through the octupole-generated betatron tune spread for all of unstable head-tail modes has been demonstrated.

Petr M Ivanov et al.

2003-05-27

161

Anomalous Urbach tail in GaAs  

NASA Astrophysics Data System (ADS)

The Urbach tail in crystalline GaAs and Si due to thermal vibration is evaluated in the temperature range 0-810 K. Recent experiments suggest that there is no thermally induced Urbach tail in undoped GaAs. This is most unexpected since thermally induced tails at the absorption edge having the Urbach form and widths E0(T) linear in T are observed in a wide range of crystalline and amorphous semiconductors. Clear understanding of the tail is important in device applications. In our calculations, we obtain an absorption tail having a simple exponential energy dependence (Urbach form) in GaAs at all temperatures with E0(T) proportional to T. However, due to a very weak electron-phonon interaction, the magnitude of E0(T) is unusually small, much smaller than the temperature independent, structurally induced component E0~=10 meV. As a test of the method, the tail is similarly evaluated in Si providing an E0(T) value in agreement with experiment.

Greeff, C. W.; Glyde, H. R.

1995-01-01

162

The sodium tail of the Moon  

NASA Astrophysics Data System (ADS)

During the few days centered about new Moon, the lunar surface is optically hidden from Earth-based observers. However, the Moon still offers an observable: an extended sodium tail. The lunar sodium tail is the escaping "hot" component of a coma-like exosphere of sodium generated by photon-stimulated desorption, solar wind sputtering and meteoroid impact. Neutral sodium atoms escaping lunar gravity experience solar radiation pressure that drives them into the anti-solar direction forming a comet-like tail. During new Moon time, the geometry of the Sun, Moon and Earth is such that the anti-sunward sodium flux is perturbed by the terrestrial gravitational field resulting in its focusing into a dense core that extends beyond the Earth. An all-sky camera situated at the El Leoncito Observatory (CASLEO) in Argentina has been successfully imaging this tail through a sodium filter at each lunation since April 2006. This paper reports on the results of the brightness of the lunar sodium tail spanning 31 lunations between April 2006 and September 2008. Brightness variability trends are compared with both sporadic and shower meteor activity, solar wind proton energy flux and solar near ultra violet (NUV) patterns for possible correlations. Results suggest minimal variability in the brightness of the observed lunar sodium tail, generally uncorrelated with any single source, yet consistent with a multi-year period of minimal solar activity and non-intense meteoric fluxes.

Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M.

2009-12-01

163

An acceleration mechanism for cometary plasma tails  

NASA Technical Reports Server (NTRS)

Cometary plasma tail formation by the interaction between the solar wind plasma flow and the plasma at the head of the coma is discussed using the unipolar electric generation theory. The plasma in the 'plasma tail' is almost directly accelerated from the cometary ionopause along the sun-nucleus line where the tail current flows. For steady state solar wind conditions, the cometary 'plasma tail' velocity distribution is obtained self-consistently. The solution of a kinetic equation gives the velocity of the cometary plasma as a function of the cometary tail position. The characteristic length is 3 x 10 to the 6th km when the plasma density near the nucleus of the comet is 10 to the 6th/cu cm and the component of the interplanetary magnetic field perpendicular to the solar wind flow is 3 nT. The tailward cometary plasma is finally accelerated to the speed of the solar wind. The theory is compared with the observational plasma velocities in the tails of comet Bennett (1970II) and Comet Halley (1985).

Minami, S.; White, R. S.

1986-01-01

164

Snapshot of haloarchaeal tailed virus genomes  

PubMed Central

The complete genome sequences of archaeal tailed viruses are currently highly underrepresented in sequence databases. Here, we report the genomic sequences of 10 new tailed viruses infecting different haloarchaeal hosts. Among these, only two viral genomes are closely related to each other and to previously described haloviruses HF1 and HF2. The approximately 760 kb of new genomic sequences in total shows no matches to CRISPR/Cas spacer sequences in haloarchaeal host genomes. Despite their high divergence, we were able to identify virion structural and assembly genes as well as genes coding for DNA and RNA metabolic functions. Interestingly, we identified many genes and genomic features that are shared with tailed bacteriophages, consistent with the hypothesis that haloarchaeal and bacterial tailed viruses share common ancestry, and that a viral lineage containing archaeal viruses, bacteriophages and eukaryotic viruses predates the division of the three major domains of non-viral life. However, as in tailed viruses in general and in haloarchaeal tailed viruses in particular, there are still a considerable number of predicted genes of unknown function.

Sencilo, Ana; Jacobs-Sera, Deborah; Russell, Daniel A.; Ko, Ching-Chung; Bowman, Charles A.; Atanasova, Nina S.; Osterlund, Eija; Oksanen, Hanna M.; Bamford, Dennis H.; Hatfull, Graham F.; Roine, Elina; Hendrix, Roger W.

2013-01-01

165

Field investigation of evaporation from freshwater tailings  

SciTech Connect

Safe and economical storage of tailings is now a major consideration in the operation of many mining operations. Tailings in slurried form, particularly if they have a significant clay content, can take a very long time to consolidate under the action of self-weight consolidation alone. However, if the operation is located in an area of high potential evaporation, this can be used to accelerate the rate of tailings densification. This paper presents a study of the evaporation behavior of a clayey tailings slurry deposited into an evaporation pond in the southwest of Western Australia. Over a six-month period, the rate of evaporation from the tailings surface was monitored using the Bowen Ratio method and the microlysimeter method. This was compared with the evaporation from a Class A pan located nearby. The tailings underwent very significant cracking as drying proceeded, and it was found that these cracks had a significant influence on the overall rate of evaporation once the top surface of the deposit started to desaturate. A large strain consolidation model was used to model the behavior, and the algorithm used in this model to include the effects of evaporation is shown to provide a reasonable prediction of the observed evaporation behavior.

Fujiyasu, Yoshimasa; Fahey, M.; Newson, T.

2000-06-01

166

The Sodium Tail of the Moon  

NASA Technical Reports Server (NTRS)

During the few days centered about new Moon, the lunar surface is optically hidden from Earth-based observers. However, the Moon still offers an observable: an extended sodium tail. The lunar sodium tail is the escaping "hot" component of a coma-like exosphere of sodium generated by photon-stimulated desorption, solar wind sputtering and meteoroid impact. Neutral sodium atoms escaping lunar gravity experience solar radiation pressure that drives them into the anti-solar direction forming a comet-like tail. During new Moon time, the geometry of the Sun, Moon and Earth is such that the anti-sunward sodium flux is perturbed by the terrestrial gravitational field resulting in its focusing into a dense core that extends beyond the Earth. An all-sky camera situated at the El Leoncito Observatory (CASLEO) in Argentina has been successfully imaging this tail through a sodium filter at each lunation since April 2006. This paper reports on the results of the brightness of the lunar sodium tail spanning 31 lunations between April 2006 and September 2008. Brightness variability trends are compared with both sporadic and shower meteor activity, solar wind proton energy flux and solar near ultra violet (NUV) patterns for possible correlations. Results suggest minimal variability in the brightness of the observed lunar sodium tail, generally uncorrelated with any single source, yet consistent with a multi-year period of minimal solar activity and non-intense meteoric fluxes.

Matta, M.; Smith, S.; Baumgardner, J.; Wilson, J.; Martinis, C.; Mendillo, M.

2009-01-01

167

The Tail Movement of Bull Spermatozoa  

PubMed Central

Detailed observations of the tail movement of non-rotating and rotating bull spermatozoa have been carried out. For rotating sperm a helical tail wave was found with a ratio of the amplitudes of the two perpendicular components of approximately 3 to 1. For both types of cells the variation of the amplitude and the phase shift of the wave as it travels from the proximal to the distal part are reported. Model calculations indicate that the stiffness of the tail originates in the fibrous sheath, which has a Young's modulus of 3 × 107 dynes/cm2. Active contractile elements distributed continuously along the tail are found necessary to maintain the amplitude of the tail wave against damping by the fluid drag. If the longitudinal fibers are identified with the contractile elements the maximum tension to be developed by these fibers is 4 × 106 dynes/cm2. The energy dissipated by the “active” part of the tail wave is at least approximately 70 percent of the total dissipation. ImagesFigure 1

Rikmenspoel, Robert

1965-01-01

168

Clinical and Myopathological Characteristics of Desminopathy Caused by a Mutation in Desmin Tail Domain  

PubMed Central

Background Most of the previously described pathogenic mutations in desmin are located in highly conserved ?-helical domains that play an important role in intermediate filament assembly. The role of the C-terminus non-?-helical “tail” domain is much less investigated and until recently mutations in this domain have been implicated in only a few patients. The majority of reported desminopathy cases caused by the tail mutations were sporadic, creating a representation bias regarding the disease frequency and phenotypic characteristics. Methods We performed detailed genotype-phenotype analysis of autosomal dominant desminopathy associated with tail domain mutations in a 4-generation autosomal dominant family with 16 members affected by a progressive cardiac and/or skeletal myopathy caused by a c.1346A>C (p.Lys449Thr) mutation located in the tail domain of desmin. Results Phenotypic features in patients with tail domain mutations are similar to those in patients with mutations localized in the 1B and 2B ?-helical domains. Conclusion We recommend that the tail domain is searched for mutations as intensely as desmin coil domains which until recently were considered to be more “functional”.

Maddison, Paul; Damian, Maxwell S.; Sewry, Caroline; McGorrian, Catherine; Winer, John B.; Odgerel, Zagaa; Shatunov, Alexey; Lee, Hee Suk.; Goldfarb, Lev G.

2013-01-01

169

Detection and tracking of low contrast human sperm tail  

Microsoft Academic Search

Tracking sperm tail movement provides important information for clinical sperm research. It is also a crucial step for sperm immobilization in Intracytoplasmic Sperm Injection (ICSI). However, the low visibility of the sperm tail under optical microscopy, coupled with the sperm fast motility, render sperm tail identification and tracking challenging tasks to execute. This paper presents two approaches for sperm tail

Clement Leung; Zhe Lu; Navid Esfandiari; Robert F. Casper; Yu Sun

2010-01-01

170

A safety assessment of the new Xiangyun phosphogypsum tailings pond  

Microsoft Academic Search

Phosphogypsum tailings are piled up to form a phosphogypsum tailings pond. In the design and operation stages of a tailings project, the stability of the tailings pond, the control capacity for flood, and the reliability of the drainage and safety monitoring facilities should be fully evaluated. Key contents of the safety assessment are analyzed in view of the new Xiangyun

T. Wang; Y. Zhou; Q. Lv; Yuanle Zhu; C. Jiang

2011-01-01

171

Degrons at the C terminus of the pathogenic but not the nonpathogenic hantavirus G1 tail direct proteasomal degradation.  

PubMed

Pathogenic hantaviruses cause two human diseases: hantavirus pulmonary syndrome (HPS) and hemorrhagic fever with renal syndrome (HFRS). The hantavirus G1 protein contains a long, 142-amino-acid cytoplasmic tail, which in NY-1 virus (NY-1V) is ubiquitinated and proteasomally degraded (E. Geimonen, I. Fernandez, I. N. Gavrilovskaya, and E. R. Mackow, J. Virol. 77: 10760-10768, 2003). Here we report that the G1 cytoplasmic tails of pathogenic Andes (HPS) and Hantaan (HFRS) viruses are also degraded by the proteasome and that, in contrast, the G1 tail of nonpathogenic Prospect Hill virus (PHV) is stable and not proteasomally degraded. We determined that the signals which direct NY-1V G1 tail degradation are present in a hydrophobic region within the C-terminal 30 residues of the protein. In contrast to that of PHV, the NY-1V hydrophobic domain directs the proteasomal degradation of green fluorescent protein and constitutes an autonomous degradation signal, or "degron," within the NY-1V G1 tail. Replacing 4 noncontiguous residues of the NY-1V G1 tail with residues present in the stable PHV G1 tail resulted in a NY-1V G1 tail that was not degraded by the proteasome. In contrast, changing a different but overlapping set of 4 PHV residues to corresponding NY-1V residues directed proteasomal degradation of the PHV G1 tail. The G1 tails of pathogenic, but not nonpathogenic, hantaviruses contain intervening hydrophilic residues within the C-terminal hydrophobic domain, and amino acid substitutions that alter the stability or degradation of NY-1V or PHV G1 tails result from removing or adding intervening hydrophilic residues. Our results identify residues that selectively direct the proteasomal degradation of pathogenic hantavirus G1 tails. Although a role for the proteasomal degradation of the G1 tail in HPS or HFRS is unclear, these findings link G1 tail degradation to viral pathogenesis and suggest that degrons within hantavirus G1 tails are potential virulence determinants. PMID:17267477

Sen, Nandini; Sen, Adrish; Mackow, Erich R

2007-04-01

172

Plasma entry into the distant tail lobes - ISEE-3  

NASA Technical Reports Server (NTRS)

ISEE-3 measurements indicate that a broad mantle-like boundary layer plasma often exists within the distant geomagnetic tail lobes at all latitudes, directly adjacent to the tail magnetopause. The presence of this boundary layer at large tail distances indicates that plasma from the magnetosheath often crosses the magnetopause locally along much of the length of the tail, and is evidence that the tail is 'open'.

Gosling, J. T.; Baker, D. N.; Bame, S. J.; Hones, E. W., Jr.; Mccomas, D. J.; Zwickl, R. D.; Slavin, J. A.; Smith, E. J.; Tsurutani, B. T.

1984-01-01

173

Forest cover influences dispersal distance of white-tailed deer  

USGS Publications Warehouse

Animal dispersal patterns influence gene flow, disease spread, population dynamics, spread of invasive species, and establishment of rare or endangered species. Although differences in dispersal distances among taxa have been reported, few studies have described plasticity of dispersal distance among populations of a single species. In 2002-2003, we radiomarked 308 juvenile (7- to 10-month-old), male white-tailed deer (Odocoileus virginianus) in 2 study areas in Pennsylvania. By using a meta-analysis approach, we compared dispersal rates and distances from these populations together with published reports of 10 other nonmigratory populations of white-tailed deer. Population density did not influence dispersal rate or dispersal distance, nor did forest cover influence dispersal rate. However, average (r2 = 0.94, P < 0.001, d.f. = 9) and maximum (r2 = 0.86, P = 0.001, d.f. = 7) dispersal distances of juvenile male deer were greater in habitats with less forest cover. Hence, dispersal behavior of this habitat generalist varies, and use of landscape data to predict population-specific dispersal distances may aid efforts to model population spread, gene flow, or disease transmission. ?? 2005 American Society of Mammalogists.

Long, E. S.; Diefenbach, D. R.; Rosenberry, C. S.; Wallingford, B. D.; Grund, M. D.

2005-01-01

174

Transonic Base and Boat-Tail Pressure Drag of Cylindrical Bodies with Conical Boat-Tails.  

National Technical Information Service (NTIS)

This Item provides a means of estimating the base and boat-tail pressure-drag coefficients of cylindrical bodies with conical boat-tailing for the Mach number range 0.9 less than or equal to 1.3. The method is purely empirical and is based on one develope...

1978-01-01

175

Growth performance and carcass quality of fattening lambs from fat-tailed and tailed sheep breeds  

Microsoft Academic Search

The growth performance and carcass traits of two fat-tailed breeds (Chaal and Zandi) and their crosses with rams of a tailed breed (Zel) were compared. After weaning, the growth and feed consumption of male and female lambs fattened for 114 days were recorded. A total of 45 male and female lambs were slaughtered and the left side of the carcasses

N. E. J. Kashan; G. H. Manafi Azar; A. Afzalzadeh; A. Salehi

2005-01-01

176

Grouting of uranium mill tailings piles  

SciTech Connect

A program of remedial action was initiated for a number of inactive uranium mill tailings piles. These piles result from mining and processing of uranium ores to meet the nation's defense and nuclear power needs and represent a potential hazard to health and the environment. Possible remedial actions include the application of covers to reduce radon emissions and airborne transport of the tailings, liners to prevent groundwater contamination by leachates from the piles, physical or chemical stabilization of the tailings, or moving the piles to remote locations. Conventional installation of liners would require excavation of the piles to emplace the liner; however, utilization of grouting techniques, such as those used in civil engineering to stabilize soils, might be a potential method of producing a liner without excavation. Laboratory studies on groutability of uranium mill tailings were conducted using samples from three abandoned piles and employing a number of particulate and chemical grouts. These studies indicate that it is possible to alter the permeability of the tailings from ambient values of 10/sup -3/ cm/s to values approaching 10/sup -7/ cm/s using silicate grouts and to 10/sup -8/ cm/s using acrylamide and acrylate grouts. An evaluation of grouting techniques, equipment required, and costs associated with grouting were also conducted and are presented. 10 references, 1 table.

Boegly, W.J. Jr.; Tamura, T.; Williams, J.D.

1984-03-01

177

THE DUST TAIL OF ASTEROID (3200) PHAETHON  

SciTech Connect

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears {approx}>350'' (2.5 Multiplication-Sign 10{sup 8} m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius {approx}1 {mu}m and a combined mass {approx}3 Multiplication-Sign 10{sup 5} kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high surface temperatures ({approx}1000 K) experienced by Phaethon at perihelion. The existence of the tail confirms earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active.

Jewitt, David; Li Jing [Department of Earth and Space Sciences, University of California at Los Angeles, 595 Charles Young Drive East, Los Angeles, CA 90095-1567 (United States); Agarwal, Jessica, E-mail: jewitt@ucla.edu [Max Planck Institute for Solar System Research, Max-Planck-Str. 2, D-37191 Katlenburg-Lindau (Germany)

2013-07-10

178

Tail vaccination in cats: a pilot study.  

PubMed

Feline injection site sarcomas affect 1-10 cats per every 10,000 vaccinated and are associated with high mortality. Radical resection may be curative, but is often associated with prolonged recovery, disfigurement and loss of function when tumors occur at currently recommended injection sites. The objective of this study was to assess alternatives to currently recommended vaccination sites in terms of preference by oncology practitioners, ease of injection and serological responses. Surgical, radiation and medical oncology practitioners were surveyed regarding their preference for vaccination sites based on the ease of tumor resection. A six-point Likert scale was used to measure each cat's behavioral reaction to vaccination when injected subcutaneously in the distal hind limb or the distal tail. Serum collected before and 1-2 months after vaccination was tested for antibody titers against feline panleukopenia virus (FPV) and rabies virus (RV). The preferred sites for vaccination by 94 oncology practitioners were below the stifle (41%) and the tail (30%). There were no significant differences in the cats' behavioral reaction to vaccination below the stifle (n = 31) and in the distal tail (n = 29). Of the cats seronegative for FPV at the time of vaccination, 100% developed protective antibody titers (?40) against FPV 1-2 months following vaccination. For cats seronegative for RV, all but one cat (tail vaccine) developed acceptable antibody titers (?0.5 IU/ml) against RV. Tail vaccination was well tolerated and elicited similar serological responses to vaccination in the distal limbs. PMID:24108201

Hendricks, Cleon G; Levy, Julie K; Tucker, Sylvia J; Olmstead, Shaye M; Crawford, P Cynda; Dubovi, Edward J; Hanlon, Cathleen A

2014-04-01

179

Design of tailing dam using red mud  

NASA Astrophysics Data System (ADS)

Red mud, waste industrial product from aluminum industries produced approximately 75 million tonnes every year with less than half of this is used. Storage of this unutilized red mud takes vast tracts of usable land and pollutes, land, air and water. Construction of high embankments, under passes, flyovers, tailing dams uses vast tract of natural resources (top soil) is also matter of concern as its takes thousands of years to form the natural soil. This paper discusses use of red mud for construction of tailing dam based on laboratory findings and finite element analysis. The geotechnical properties such as plasticity, compaction, permeability, shear strength characteristics and dispersion of red mud are presented. Stability and seepage analysis of tailing dams as per finite element analysis using the above geotechnical parameters is presented.

Rout, Subrat K.; Sahoo, Tapaswini; Das, Sarat K.

2013-06-01

180

Radial tail resolution in the SELEX RICH  

NASA Astrophysics Data System (ADS)

We use a seven million event data sample of 600 GeV/c single-track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. We build the RICH ring radius histogram distribution and count the tail events that fall outside 5?, giving a fraction of 4×10-5 events outside the Gaussian tails. This control of events establishes the ability of using the RICH as a velocity spectrometer for high-precision searches of the K+??+ ? ?¯ decay like it is planned in the CKM experiment.

Morelos, A.; Mata, J.; Cooper, P. S.; Engelfried, J.; Aguilera-Servin, J. L.

2005-11-01

181

Gaps and tails in graphene and graphane  

NASA Astrophysics Data System (ADS)

We study the density of states (DOS) in monolayer and bilayer graphene in the presence of a random potential that breaks sublattice symmetries. While a uniform symmetry-breaking potential (SBP) opens a uniform gap, a random SBP also creates tails in the DOS. The latter can close the gap again, preventing the system from becoming an insulator. However, for a sufficiently large gap the tails contain localized states with nonzero DOS. These localized states allow the system to conduct at nonzero temperature via variable-range hopping. This result is in agreement with recent experimental observations in graphane by Elias et al (2009 Science 323 610).

Dóra, B.; Ziegler, K.

2009-09-01

182

Radial tail resolution in the SELEX RICH  

SciTech Connect

The authors use a 7 Million event data sample of 600 GeV/c single track pion events, where the pion track is reconstructed upstream and downstream of the SELEX RICH. They build the RICH ring radius histogram distribution and count the tail events that fall outside 5{sigma}, giving a fraction of 4 x 10{sup -5} events outside the Gaussian tails. This control of events establishes the ability of using the RICH as velocity spectrometer for high precision searches of the K{sup +} {yields} {pi}{sup +} {nu}{bar {nu}} decay like it is planned in the CKM experiment.

Morelos, A.; Mata, J.; Cooper, P.S.; Engelfried, J.; Aguilera-Servin, J.L.; /San Luis Potosi U. /Fermilab

2005-01-01

183

Pioneer fauna of nepheline-containing tailings  

NASA Astrophysics Data System (ADS)

The zoological analysis of nepheline-containing sands deposited in tailings 10-40 years ago showed that the pioneer colonists of this technogenic substrate are collembolan and mites, whose proportions depend on the succession of the bacterial and fungal components of the microbiota. The pioneer groups of mesofauna on 10- to 30-year-old tailings include carnivorous herpetobiontic arthropods and phytophagous insects. An impoverished version of the fauna of northern-taiga podzols is developed in the sands rehabilitated more than 40 years ago.

Zenkova, I. V.; Kalmykova, V. V.; Liskovaya, A. A.

2009-08-01

184

Dynamics of Histone Tails within Chromatin  

NASA Astrophysics Data System (ADS)

Genetic information in humans is encoded within DNA molecules that is wrapped around histone octamer proteins and compacted into a highly conserved structural polymer, chromatin. The physical and material properties of chromatin appear to influence gene expression by altering the accessibility of proteins to the DNA. The tails of the histones are flexible domains that are thought to play a role in regulating DNA accessibility and compaction; however the molecular mechanisms for these phenomena are not understood. I will present CW-EPR studies on site directed spin labeled nucleosomes that probe the structure and dynamics of these histone tails within nucleosomes.

Bernier, Morgan; North, Justin; Page, Michael; Jaroniec, Christopher; Hammel, Christopher; Poirier, Michael

2012-02-01

185

An improved technique for tail-cuff blood pressure measurements with dark-tailed mice.  

PubMed

Study of the genetics of hypertension has been facilitated greatly by the use of mice with modified genes that affect blood pressure. A current successful method for measuring blood pressure in mice relies on detection of light passing through the tail to determine the pressure in a tail-cuff necessary to stop pulsed flow. Success in obtaining reliable blood pressure measurements in light-tailed strains of mice (e.g., C57BL/6J) has been excellent. However, in our and others' experience, mice having highly pigmented tails (e.g., 129S6/SvEvTac) have yielded less consistent measurements. We report here that simple modifications to the channel containing the pulse detection sensor can greatly improve the pulse detection of dark-tailed mice. The first modification--lining the sensor channel with four layers of clear plastic wrap--increased the frequency of successful blood pressure measurements of 129S6/SvEvTac mice twofold and reduced variability by one-third. The second modification--lining the sides of the channel with reflective foil--also improved the success rate with dark-tailed mice. Mean blood pressures were unaffected by these modifications, which enhance detection of the pulse wave and likely will be helpful in diverse applications in which blood pressure is measured in rodent strains with pigmented tails. PMID:16138782

Hagaman, John R; John, Simon; Xu, Lonquan; Smithies, Oliver; Maeda, Nobuyo

2005-09-01

186

Structure and stability of the lamin A tail domain and HGPS mutant  

PubMed Central

Hutchinson-Gilford progeria syndrome (HGPS) is a premature aging syndrome caused by the expression and accumulation of a mutant form of lamin A, ?50 lamin A. As a component of the cell's nucleoskeleton, lamin A plays an important role in the mechanical stabilization of the nuclear envelope and in other nuclear functions. It is largely unknown how the characteristic 50 amino acid deletion affects the conformation of the mostly intrinsically disordered tail domain of lamin A. Here we perform replica exchange molecular dynamics simulations of the tail domain and determine an ensemble of semi-stable structures. Based on these structures we show that the ZMPSTE 24 cleavage site on the precursor form of the lamin A tail domain orients itself in such a way as to facilitate cleavage during the maturation process. We confirm our simulated structures by comparing the thermodynamic properties of the ensemble structures to in vitro stability measurements. Using this combination of techniques, we compare the size, heterogeneity of size, thermodynamic stability of the Ig-fold, as well as the mechanisms of force-induced denaturation. Our data shows that the ?50 lamin A tail domain is more compact and displays less heterogeneity than the mature lamin A tail domain. Altogether these results suggest that the altered structure and stability of the tail domain can explain changed protein-protein and protein-DNA interactions and may represent an etiology of the disease. Also, this study provides the first molecular structure(s) of the lamin A tail domain, which is confirmed by thermodynamic tests.

Qin, Zhao; Kalinowski, Agnieszka; Dahl, Kris Noel; Buehler, Markus J.

2011-01-01

187

TIDAL TAILS OF MINOR MERGERS: STAR FORMATION EFFICIENCY IN THE WESTERN TAIL OF NGC 2782  

SciTech Connect

While major mergers and their tidal debris are well studied, they are less common than minor mergers (mass ratios {approx}< 0.3). The peculiar spiral NGC 2782 is the result of a merger between two disk galaxies with a mass ratio of {approx}4: 1 occurring {approx}200 Myr ago. This merger produced a molecular and H I-rich, optically bright eastern tail and an H I-rich, optically faint western tail. Non-detection of CO in the western tail by Braine et al. suggested that star formation had not yet begun to occur in that tidal tail. However, deep H{alpha} narrowband images show evidence of recent star formation in the western tail. Across the entire western tail, we find the global star formation rate per unit area ({Sigma}{sub SFR}) to be several orders of magnitude less than expected from the total gas density. Together with extended FUV+NUV emission from Galaxy Evolution Explorer along the tail, this indicates a low global star formation efficiency in the tidal tail producing lower mass star clusters. The H II region that we observed has a local (few-kiloparsec scale) {Sigma}{sub SFR} from H{alpha} that is less than that expected from the total gas density, which is consistent with other observations of tidal debris. The star formation efficiency of this H II region inferred from the total gas density is low, but normal when inferred from the molecular gas density. These results suggest the presence of a very small, locally dense region in the western tail of NGC 2782 or of a low-metallicity and/or low-pressure star-forming region.

Knierman, Karen; Scowen, Paul; Jansen, Rolf A. [School of Earth and Space Exploration, Arizona State University, 550 East Tyler Mall, Room PSF-686 (P.O. Box 871404), Tempe, AZ 85287-1404 (United States); Knezek, Patricia M. [WIYN Consortium, Inc., 950 North Cherry Avenue, Tucson, AZ 85719 (United States); Wehner, Elizabeth, E-mail: karen.knierman@asu.edu, E-mail: paul.scowen@asu.edu, E-mail: rolf.jansen@asu.edu, E-mail: pknezek@noao.edu, E-mail: ewehner@haverford.edu [Department of Astronomy, Haverford College, Haverford, PA 19041 (United States)

2012-04-10

188

Effect of horizontal-tail span and vertical location on the aerodynamic characteristics of an unswept tail assembly in sideslip  

NASA Technical Reports Server (NTRS)

An investigation has been conducted in the Langley stability tunnel on a vertical-tail model with a stub fuselage in combination with various horizontal tails to determine the effect of horizontal-tail span and vertical location of the horizontal tail relative to the vertical tail on the aerodynamic characteristics of an unswept tail assembly in sideslip. The results of the investigation indicated that the induced loading carried by the horizontal tail produced a rolling moment about the point of attachment to the vertical tail which was strongly influenced by horizontal-tail span and vertical locations. The greatest effect of horizontal-tail span on the rolling-moment derivative of the complete tail assembly was obtained for horizontal-tail locations near the top of the vertical tail. Span loadings which were reduced to the static-stability derivatives were calculated for each configuration tested by applying the well-known finite-step method used for wings to the intersecting surfaces of the vertical and horizontal tails. The finite-step method provides a simple and effective means of investigating the span loadings of intersecting surfaces.

Riley, Donald R

1954-01-01

189

Experiments on a tail-wheel shimmy  

NASA Technical Reports Server (NTRS)

Model tests on the "running belt" and tests with a full-scale tail wheel were made on a rotating drum as well as on a runway in order to investigate the causes of the undesirable shimmy phenomena frequently occurring on airplane tail wheels, and the means of avoiding them. The small model (scale 1:10) permitted simulation of the mass, moments of inertia, and fuselage stiffness of the airplane and determination of their influence on the shimmy, whereas by means of the larger model with pneumatic tires (scale 1:2) more accurate investigations were made on the tail wheel itself. The results of drum and road tests show good agreement with one another and with model values. Detailed investigations were made regarding the dependence of the shimmy tendency on trail, rolling speed, load, size of tires, ground friction,and inclination of the swivel axis; furthermore, regarding the influence of devices with restoring effect on the tail wheel, and the friction damping required for prevention of shimmy. Finally observations from slow-motion pictures are reported and conclusions drawn concerning the influence of tire deformation.

Harling, R; Dietz, O

1954-01-01

190

Investigations Relating to Fat-Tail Sheep.  

National Technical Information Service (NTIS)

The only Fat-tail type of sheep known to be present in the U.S. is the Karakul. In 1979 a small number of Karakul sheep were obtained and brought to the experimental flock maintained at San Angelo, Texas. The animals were obtained from range flocks in New...

M. Shelton R. Lewis T. Willingham G. C. Smith J. W. Savell

1986-01-01

191

Controlled Impact Demonstration (CID) tail camera video  

NASA Technical Reports Server (NTRS)

The Controlled Impact Demonstration (CID) was a joint research project by NASA and the FAA to test a survivable aircraft impact using a remotely piloted Boeing 720 aircraft. The tail camera movie is one shot running 27 seconds. It shows the impact from the perspective of a camera mounted high on the vertical stabilizer, looking forward over the fuselage and wings.

1984-01-01

192

Factors Influencing Radon Attenuation by Tailing Covers.  

National Technical Information Service (NTIS)

The US NRC, in its Generic Environmental Impact Statement on uranium milling has specified that the radon flux escaping a uranium mill tailings pile will be reduced to pCi/m exp 2 s by application of covering layers of soils and clays. These covers presen...

V. C. Rogers W. B. Silker

1981-01-01

193

VideoLab: Heads and Tails  

NSDL National Science Digital Library

The flatworms known as planaria are proverbial for their ability to regenerate a head or tail properly when amputated (first clip in movie). But how does the organism "know" which end to regenerate? Gurley et al. found an answer in a molecular "switch", beta-catenin, a protein that regulates a variety of cell processes during development.

Kyle A. Gurley (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy); Jochen C. Rink (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy); Alejandro Sánchez Alvarado (Howard Hughes Medical Institute, University of Utah School of Medicine;Department of Neurobiology and Anatomy)

2008-01-18

194

Tail-Wagging Event in Comet Austin.  

National Technical Information Service (NTIS)

On the morning of 21 May 1990, a sequence of images of Comet Austin was obtained in the light of H2O+. The filter was centered at 602.5 nm with FWHM of 5.0 nm. At least two waves were followed out through the main ion tail structure. During the course of ...

D. A. Klinglesmith M. B. Niedner R. J. Oliversen D. Westpfahl

1990-01-01

195

Mine Waste Technology Program Electrochemical Tailings Cover  

EPA Science Inventory

This report summarizes the results of Mine Waste Technology Program (MWTP) Activity III, Project 40, Electrochemical Tailings Cover, funded by the U.S. Environmental Protection Agency (EPA) and jointly administered by EPA and the U.S. Department of Energy (DOE). MSE Technology A...

196

The mine tailing accident in Aznalcollar  

Microsoft Academic Search

Massive amounts of acidic waters and mud (pH?3) containing toxic metals such as zinc, lead, arsenic, copper, antimony, cobalt, thallium, bismuth, cadmium, silver, mercury and selenium were released in the surroundings of Doñana Park as a consequence of the mine tailings spill accident in Aznalcollar (SW Spain). This introductory paper describes the main characteristics of Doñana Park, the mine activities

Joan O Grimalt; Miguel Ferrer; Enrique Macpherson

1999-01-01

197

The Mechanical Properties of Rat Tail Tendon  

Microsoft Academic Search

The load-strain and stress-relaxation behavior of wet rat tail tendon has been examined with respect to the parameters strain, rate of strain- ing, and temperature. It is found that this mechanical behavior is reproducible after resting tile tendon for a few minutes after each extension so long as the strain does not exceed about 4 per cent. If this strain

BERNARD J. RIGBY; OHN D. SPIKES; HENRY EYRING

1959-01-01

198

Constraining Dark Halo Potentials with Tidal Tails  

Microsoft Academic Search

Massive and extended dark halos can inhibit the formation of long tidal tails in galaxy collisions. We examine this effect using an extensive survey of simulations with different dark halo potentials to constrain halo properties of interacting galaxies. These constraints are compared to other observational limits and theoretical predictions of halo structure. The dark halos predicted by $\\\\Omega=1$ cosmological models

J. Dubinski; L. Hernquist; J. C. Mihos

1998-01-01

199

Dispersal in female white-tailed deer  

USGS Publications Warehouse

Seven of 35 yearling female white-tailed deer (Odocoileus virginianus) in a migratory herd in northeastern Minnesota dispersed 18-168 km from natal ranges during late May through June. Dispersal as a proximate event appears voluntary and independent of deer density.

Nelson, M. E.; Mech, L. D.

1992-01-01

200

Radiological hazards of uranium mill tailings piles  

Microsoft Academic Search

This paper examines reasons for the radiological health problems associated with the front end of the nuclear fuel cycle. The increases of radioactivity in the general environment attributable to uranium mill tailings are small but never ending. Sources of radiation - mainly particulate matter and radon gas - are discussed. Management of the piles seems to provide the only viable

G. A. Watford; J. A. Jr. Wethington

1981-01-01

201

Analysis of three-dimensional kinematics of carp tail fin  

NASA Astrophysics Data System (ADS)

In this paper, a test based on the wavelet transform for instantaneous three dimensional (3D) Carp tail fin profile measurements and analysis the kinematics of Carp tail fin method was proposed to understand the function of the tail fin. This experiment method is used in cruising carp. Projecting a moiré fringes onto a tail fin, the deformed fringe pattern containing 3D information was produced and varied with the movement of tail fin. The time-sequence deformed fringe pattern images were captured by a high speed camera. By wavelet transform profilometry, the tail fin movements were really reconstructed. On this basis, the kinematics parameter of tail fin was analyses. Experimental results indicate that the 3D profile of tail fin was varied during the tail-beat cycle. Analysis of tail kinematics suggests that, at a swimming speed 0.5Ls-1, the tail beat frequency is 1.42Hz and the dorsal lobe of the tail undergoes a 15.6% greater lateral excursion than does the ventral lobe. The timing of maximal lateral excursion was different at different location of tail fin.

Jiang, Ming; Zhang, Shu; He, Xiaoyuan

2009-12-01

202

Flight costs of long, sexually selected tails in hummingbirds.  

PubMed

The elongated tails adorning many male birds have traditionally been thought to degrade flight performance by increasing body drag. However, aerodynamic interactions between the body and tail can be substantial in some contexts, and a short tail may actually reduce rather than increase overall drag. To test how tail length affects flight performance, we manipulated the tails of Anna's hummingbirds (Calypte anna) by increasing their length with the greatly elongated tail streamers of the red-billed streamertail (Trochilus polytmus) and reducing their length by removing first the rectrices and then the entire tail (i.e. all rectrices and tail covert feathers). Flight performance was measured in a wind tunnel by measuring (i) the maximum forward speed at which the birds could fly and (ii) the metabolic cost of flight while flying at airspeeds from 0 to 14 m s(-1). We found a significant interaction effect between tail treatment and airspeed: an elongated tail increased the metabolic cost of flight by up to 11 per cent, and this effect was strongest at higher flight speeds. Maximum flight speed was concomitantly reduced by 3.4 per cent. Also, removing the entire tail decreased maximum flight speed by 2 per cent, suggesting beneficial aerodynamic effects for tails of normal length. The effects of elongation are thus subtle and airspeed-specific, suggesting that diversity in avian tail morphology is associated with only modest flight costs. PMID:19324747

Clark, Christopher James; Dudley, Robert

2009-06-01

203

Hydrologic Considerations for Rock RIPRAP Protection of Uranium Tailings Impoundments.  

National Technical Information Service (NTIS)

Pacific Northwest Laboratory is conducting an in-depth study of the application of rock riprap for the long-term protection of uranium tailings impoundments. Decommissioned tailings sites at Grand Junction and Slickrock, Colorado were selected to review t...

W. H. Walters R. L. Skaggs

1984-01-01

204

Radiological Impact of Uranium Tailings and Alternatives for Their Management.  

National Technical Information Service (NTIS)

Uncontrolled tailings piles are mobile sources of fugitive dust that may produce a practically uncleanable adjacent environment. A practical procedure for managing solid tailings is addition of surface moisture, mechanical and gravitational separation of ...

M. H. Momeni W. E. Kisieleski S. Tyler A. Zielen Y. Yuan

1979-01-01

205

14. Credit PED. Downstream elevation, near completion, showing tail race ...  

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

14. Credit PED. Downstream elevation, near completion, showing tail race and trestle used to carry excavated rock and construction materials across tail race. Photo c. 1909. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

206

Tail Approximation for Credit Risk Portfolios With Heavy-Tailed Risk Factors  

Microsoft Academic Search

We consider a portfolio credit risk model in the spirit of CreditMetrics (15). The multivariate normally distributed underlying risk factors in that model are replaced by more general multivariate elliptical factors with heavy-tailed marginals, intro- ducing tail-dependence. We consider a full-scale version of the model, i.e. we incor- porate not only the default risk, but also rating migrations, credit spread

Krassimir Kostadinov

207

Waiting-time tail probabilities in queues with long-tail service-time distributions  

Microsoft Academic Search

We consider the standard GI\\/G\\/1 queue with unlimited waiting room and the first-in first-outservice discipline. We investigate the steady-state waiting-time tail probabilities P(W > x) whenthe service-time distribution has a long-tail distribution, i.e., when the service-time distributionfails to have a finite moment generating function. We have developed algorithms for computingthe waiting-time distribution by Laplace transform inversion when the Laplace transforms

Joseph Abate; Gagan L. Choudhury; Ward Whitt

1994-01-01

208

Improved Tail-Current Representation in the Rice Field Model  

Microsoft Academic Search

The Rice Field Model (RFM) represents the magnetic field of the steady-state open magnetosphere. In order to improve the mapping of field lines in the near Earth region, the simple Harris-sheet field representing the cross-tail current is replaced near the Earth by a more flexible tail current model developed by Hilmer and Voigt In the far-tail region the tail current

S. Naehr; F. R. Toffoletto

2001-01-01

209

Tail-assisted pitch control in lizards, robots and dinosaurs.  

PubMed

In 1969, a palaeontologist proposed that theropod dinosaurs used their tails as dynamic stabilizers during rapid or irregular movements, contributing to their depiction as active and agile predators. Since then the inertia of swinging appendages has been implicated in stabilizing human walking, aiding acrobatic manoeuvres by primates and rodents, and enabling cats to balance on branches. Recent studies on geckos suggest that active tail stabilization occurs during climbing, righting and gliding. By contrast, studies on the effect of lizard tail loss show evidence of a decrease, an increase or no change in performance. Application of a control-theoretic framework could advance our general understanding of inertial appendage use in locomotion. Here we report that lizards control the swing of their tails in a measured manner to redirect angular momentum from their bodies to their tails, stabilizing body attitude in the sagittal plane. We video-recorded Red-Headed Agama lizards (Agama agama) leaping towards a vertical surface by first vaulting onto an obstacle with variable traction to induce a range of perturbations in body angular momentum. To examine a known controlled tail response, we built a lizard-sized robot with an active tail that used sensory feedback to stabilize pitch as it drove off a ramp. Our dynamics model revealed that a body swinging its tail experienced less rotation than a body with a rigid tail, a passively compliant tail or no tail. To compare a range of tails, we calculated tail effectiveness as the amount of tailless body rotation a tail could stabilize. A model Velociraptor mongoliensis supported the initial tail stabilization hypothesis, showing as it did a greater tail effectiveness than the Agama lizards. Leaping lizards show that inertial control of body attitude can advance our understanding of appendage evolution and provide biological inspiration for the next generation of manoeuvrable search-and-rescue robots. PMID:22217942

Libby, Thomas; Moore, Talia Y; Chang-Siu, Evan; Li, Deborah; Cohen, Daniel J; Jusufi, Ardian; Full, Robert J

2012-01-12

210

Ecological aspects of microorganisms inhabiting uranium mill tailings  

Microsoft Academic Search

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the

Christine L. Miller; Edward R. Landa; David M. Updegraff

1987-01-01

211

True vestigeal tail with lumbosacral meningomyelocoel: a rare case report.  

PubMed

A human tail is a rare congenital anomaly with a prominent lesion from the lumbosacro-coccygeal region. It is usually classified either as a true tail or as a pseudo-tail. All the lumbosacro-coccygeal protrusions without the evidence of mesenchymal tissue are classified as pseudo-tail. The association of this rare vestigial entity along with meningomyelocele is rarer still. PMID:20868247

Akhil, Prakash; Ashutosh, Niranjan; Fais, Fiages; Shashank, Mishra; Sanjay, Pandey; Singhal, B M; Attri, P C; Arvind, Gupta

2010-10-01

212

14 CFR 25.481 - Tail-down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2009-01-01 2009-01-01 false Tail-down landing conditions. 25.481 Section...CATEGORY AIRPLANES Structure Ground Loads § 25.481 Tail-down landing conditions. (a) In the tail-down attitude, the airplane is...

2009-01-01

213

14 CFR 25.481 - Tail-down landing conditions.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Tail-down landing conditions. 25.481 Section...CATEGORY AIRPLANES Structure Ground Loads § 25.481 Tail-down landing conditions. (a) In the tail-down attitude, the airplane is...

2010-01-01

214

Environmental desulphurization of four Canadian mine tailings using froth flotation  

Microsoft Academic Search

Environmental desulphurization is an attractive alternative for management of acid generating tailings. This process placed at the end of the primary process treatment circuit will reduce a large amount of the problematic tailings by concentrating the sulphide fraction. To produce desulphurized tailings, non-selective froth flotation is the most adapted method. The desulphurization level is fixed by the sulphide content of

M Benzaazoua; B Bussière; M Kongolo; J McLaughlin; P Marion

2000-01-01

215

Long term fate of uranium tailings in mountain areas  

Microsoft Academic Search

Common passive controls for uranium tailings include constructing thick earthen covers, protected by rock, over the waste. Earthen covers effectively limit dust and radon emissions and gamma radiation and, in conjunction with the rock covers, help stabilizing the tailings to prevent dispersion of the tailings through erosion or intrusion. In some cases, piles may be moved to safer locations (e.g.

Broder J. Merkel

216

The Action of Waving Cylindrical Tails in Propelling Microscopic Organisms  

Microsoft Academic Search

The action of the tail of a spermatozoon is discussed from the hydrodynamical point of view. The tail is assumed to be a flexible cylinder which is distorted by waves of lateral displacement propagated along its length. The resulting stress and motion in the surrounding fluid is analyzed mathematically. Waves propagated backwards along the tail give rise to a forward

Geoffrey Taylor

1952-01-01

217

14. TIP TOP MINE. TAILINGS LOCATED DIRECTLY WEST FROM TIP ...  

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

14. TIP TOP MINE. TAILINGS LOCATED DIRECTLY WEST FROM TIP TOP HOUSE. ID-31-C-12 WOODEN STRUCTURE IS VISIBLE IN TOP LEFT. CABLES VISIBLE LEFT AND CENTER OF TAILINGS. HOUSE IS JUST OVER APEX OF TAILINGS. CAMERA POINTED EAST. - Florida Mountain Mining Sites, Tip Top Mine, West face Florida Mountain, approximately 150 feet below summit, Silver City, Owyhee County, ID

218

Uranium Mill Tailings Remedial Action Project surface project management plan  

SciTech Connect

This Project Management Plan describes the planning, systems, and organization that shall be used to manage the Uranium Mill Tailings Remedial Action Project (UMTRA). US DOE is authorized to stabilize and control surface tailings and ground water contamination at 24 inactive uranium processing sites and associated vicinity properties containing uranium mill tailings and related residual radioactive materials.

Not Available

1994-09-01

219

Estimation of first and second order parameters in heavy tails  

Microsoft Academic Search

Any distribution in the positive axis can be used as the associated model of severity for individual claims. However, if we consider heavy tailed distributions, the large claims have great influence for the total claim amount. One parameter that is used to have some insight of the weight of the tail is the well- known tail index, ?, which plays

M. I. Fraga Alves

220

Computational modelling of final covers for uranium mill tailings impoundments  

Microsoft Academic Search

To properly design a final cover for uranium mill tailings impoundments the designer must attempt to find an effective geotechnical solution which addresses the radiological and non-radiological potential impact and prevents geochemical processes from occurring within the tailings. This paper presents a computer-based method for evaluating the performance of engineered final covers for the remediation of uranium mill tailings impoundments.

Guilherme Lu??s Menegassi Leoni; Márcio de Souza Soares Almeida; Horst Monken Fernandes

2004-01-01

221

Processes for extracting radium from uranium mill tailings  

Microsoft Academic Search

This patent describes a process for the extraction of radium from uranium mill tailings solids including the steps of contacting the tailings with a liquid leaching agent, leaching the tailings therewith and subsequently separating the leachate liquid and the leached solids. The improvement described here is wherein the leaching agent comprises: (a) a complexing agent in an amount of from

I. Nirdosh; M. H. Baird; S. V. Muthuswami

1987-01-01

222

Decommissioning of Uranium mill tailings ponds at WISMUT (Germany)  

Microsoft Academic Search

Approximately 577 ha of Uranium mill tailings ponds containing approx. 154 Mio. m3 of mill tailings were left as part of the legacy of the uranium mining and milling in Eastern Germany. The decommissioning of these tailings ponds belongs to the most challenging tasks of the entire Wismut remediation project. The remediation activities started in 1990 with defence measures against

Albrecht Neudert; Ulf Barnekow

223

Serological activity of white-tail deer against several species of Brucella.  

PubMed

In Mexico, brucellosis is a widely distributed disease of domesticated ruminants, but its frequency in wild ruminants has not been documented. Since northeast Mexico is the main distribution area of white-tailed deer and has been reported as an area positive for brucellosis in domesticated species, the present study was conducted in order to determine serological activity against several species of the genus Brucella in white-tailed deer. A total of 208 sera of white-tailed deer were collected during the springs of 1994 and 1995 in the north part of the states of Nuevo León and Coahuila. Each serum was analyzed for the detection of antibodies against two smooth (B. abortus and B. melitensis) and one rough (B. ovis) species of the genus Brucella. The serological tests used for the determination of the presence of antibodies against Brucella were card and plate agglutination for B. abortus, plate agglutination and rivanol precipitation for B. melitensis, and agar gel immunodiffusion for B. ovis. Each assay had positive and negative controls. None of the analyzed samples was found to be positive, and only two sera showed partial plate agglutination against B. melitensis at a dilution of 1:25; however, at higher dilutions and to the rivanol precipitation test the same samples were negative. Therefore, the percentage of positive sera was estimated at 0% (0/208). This result makes evident the absence of positive white-tailed deer against Brucella in the sampled area, despite that this disease is considered present in domesticated species. Therefore, white-tailed deer does not have, at the present time, an important role for the dispersion of the disease. The same result has been reported in other countries. PMID:10932740

Salinas-Meléndez, J A; Martínez-Muñoz, A; Avalos-Ramírez, R; Cerutti-Pereyra, N; Riojas-Valdés, V M

1998-01-01

224

Experimental verification of a simplified vee-tail theory and analysis of available data on complete models with vee tails  

NASA Technical Reports Server (NTRS)

An analysis has been made of available data on vee tail surfaces. Previously published theoretical studies of vee tails have been extended to include the control effectiveness and control forces in addition to the stability. Tests of two isolated tail surfaces with various amounts of dihedral provided a check of the theory. Methods for designing vee tails were also developed and are given in the present paper.

Purser, Paul E; Campbell, John P

1945-01-01

225

Structures and Interaction Analyses of Integrin ?M?2 Cytoplasmic Tails*  

PubMed Central

Integrins are heterodimeric (? and ? subunits) signal transducer proteins involved in cell adhesions and migrations. The cytosolic tails of integrins are essential for transmitting bidirectional signaling and also implicated in maintaining the resting states of the receptors. In addition, cytosolic tails of integrins often undergo post-translation modifications like phosphorylation. However, the consequences of phosphorylation on the structures and interactions are not clear. The leukocyte-specific integrin ?M?2 is essential for myeloid cell adhesion, phagocytosis, and degranulation. In this work, we determined solution structures of the myristoylated cytosolic tail of ?M and a Ser phosphorylated variant in dodecylphosphocholine micelles by NMR spectroscopy. Furthermore, the interactions between non-phosphorylated and phosphorylated ?M tails with ?2 tail were investigated by NMR and fluorescence resonance energy transfer (FRET). The three-dimensional structures of the 24-residue cytosolic tail of ?M or phosphorylated ?M are characterized by an N-terminal amphipathic helix and a loop at the C terminus. The residues at the loop are involved in packing interactions with the hydrophobic face of the helix. 15N-1H heteronuclear single quantum coherence experiments identified residues of ?M and ?2 tails that may be involved in the formation of a tail-tail heterocomplex. We further examined interactions between myristoylated ?2 tail in dodecylphosphocholine micelles with dansylated ?M tail peptides by FRET. These studies revealed enhanced interactions between ?M or phosphorylated ?M tails with ?2 tail with Kd values ?5.2 ± 0.6 and ?4.4 ± 0.7 ?m, respectively. Docked structures of tail-tail complexes delineated that the ?M/?2 interface at the cytosolic region could be sustained by a network of polar interactions, ionic interactions, and/or hydrogen bonds.

Chua, Geok-Lin; Tang, Xiao-Yan; Amalraj, Monalisa; Tan, Suet-Mien; Bhattacharjya, Surajit

2011-01-01

226

The effect of biting tails and having tails bitten in pigs.  

PubMed

Tail-biting is a behavioral abnormality which compromises the welfare of pigs. The goal of this study was to characterize the tail-biting phenotype using behavior and measures of heart-rate (HR) and its variability (HRV) in pigs. Thirty pigs were categorized as tail-biters (n=10), tail-bite victims (n=10), and control pigs (n=10) based on the frequency of tail-biting behavior that they performed or received at the farm. The animals' behavioral responses were registered at the experimental facilities for 10 min during test sessions whereas physiological responses were registered for 10 min prior to (basal) and during sessions when subjected to a novel object test (NOT) and to a novel arena test (NAT). Phenotypes differed in most behaviors during the two tests and in the NOT their physiological responses suggested different regulation of vagal tone. Biters had a reduction from baseline values to values during testing for the root mean square of successive R-R intervals (RMSSD) and the high-frequency band (HF) compared to victims, whose RMSSD and HF increased from baseline to test values. In the low-frequency band (LF), an increase was shown in biters and controls while a decrease in victims. LF was found to be strongly positively correlated with HF and RMSSD in biters. During baseline, victims tended to have lower HF and significantly higher power of the low-frequency component divided by power of the high-frequency band (LF:HF ratio) compared to biters and controls. The activity of the autonomic nervous system, especially the suppression of parasympathetic tone, indicated that both victims and biters may have a dysfunctional autonomic regulation which may indicate psychological disturbance. We provide the first documentation of phenotypic differences between pigs that have performed tail-biting, have been victimized, or have not been involved in tail biting using HRV data. PMID:22579933

Zupan, Manja; Janczak, Andrew M; Framstad, Tore; Zanella, Adroaldo J

2012-07-16

227

Missile rolling tail brake torque system  

NASA Astrophysics Data System (ADS)

Apparatus for simulating varying levels of friction in the bearings of a free rolling tail afterbody on a canard-controlled missile to determine friction effects on aerodynamic control characteristics is described. A ring located between the missile body and the afterbody is utilized in a servo system to create varying levels of friction between the missile body and the afterbody to simulate bearing friction.

Davis, W. T.

1984-01-01

228

Automated registration of tail bleeding in rats.  

PubMed

An automated system for registration of tail bleeding in rats using a camera and a user-designed PC-based software program has been developed. The live and processed images are displayed on the screen and are exported together with a text file for later statistical processing of the data allowing calculation of e.g. number of bleeding episodes, bleeding times and bleeding areas. Proof-of-principle was achieved when the camera captured the blood stream after infusion of rat whole blood into saline. Suitability was assessed by recording of bleeding profiles in heparin-treated rats, demonstrating that the system was able to capture on/off bleedings and that the data transfer and analysis were conducted successfully. Then, bleeding profiles were visually recorded by two independent observers simultaneously with the automated recordings after tail transection in untreated rats. Linear relationships were found in the number of bleedings, demonstrating, however, a statistically significant difference in the recording of bleeding episodes between observers. Also, the bleeding time was longer for visual compared to automated recording. No correlation was found between blood loss and bleeding time in untreated rats, but in heparinized rats a correlation was suggested. Finally, the blood loss correlated with the automated recording of bleeding area. In conclusion, the automated system has proven suitable for replacing visual recordings of tail bleedings in rats. Inter-observer differences can be eliminated, monotonous repetitive work avoided, and a higher through-put of animals in less time achieved. The automated system will lead to an increased understanding of the nature of bleeding following tail transection in different rodent models. PMID:18449428

Johansen, Peter B; Henriksen, Lars; Andresen, Per R; Lauritzen, Brian; Jensen, Kåre L; Juhl, Trine N; Tranholm, Mikael

2008-05-01

229

Small head-to-tail macrocyclic ?-peptoids.  

PubMed

A convenient and efficient methodology for the head-to-tail macrocyclization of small 3-mer, 4-mer, and 5-mer ?-peptoid acids (9-, 12-, and 15-atom N-substituted glycine oligomers) is described. The cyclic trimer has a ccc amide sequence in the crystal structure, whereas the tetramer has ctct and the pentamer has ttccc stereochemistry. NMR analysis reveals rigid structures in solution. These synthetic macrocycles may prove useful in medicinal and materials applications. PMID:24797336

Culf, Adrian S; ?uperlovi?-Culf, Miroslava; Léger, Daniel A; Decken, Andreas

2014-05-16

230

Heavy Tail Modeling And Teletraffic Data  

Microsoft Academic Search

. Huge data sets from the teletraffic industry exhibit many non-standard characteristics such as heavytails and long range dependence. Various estimation methods for heavy tailed time series with positive innovationsare reviewed. These include parameter estimation and model identification methods for autoregressions and movingaverages. Parameter estimation methods include those of Yule-Walker and the linear programming estimators ofFeigin and Resnick as well

Sidney I. Resnick

1997-01-01

231

Tail Rotor Airfoils Stabilize Helicopters, Reduce Noise  

NASA Technical Reports Server (NTRS)

Founded by former Ames Research Center engineer Jim Van Horn, Van Horn Aviation of Tempe, Arizona, built upon a Langley Research Center airfoil design to create a high performance aftermarket tail rotor for the popular Bell 206 helicopter. The highly durable rotor has a lifetime twice that of the original equipment manufacturer blade, reduces noise by 40 percent, and displays enhanced performance at high altitudes. These improvements benefit helicopter performance for law enforcement, military training, wildfire and pipeline patrols, and emergency medical services.

2010-01-01

232

Constraining dark halos with tidal tails  

Microsoft Academic Search

Massive and extended dark halos can inhibit the formation of long tidal tails\\u000ain galaxy collisions. We examine this effect using an extensive survey of\\u000asimulations with different dark halo potentials to constrain halo properties of\\u000ainteracting galaxies. These constraints are compared to other observational\\u000alimits and theoretical predictions of halo structure. The dark halos predicted\\u000aby $\\\\Omega=1$ cosmological models

John Dubinski; Chris Mihos; Lars Hernquist

1997-01-01

233

Adding tails to C*-correspondences  

Microsoft Academic Search

We describe a method of adding tails to C*-correspondences which generalizes the process used in the study of graph C*-algebras. We show how this technique can be used to extend results for augmented Cuntz-Pimsner algebras to C*-algebras associated to general C*-correspondences, and as an application we prove a gauge-invariant uniqueness theorem for these algebras. We also define a notion of

Paul S. Muhly; Mark Tomforde

2002-01-01

234

Radium226 in uranium mill tailings  

Microsoft Academic Search

A study of the physical state of226Ra in uranium mill tailings was undertaken by Chemex Laboratories Ltd. under contract to NUTP. A test portion of a leached uranium ore was collected just prior to neutralization with lime and subjected to repetitive batch water leaching. The leachates were analyzed for barium, lead,226Ra, iron and sulphate. The experimental results suggest that226Ra is

H. F. Steger; M. Legeyt

1987-01-01

235

The kangaroo's tail propels and powers pentapedal locomotion.  

PubMed

When moving slowly, kangaroos plant their tail on the ground in sequence with their front and hind legs. To determine the tail's role in this 'pentapedal' gait, we measured the forces the tail exerts on the ground and calculated the mechanical power it generates. We found that the tail is responsible for as much propulsive force as the front and hind legs combined. It also generates almost exclusively positive mechanical power, performing as much mass-specific mechanical work as does a human leg during walking at the same speed. Kangaroos use their muscular tail to support, propel and power their pentapedal gait just like a leg. PMID:24990111

O'Connor, Shawn M; Dawson, Terence J; Kram, Rodger; Donelan, J Maxwell

2014-07-01

236

Transient effects of the wing wake on the horizontal tail  

NASA Technical Reports Server (NTRS)

The effect of wing wake on the lift of the horizontal tail surfaces was studied. In the development of expressions for this effect, the growth of wing circulation and wing wake, the time interval represented by the tail length, and the development of lift by the tail were considered. The theory has been applied to a specific case to show the magnitude of the effect to be expected. It is shown that, for motions below a certain frequency, the development of lift by the tail may be represented by a simple lag function. The lag is, however, somewhat greater than that indicated by the tail length.

Jones, R. T.; Fehlner, L. F.

1976-01-01

237

Development of a biologically inspired hydrobot tail  

NASA Astrophysics Data System (ADS)

It has been hypothesized that Europa, one of the moons of Jupiter, has a large ocean underneath a thick layer of ice. In order to determine whether life exists, it has been proposed that an underwater glider (hydrobot) capable of propulsion could be sent to explore the vast ocean. In this research, we considered various smart materials to create a propulsion device inspired by dolphin tails. Dolphins are highly efficient and excellent gliders, which makes them the ideal candidate for ocean exploration. In order to select the best dolphin species, we began by reviewing literature and then utilized the Analytical Hierarchy Process (AHP) to compare the different species. Lagenorhynchus obliquidens (Pacific White-Sided Dolphin) was found to be the best choice for creating a bioinspired hydrobot. We then conducted literature review of various smart materials and using this knowledge constructed a hydrobot tail prototype. This prototype demonstrates that smart materials can be fashioned into suitable actuators to control a tail fashioned after a dolphin.

Moore, Danielle; Janneh, Alhaji; Philen, Michael

2014-04-01

238

Asphalt emulsion sealing of uranium mill tailings. 1979 annual report  

SciTech Connect

Uranium mill tailings are a source of low-level radiation and radioactive materials that may be released into the environment. Stabilization or disposal of these tailings in a safe and environmentally sound way is necessary to minimize radon exhalation and other radioactive releases. One of the most promising concepts for stabilizing uranium tailings is being investigated at the Pacific Northwest Laboratory: the use of asphalt emulsion to contain radon and other potentially hazardous materials in uranium tailings. Results of these studies indicate that radon flux from uranium tailings can be reduced by greater than 99% by covering the tailings with an asphalt emulsion that is poured on or sprayed on (3.0 to 7.0 mm thick), or mixed with some of the tailings and compacted to form an admixture seal (2.5 to 15.2 cm) containing 18 wt % residual asphalt.

Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.

1980-06-01

239

Ecological aspects of microorganisms inhabiting uranium mill tailings  

USGS Publications Warehouse

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques. Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereas Bacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. ?? 1987 Springer-Verlag New York Inc.

Miller, C. L.; Landa, E. R.; Updegraff, D. M.

1987-01-01

240

Ecological aspects of microorganisms inhabiting uranium mill tailings.  

PubMed

Numbers and types of microorganisms in uranium mill tailings were determined using culturing techniques.Arthrobacter were found to be the predominant microorganism inhabiting the sandy tailings, whereasBacillus and fungi predominated in the slime tailings. Sulfate-reducing bacteria, capable of leaching radium, were isolated in low numbers from tailings samples but were isolated in significantly high numbers from topsoil in contact with the tailings. The results are placed in the context of the magnitude of uranium mill tailings in the United States, the hazards posed by the tailings, and how such hazards could be enhanced or diminished by microbial activities. Patterns in the composition of the microbial population are evaluated with respect to the ecological variables that influence microbial growth. PMID:24202642

Miller, C L; Landa, E R; Updegraff, D M

1987-09-01

241

Modeling distribution of dispersal distances in male white-tailed deer  

USGS Publications Warehouse

Dispersal distances and their distribution pattern are important to understanding such phenomena as disease spread and gene flow, but oftentimes dispersal characteristics are modeled as a fixed trait for a given species. We found that dispersal distributions differ for spring and autumn dispersals of yearling male white-tailed deer (Odocoileus virginianus) but that combined data can be adequately modeled based on a log-normal distribution. We modeled distribution of dispersal distances from 3 distinct populations in Pennsylvania and Maryland, USA, based on the relationship between percent forest cover and mean dispersal distance and the relationship between mean and variance of dispersal distances. Our results suggest distributions of distances for dispersing yearling male white-tailed deer can be modeled by simply measuring a readily obtained landscape metric, percent forest cover, which could be used to create generalized spatially explicit disease or gene.

Diefenbach, D. R.; Long, E. S.; Rosenberry, C. S.; Wallingford, B. D.; Smith, D. R.

2008-01-01

242

Improving clay-based tailings disposal: Case study on coal tailings  

SciTech Connect

The role of swelling clays in hindering the compressional dewatering characteristics of coal-mine tailings is examined. The effects of electrolyte concentration and ion exchange in improving the shear and compressional rheology are compared. Suspensions studied include actual mine tailings (thickener feed and thickener underflow) as well as synthetic clay dispersions made from clay collected from the coal seam. It was shown that the most important parameter in controlling the properties of the tailings suspension is controlled dispersion in the presence of a Ca{sup 2+} electrolyte concentration in excess of that required to (1) prevent initial swelling and (2) provide full cation exchange of the clay. Under these electrolyte conditions, complete delamination of the clay did not occur, and both the dewatering and handling characteristics of the resultant suspensions improved dramatically.

Kretser, R. de; Scales, P.J.; Boger, D.V. [Univ. of Melbourne, Parkville (Australia)] [Univ. of Melbourne, Parkville (Australia)

1997-07-01

243

Metal mobilization under alkaline conditions in ash-covered tailings.  

PubMed

The aim of this study was to determine element mobilization and accumulation in mill tailings under alkaline conditions. The tailings were covered with 50 cm of fly ash, and above a sludge layer. The tailings were geochemically and mineralogically investigated. Sulfides, such as pyrrhotite, sphalerite and galena along with gangue minerals such as dolomite, calcite, micas, chlorite, epidote, Mn-pyroxene and rhodonite were identified in the unoxidized tailings. The dissolution of the fly ash layer resulted in a high pH (close to 12) in the underlying tailings. This, together with the presence of organic matter, increased the weathering of the tailings and mobilization of elements in the uppermost 47 cm of the tailings. All primary minerals were depleted, except quartz and feldspar which were covered by blurry secondary carbonates. Sulfide-associated elements such as Cd, Fe, Pb, S and Zn and silicate-associated elements such as Fe, Mg and Mn were released from the depletion zone and accumulated deeper down in the tailings where the pH decreased to circum-neutral. Sequential extraction suggests that Cd, Cu, Fe, Pb, S and Zn were retained deeper down in the tailings and were mainly associated with the sulfide phase. Calcium, Cr, K and Ni released from the ash layer were accumulated in the uppermost depletion zone of the tailings. PMID:24681363

Lu, Jinmei; Alakangas, Lena; Wanhainen, Christina

2014-06-15

244

Flexible Histone Tails in a New Mesoscopic Oligonucleosome Model  

PubMed Central

We describe a new mesoscopic model of oligonucleosomes that incorporates flexible histone tails. The nucleosome cores are modeled using the discrete surface-charge optimization model, which treats the nucleosome as an electrostatic surface represented by hundreds of point charges; the linker DNAs are treated using a discrete elastic chain model; and the histone tails are modeled using a bead/chain hydrodynamic approach as chains of connected beads where each bead represents five protein residues. Appropriate charges and force fields are assigned to each histone chain so as to reproduce the electrostatic potential, structure, and dynamics of the corresponding atomistic histone tails at different salt conditions. The dynamics of resulting oligonucleosomes at different sizes and varying salt concentrations are simulated by Brownian dynamics with complete hydrodynamic interactions. The analyses demonstrate that the new mesoscopic model reproduces experimental results better than its predecessors, which modeled histone tails as rigid entities. In particular, our model with flexible histone tails: correctly accounts for salt-dependent conformational changes in the histone tails; yields the experimentally obtained values of histone-tail mediated core/core attraction energies; and considers the partial shielding of electrostatic repulsion between DNA linkers as a result of the spatial distribution of histone tails. These effects are crucial for regulating chromatin structure but are absent or improperly treated in models with rigid histone tails. The development of this model of oligonucleosomes thus opens new avenues for studying the role of histone tails and their variants in mediating gene expression through modulation of chromatin structure.

Arya, Gaurav; Zhang, Qing; Schlick, Tamar

2006-01-01

245

Dwarf Galaxies Swimming in Tidal Tails  

NASA Technical Reports Server (NTRS)

This false-color infrared image from NASA's Spitzer Space Telescope shows little 'dwarf galaxies' forming in the 'tails' of two larger galaxies that are colliding together. The big galaxies are at the center of the picture, while the dwarfs can be seen as red dots in the red streamers, or tidal tails. The two blue dots above the big galaxies are stars in the foreground.

Galaxy mergers are common occurrences in the universe; for example, our own Milky Way galaxy will eventually smash into the nearby Andromeda galaxy. When two galaxies meet, they tend to rip each other apart, leaving a trail, called a tidal tail, of gas and dust in their wake. It is out of this galactic debris that new dwarf galaxies are born.

The new Spitzer picture demonstrates that these particular dwarfs are actively forming stars. The red color indicates the presence of dust produced in star-forming regions, including organic molecules called polycyclic aromatic hydrocarbons. These carbon-containing molecules are also found on Earth, in car exhaust and on burnt toast, among other places. Here, the molecules are being heated up by the young stars, and, as a result, shine in infrared light.

This image was taken by the infrared array camera on Spitzer. It is a 4-color composite of infrared light, showing emissions from wavelengths of 3.6 microns (blue), 4.5 microns (green), 5.8 microns (orange), and 8.0 microns (red). Starlight has been subtracted from the orange and red channels in order to enhance the dust features.

2005-01-01

246

HERA BEAM TAIL SHAPING BY TUNE MODULATION.  

SciTech Connect

To study CP violation, the HEM-B experiment uses an internal wire target in the transverse halo of the stored HERA proton beam. Operational experience shows that the resulting interaction rates are extremely sensitive to tiny orbit jitter amplitudes. Various methods have been studied to stabilize these interaction rates by increasing diffusion in the transverse proton beam tails without affecting the luminosity at the electron-proton collider experiments ZEUS and H1. Tune modulation was found to be a promising method for this task. Experiments performed in recent years will be reported.

MONTAG,C.

2003-05-19

247

Aerodynamic characteristics of horizontal tail surfaces  

NASA Technical Reports Server (NTRS)

Collected data are presented on the aerodynamic characteristics of 17 horizontal tail surfaces including several with balanced elevators and two with end plates. Curves are given for coefficients of normal force, drag, and elevator hinge moment. A limited analysis of the results has been made. The normal-force coefficients are in better agreement with the lifting-surface theory of Prandtl and Blenk for airfoils of low aspect ratio than with the usual lifting-line theory. Only partial agreement exists between the elevator hinge-moment coefficients and those predicted by Glauert's thin-airfoil theory.

Silverstein, Abe; Katzoff, S

1940-01-01

248

Culture and Serologic Survey for Mycobacterium avium subsp. paratuberculosis Infection among Southeastern White-tailed Deer (Odocoileus virginianus)  

Microsoft Academic Search

From July 1998 through October 2002, radiometric culture (ileocecal lymph node, mesenteric lymph node, and feces) and serologic testing by enzyme-linked immunosor- bent assay (ELISA) were used to survey white- tailed deer (Odocoileus virginianus) from the southeastern United States for infection by My- cobacterium avium subsp. paratuberculosis (Mptb), the causative agent of paratuberculosis (Johne's disease). Mycobacterium avium subsp. paratuberculosis was

William R. Davidson; Elizabeth J. B. Manning; Victor F. Nettles; D. B. Warnell

249

Star Clusters in the Tidal Tails of Interacting Galaxies: Cluster Populations Across a Variety of Tail Environments  

NASA Astrophysics Data System (ADS)

We have searched for compact stellar structures within 17 tidal tails in 13 different interacting galaxies using F606W- and F814W-band images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope. The sample of tidal tails includes a diverse population of optical properties, merging galaxy mass ratios, H I content, and ages. Combining our tail sample with Knierman et al., we find evidence of star clusters formed in situ with M V < -8.5 and V - I < 2.0 in 10 of 23 tidal tails; we are able to identify cluster candidates to M V = -6.5 in the closest tails. Three tails offer clear examples of "beads on a string" star formation morphology in V - I color maps. Two tails present both tidal dwarf galaxy candidates and cluster candidates. Statistical diagnostics indicate that clusters in tidal tails may be drawn from the same power-law luminosity functions (with logarithmic slopes ?-2 to -2.5) found in quiescent spiral galaxies and interiors of interacting systems. We find that the tail regions with the largest number of observable clusters are relatively young (lsim250 Myr old) and bright (V <~ 24 mag arcsec-2), probably attributed to the strong bursts of star formation in interacting systems soon after periapse. Otherwise, we find no statistical difference between cluster-rich and cluster-poor tails in terms of many observable characteristics, though this analysis suffers from complex, unresolved gas dynamics and projection effects.

Mullan, B.; Konstantopoulos, I. S.; Kepley, A. A.; Lee, K. H.; Charlton, J. C.; Knierman, K.; Bastian, N.; Chandar, R.; Durrell, P. R.; Elmegreen, D.; English, J.; Gallagher, S. C.; Gronwall, C.; Hibbard, J. E.; Hunsberger, S.; Johnson, K. E.; Maybhate, A.; Palma, C.; Trancho, G.; Vacca, W. D.

2011-04-01

250

Role of Histone Tails in Structural Stability of the Nucleosome  

PubMed Central

Histone tails play an important role in nucleosome structure and dynamics. Here we investigate the effect of truncation of histone tails H3, H4, H2A and H2B on nucleosome structure with 100 ns all-atom molecular dynamics simulations. Tail domains of H3 and H2B show propensity of -helics formation during the intact nucleosome simulation. On truncation of H4 or H2B tails no structural change occurs in histones. However, H3 or H2A tail truncation results in structural alterations in the histone core domain, and in both the cases the structural change occurs in the H2A3 domain. We also find that the contacts between the histone H2A C terminal docking domain and surrounding residues are destabilized upon H3 tail truncation. The relation between the present observations and corresponding experiments is discussed.

Biswas, Mithun; Voltz, Karine; Smith, Jeremy C.; Langowski, Jorg

2011-01-01

251

Simulation of tail buffet using delta wing-vertical tail configuration  

NASA Technical Reports Server (NTRS)

Computational simulation of the vertical tail buffet problem is accomplished using a delta wing-vertical tail configuration. Flow conditions are selected such that the wing primary-vortex cores experience vortex breakdown and the resulting flow interacts with the vertical tail. This multidisciplinary problem is solved successively using three sets of equations for the fluid flow, aeroelastic deflections and grid displacements. For the fluid dynamics part, the unsteady, compressible, full Navier-Stokes equations are solved accurately in time using an implicit, upwind, flux-difference splitting, finite-volume scheme. For the aeroelastic part, the aeroelastic equation for bending vibrations is solved accurately in time using the Galerkin method and the four-stage Runge-Kutta scheme. The grid for the fluid dynamics computations is updated every few time steps using a third set of interpolation equations. The computational application includes a delta wing of aspect ratio 1 and a rectangular vertical tail of aspect ratio 2, which is placed at 0.5 root-chord length downstream of the wing trailing edge. The wing angle of attack is 35 deg and the flow Mach number and Reynolds number are 0.4 and 10,000, respectively.

Kandil, Osama A.; Kandil, Hamdy A.; Massey, Steven J.

1993-01-01

252

Cross-tail current, field-aligned current, and By  

Microsoft Academic Search

Orbits of individual charged particles were traced in a one-dimensional magnetic field model that included a uniform cross-tail component Byo. The effects of Byo on the cross-tail current distribution jy(z), the average cross-tail drift velocity , and the average pitch angle change experienced during current sheet encounters were calculated. The addition of a Byo that exceeded several tenths of one

Richard L. Kaufmann; Chen Lu; Douglas J. Larson

1994-01-01

253

Phytoremediation of mine tailings in temperate and arid environments  

Microsoft Academic Search

Phytoremediation is an emerging technology for the remediation of mine tailings, a global problem for which conventional remediation\\u000a technologies are costly. There are two approaches to phytoremediation of mine tailings, phytoextraction and phytostabilization.\\u000a Phytoextraction involves translocation of heavy metals from mine tailings to the plant shoot biomass followed by plant harvest,\\u000a while phytostabilization focuses on establishing a vegetative cap that

Monica O. Mendez; Raina M. Maier

2008-01-01

254

Estimating the Heavy Tail Index from Scaling Properties  

Microsoft Academic Search

This paper deals with the estimation of the tail index ff for empirical heavy-tailed distributions,such as have been encountered in telecommunication systems. We present a method (called the"scaling estimator") based on the scaling properties of sums of heavy-tailed random variables.It has the advantages of being nonparametric, of being easy to apply, of yielding a single value,and of being relatively accurate

Mark E. Crovella; Murad S. Taqqu

1999-01-01

255

Minimal tail-biting trellises: The Golay code and more  

Microsoft Academic Search

Tail-biting trellis representations of block codes are investigated. We develop some elementary theory, and present several intriguing examples, which we hope will stimulate further developments in this field. In particular, we construct a 16-state 12-section structurally invariant tail-biting trellis for the (24, 12, 8) binary Golay code. This tail-biting trellis representation is minimal: it simultaneously minimizes all conceivable measures of

A. Robert Calderbank; G. David Forney Jr.; Alexander Vardy

1999-01-01

256

Female choice selects for extreme tail length in a widowbird  

Microsoft Academic Search

Darwin's1 hypothesis that male secondary sexual ornaments evolve through female preferences is theoretically plausible2-7, but there is little experimental field evidence that such preferences exist8-10. I have studied female choice in relation to male tail length in the long-tailed widowbird, Euplectes progne, and report here that males in which the tail was experimentally elongated showed higher mating success than males

Malte Andersson

1982-01-01

257

54. Photocopied August 1978. INTERIOR OF A TAIL PIT OR ...  

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

54. Photocopied August 1978. INTERIOR OF A TAIL PIT OR TAIL RACE AT THE EAST END OF THE POWER HOUSE, SEPTEMBER 17, 1900. THE PRE-MOULDED BLOCKS WHICH FORMED THE SIDE WALLS AND THE ARCHED FOREBAY WALL ARE CLEARLY VISIBLE. THE MONOLITHIC FLOOR OF THE TAIL PIT, HOWEVER, HAS NOT YET BEEN POURED: NEITHER HAS THE MONOLITHIC ARCHED ROOF. (75) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

258

Long Tail Tourism: New Geographies For Marketing Niche Tourism Products  

Microsoft Academic Search

ABSTRACT. The Long Tail concept refers to the Internet?based economy that has enabled company success through a focus on highly specialized services and products that are not in high volume demand, but maybe in high?value demand. The concept of the post?tourist, for example, is a Long Tail phenomenon. Long Tail marketing approaches are proving success due to advances in communication

Alan A. Lew

2008-01-01

259

Macrophages modulate adult zebrafish tail fin regeneration  

PubMed Central

Neutrophils and macrophages, as key mediators of inflammation, have defined functionally important roles in mammalian tissue repair. Although recent evidence suggests that similar cells exist in zebrafish and also migrate to sites of injury in larvae, whether these cells are functionally important for wound healing or regeneration in adult zebrafish is unknown. To begin to address these questions, we first tracked neutrophils (lyzC+, mpo+) and macrophages (mpeg1+) in adult zebrafish following amputation of the tail fin, and detailed a migratory timecourse that revealed conserved elements of the inflammatory cell response with mammals. Next, we used transgenic zebrafish in which we could selectively ablate macrophages, which allowed us to investigate whether macrophages were required for tail fin regeneration. We identified stage-dependent functional roles of macrophages in mediating fin tissue outgrowth and bony ray patterning, in part through modulating levels of blastema proliferation. Moreover, we also sought to detail molecular regulators of inflammation in adult zebrafish and identified Wnt/?-catenin as a signaling pathway that regulates the injury microenvironment, inflammatory cell migration and macrophage phenotype. These results provide a cellular and molecular link between components of the inflammation response and regeneration in adult zebrafish.

Petrie, Timothy A.; Strand, Nicholas S.; Tsung-Yang, Chao; Rabinowitz, Jeremy S.; Moon, Randall T.

2014-01-01

260

Uranium mill tailings backfill management. Final report  

SciTech Connect

Backfilling, the disposal of spent uranium mill tailings in empty mine stopes, has been practiced in the Grants Mineral Belt of New Mexico for nearly 20 years. The principal objective of backfilling is the prevention of roof collapse and hydraulic connection with overlying aquifers, increasing mine dewatering requirements. Backfilling is accomplished by gravity feed of a slurry of sand-fraction tailings and treated mine water into the slope. The effects of backfilling on surface discharge of mine wastewater are negligible due to the small fraction of the total flow represented by slurry decant. Furthermore, quality of the decant is not significantly below that of other mine waters. Groundwater effects of backfilling may be classified as short-term (while the mine is operational) and long-term (after dewatering operations have been terminated). Short-term effects are insignificant because of rapid and continuous flow to the mine sump. Long-term effects on aquifer water quality are predicted to be minimal due to (1) the small amount of slurry liquor present after drainage, (2) the precipitation of SO/sub 4/ and CO/sub 3/ phases, and (3) the reestablishment of reducing conditions and subsequent precipitation of major contaminants including U, As, Mo, Se, and V. 28 references, 19 figures, 9 tables.

Thomson, B.M.; Heggen, R.J.

1984-01-01

261

Transverse tails and higher order moments  

SciTech Connect

The tails that may be engendered in a beam`s transverse phase space distribution by, e.g., intrabunch wakefields and nonlinear magnetic fields, are all important diagnostic and object of tuning in linear colliders. Wire scanners or phosphorescent screen monitors yield one dimensional projected spatial profiles of such beams that are generically asymmetric around their centroids, and therefore require characterization by the third moment {l_angle}x{sup 3}{r_angle} in addition to the conventional mean-square or second moment. A set of measurements spread over sufficient phase advance then allows the complete set {l_angle}x{sup 3}{r_angle}, {l_angle}xx{prime}{sup 2}{r_angle}, {l_angle}x{prime}{sup 3}{r_angle}, and {l_angle}x{sup 2}x{prime}{r_angle} to be deduced -- the natural extension of the well-known ``emittance measurement`` treatment of second moments. The four third moments may be usefully decomposed into parts rotating in phase space at the {beta}-tron frequency and at its third harmonic, each specified by a phase-advance-invariant amplitude and a phase. They provide a framework for the analysis and tuning of transverse wakefield tails.

Spence, W.L.; Decker, F.J.; Woodley, M.D.

1993-05-01

262

Review of fugitive dust control for uranium mill tailings  

SciTech Connect

An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques.

Li, C.T.; Elmore, M.R.; Hartley, J.N.

1983-01-01

263

A potential role for bat tail membranes in flight control.  

PubMed

Wind tunnel tests conducted on a model based on the long-eared bat Plecotus auritus indicated that the positioning of the tail membrane (uropatagium) can significantly influence flight control. Adjusting tail position by increasing the angle of the legs ventrally relative to the body has a two-fold effect; increasing leg-induced wing camber (i.e., locally increased camber of the inner wing surface) and increasing the angle of attack of the tail membrane. We also used our model to examine the effects of flying with and without a tail membrane. For the bat model with a tail membrane increasing leg angle increased the lift, drag and pitching moment (nose-down) produced. However, removing the tail membrane significantly reduced the change in pitching moment with increasing leg angle, but it had no significant effect on the level of lift produced. The drag on the model also significantly increased with the removal of the tail membrane. The tail membrane, therefore, is potentially important for controlling the level of pitching moment produced by bats and an aid to flight control, specifically improving agility and manoeuvrability. Although the tail of bats is different from that of birds, in that it is only divided from the wings by the legs, it nonetheless, may, in addition to its prey capturing function, fulfil a similar role in aiding flight control. PMID:21479137

Gardiner, James D; Dimitriadis, Grigorios; Codd, Jonathan R; Nudds, Robert L

2011-01-01

264

Why do male snakes have longer tails than females?  

PubMed Central

In most snake species, males have longer tails than females of the same body length. The adaptive significance of this widespread dimorphism has attracted much speculation, but few tests. We took advantage of huge mating aggregations of red-sided gartersnakes (Thamnophis sirtalis parietalis) in southern Manitoba to test two (non-exclusive) hypotheses about the selective forces responsible for this dimorphism. Our data support both hypotheses. First, relative tail length affects the size of the male copulatory organs (hemipenes). Males with longer tails relative to body length have longer hemipenes, presumably because of the additional space available (the hemipenes are housed inside the tail base). Second, relative tail length affects male mating success. Males with partial tail loss (due to predation or misadventure) experienced a threefold reduction in mating success. Among males with intact tails, we detected strong stabilizing selection on relative tail length in one of the two years of our study. Thus, our data support the notion that sex divergence in tail length relative to body length in snakes reflects the action of sexual selection for male mating success.

Shine, R.; Olsson, M. M.; Moore, I. T.; LeMaster, M. P.; Mason, R. T.

1999-01-01

265

Simulation of a Plunging Airfoil with a Flexible Tail  

NASA Astrophysics Data System (ADS)

The fluid motion of an airfoil with a flexible tail is simulated using an unsteady panel method with diffusive wake modeling. The fluid simulation is coupled with a CSD solver to simulate the deflection of the flexible tail due to both inertial and aerodynamic forces. The modal equations were used to calculate the structural deformation under an aerodynamic load. Computations with varying stiffness coefficient and reduced frequencies were performed to produce a performance map of a plunging airfoil with a flexible tail. The results showed a range of reduced frequencies and tail stiffness that increased the thrust produced by the plunging motion by as much as 45% when compared with the same airfoil that has a rigid tail. The propulsive efficiency with a flexible tail increased slightly as well. The upper limit of the thrust enhancement is bounded by the first natural frequency of the flexible tail. A stiffer tail is shown to be most beneficial, but the minimum reduced frequency where thrust is improved increases with increasing stiffness. Spectral analysis of the unsteady forces and wake velocities showed that the increase in thrust can be directly attributed to the effect the flexible tail has on the wake vorticies.

Lai, Alan; Liu, Feng

2010-11-01

266

Laboratory experiments in electrokinetic densification of mill tailings. II. Application to various types and classifications of tailings  

Microsoft Academic Search

This report describes Bureau of Mines laboratory test results in electrokinetic dewatering and consolidation of metal-mine mill tailings from five mines in the Coeur d'Alene, Idaho, district. Classified (coarse) tailings, slimes, and unclassified material were separately tested. Tailings were placed in 0.3 ft³ plexiglass models, and dc potential was applied until dewatering ceased. Time-oriented measurements of water removal, changes in

R. H. Sprute; D. J. Kelsh

1974-01-01

267

Physiologic Reference Ranges for Captive Black-Tailed Prairie Dogs (Cynomys ludovicianus)  

PubMed Central

The black-tailed prairie dog (Cynomys ludovicianus) is a member of the order Rodentia and the family Sciuridae. Ecologically, prairie dogs are a keystone species in prairie ecology. This species is used as an animal model for human gallbladder disease and diseases caused by infection with Clostridium difficile, Yersinia pestis, Francisella tularensis, and most recently, Orthopoxvirus. Despite increasing numbers of prairie dogs used in research and kept as pets, few data are available on their baseline physiology in animal facility housing conditions. To establish baseline physiologic reference ranges, we designed a study using 18 wild-caught black-tailed prairie dogs. Telemetry data were analyzed to establish circadian rhythms for activity and temperature. In addition, hematologic and serum chemistry analyses were performed. Baseline measurements were used to establish the mean for each animal, which then were compiled and analyzed to determine the reference ranges. Here we present physiologic data on serum chemistry and hematology profiles, as well as weight, core body temperature, and daily activity patterns for black-tailed prairie dogs. These results reflect the use of multiple measurements from species- and age-matched prairie dogs and likely will be useful to ecologists, scientists interested in using this animal model in research, and veterinarians caring for pet prairie dogs.

Keckler, M Shannon; Gallardo-Romero, Nadia F; Langham, Gregory L; Damon, Inger K; Karem, Kevin L; Carroll, Darin S

2010-01-01

268

Resistance of young gelatinase B-deficient mice to experimental autoimmune encephalomyelitis and necrotizing tail lesions  

PubMed Central

Regulated expression of matrix metalloproteinases (MMPs) and their inhibitors (TIMPs) plays a role in various physiological processes. To determine in vivo how unbalanced expression of these factors can promote or affect the course of pathologies, we knocked out the mouse gelatinase B gene by replacing the catalytic and zinc-binding domains with an antisense-oriented neomycin resistance gene. Adult gelatinase B–deficient mice and wild-type controls could be induced to develop experimental autoimmune encephalomyelitis (EAE) with similar scores for neurologic disease, blood-brain barrier permeability, and central nervous system histopathology. However, whereas diseased control animals showed necrotizing tail lesions with hyperplasia of osteocartilaginous tissue, adult gelatinase B–deficient mice were resistant to this tail pathology. Gelatinase B–deficient mice younger than 4 weeks of age were significantly less susceptible to the development of EAE than were age matched controls and, even as they aged, they remained resistant to tail lesions. These data illustrate that gelatinase B expression plays a role in the development of the immune system and that, in ontogenesis, the propensity to develop autoimmunity is altered by the absence of this MMP. J. Clin. Invest. 104:1507–1515 (1999).

Dubois, Benedicte; Masure, Stefan; Hurtenbach, Ursula; Paemen, Liesbet; Heremans, Hubertine; van den Oord, Joost; Sciot, Raf; Meinhardt, Thorsten; Hammerling, Gunter; Opdenakker, Ghislain; Arnold, Bernd

1999-01-01

269

The Narrow X-Ray Tail and Double H? Tails of ESO 137-002 in A3627  

NASA Astrophysics Data System (ADS)

We present the analysis of a deep Chandra observation of a ~2 L * late-type galaxy, ESO 137-002, in the closest rich cluster A3627. The Chandra data reveal a long (gsim40 kpc) and narrow tail with a nearly constant width (~3 kpc) to the southeast of the galaxy, and a leading edge ~1.5 kpc from the galaxy center on the upstream side of the tail. The tail is most likely caused by the nearly edge-on stripping of ESO 137-002's interstellar medium (ISM) by ram pressure, compared to the nearly face-on stripping of ESO 137-001 discussed in our previous work. Spectral analysis of individual regions along the tail shows that the gas throughout it has a rather constant temperature, ~1 keV, very close to the temperature of the tails of ESO 137-001, if the same atomic database is used. The derived gas abundance is low (~0.2 solar with the single-kT model), an indication of the multiphase nature of the gas in the tail. The mass of the X-ray tail is only a small fraction (<5%) of the initial ISM mass of the galaxy, suggesting that the stripping is most likely at an early stage. However, with any of the single-kT, double-kT, and multi-kT models we tried, the tail is always "over-pressured" relative to the surrounding intracluster medium (ICM), which could be due to the uncertainties in the abundance, thermal versus non-thermal X-ray emission, or magnetic support in the ICM. The H? data from the Southern Observatory for Astrophysical Research show a ~21 kpc tail spatially coincident with the X-ray tail, as well as a secondary tail (~12 kpc long) to the east of the main tail diverging at an angle of ~23° and starting at a distance of ~7.5 kpc from the nucleus. At the position of the secondary H? tail, the X-ray emission is also enhanced at the ~2? level. We compare the tails of ESO 137-001 and ESO 137-002, and also compare the tails to simulations. Both the similarities and differences of the tails pose challenges to the simulations. Several implications are briefly discussed. Based on observations made with the Chandra X-Ray Observatory and the Southern Observatory for Astrophysical Research (SOAR) telescope.

Zhang, B.; Sun, M.; Ji, L.; Sarazin, C.; Lin, X. B.; Nulsen, P. E. J.; Roediger, E.; Donahue, M.; Forman, W.; Jones, C.; Voit, G. M.; Kong, X.

2013-11-01

270

Novel hemotropic Mycoplasma species in white-tailed deer (Odocoileus virginianus).  

PubMed

Globally, hemotropic Mycoplasma spp. are emerging or re-emerging zoonotic pathogens that affect livestock, wildlife, companion animals, and humans, potentially causing serious and economically important disease problems. Little is known about hemotropic Mycoplasma spp. prevalence, host-specificity, or route of transmission in most species, including wildlife. DNA amplification by PCR targeting the 16SrRNA and the RNaseP genes was used to establish the presence and prevalence of hemotropic Mycoplasma spp. in a white-tailed deer (O. virginianus) population in eastern North Carolina. Sixty-five deer (89%) tested positive for hemotropic Mycoplasma spp. where sequence analysis of the 16SsRNA and the RNaseP genes indicated the presence of at least three distinct species. This study represents the first detection of three distinct hemotropic Mycoplasma species in white-tailed deer and the first report of two novel hemotropic Mycoplasma species. PMID:24018179

Maggi, Ricardo G; Chitwood, M Colter; Kennedy-Stoskopf, Suzanne; DePerno, Christopher S

2013-12-01

271

The Logarithmic Tail of Néel Walls  

NASA Astrophysics Data System (ADS)

We study the multiscale problem of a parametrized planar 180° rotation of magnetization states in a thin ferromagnetic film. In an appropriate scaling and when the film thickness is comparable to the Bloch line width, the underlying variational principle has the form where the reduced stray-field operator Q approximates (-?)1/2 as the quality factor Q tends to zero. We show that the associated Néel wall profile u exhibits a very long logarithmic tail. The proof relies on limiting elliptic regularity methods on the basis of the associated Euler-Lagrange equation and symmetrization arguments on the basis of the variational principle. Finally we study the renormalized limit behavior as Q tends to zero.

Melcher, Christof

272

The Tail of Integrins, Talin, and Kindlins  

NSDL National Science Digital Library

Integrins are transmembrane cellâÂÂadhesion molecules that carry signals from the outside to the inside of the cell and vice versa. Like other cell surface receptors, integrins signal in response to ligand binding; however, events within the cell can also regulate the affinity of integrins for ligands. This feature is important in physiological situations such as those in blood, in which cells are always in close proximity to their ligands, yet cell-ligand interactions occur only after integrin activation in response to specific external cues. This review focuses on the mechanisms whereby two key proteins, talin and the kindlins, regulate integrin activation by binding the tails of integrin-ò subunits.

Markus Moser (Max Planck Institute of Biochemistry;); Kyle Legate (Max Planck Institute of Biochemistry;); Roy Zent (Vanderbilt Medical Center and Veterans Affairs Hospital;); Reinhard Fässler (Max Planck Institute of Biochemistry;)

2009-05-15

273

Computerized semen analysis with sperm tail detection.  

PubMed

We evaluated a recently developed computerized semen analyser that detects spermatozoa not only by the criteria of size, contrast and movement but also by the morphological characteristics of the sperm tail. Comparison of the sperm concentration in 33 semen samples measured by conventional and by computerized semen analysis, as well as by flow cytometry, showed acceptable agreement between all three methods, although the mean differences and standard deviations were less for conventional than for computerized analysis when compared to flow cytometry as a reference method. Motility estimates were lower by the computer system for values between 1 and 40%. Higher motilities showed no systematic error. In conclusion, the improved algorithms for sperm detection yield more reliable data for sperm concentration and motility than previous systems of computerized semen analysis. PMID:2254406

Neuwinger, J; Behre, H M; Nieschlag, E

1990-08-01

274

Sulfur Biogeochemistry of Athabasca Oilsands Composite Tailings  

NASA Astrophysics Data System (ADS)

Oil sands tailings are important, globally relevant, S reservoirs, known to contain active and diverse microbial communities. As evidenced by increasing S emissions from the oil sands, active biogeochemical S cycling within composite tailings (CT, a mixture of tailings, post-processed sand and gypsum, used for dry reclamation), is likely; however the S biogeochemistry of these residues has not been investigated to date. With surface mining of Alberta's oil sands spanning over 142,000 square km and accelerated production, these tailings-based landscapes will become increasingly prevalent with the potential for significant environmental impacts. The objectives here, were thus to characterize depth dependent S biogeochemistry of a 40 meter CT deposit (Fort McMurray, AB, CANADA). Drill samples were collected in December of 2012 from 5 depths spanning 36 m in the CT deposit, for geochemical, metagenomic and functional enrichment analyses. Results establish widespread microbial S biogeochemical cycling within the CT deposit. Porewater H2S was detected extensively throughout the deposit with background levels ranging from 14-23 ?M and a concentrated pocket of 300 ?M occurring at depth. Porewater Fe(II) (1-40 ?M) was detected only within surficial depth samples. Current Fe(II) concentrations are not sufficient to sequester the levels of H2S generated by CT, indicating CT may become a net source of S emissions, as generated H2S at depth migrates to the surface, in untreated CT deposits. Metagenomic (454 pyrosequencing) characterization revealed highly diverse CT microbial communities, with 21 different phyla encountered overall and 1/3 of these presenting as candidate divisions. The cultivation independent identification of several known IRB and sulphate (SRB) reducing bacteria within these communities was consistent with observed positive growth in IRB and SRB functional metabolic enrichments. Furthermore, two depth dependent structurally distinct communities emerged: a surficial CT zone of Fe(III) reduction and an underlying zone of sulphate reduction, from multivariate statistical analyses of phylogenetic data (UniFrac http://bmf.colorado.edu/unifrac). The emergence of a distinct IRB surficial zone, despite ~65% of the total bacterial community putatively having the capacity for Fe(III) reduction over the entire deposit depth and evident and increasing Fe(III) sources down core, suggests limitation of Fe(III) reducing bacteria (IRB) through some other factor. Indeed UniFrac analyses identified that the differentiation in microbial communities occurring in these Fe and S zones was driven by environmental parameters of DOC, ORP and salinity; revealing that IRB may be unable to access the more complex OC constituents of these materials. Pilot reclamation for CT is currently focusing on capping CT with a freshwater fen, which may provide a more labile OC source for CT associated IRB, potentially stimulating greater H2S sequestration through FeS formation. These processes will be evaluated in the on-going assessment of S biogeochemistry within untreated and treated CT as pilot reclamation proceeds.

Warren, L. A.; Kendra, K. E.

2013-12-01

275

A Glimpse of the genomic diversity of haloarchaeal tailed viruses  

PubMed Central

Tailed viruses are the most common isolates infecting prokaryotic hosts residing in hypersaline environments. Archaeal tailed viruses represent only a small portion of all characterized tailed viruses of prokaryotes. But even this small dataset revealed that archaeal tailed viruses have many similarities to their counterparts infecting bacteria, the bacteriophages. Shared functional homologs and similar genome organizations suggested that all microbial tailed viruses have common virion architectural and assembly principles. Recent structural studies have provided evidence justifying this thereby grouping archaeal and bacterial tailed viruses into a single lineage. Currently there are 17 haloarchaeal tailed viruses with entirely sequenced genomes. Nine viruses have at least one close relative among the 17 viruses and, according to the similarities, can be divided into three groups. Two other viruses share some homologs and therefore are distantly related, whereas the rest of the viruses are rather divergent (or singletons). Comparative genomics analysis of these viruses offers a glimpse into the genetic diversity and structure of haloarchaeal tailed virus communities.

Sencilo, Ana; Roine, Elina

2014-01-01

276

Adaptive Suction and Blowing for Twin-Tail Buffet Control  

NASA Technical Reports Server (NTRS)

Adaptive active flow control for twin-tail buffet alleviation is investigated. The concept behind this technique is to place control ports on the tail outer and inner surfaces with flow suction or blowing applied through these ports in order to minimize the pressure difference across the tail. The suction or blowing volume flow rate from each port is proportional to the pressure difference across the tail at this location. A parametric study of the effects of the number and location of these ports on the buffet response is carried out. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. This complex multidisciplinary problem is solved sequentially using three sets of equations for the fluid flow, aeroelastic response and grid deformation, using a dynamic multi-block grid structure. The computational model is pitched at 30 deg angle of attack. The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. The model is investigated for the inboard position of the twin tails, which corresponds to a separation distance between the twin tails of 33% of the wing span. Comparison of the time history and power spectral density responses of the tails for various distributions of the control ports are presented and discussed.

Kandil, Osama A.; Yang, Zhi

1999-01-01

277

Structural conservation of the Myoviridae phage tail sheath protein fold  

PubMed Central

Bacteriophage phiKZ is a giant phage that infects Pseudomonas aeruginosa, a human pathogen. The phiKZ virion consists of a 1450 Å diameter icosahedral head and a 2000 Å-long contractile tail. The structure of the whole virus was previously reported, showing that its tail organization in the extended state is similar to the well-studied Myovirus bacteriophage T4 tail. The crystal structure of a tail sheath protein fragment of phiKZ was determined to 2.4 Å resolution. Furthermore, crystal structures of two prophage tail sheath proteins were determined to 1.9 and 3.3 Å resolution. Despite low sequence identity between these proteins, all of these structures have a similar fold. The crystal structure of the phiKZ tail sheath protein has been fitted into cryo-electron-microscopy reconstructions of the extended tail sheath and of a polysheath. The structural rearrangement of the phiKZ tail sheath contraction was found to be similar to that of phage T4.

Aksyuk, Anastasia A.; Kurochkina, Lidia P.; Fokine, Andrei; Forouhar, Farhad; Mesyanzhinov, Vadim V.; Tong, Liang; Rossmann, Michael G.

2011-01-01

278

SPONTANEOUS CRYPTOSPORIDIOSIS IN CAPTIVE WHITE-TAILED DEER (ODOCOILEUS VIRGINIANUS)  

Microsoft Academic Search

In August 1994, cryptosporidiosis was diagnosed in a diarrheic fawn from a captive white-tailed deer (Odocoileus virginianus) herd maintained for research purposes at The Uni- versity of Georgia's Warnell School of Forest Resources in Athens, Georgia (USA). From June through August 1995, 11 captive female white-tailed deer were housed in individual barn stalls where they gave birthto 18 fawns. Feces

Ronald Fayer; John R. Fischer; Christopher T. Sewell; Darrell M. Kavanaugh; David A. Osborn

279

Selenium toxicosis in a white-tailed deer herd  

PubMed Central

Chronic selenium (Se) toxicosis was found in a herd of white-tailed deer showing signs of anorexia, weight loss, and lameness. Concentration of Se in the liver ranged from 2.7 to 8.97 mg/kg wet weight. Myocardial necrosis, mineralization, and fibroplasia were seen histologically. This is the first report of this toxicosis in white-tailed deer.

Al-Dissi, Ahmad N.; Blakley, Barry R.; Woodbury, Murray R.

2011-01-01

280

The function and evolution of the tail streamer in hirundines  

Microsoft Academic Search

The morphology of a bird's tail may result from compromises between aerodynamic efficiency, phylogenetic constraints and selection for non-aerodynamic characteristics, such as mate attraction. A good example of a trait shaped by trade-offs between aerodynamic efficiency and reproductive benefits mediated through female preference is the tail streamer of the barn swallow. Here we use a standardized task to measure the

Louise V. Rowe; Matthew R. Evans; Katherine L. Buchanan

2001-01-01

281

Effect of Configuration Pitching Motion on Twin Tail Buffet Response  

NASA Technical Reports Server (NTRS)

The effect of dynamic pitch-up motion of delta wing on twin-tail buffet response is investigated. The computational model consists of a delta wing-twin tail configuration. The computations are carried out on a dynamic multi-block grid structure. This multidisciplinary problem is solved using three sets of equations which consists of the unsteady Navier-Stokes equations, the aeroelastic equations, and the grid displacement equations. The configuration is pitched-up from zero up to 60 deg. angle of attack, and the freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. With the twin tail fixed as rigid surfaces and with no-forced pitch-up motion, the problem is solved for the initial flow conditions. Next, the problem is solved for the twin-tail response for uncoupled bending and torsional vibrations due to the unsteady loads on the twin tail and due to the forced pitch-up motion. The dynamic pitch-up problem is also solved for the flow response with the twin tail kept rigid. The configuration is investigated for inboard position of the twin tail which corresponds to a separation distance between the twin tail of 33% wing chord. The computed results are compared with the available experimental data.

Sheta, Essam F.; Kandil, Osama A.

1998-01-01

282

On the average configuration of the geomagnetic tail  

NASA Technical Reports Server (NTRS)

Over 3000 hours of IMP-6 magnetic field data obtained between 20 and 33 R sub E in the geomagnetic tail have been used in a statistical study of the tail configuration. A distribution of 2.5 minute averages of B sub Z as a function of position across the tail reveals that more flux crosses the equatorial plane near the dawn and dusk flanks than near midnight. The tail field projected in the solar magnetospheric equatorial plane deviates from the X axis due to flaring and solar wind aberration by an angle alpha = -0.9 y sub SM - 1.7 where Y sub SM is in earth radii and alpha is in degrees. After removing these effects the Y component of the tail field is found to depend on interplanetary sector structure. During an away sector the B sub Y component of the tail field is on average 0.5 gamma greater than that during a toward sector, a result that is true in both tail lobes and is independent of location across the tail.

Fairfield, D. H.

1978-01-01

283

Lightning location using the slow tails of sferics  

Microsoft Academic Search

Electromagnetic waves produced by lightning strikes, known as sferics, and their extremely low frequency components, known as slow tails, propagate across the Earth-ionosphere waveguide. The properties of the recorded time domain slow tail vary with the causative lightning strike's current moment, the waveguide's characteristics, and the distance of propagation. These variations allow us to approximate the location of a causal

C. Mackay; A. C. Fraser-Smith

2010-01-01

284

Development in helicopter tail boom strake applications in the US  

NASA Technical Reports Server (NTRS)

The use of a strake or spoiler on a helicopter tail boom to beneficially change helicopter tail boom air loads was suggested in the United States in 1975. The anticipated benefits were a change of tail boom loads to reduce required tail rotor thrust and power and improve directional control. High tail boom air loads experienced by the YAH-64 and described in 1978 led to a wind tunnel investigation of the usefullness of strakes in altering such loads on the AH-64, UH-60, and UH-1 helicopters. The wind tunnel tests of 2-D cross sections of the tail boom of each demonstrated that a strake or strakes would be effective. Several limited test programs with the U.S. Army's OH-58A, AH-64, and UH-60A were conducted which showed the effects of strakes were modest for those helicopters. The most recent flight test program, with a Bell 204B, disclosed that for the 204B the tail boom strake or strakes would provide more than a modest improvement in directional control and reduction in tail rotor power.

Wilson, John C.; Kelley, Henry L.; Donahue, Cynthia C.; Yenni, Kenneth R.

1988-01-01

285

Optimum Sampling Scheme for Characterization of Mine Tailings  

Microsoft Academic Search

The paper describes a novice method for sampling geochemicals to characterize mine tailings. We model the spatial relationships between a multi-element signature and, as covariates, abundance estimates of secondary iron-bearing minerals in mine tailings dumps. The covariates of interest, are readily, but less accurately obtainable by using airborne hyperspectral data and estimated through spectral unmixing. Via simulated annealing an optimal

Pravesh Debba; Emmanuel John M. Carranza; Alfred Stein; Freek D. van der Meer

2009-01-01

286

Moment Estimator for Random Vectors with Heavy Tails  

Microsoft Academic Search

If a set of independent, identically distributed random vectors has heavy tails, so that the covariance matrix does not exist, there is no reason to expect that the sample covariance matrix conveys useful information. On the contrary, this paper shows that the eigenvalues and eigenvectors of the sample covariance matrix contain detailed information about the probability tails of the data.

Mark M. Meerschaert; Hans-Peter Scheffler

1999-01-01

287

NONINVASIVE, CONTINUOUS MEASUREMENT OF RAT TAIL SKIN TEMPERATURE BY RADIOTELEMETRY.  

EPA Science Inventory

Tail skin temperature (Tsk) can provide a wealth of information on the thermoregulatory status of the rat. Drug- and toxic-induced changes in body temperature are often mediated by vasodilation or constriction of blood flow to the tail and Tsk can generally be used as an indica...

288

VIEW OF BOEING 737200 FUSELAGE FROM TOP LEVEL OF TAIL ...  

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

VIEW OF BOEING 737-200 FUSELAGE FROM TOP LEVEL OF TAIL DOCK AND. A NEW SAFETY CABLE FROM THE TAIL DOCK WILL ALLOW INSPECTORS TO WALK UP AND DOWN THE FUSELAGE TO CHECK FOR CRACKS OR MISSING FASTENERS. - Greater Buffalo International Airport, Maintenance Hangar, Buffalo, Erie County, NY

289

Simulation on particle crushing of tailings material under high pressure  

NASA Astrophysics Data System (ADS)

With continuous increase of the high tailings dam, it has an important practical and theoretical significance to study the mechanical characteristics of the tailings material under high pressures. It is indicated that strength envelopes of the tailings material have a remarkable nonlinear characteristics through the triaxial test under high pressures. A further study stated that the particle crushing has a critical effect on the mechanical behavior of the tailings material. In order to quantitatively research its influence, the grain size distribution of the tailings material is analyzed for pre-and post-test and the particle crushing of the tailings material is measured. The particle flow code is employed to simulate and monitor the sample during testing. Firstly, a model which considers the particle crushing is built under the plane strain condition. Then, a series of biaxial numerical tests of the tailings specimen are simulated by using the model. It is found that the simulation result agrees with the triaxial test. Finally, a law between the particle crushing and strain of the tailings material under different confining pressures is obtained.

Liu, Hai-ming; Liu, Yi-ming; Yang, Chun-he; Cao, Jing

2013-06-01

290

106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL ...  

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

106. Photocopied August 1978. EXTENSION OF TAIL PIT WALLS, APRIL 28, 1917. THE TIMBERWORK IN THE FOREGROUND WAS USED AS A COMBINATION COFFER DAM AND FORM FOR POURING THE CONCRETE TAIL RACE WALL EXTENSION. IN THE BACKGROUND ALONG THE POWER HOUSE SEVERAL COMPLETED WALL EXTENSIONS CAN BE SEEN DIMLY. (787) - Michigan Lake Superior Power Company, Portage Street, Sault Ste. Marie, Chippewa County, MI

291

3. VIEW OF EMPIRE STATE MINE WITH TAILING PILE IN ...  

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

3. VIEW OF EMPIRE STATE MINE WITH TAILING PILE IN BOTTOM LEFT AND COLLAPSED ADIT LOCATED BELOW DARK SHADOWS IN FAR RIGHT/LOWER THIRD. COLLAPSED BUILDING AND PARTIAL VIEW OF ORE CHUTE/BIN IS VISIBLE ON HILLSIDE ABOVE TAILINGS. CAMERA POINTED NORTH/NORTHWEST. - Florida Mountain Mining Sites, Empire State Mine, West side of Florida Mountain, Silver City, Owyhee County, ID

292

Tail Bounds for Occupancy and the Satisfiability Threshold Conjecture  

Microsoft Academic Search

The classical occupancy problem is concerned with studying the number of empty binsresulting from a random allocation of m balls to n bins. We provide a series of tail boundson the distribution of the number of empty bins. These tail bounds should find application inrandomized algorithms and probabilistic analysis. Our motivating application is the followingwell-known conjecture on threshold phenomenon for

Anil Kamath; Rajeev Motwani; Krishna V. Palem; Paul G. Spirakis

1995-01-01

293

Evidence for current sheet acceleration in the geomagnetic tail  

Microsoft Academic Search

The existence of the current sheet and the dawn to dusk electric field in the geomagnetic tail implies there is particle energization in the tail current sheet of the order 2--10% of the total solar wind energy incident upon the dayside magnetopause. In this paper we determine that ion acceleration in a current sheet with a small magnetic field across

L. R. Lyons; T. W. Speiser

1982-01-01

294

12. Credit PED. View of tail race and dam showing ...  

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

12. Credit PED. View of tail race and dam showing dumping of construction rubble into river bed by rail car; and preparations for pouring a concrete cap onto tail race wall. Photo c. 1909. - Dam No. 4 Hydroelectric Plant, Potomac River, Martinsburg, Berkeley County, WV

295

6. UPPER NOTTINGHAM TAILING PILE LOOKING DOWN STREAM BED TO ...  

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

6. UPPER NOTTINGHAM TAILING PILE LOOKING DOWN STREAM BED TO LOWER NOTTINGHAM. COLLAPSED BUILDINGS, 'B' AND 'C' AND TOP EDGE OF TAILING PILES ARE VISIBLE IN CENTRAL ARE OF PRINT. CAMERA POINTED SOUTHWEST. - Florida Mountain Mining Sites, Upper Nottingham Mine, West face of Florida Mountain, head of Jacobs Gulch, Silver City, Owyhee County, ID

296

Data Driven Rank Tests for Classes of Tail Alternatives.  

National Technical Information Service (NTIS)

Tail alternatives describe the frequent occurrence of a non-constant shift in the two-sample problem with a shift function increasing in the tail. The classes of shift functions can be built up using Legendre polynomials. It is important to rightly choose...

W. Albers W. C. M. Kallenberg F. Martini

1999-01-01

297

FACTORS AFFECTING THE EFFICIENT FLOCCULATION OF TAILINGS BY POLYACRYLAMIDES  

Microsoft Academic Search

The flocculation of coal preparation plant tailings is an established technology, and the scientific basis of flocculation is well understood, Nevertheless, conditions specific to the preparation plant affect the efficiency of the process. The sedimentation rate obtained with flocculated tailings depends on the molecular size of the polyacrylamide. Modern flocculants are very high molecular weight polymers and the size of

J. M. HENDERSON; A. D. WHEATLEY

1987-01-01

298

Long-Term Protection of Uranium Mill Tailings.  

National Technical Information Service (NTIS)

US Environmental Protection Agency standards for the cleanup and disposal of inactive tailings sites require that control measures for disposal of tailings be designed to be effective for up to 1000 years if reasonably achievable, and, in any case, for 20...

P. A. Beedlow J. N. Hartley

1984-01-01

299

Mobility and bioavailability of uranium mill tailings contaminants  

Microsoft Academic Search

An evaluation of environmental transport and contamination resulting from the release of trace elements and radionuclides from uranium mill tailings was performed by utilizing both laboratory and field studies. The composition of tailings showed the enrichment of a suite of uranium analogue elements (As, Mo, Se, and V) as well as the frequent occurrence of heavy metals generally associated with

David R. Dreesen; Joel M. Williams; M. Lynn Marple; Ernest S. Gladney; Daniel R. Perrin

1982-01-01

300

Behavioural and Brain Gene Expression Profiling in Pigs during Tail Biting Outbreaks - Evidence of a Tail Biting Resistant Phenotype  

PubMed Central

Abnormal tail biting behaviour is a major welfare problem for pigs receiving the behaviour, as well as an indication of decreased welfare in the pigs performing it. However, not all pigs in a pen perform or receive tail biting behaviour and it has recently been shown that these ‘neutral’ pigs not only differ in their behaviour, but also in their gene expression compared to performers and receivers of tail biting in the same pen. To investigate whether this difference was linked to the cause or a consequence of them not being involved in the outbreak of tail biting, behaviour and brain gene expression was compared with ‘control’ pigs housed in pens with no tail biting. It was shown that the pigs housed in control pens performed a wider variety of pig-directed abnormal behaviour (belly nosing 0.95±1.59, tail in mouth 0.31±0.60 and ‘other‘ abnormal 1.53±4.26; mean±S.D) compared to the neutral pigs (belly nosing 0.30±0.62, tail in mouth 0.13±0.50 and “other“ abnormal 0.42±1.06). With Affymetrix gene expression arrays, 107 transcripts were identified as differently expressed (p<0.05) between these two categories of pigs. Several of these transcripts had already been shown to be differently expressed in the neutral pigs when they were compared to performers and receivers of tail biting in the same pen in an earlier study. Hence, the different expression of these genes cannot be a consequence of the neutral pigs not being involved in tail biting behaviour, but rather linked to the cause contributing to why they were not involved in tail biting interactions. These neutral pigs seem to have a genetic and behavioural profile that somehow contributes to them being resistant to performing or receiving pig-directed abnormal behaviour, such as tail biting, even when housed in an environment that elicits that behaviour in other pigs.

Brunberg, Emma; Jensen, Per; Isaksson, Anders; Keeling, Linda J.

2013-01-01

301

PERIODICAL OCCURRENCE OF THE DISRUPTIONS ALONG THE EARTH'S MAGNETIC TAIL AND CROSS-TAIL CURRENT AMPLIFICATIONS  

Microsoft Academic Search

The field-aligned currents (FACs) flow to the ionosphere from the edges of the inhomogeneities of the perpendicular magne- tospheric current (PMC) which is the source of these FACs. One such PMC is the dawn-dusk cross-tail current in the substorm current wedge (SCW) with pair of FACs in the night sector of the Iijima-Potemra Region 1 (thereinafter R1). This FACs pair

V. Mishin; Z. Pu; L. Sapronova; M. Tolochko

2008-01-01

302

Numerical investigation of tail buffet on F-18 aircraft  

NASA Technical Reports Server (NTRS)

Numerical investigation of vortex induced tail buffet is conducted on the F-18 aircraft at high angles of attack. The Reynolds-averaged Navier-Stokes equations are integrated using a time-accurate, implicit procedure. A generalized overset zonal grid scheme is used to decompose the computational space around the complete aircraft with faired-over inlet. A weak coupling between the aerodynamics and structures is assumed to compute the structural oscillation of the flexible vertical tail. Time-accurate computations of the turbulent flow around the F-18 aircraft at 30 degrees angle of attack show the surface and off-surface flowfield details, including the unsteadiness created by the vortex burst and its interaction with the vertical twin tail which causes the tail buffet. The effect of installing a LEX fence on modifying the vortex structure upstream of the tail is also examined.

Rizk, Yehia M.; Guruswamy, Guru P.; Gee, Ken

1992-01-01

303

Accelerated aging tests of liners for uranium mill tailings disposal  

SciTech Connect

This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing.

Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

1981-11-01

304

Mycobacteriosis in a black-tailed deer (Odocoileus hemionus columbianus) caused by Mycobacterium kansasii  

USGS Publications Warehouse

An eviscerated hunter-harvested female black-tailed deer (Odocoileus hemionus columbianus) was submitted to the Washington Department of Fish and Wildlife. The deer was emaciated, devoid of adipose tissue, and the parietal surface of the thoracic cavity contained multiple granulomas. Acid-fast bacteria were detected histologically from the granulomas and were isolated and identified as Mycobacterium kansasii, a nontuberculous mycobacterium sporadically reported to cause tuberculosis-like disease in a variety of vertebrates. This was the first report of symptomatic disease caused by M. kansasii in free-ranging deer. This case indicates that atypical mycobacteria can cause tuberculosis-like disease in free-ranging deer and illustrates the importance of identifying causative agents of tuberculosis-like disease in wildlife. Copyright 2005 by American Association of Zoo Veterinarians.

Hall, P. B.; Bender, L. C.; Garner, M. M.

2005-01-01

305

Research on the characterization and conditioning of uranium mill tailings. Volume 1. I. Characterization and leaching behavior of uranium mill tailings  

Microsoft Academic Search

The goal of these studies on tailings characterization was to determine the mineralogical and elemental composition of various tailings materials, as well as to evaluate their contaminant leachability and radon emanation properties. Extreme variability within and between tailings piles was noted for major, minor, and trace elements and radionuclides. The most commonly enriched contaminants found in 12 tailings site composites

D. R. Dreesen; M. E. Bunker; E. J. Cokal; M. M. Denton; J. W. Starner; E. F. Thode; L. E. Wangen; J. M. Williams

1983-01-01

306

How regenerating lymphatics function: lessons from lizard tails.  

PubMed

Rational treatment of lymphoedema may be improved in the future with a better understanding of the physiological processes involved in the regeneration of new lymphatic vessels (lymphangiogenesis). Many lizard species undergo tail autotomy as a predator escape response and subsequently regenerate nonlymphoedematous tails. Such species may offer novel models for examining lymphangiogenesis. In this lymphoscintigraphic evaluation, three radioactive tracers were employed, (99m)Tc-antimony trisulphide colloid (approximately 10 nm diameter), (99m)Tc-tin fluoride colloid (approximately 2,000 nm; (99m)Tc-TFC), and (99m)Tc-diethylenetriaminepentaacetic acid (soluble; (99m)Tc-DTPA), to examine lymphatic function in regenerating tails of the Australian marbled gecko, Christinus marmoratus. Rate of local clearance and velocity of migration were determined in geckos with original tails and at 6, 9, 12, and >24 weeks after autotomy. In original-tailed geckos, the smaller radiocolloid was cleared to a greater extent and had a faster lymph velocity than in geckos with regenerated tails. The same parameters measured for larger particles were greater in early regeneration than later. (99m)Tc-TFC did not migrate from the injection site in fully regenerated and original gecko tails, which indicates that larger particles are increasingly impeded as tail regeneration progresses. Soluble (99m)Tc-DTPA diffused from the injection site extremely rapidly via venous capillaries in all tails, confirming that the slower clearance of the colloids is solely via the lymphatics. Differences in clearance and lymph velocity between differently sized colloids throughout tail regeneration may be influenced by changes in surrounding tissue structure density and the lymphatic vessel porosity. PMID:17441203

Blacker, Helen A; Tsopelas, Chris; Orgeig, Sandra; Daniels, Christopher B; Chatterton, Barry E

2007-01-01

307

Radon emanation from backfilled mill tailings in underground uranium mine.  

PubMed

Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as (226)Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12-7.03 Bq m(-2) s(-1) with geometric mean of 1.01 Bq m(-2) s(-1) and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08-0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between (222)Rn emanation rate and (226)Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. PMID:24412814

Sahu, Patitapaban; Mishra, Devi Prasad; Panigrahi, Durga Charan; Jha, Vivekananda; Patnaik, R Lokeswara; Sethy, Narendra Kumar

2014-04-01

308

Lipid Binding to the Tail Domain of Vinculin  

PubMed Central

Vinculin is a highly conserved and abundant cytoskeletal protein involved in linking the actin cytoskeleton to the cell membrane at sites of cellular adhesion. At these sites of adhesion, vinculin plays a role in physiological processes such as cell motility, migration, development, and wound healing. Loss of normal vinculin function has been associated with cancer phenotypes, cardiovascular disease, and lethal errors in embryogenesis. The tail domain of vinculin (Vt) binds to acidic phospholipids and has been proposed to play a role in vinculin activation and focal adhesion turnover. To better characterize Vt-lipid specificity, we conducted a series of lipid co-sedimentation experiments and find that Vt shows specific association with phosphatidylinositol 4,5-bisphosphate (PIP2), compared with phosphatidylethanolamine (PE), phosphatidylcholine (PC), phosphatidylserine (PS), or phosphatidylinositol (PI) in the context of mixed lipid vesicles. The C terminus of Vt has been proposed to be important for PIP2 association, as various mutations and deletions within the C-terminal reduce PIP2 association. Lipid co-sedimentation and NMR analyses indicate that removal of the hydrophobic hairpin does not alter Vt structure or PIP2 association. However, more extensive deletions within the C-terminal introduce Vt structural perturbations and reduce PIP2 binding. Intriguingly, a significant increase in PIP2 binding was observed for multiple Vt variants that perturb interactions between the N-terminal strap and helix bundle, suggesting that a rearrangement of this N-terminal strap may be required for PIP2 binding.

Palmer, Sean M.; Playford, Martin P.; Craig, Susan W.; Schaller, Michael D.; Campbell, Sharon L.

2009-01-01

309

Resistance to Plague Among Black-Tailed Prairie Dog Populations  

PubMed Central

Abstract In some rodent species frequently exposed to plague outbreaks caused by Yersinia pestis, resistance to the disease has evolved as a population trait. As a first step in determining if plague resistance has developed in black-tailed prairie dogs (Cynomys ludovicianus), animals captured from colonies in a plague-free region (South Dakota) and two plague-endemic regions (Colorado and Texas) were challenged with Y. pestis at one of three doses (2.5, 250, or 2500 mouse LD50s). South Dakota prairie dogs were far more susceptible to plague than Colorado and Texas prairie dogs (p<0.001), with a mortality rate of nearly 100% over all doses. Colorado and Texas prairie dogs were quite similar in their response, with overall survival rates of 50% and 60%, respectively. Prairie dogs from these states were heterogenous in their response, with some animals dying at the lowest dose (37% and 20%, respectively) and some surviving even at the highest dose (29% and 40%, respectively). Microsatellite analysis revealed that all three groups were distinct genetically, but further studies are needed to establish a genetic basis for the observed differences in plague resistance.

Williamson, Judy; Cobble, Kacy R.; Busch, Joseph D.; Antolin, Michael F.; Wagner, David M.

2012-01-01

310

The ticking tail: daily oscillations in mRNA poly(A) tail length drive circadian cycles in protein synthesis  

PubMed Central

In this issue of Genes & Development, Kojima and colleagues (pp. 2724–2736) examined the impact of mRNA poly(A) tail length on circadian gene expression. Their study demonstrates how dynamic changes in transcript poly(A) tail length can lead to rhythmic protein expression, irrespective of whether mRNA accumulation is circadian or constitutive.

Gotic, Ivana; Schibler, Ueli

2012-01-01

311

Development of the Disposal Technology Research Component of the National Uranium Tailings Program. Final Report.  

National Technical Information Service (NTIS)

The National Technical Planning Group on Uranium Tailings Research, organized by CANMET in 1980, recommended the establishment of a National Uranium Tailings Program to develop research on the long-term abandonment of uranium mine tailings. This report de...

L. A. Melis

1983-01-01

312

Chronic Wasting Disease  

USGS Publications Warehouse

Chronic wasting disease (CWD) is an always-fatal, neurological illness occurring in North American cervids (members of the deer family), including white-tailed deer, mule deer, elk and moose. Since its discovery in 1967, CWD has spread geographically and increased in prevalence locally. CWD is contagious; it can be transmitted freely within and among free-ranging populations. It is likely that diseased animals can transmit CWD to healthy animals long before they become clinically ill. Managing CWD in free-ranging populations is extremely difficult, therefore preventative measures designed to reduce the chance for disease spread are critically important.

Richards, Bryan

2007-01-01

313

A tale of tails: How histone tails mediate chromatin compaction in different salt and linker histone environments  

PubMed Central

To elucidate the role of the histone tails in chromatin compaction and in higher-order folding of chromatin under physiological conditions, we extend a mesoscale model of chromatin [Arya, Zhang, and Schlick, Biophys. J. 91, 133 (2006); Arya and Schlick, Proc. Natl. Acad. Sci. USA 103, 16236 (2006)] to account for divalent cations (Mg2+) and linker histones. Configurations of 24-nucleosome oligonucleosomes in different salt environments and in the presence and absence of linker histones are sampled by a mixture of local and global Monte Carlo methods. Analyses of the resulting ensembles reveals a dynamic synergism between the histone tails, linker histones, and physiological ions in forming compact higher-order structures of chromatin. In the presence of monovalent salt alone, oligonucleosomes remain relatively unfolded and the histone tails do not mediate many internucleosomal interactions. Upon the addition of linker histones and divalent cations, the oligonucleosomes undergo a significant compaction triggered by: a dramatic increase in the internucleosomal interactions mediated by the histone tails; formation of a rigid linker DNA “stem” around the linker histones' C-terminal domains; and reducion in the electrostatic repulsion between linker DNAs via sharp bending in some linker DNAs caused by the divalent cations. Among all histone tails, the H4 tails mediate the most internucleosomal interactions, consistent with experimental observations, followed by the H3, H2A, and H2B tails in decreasing order. Apart from mediating internucleosomal interactions, the H3 tails also contribute to chromatin compaction by attaching to the entering and exiting linker DNA to screen electrotatic repulsion among the linker DNAs. This tendency of the H3 tails to attach to linker DNA, however, decreases significantly upon the addition of linker histones due to competition effects. The H2A and H2B tails do not mediate significant internucleosomal interactions but are important for mediating fiber/fiber intractions, especially in relatively unfolded chromatin in monovalent salt environments.

Arya, Gaurav; Schlick, Tamar

2009-01-01

314

STAR CLUSTERS IN THE TIDAL TAILS OF INTERACTING GALAXIES: CLUSTER POPULATIONS ACROSS A VARIETY OF TAIL ENVIRONMENTS  

SciTech Connect

We have searched for compact stellar structures within 17 tidal tails in 13 different interacting galaxies using F606W- and F814W-band images from the Wide Field Planetary Camera 2 on the Hubble Space Telescope. The sample of tidal tails includes a diverse population of optical properties, merging galaxy mass ratios, H I content, and ages. Combining our tail sample with Knierman et al., we find evidence of star clusters formed in situ with M{sub V} < -8.5 and V - I < 2.0 in 10 of 23 tidal tails; we are able to identify cluster candidates to M{sub V} = -6.5 in the closest tails. Three tails offer clear examples of 'beads on a string' star formation morphology in V - I color maps. Two tails present both tidal dwarf galaxy candidates and cluster candidates. Statistical diagnostics indicate that clusters in tidal tails may be drawn from the same power-law luminosity functions (with logarithmic slopes {approx}-2 to -2.5) found in quiescent spiral galaxies and interiors of interacting systems. We find that the tail regions with the largest number of observable clusters are relatively young ({approx}<250 Myr old) and bright (V {approx}< 24 mag arcsec{sup -2}), probably attributed to the strong bursts of star formation in interacting systems soon after periapse. Otherwise, we find no statistical difference between cluster-rich and cluster-poor tails in terms of many observable characteristics, though this analysis suffers from complex, unresolved gas dynamics and projection effects.

Mullan, B.; Konstantopoulos, I. S.; Lee, K. H.; Charlton, J. C.; Gronwall, C.; Hunsberger, S.; Palma, C. [Department of Astronomy and Astrophysics, Pennsylvania State University, 525 Davey Lab, University Park, PA 16803 (United States); Kepley, A. A.; Johnson, K. E. [Department of Astronomy, University of Virginia, P.O. Box 400325, Charlottesville, VA 22904-4325 (United States); Knierman, K. [School of Earth and Space Exploration, Bateman Physical Sciences Center, Arizona State University, F-wing Room 686, Tempe, AZ 85287-1404 (United States); Bastian, N. [School of Physics, University of Exeter, Stocker Road, Exeter EX4 4QL (United Kingdom); Chandar, R. [Department of Physics and Astronomy, University of Toledo, 2801 West Bancroft Street, Toledo, OH 43606 (United States); Durrell, P. R. [Department of Physics and Astronomy, Youngstown State University, Youngstown, OH 44555 (United States); Elmegreen, D. [Department of Physics and Astronomy, Vassar College, Box 745, Poughkeepsie, NY 12604 (United States); English, J. [Department of Physics and Astronomy, University of Manitoba, Winnipeg, Manitoba R3T 2N2 (Canada); Gallagher, S. C. [Department of Physics and Astronomy, University of Western Ontario, 1151 Richmond Street, London, Ontario, N6A 3K7 (Canada); Hibbard, J. E. [National Radio Astronomy Observatory, 520 Edgemont Road, Charlottesville, VA 22903-2475 (United States); Maybhate, A. [Space Telescope Science Institute, 3700 San Martin Drive, Baltimore, MD 21218 (United States); Trancho, G. [Gemini Observatory, Casilla 603, Colina el Pino S/N, La Serena (Chile); Vacca, W. D., E-mail: mullan@astro.psu.edu [Stratospheric Observatory for Infrared Astronomy/Universities Space Research Association, NASA Ames Research Center, MS 144-2, Moffett Field, CA 94035 (United States)

2011-04-20

315

Ultrastructural aspects of rat tail tendon sheaths.  

PubMed Central

An investigation was carried out on the sheaths which envelop rat tail tendons. The samples were processed for observation by light and electron microscopy. In the case of electron microscopy, thin sections of specimens embedded in epoxy resin and replicas of freeze etched samples were used. On the basis of histological and ultrastructural observations, four distinct connective tissue sheaths have been detected. The paratendineum is a thick fibrous sheath that covers externally the four groups of tendons arranged around the vertebrae of the tail; the epitendineum is a distinct fibrous sheath surrounding each tendon group; the peritendineum is composed of concentric cellular laminae enveloping each tendon; lastly, the endotendineum is made up of one cellular lamella which adheres to the fibres of the tendon, projecting trabeculae between the individual tendon fascicles. In the para- and epitendineum, thick bundles of collagen fibrils, running parallel to the fibres of the tendon, were visible. The collagen fibrils had a wide variability of diameters (from 35 to 220 nm) and, when examined in replica, their microfibrillar arrangement appeared to be straight. In the peri- and endotendineum, thin bundles of collagen fibrils were visible between the cellular laminae, parallel to the main axis of the tendon. Among these collagen bundles, elastic fibres and numerous glycoproteins containing microfibril-like filaments were visible. The collagen fibrils were small and of uniform diameter (50 nm) and, when observed on replica, showed a helicoidal microfibrillar arrangement. The cell layers of the peri- and endotendineum were made up of flattened fibroblasts which were connected by specialised junctions and which contained numerous micropinocytotic vesicles. A thin layer of granular electron-dense material, with ultrastructural characteristics similar to those of a basement membrane, was visible on the surface of the most external cellular layer of the peritendineum and on the outer surface of the cellular lamella of the endotendineum. Due to their morphological characteristics it is supposed that the four tendon sheaths are involved in different and special functions. Moreover, collagen Type I and collagen Type III, demonstrated by means of immunofluorescence techniques in previous investigations, show respectively a close similarity in distribution to the thick collagen fibrils, with a straight microfibrillar arrangement, of the two external sheaths, and to the thin collagen fibrils, with a helicoidal microfibrillar arrangement, of the two internal sheaths. Images Fig. 2 Fig. 3 Fig. 4 Fig. 5 Fig. 6 Fig. 7 Fig. 8 Fig. 9

Strocchi, R; Leonardi, L; Guizzardi, S; Marchini, M; Ruggeri, A

1985-01-01

316

Predicting arsenic concentrations in porewaters of buried uranium mill tailings  

SciTech Connect

The proposed JEB Tailings Management Facility (TMF) to be emplaced below the groundwater table in northern Saskatchewan, Canada, will contain uranium mill tailings from McClean Lake, Midwest and Cigar Lake ore bodies, which are high in arsenic (up to 10%) and nickel (up to 5%). A serious concern is the possibility that high arsenic and nickel concentrations may be released from the buried tailings, contaminating adjacent groundwaters and a nearby lake. Laboratory tests and geochemical modeling were performed to examine ways to reduce the arsenic and nickel concentrations in TMF porewaters so as to minimize such contamination from tailings buried for 50 years and longer. The tests were designed to mimic conditions in the mill neutralization circuit (3 hr tests at 25 C), and in the TMF after burial (5--49 day aging tests). The aging tests were run at 50, 25 and 4 C (the temperature in the TMF). In order to optimize the removal of arsenic by adsorption and precipitation, ferric sulfate was added to tailings raffinates having Fe/As ratios of less than 3--5. The acid raffinates were then neutralized by addition of slaked lime to nominal pH values of 7, 8, or 9. Analysis and modeling of the test results showed that with slaked lime addition to acid tailings raffinates, relatively amorphous scorodite (ferric arsenate) precipitates near pH 1, and is the dominant form of arsenate in slake limed tailings solids except those high in Ni and As and low in Fe, in which cabrerite-annabergite (Ni, Mg, Fe(II) arsenate) may also precipitate near pH 5--6. In addition to the arsenate precipitates, smaller amounts of arsenate are also adsorbed onto tailings solids. The aging tests showed that after burial of the tailings, arsenic concentrations may increase with time from the breakdown of the arsenate phases (chiefly scorodite). However, the tests indicate that the rate of change decreases and approaches zero after 72 hrs at 25 C, and may equal zero at all times in the TMF at 4 C. Consistent with a kinetic model that describes the rate of breakdown of scorodite to form hydrous ferric oxide, the rate of release of dissolved arsenate to tailings porewaters from slake limed tailings: (1) is proportional to pH above pH 6--7; (2) decreases exponentially as the total molar Fe/As ratio of tailings raffinates is increased from 1/1 to greater than 5/1; and (3) is proportional to temperature with an average Arrhenius activation energy of 13.4 {+-} 4.2 kcal/mol. Study results suggest that if ferric sulfate and slaked lime are added in the tailings neutralization circuit to give a raffinate Fe/As molar ratio of at least 3--5 and a nominal (initial) pH of 8 (final pH of 7--8), arsenic and nickel concentrations of 2 mg/L or less, are probable in porewaters of individual tailings in the TMF for 50 to 10,000 yrs after tailings disposal. However, the tailings will be mixed in the TMF, which will contain about 35% tailings with Fe/As = 3.0, and 65% tailings with Fe/As = 5.0--7.7. Thus, it seems likely that average arsenic pore water concentrations in the TMF may not exceed 1 mg/L.

Langmuir, D.; Mahoney, J.; MacDonald, A.; Rowson, J.

1999-10-01

317

Tail Lobe Revisited: Magnetic Field Modeling Based on Plasma Data  

NASA Technical Reports Server (NTRS)

Plasma data from the ISEE-1 and -2 spacecraft during 1977-1980 have been used to determine the distribution of data points in the magnetotail in the range of distances -20 < XGSM < --15, i.e. which of the records that were located in the current sheet, in the tail lobe, in the magnetosheath and in the boundary layers respectively. The ISEE-1 and -2 magnetic field data for the records in the tail lobe were then used to model the tail lobe magnetic field dependence on the solar wind dynamic pressure, on the Interplanetary Magnetic Field (IMF) and on the Dst index. The tail lobe magnetic field was assumed to be dependent on the square root of the dynamic pressure based on the balance between the total magnetic pressure in the tail lobes and the dynamic pressure of the solar wind. The IMF dependent terms, added to the pressure term, were sought in many different forms while the Dst dependence of the tail lobe magnetic field was assumed to be linear. The field shows a strong dependence on the square root of the dynamic pressure and the different IMF dependent terms all constitute a significant contribution to the total field. However, the dependence on the Dst index turned out to be very weak at those down-tail distances. The results of this study are intended to be used for parameterizing future versions of the data-based models of the global magnetospheric magnetic field.

Karlsson, S. B. P.; Tsyganenko, N. A.

1999-01-01

318

Improved Tail-Current Representation in the Rice Field Model  

NASA Astrophysics Data System (ADS)

The Rice Field Model (RFM) represents the magnetic field of the steady-state open magnetosphere. In order to improve the mapping of field lines in the near Earth region, the simple Harris-sheet field representing the cross-tail current is replaced near the Earth by a more flexible tail current model developed by Hilmer and Voigt In the far-tail region the tail current and expansion fan fields are modified to allow for variations in the IMF and the interconnection field down the tail. The new tail-current is completely shielded by the magnetopause current system. The effects of time-dependent IMF on the polar cap potential pattern are explored by propagating a Northward turning down the tail. To evaluate the new tail-current in the near Earth region, magnetometer data from the GOES-8 satellite (in geosynchronous orbit) for the period of March 9-17, 1998 is compared to model predictions. The combination of RFM shielding with the Hilmer-Voigt tail-current proves significantly more accurate in determining the magnetic field at GEO than either of the two models alone. Ding, C., T. W. Hill, and F. R. Toffoletto. Improvement of the Toffoletto-Hill Open Magnetospheric Model, in Physics of Space Plasmas (1995): Proceedings of the 1995 Cambridge Syposium/Workshop in Geoplasma Physics on "Multiscale Phenomena in Space Plasmas", edited by T. Chang, and J.R. Jasperse, pp. 639-644, MIT Center for Theoretical Geo/Cosmo Plasma Physics, Cambridge, Massachusetts, 1996.

Naehr, S.; Toffoletto, F. R.

2001-05-01

319

Modelling of contaminant release from a uranium mine tailings site  

SciTech Connect

Available in abstract form only. Full text of publication follows: Uranium mining and milling continuing from the early 1960's until 1990 close to the town of Seelingstaedt in Eastern Germany resulted in 4 tailings impoundments with a total tailings volume of about 105 Mio. m{sup 3}. Leakage from these tailings impoundments enters the underlying aquifers and is discharged into surface water streams. High concentration of salts, uranium and several heavy metals are released from the tailings. At present the tailings impoundments are reshaped and covered. For the identification of suitable remediation options predictions of the contaminant release for different remediation scenarios have to be made. A compartment model representing the tailings impoundments and the surrounding aquifers for the calculation of contaminant release and transport was set up using the software GOLDSIM. This compartment model describes the time dependent hydraulic conditions within the tailings and the surrounding aquifers taking into account hydraulic and geotechnical processes influencing the hydraulic properties of the tailings material. A simple geochemical approach taking into account sorption processes as well as retardation by applying a k{sub d}-approach was implemented to describe the contaminant release and transport within the hydraulic system. For uranium as the relevant contaminant the simple approach takes into account additional geochemical conditions influencing the mobility. Alternatively the model approach allows to include the results of detailed geochemical modelling of the individual tailings zones which is than used as source term for the modelling of the contaminant transport in the aquifer and to the receiving streams. (authors)

Kahnt, Rene [G.E.O.S. Freiberg Ingenieurgesellschaft mbH, P.O.Box 1162. D-09581 Freiberg (Germany); Metschies, Thomas [Wismut GmbH, Jagdschaenkenstrasse 29. D-09117 Chemnitz (Germany)

2007-07-01

320

The Tail of KdsC  

PubMed Central

The phosphatase KdsC cleaves 3-deoxy-d-manno-octulosonate 8-phosphate to generate a molecule of inorganic phosphate and Kdo. Kdo is an essential component of the lipopolysaccharide envelope in Gram-negative bacteria. Because lipopolysaccharide is an important determinant of bacterial resistance and toxicity, KdsC is a potential target for novel antibacterial agents. KdsC belongs to the broad haloacid dehalogenase superfamily. In haloacid dehalogenase superfamily enzymes, substrate specificity and catalytic efficiency are generally dictated by a fold feature called the cap domain. It is therefore not clear why KdsC, which lacks a cap domain, is catalytically efficient and highly specific to 3-deoxy-d-manno-octulosonate 8-phosphate. Here, we present a set of seven structures of tetrameric Escherichia coli KdsC (ranging from 1.4 to 3.06 Å in resolution) that model different intermediate states in its catalytic mechanism. A crystal structure of product-bound E. coli KdsC shows how the interface between adjacent monomers defines the active site pocket. Kdo is engaged in a network of polar and nonpolar interactions with residues at this interface, which explains substrate specificity. Furthermore, this structural and kinetic analysis strongly suggests that the binding of the flexible C-terminal region (tail) to the active site makes KdsC catalytically efficient by facilitating product release.

Biswas, Tapan; Yi, Li; Aggarwal, Parag; Wu, Jing; Rubin, John R.; Stuckey, Jeanne A.; Woodard, Ronald W.; Tsodikov, Oleg V.

2009-01-01

321

Cross-tail current - Resonant orbits  

NASA Technical Reports Server (NTRS)

A technique to generate self-consistent 1D current sheets is described. Groups of monoenergetic protons were followed in a modified Harris magnetic field. This sample current sheet is characterized by resonant quasi-adiabatic orbits. The magnetic moment of a quasi-adiabatic ion which is injected from outside a current sheet changes substantially during the orbit but returns to almost its initial value by the time the ion leaves. Several ion and electron groups were combined to produce a plasma sheet in which the charged particles carry the currents needed to generate the magnetic field in which the orbits were traced. An electric field also is required to maintain charge neutrality. Three distinct orbit types, one involving untrapped ions and two composed of trapped ions, were identified. Limitations associated with the use of a 1D model also were investigated; it can provide a good physical picture of an important component of the cross-tail current, but cannot adequately describe any region of the magnetotail in which the principal current sheet is separated from the plasma sheet boundary layer by a nearly isotropic outer position of the central plasma sheet.

Kaufmann, Richard L.; Lu, Chen

1993-01-01

322

Assessment of computational prediction of tail buffeting  

NASA Technical Reports Server (NTRS)

Assessments of the viability of computational methods and the computer resource requirements for the prediction of tail buffeting are made. Issues involved in the use of Euler and Navier-Stokes equations in modeling vortex-dominated and buffet flows are discussed and the requirement for sufficient grid density to allow accurate, converged calculations is stressed. Areas in need of basic fluid dynamics research are highlighted: vorticity convection, vortex breakdown, dynamic turbulence modeling for free shear layers, unsteady flow separation for moderately swept, rounded leading-edge wings, vortex flows about wings at high subsonic speeds. An estimate of the computer run time for a buffeting response calculation for a full span F-15 aircraft indicates that an improvement in computer and/or algorithm efficiency of three orders of magnitude is needed to enable routine use of such methods. Attention is also drawn to significant uncertainties in the estimates, in particular with regard to nonlinearities contained within the modeling and the question of the repeatability or randomness of buffeting response.

Edwards, John W.

1990-01-01

323

Idealized tip-to-tail waverider model  

NASA Technical Reports Server (NTRS)

The flow field of an idealized cone-derived waverider is axisymmetric. This forebody feature is preserved for the rest of the vehicle, including the inlet, cowl, combustor, and nozzle. There is thus an inviscid, tip-to-tail model in which both the external and internal flows are axisymmetric. The assumption of axial symmetry provides a major simplification for the analysis and allows for a systematic integration of the propulsion unit with the aerodynamics. The code is an initial formulation that provides only the most basic engineering data, such as lift, thrust, drag, and fuel consumption for a point-designed vehicle that may be cruising at a low hypersonic Mach number. The user may specify flight altitude and Mach number, a multiple shock configuration for the inlet, a few basic geometric parameter, H2 or CH4 as fuel, the fuel/air ratio, etc. A new design concept is used for the nozzle that avoids shock waves, minimizes the nozzle length, and may maximize its thrust. A general description of the model is provided with emphasis on the design of the nozzle and fins. Preliminary results are presented that compare the cruise flight range using H2 or CH4 as the fuel.

Emanuel, G.; Park, H.-K.

1990-01-01

324

Myosin V from head to tail  

PubMed Central

Myosin V (myoV), a processive cargo transporter, has arguably been the most well-studied unconventional myosin of the past decade. Considerable structural information is available for the motor domain, the IQ motifs with bound calmodulin or light chains, and the cargo-binding globular tail, all of which have been crystallized. The repertoire of adapter proteins that link myoV to a particular cargo is becoming better understood, enabling cellular transport processes to be dissected. MyoV is processive, meaning that it takes many steps on actin filaments without dissociating. Its extended lever arm results in long 36 nm steps, making it ideal for single molecule studies of processive movement. In addition, electron microscopy revealed the structure of the inactive, folded conformation of myoV when it is not transporting cargo. This review provides a background on myoV, and highlights recent discoveries that show why myoV will continue to be an active focus of investigation.

Trybus, Kathleen M.

2008-01-01

325

Statics and dynamics of Giacobini-Zinner magnetic tail  

NASA Technical Reports Server (NTRS)

The data gathered by the International Cometary Explorer during its traversal of Comet Giacobini-Zinner's tail are subjected to stress balance requirements, yielding estimates of unmeasured quantities. It is noted that the comet's tail is embedded in an ionosheath whose static pressure is nearly equal to the solar wind stagnation pressure, leading to a large lobe field strength. A systematic variation is found in the ion temperature across the tail, implying the variation of the pickup velocity of new ions. Axial stress balance yields an expression for the strength of the lobe field which reveals weak variation with axial distance.

Siscoe, G. L.; Slavin, J. A.; Smith, E. J.; Tsurutani, B. T.; Jones, D. E.

1986-01-01

326

Transient Effects of the Wing Wake on the Horizontal Tail  

NASA Technical Reports Server (NTRS)

An investigation was made of the effect of the wing wake on the lift of the horizontal tail surfaces. In the development of expressions for this effect, the growth of wing circulation and wing wake, the time interval represented by the tail length, and the development of lift by the rail were considered. The theory has been applied to a specific case to show the magnitude of the effect to be expected. It is shown that, for motions below a certain frequency, the development of lift by the tail may be represented by a simple lag function. The lag is, however, somewhat greater than that indicated by the rail length.

Jones, Robert T; Fehlner, Leo F

1940-01-01

327

Tail terms in gravitational radiation reaction via effective field theory  

NASA Astrophysics Data System (ADS)

Gravitational radiation reaction affects the dynamics of gravitationally bound binary systems. Here we focus on the leading “tail” term which modifies binary dynamics at fourth post-Newtonian order, as first computed by Blanchet and Damour. We reproduce this result using effective field theory techniques in the framework of the Lagrangian formalism suitably extended to include dissipation effects. We recover the known logarithmic tail term, consistently with the recent interpretation of the logarithmic tail term in the mass parameter, as a renormalization group effect of the Bondi mass of the system.

Foffa, Stefano; Sturani, Riccardo

2013-02-01

328

Band tailing and efficiency limitation in kesterite solar cells  

NASA Astrophysics Data System (ADS)

We demonstrate that a fundamental performance bottleneck for hydrazine processed kesterite Cu2ZnSn(S,Se)4 (CZTSSe) solar cells with efficiencies reaching above 11% can be the formation of band-edge tail states, which quantum efficiency and photoluminescence data indicate is roughly twice as severe as in higher-performing Cu(In,Ga)(S,Se)2 devices. Low temperature time-resolved photoluminescence data suggest that the enhanced tailing arises primarily from electrostatic potential fluctuations induced by strong compensation and facilitated by a lower CZTSSe dielectric constant. We discuss the implications of the band tails for the voltage deficit in these devices.

Gokmen, Tayfun; Gunawan, Oki; Todorov, Teodor K.; Mitzi, David B.

2013-09-01

329

Prenatal diagnosis of fetal tail and postabortum anatomical description.  

PubMed

Fetal ultrasound examination at 13 weeks of gestation demonstrated a homogeneously echogenic protrusion, or tail, 7 mm in length, in the sacral region. At 15 weeks, the ultrasound appearance was consistent with a regression of the tail and by 21 weeks it had completely disappeared. Severe intrauterine growth restriction with reduced uterine blood flow was diagnosed at 21 weeks and intrauterine death occurred at 24 weeks of gestation. Postmortem examination revealed a 4-mm caudal appendage which contained no vertebrae on radiography. The appendage was located under and behind the last sacral vertebra suggesting a true vestigial tail with a delayed process of regression. PMID:11844178

Grangé, G; Tantau, J; Pannier, E; Aubry, M C; Viot, G; Fallet-Bianco, C; Terrasse, G; Cabrol, D

2001-11-01

330

STEREO Watches as Comet Encke Loses Its Tail  

NASA Video Gallery

As comet Encke dipped inside the orbit of Mercury, STEREO A recorded its tail getting ripped off by a solar eruption on April 20, 2007. The eruption that hit Encke was a coronal mass ejection (CME)...

331

Decision Support System for White-Tailed Deer Management.  

National Technical Information Service (NTIS)

Effective management of white-tailed deer (Odocoileus virginianus) can be enhanced by the integration of wildlife science, modern technology, and wildlife managers' expertise. The goal of this research was to integrate the population modeling, landscape s...

J. Xie

1999-01-01

332

Wind Erosion Research at an Uranium Mill Tailings Site.  

National Technical Information Service (NTIS)

A uranium mill tailings pile at Grants, New Mexico, was selected for wind erosion research since the configuration provides flat area containing fine sand and made up of larger particles. The wind erosion experiment is discussed. Experimental equipment co...

G. A. Sehmel

1977-01-01

333

Lead concentrations in white-tailed deer mandibles and teeth  

SciTech Connect

Mandibles and teeth of 48 white-tailed deer from 6 counties in Pennsylvania were analyzed for lead by flame atomic absorption spectrophotometry. Results indicate little influence of age, sex, and county on lead levels. (JMT)

Witkowski, S.A.; Ault, S.R.; Field, R.W.

1982-05-01

334

J SERIES MAGAZINE. J 106 INTERIOR. BOMB TAILS ON LEFT. ...  

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

J SERIES MAGAZINE. J 106 INTERIOR. BOMB TAILS ON LEFT. - Naval Magazine Lualualei, Headquarters Branch, Inert Storehouse Type, Twelfth Street between Kwajulein & New Mexico Streets, Pearl City, Honolulu County, HI

335

Elucidating Internucleosome Interactions and the Roles of Histone Tails  

PubMed Central

The nucleosome is the first level of genome organization and regulation in eukaryotes where negatively charged DNA is wrapped around largely positively charged histone proteins. Interaction between nucleosomes is dominated by electrostatics at long range and guided by specific contacts at short range, particularly involving their flexible histone tails. We have thus quantified how internucleosome interactions are modulated by salts (KCl, MgCl2) and histone tail deletions (H3, H4 N-terminal), using small-angle x-ray scattering and theoretical modeling. We found that measured effective charges at low salts are ?1/5th of the theoretically predicted renormalized charges and that H4 tail deletion suppresses the attraction at high salts to a larger extent than H3 tail deletion.

Howell, Steven C.; Andresen, Kurt; Jimenez-Useche, Isabel; Yuan, Chongli; Qiu, Xiangyun

2013-01-01

336

Thyroxine Induced Resorption of Xenopus Laevis Tail Tissue in Vitro.  

ERIC Educational Resources Information Center

A simple method of studying thyroxine-induced resorption of tadpole tails in vitro is described. This procedure demonstrates that resorption is dependent on thyroxine and requires protein synthesis. It introduces students to the use of tissue culture methods. (Author)

Scadding, Steven R.

1984-01-01

337

42. FOUNDATIONS TAIL RACE, ETC., POWER HOUSE SANTA ANA ...  

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

42. FOUNDATIONS - TAIL RACE, ETC., POWER HOUSE SANTA ANA RIVER NO. 2, EDISON ELECTRIC CO., NOV. 3, 1904. SCE drawing no. 5393. - Santa Ana River Hydroelectric System, SAR-2 Powerhouse, Redlands, San Bernardino County, CA

338

DETAIL VIEW OF CLASSIFIER, TAILINGS LAUNDER TROUGH, LINESHAFTS, AND CONCENTRATION ...  

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

DETAIL VIEW OF CLASSIFIER, TAILINGS LAUNDER TROUGH, LINESHAFTS, AND CONCENTRATION TABLES WITH SIX FOOT SCALE, LOOKING SOUTHWEST. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

339

5. NORTH ELEVATION OF SKIDOO MILL, LOOKING SOUTH. TAILINGS IN ...  

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

5. NORTH ELEVATION OF SKIDOO MILL, LOOKING SOUTH. TAILINGS IN FOREGROUND, DOWN SLOPE FROM SYANIDE PROCESSING TANKS. SEE CA-290-40 (CT) FOR IDENTICAL COLOR TRANSPARENCY. - Skidoo Mine, Park Route 38 (Skidoo Road), Death Valley Junction, Inyo County, CA

340

Western Red-tailed Skink Distribution in Southern Nevada  

SciTech Connect

This slide show reports a study to: determine Western Red-tailed Skink (WRTS) distribution on Nevada National Security Site (NNSS); identify habitat where WRTS occur; learn more about WRTS natural history; and document distribution of other species.

Hall, D. B. and Gergor, P. D.

2011-11-01

341

Long-Term Stabilization of Uranium Mill Tailings.  

National Technical Information Service (NTIS)

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of e...

L. D. Voorhees M. J. Sale J. W. Webb P. J. Mulholland

1983-01-01

342

Radon Diffusion Through Uranium Mill Tailings and Cover Defects  

SciTech Connect

Research was conducted at Pacific Northwest Laboratory to define the effects of cover defects on the emission of radon gas from covered uranium mill tailings piles. This report describes the results from the analysis of four geometrically simplified cover defects.

Mayer, D. W.; Zimmerman, D. A.

1981-12-01

343

Scoring tail damage in pigs: an evaluation based on recordings at Swedish slaughterhouses  

PubMed Central

Background There is increasing interest in recording tail damage in pigs at slaughter to identify problem farms for advisory purposes, but also for benchmarking within and between countries as part of systematic monitoring of animal welfare. However, it is difficult to draw conclusions when comparing prevalence’s between studies and countries partly due to differences in management (e.g. differences in tail docking and enrichment routines) and partly due to differences in the definition of tail damage. Methods Tail damage and tail length was recorded for 15,068 pigs slaughtered during three and four consecutive days at two slaughterhouses in Sweden. Tail damage was visually scored according to a 6-point scale and tail length was both visually scored according to a 5-point scale and recorded as tail length in centimetres for pigs with injured or shortened tails. Results The total prevalence of injury or shortening of the tail was 7.0% and 7.2% in slaughterhouse A and B, respectively. When only considering pigs with half or less of the tail left, these percentages were 1.5% and 1.9%, which is in line with the prevalence estimated from the routine recordings at slaughter in Sweden. A higher percentage of males had injured and/or shortened tails, and males had more severely bitten tails than females. Conclusions While the current method to record tail damage in Sweden was found to be reliable as a method to identify problem farms, it clearly underestimates the actual prevalence of tail damage. For monitoring and benchmarking purposes, both in Sweden and internationally, we propose that a three graded scale including both old and new tail damage would be more appropriate. The scale consists of one class for no tail damage, one for mild tail damage (injured or shortened tail with more than half of the tail remaining) and one for severe tail damage (half or less of the tail remaining).

2012-01-01

344

Uranium Mill Tailings Remedial Action 1993 Roadmap  

SciTech Connect

The 1993 Roadmap for the Uranium Mill Tailings Remedial Action (UMTRA) Project office is a tool to assess and resolve issues. The US Department of Energy (DOE) UMTRA Project Office uses the nine-step roadmapping process as a basis for Surface and Groundwater Project planning. This is the second year the Roadmap document has been used to identify key issues and assumptions, develop logic diagrams, and outline milestones. This document is a key element of the DOE planning process. A multi-interest group used the nine-step process to focus on issues, root cause analysis and resolutions. This core group updated and incorporated comments on the basic assumptions, then used these assumptions to identify issues. The list of assumptions was categorized into the following areas: institutional, regulatory compliance, project management, human resource requirements, and other site-specific assumptions. The group identified 10 issues in the analysis phase. All of the issues are ranked according to importance. The number one issue from the 1992 Roadmap, ``Lack of sufficient human resources,`` remained the number one issue in 1993. The issues and their ranking are as follows: Lack of sufficient human resources; increasing regulatory requirements; unresolved groundwater issues; extension of UMTRCA through September 30, 1998; lack of post-UMTRA and post-cell closure policies; unpredictable amounts and timing of Federal funding; lack of regulatory compliance agreements; problem with states providing their share of remedial action costs; different interests and priorities among participants; and technology development/transfer. The issues are outlined and analyzed in detail in Section 8.0, with a schedule for resolution of these issues in Section 9.0.

Not Available

1993-10-18

345

Regulation of coronaviral poly(A) tail length during infection.  

PubMed

The positive-strand coronavirus genome of ~30 kilobase in length and subgenomic (sg) mRNAs of shorter lengths, are 5' and 3'-co-terminal by virtue of a common 5'-capped leader and a common 3'-polyadenylated untranslated region. Here, by ligating head-to-tail viral RNAs from bovine coronavirus-infected cells and sequencing across the ligated junctions, it was learned that at the time of peak viral RNA synthesis [6 hours postinfection (hpi)] the 3' poly(A) tail on genomic and sgmRNAs is ~65 nucleotides (nt) in length. Surprisingly, this length was found to vary throughout infection from ~45 nt immediately after virus entry (at 0 to 4 hpi) to ~65 nt later on (at 6 h to 9 hpi) and from ~65 nt (at 6 h to 9 hpi) to ~30 nt (at 120-144 hpi). With the same method, poly(U) sequences of the same lengths were simultaneously found on the ligated viral negative-strand RNAs. Functional analyses of poly(A) tail length on specific viral RNA species, furthermore, revealed that translation, in vivo, of RNAs with the longer poly(A) tail was enhanced over those with the shorter poly(A). Although the mechanisms by which the tail lengths vary is unknown, experimental results together suggest that the length of the poly(A) and poly(U) tails is regulated. One potential function of regulated poly(A) tail length might be that for the coronavirus genome a longer poly(A) favors translation. The regulation of coronavirus translation by poly(A) tail length resembles that during embryonal development suggesting there may be mechanistic parallels. PMID:23923003

Wu, Hung-Yi; Ke, Ting-Yung; Liao, Wei-Yu; Chang, Nai-Yun

2013-01-01

346

Characteristics of the tail of Comet Giacobini-Zinner  

NASA Technical Reports Server (NTRS)

The physical structure and characteristics of the Comet Giacobini-Zinner tail are described. Variations in the vector B-field configuration, the electron distribution function, the energetic ion population, and the electromagnetic and electrostatic plasma wave spectra are analyzed. The ICE detected a two-lobe magnetic field configuration and a narrow central plasma sheet. Additional analyses proposed for the Giacobini-Zinner tail data are discussed.

Scarf, F. L.

1986-01-01

347

Urbach–Martienssen's tails in layered semiconductor GaSe  

Microsoft Academic Search

The dependence of the absorption coefficient on photon energy and temperature near the fundamental absorption edge was measured for layered single crystal, Gallium selenide (GaSe). The exponentially increasing absorption tail was explained as an Urbach–Martienssen's (U–M's) tails in the 10–340K temperature range. Temperature dependence of the characteristic Urbach's parameters such as steepness parameter ?(T) and Urbach's energy (EU=kBT\\/?) indicate that

B. Abay; H. S. Güder; Y. K. Yo?urtçu

1999-01-01

348

Bifurcation of the tail current sheet in Jovian magnetosphere  

Microsoft Academic Search

Multiple crossings of the magnetotail current sheet by a single spaceraft give possibility to distinguish between two types of electric current density distribution: single-peaked (Harris type current layer) and double-peaked (bifurcated current sheet). Magnetic field measurements in Jovian magnetic tail by Voyager-2 and Galileo reveal the bifurcation of tail current sheet. Electric current density possesses minimum at the point of

P. L. Israelevich; A. I. Ershkovich; R. Oran

2007-01-01

349

On the fine structure of cometary plasma tails  

NASA Technical Reports Server (NTRS)

It is argued that the small-scale structures observed close to the plasma tail axis of comets may be a consequence of well-known finite-resistivity instabilities in the cometary cross-tail current sheet. While the 'tearing' mode instability, which causes a breakup of the layer along the current flow lines, may be responsible for the observed small condensation or 'knots' near the axis, the 'ripple' mode instability may give rise to the small-scale wavy structures.

Morrison, P. J.; Mendis, D. A.

1978-01-01

350

Tail Biting Trellis Representation of Codes: Decoding and Construction  

NASA Technical Reports Server (NTRS)

This paper presents two new iterative algorithms for decoding linear codes based on their tail biting trellises, one is unidirectional and the other is bidirectional. Both algorithms are computationally efficient and achieves virtually optimum error performance with a small number of decoding iterations. They outperform all the previous suboptimal decoding algorithms. The bidirectional algorithm also reduces decoding delay. Also presented in the paper is a method for constructing tail biting trellises for linear block codes.

Shao. Rose Y.; Lin, Shu; Fossorier, Marc

1999-01-01

351

Shape of gas flow paths causes power law tailing  

Microsoft Academic Search

In soil and\\/or groundwater remediation, we often see prolonged tailings: continuous outflow of low concentration pollutants for very long time, and in many cases power low behavior of late-time time-concentration curves. We considered that this kind of tailing can be caused by the shape of the gaseous flow introduced in saturated\\/unsaturated porous media. When gas is introduced to porous media,

T. Kawanishi; A. Sakami; Y. Hayashi

2004-01-01

352

Naturally Occurring Tuberculosis in White-Tailed Deer  

Microsoft Academic Search

Objective—To determine the distribution of lesions and extent of tissues infected with Mycobacterium bovis in a captive population of white-tailed deer. Design—Cross-sectional study. Animals—116 captive white-tailed deer. Procedure—Deer were euthanatized, and postmortem examinations were performed. Tissues with gross lesions suggestive of tuberculosis were collected for microscopic analysis and bacteriologic culture. Tissues from the head, thorax, and abdomen of deer with

Mitchell V. Palmer; Diana L. Whipple; Janet B. Payeur; David P. Alt; Kevin J. Esch; Colleen S. Bruning-Fann; John B. Kaneene

2000-01-01

353

Electromagnetic induction for mapping textural contrasts of mine tailing deposits  

NASA Astrophysics Data System (ADS)

Mine tailings present an important legacy of past and present ore-extraction activities in the Desert Southwest. Inactive mine tailings have no immediate economic role in current mining operations, yet from an environmental point of view it is important that such deposits are stabilized to prevent mass movement, wind or water erosion, leaching of chemicals such as acid mine drainage, and to reduce visual blight. In the presented study, we assess the potential for inferring textural properties of mine tailing deposits with electromagnetic induction (EMI) mapping as a means of informing efforts to establish vegetation at mine waste sites. EMI measurements of apparent electrical conductivity (ECa) and tailing samples were collected at a mine waste site in Southern Arizona, USA and used to test empirical and theoretical relationships between ECa and physical and mineralogical properties using linear and Gaussian process regression. Sensitivity analyses of a semi-theoretical and a regression model of ECa as a function of tailing properties indicated that volumetric clay fraction in the top 60 cm was a primary influence on bulk electrical conductivity along with water content, conductivity of the soil water and the presence of conductive minerals hematite and pyrite. At this site, latitude and longitude were better predictors of clay content than ECa, and while it was possible to obtain information about the spatial distribution of tailing texture using EMI, simple Kriging of texture data was a more powerful textural mapping technique. We conclude that EMI is a useful tool for mapping tailing texture at waste deposit sites, but due to physical and chemical heterogeneity of tailing deposits, it is necessary to collect more in situ samples than are needed for agricultural applications.

Nearing, Grey S.; Tuller, Markus; Jones, Scott B.; Heinse, Robert; Meding, Mercer S.

2013-02-01

354

Sexual selection and tail streamers in the barn swallow  

Microsoft Academic Search

The functional signi¢cance of elongated, narrow tips of the tail feathers of certain birds, so-called tail streamers, has recently been discussed from an aerodynamic point of view, and the e¡ects of sexual selection on such traits have been questioned. We review our long-term ¢eld studies using observational and experimental approaches to investigate natural and sexual selection in the barn swallow,

A. P. Moller; A. Barbosa; J. J. Cuervo; F. de Lope; S. Merino; N. Saino

1998-01-01

355

Double streams of protons in the distant geomagnetic tail  

NASA Technical Reports Server (NTRS)

Two intermingled streams of protons have been observed in the distant geomagnetic tail. The number densities of the two streams are comparable, and their velocity difference tends to lie along the field direction. The lower-velocity stream is probably composed of magnetosheath protons which have diffused through the boundary of the distant tail. The higher-velocity stream appears to originate in the field reversal region.

Villante, U.; Lazarus, A. J.

1975-01-01

356

Characterization of 14-3-3-? Interactions with Integrin Tails  

PubMed Central

Integrins are a family of heterodimeric (?+?) adhesion receptors that play key roles in many cellular processes. Integrins are unusual in that their functions can be modulated from both outside and inside the cell. Inside-out signaling is mediated by binding adaptor proteins to the flexible cytoplasmic tails of the ?- and ?-integrin subunits. Talin is one well-known intracellular activator, but various other adaptors bind to integrin tails, including 14-3-3-?, a member of the 14-3-3 family of dimeric proteins that have a preference for binding phosphorylated sequence motifs. Phosphorylation of a threonine in the ?2 integrin tail has been shown to modulate ?2/14-3-3-? interactions, and recently, the ?4 integrin tail was reported to bind to 14-3-3-? and associate with paxillin in a ternary complex that is regulated by serine phosphorylation. Here, we use a range of biophysical techniques to characterize interactions between 14-3-3-? and the cytoplasmic tails of ?4, ?1, ?2 and ?3 integrins. The X-ray structure of the 14-3-3-?/?4 complex indicates a canonical binding mode for the ?4 phospho-peptide, but unexpected features are also observed: residues outside the consensus 14-3-3-? binding motif are shown to be essential for an efficient interaction; in contrast, a short ?2 phospho-peptide is sufficient for high-affinity binding to 14-3-3-?. In addition, we report novel 14-3-3-?/integrin tail interactions that are independent of phosphorylation. Of the integrin tails studied, the strongest interaction with 14-3-3-? is observed for the ?1A variant. In summary, new insights about 14-3-3-?/integrin tail interactions that have implications for the role of these molecular associations in cells are described.

Bonet, Roman; Vakonakis, Ioannis; Campbell, Iain D.

2013-01-01

357

DETAIL VIEW OF CLASSIFIER, TAILINGS LAUNDER TROUGH, LINE SHAFTS, AND ...  

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

DETAIL VIEW OF CLASSIFIER, TAILINGS LAUNDER TROUGH, LINE SHAFTS, AND CONCENTRATION TABLES, LOOKING SOUTHWEST. SLURRY EXITING THE BALL MILL WAS COLLECTED IN AN AMALGAMATION BOX (MISSING) FROM THE END OF THE MILL, AND INTRODUCED INTO THE CLASSIFIER. THE TAILINGS LAUDER IS ON THE GROUND AT LOWER RIGHT. THE LINE SHAFTING ABOVE PROVIDED POWER TO THE CONCENTRATION TABLES BELOW AT CENTER RIGHT. - Gold Hill Mill, Warm Spring Canyon Road, Death Valley Junction, Inyo County, CA

358

Speciation And Colloid Transport of Arsenic From Mine Tailings  

SciTech Connect

In addition to affecting biogeochemical transformations, the speciation of As also influences its transport from tailings at inoperative mines. The speciation of As in tailings from the Sulfur Bank Mercury Mine site in Clear Lake, California (USA) (a hot-spring Hg deposit) and particles mobilized from these tailings have been examined during laboratory-column experiments. Solutions containing two common, plant-derived organic acids (oxalic and citric acid) were pumped at 13 pore volumes d{sup -1} through 25 by 500 mm columns of calcined Hg ore, analogous to the pedogenesis of tailings. Chemical analysis of column effluent indicated that all of the As mobilized was particulate (1.5 mg, or 6% of the total As in the column through 255 pore volumes of leaching). Arsenic speciation was evaluated using X-ray absorption spectroscopy (XAS), indicating the dominance of arsenate [As(V)] sorbed to poorly crystalline Fe(III)-(hydr)oxides and coprecipitated with jarosite [KFe{sub 3}(SO{sub 4}, AsO{sub 4}){sub 2}(OH){sub 6}] with no detectable primary or secondary minerals in the tailings and mobilized particles. Sequential chemical extractions (SCE) of <45 {micro}m mine tailings fractions also suggest that As occurs adsorbed to Fe (hydr)oxides (35%) and coprecipitated within poorly crystalline phases (45%). In addition, SCEs suggest that As is associated with 1 N acid-soluble phases such as carbonate minerals (20%) and within crystalline Fe-(hydr)oxides (10%). The finding that As is transported from these mine tailings dominantly as As(V) adsorbed to Fe (hydr)oxides or coprecipitated within hydroxysulfates such as jarosite suggests that As release from soils and sediments contaminated with tailings will be controlled by either organic acid-promoted dissolution or reductive dissolution of host phases.

Slowey, A.J.; Johnson, S.B.; Newville, M.; Brown, G.E., Jr.

2007-07-13

359

Long-Tail Buffer-Content Distributions in Broadband Networks  

Microsoft Academic Search

this paper is to show that long-tail distributions such as in (1)and (3) arise quite naturally in stochastic fluid models when a sojourn time ofthe environment process Z(t) in a set of high-activity states itself has a longtaildistribution. We do not contend that long-tail bu#er-content distributionsnecessarily will prevail. Instead, we present conditions under which they willoccur, and other conditions under

Gagan L. Choudhury; Ward Whitt

1997-01-01

360

Tailings beach slope prediction: a new rheological method  

Microsoft Academic Search

A new semi-empirical model for tailings beach slope prediction is presented. The model is based on existing non-Newtonian rheology theory combined with some well-established turbulent channel flow equations. It is shown that solid particles do not deposit from the self-formed channels of the tailings slurry as it flows down the beach, and that the slope of the beach is dictated

T. G. Fitton; A. G. Chryss; S. N. Bhattacharya

2006-01-01

361

Electron energization in the geomagnetic tail current sheet  

Microsoft Academic Search

Electron motion in the distant tail current sheet is evaluated and found to violate the guiding center approximation at energies > or approx. =100 eV. Most electrons within the energy range approx.10⁻¹⁻¹°sup 2\\/ keV that enter the current sheet become trapped within the magnetic field reversal region. These electrons then convect earthward and gain energy from the cross-tail electric field.

L. R. Lyons

1984-01-01

362

Experimental determination of the effect of horizontal-tail size, tail length, and vertical location on low-speed static longitudinal stability and damping pitch of a model having 45 degree sweptback wing and tail surfaces  

NASA Technical Reports Server (NTRS)

Report presents the results of an investigation conducted in the Langley stability tunnel to determine the effects of horizontal tails of various sizes and at various tail lengths (when loaded on the fuselage center line) and also the effects of vertical location of the horizontal tail relative to the wing on the low-speed static longitudinal stability and on the steady-state rotary damping in pitch for a complete-model configuration. The wing and tail surfaces had the quarter-chord lines swept back 45 degrees and had aspect ratios of 4. The results of the investigation showed that, in agreement with analytical considerations, the contribution of the horizontal tail to static longitudinal stability was related directly to the tail size and length; whereas, its contribution to damping in pitch was related directly to tail size and the square of tail length.

Lichtenstein, Jacob H

1952-01-01

363

The Head-Tail structure of High-Velocity Clouds  

NASA Astrophysics Data System (ADS)

We like to present new observational data compiled from the new Leiden/Dwingeloo 21-cm Linie survey towards the prominent High-Velocity Cloud (HVC) complexes observable from the northern hemisphere. Our analysis revealed a significant number of HVCs with a head-tail structure. These head-tail structures seem to connect the HVCs with material at lower velocities. On one hand, these head-tail structures may imply a physical interaction of the HVC material with the intermediate-velocity (IVCs) or low-velocity clouds (LVCs). On the other hand, they may be indicators for distortions within the velocity field of the HVC matter but not a physical link between both cloud species. Our aim was to compile a complete table of head-tail structures towards the prominent HVC complexes. In total we found 42 HVCs with head-tail structure. We analysed the head-tail structures in statistical sense with respect to the physical parameters, like position, velocity (vLSR, vGSR) and column density. Moreover, we performed a first approach to derive the orientation of the unprojected velocity vector of the individual HVCs. Our finding may help to investigate the HVC phenomenon further, with respect to the recently detected soft X-ray and {H alpha} emission.

Bruens, C.

364

Long-term stabilization of uranium mill tailings  

SciTech Connect

The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%.

Voorhees, L.D.; Sale, M.J.; Webb, J.W.; Mulholland, P.J.

1983-01-01

365

Tail venting for enhanced yaw damping at spinning conditions  

NASA Technical Reports Server (NTRS)

An investigation was conducted in the NASA Langley 20-ft Vertical Spin Tunnel to determine the spin and spin-recovery characteristics of a 1/11-scale model of a low-wing general aviation airplane with a horizontal tail modified with variable-size gaps to allow ventilation of the vertical stabilizer and rudder. Erect spins at symmetric loadings were tested with varying gap sizes on either or both sides of the horizontal tail. The model results indicate that the basic airplane (with no gaps) exhibits a fast, flat spin from which no recoveries can be obtained. The airplane with the modified tail has either a fast, flat spin from which no recoveries or poor recoveries may be made, or a slower, steeper spin from which fair to excellent recoveries may be obtained, depending on the size and orientation of the tail gaps. The major contribution to spin recovery was from the gap on the leeward side of the tail. Gap widths of 15-25 percent of the tail semispan were needed to produce satisfactory recovery from the flat spin.

Stough, H. P., III; Whipple, Raymond D.; Fremaux, C. M.

1991-01-01

366

Auroral counterpart of magnetic field dipolarizations in Saturn's tail  

NASA Astrophysics Data System (ADS)

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations are initially identified in magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially stretched configuration to a more dipolar field topology. The highly stretched geometry of the kronian magnetotail lobes gives rise to a tail current which flows eastward (dusk to dawn) in the near equatorial plane across the centre of the tail. During reconnection and associated dipolarization of the field, the inner edge of this tail current can be diverted through the ionosphere, in a situation analogous to the substorm current wedge picture at Earth. We present a picture of the current circuit arising from this tail reconfiguration, and outline the equations which govern the fieldcurrent relationship. We show the first in situ example of a dipolarization identified in the Cassini magnetometer data and use this formalism to estimate the ionospheric current density that would arise for this example and the implications for auroral electron acceleration in regions of upward directed field-aligned current. We then present a separate example of data from the Cassini UVIS instrument where we observe small 'spots' of auroral emission lying near the main oval; features suggested to be associated with dipolarizations in the tail. In the example shown, such auroral features are the precursor to more intense activity associated with recurrent energisation via particle injections from the tail following reconnection.

Jackman, C. M.; Achilleos, N.; Cowley, S. W. H.; Bunce, E. J.; Radioti, A.; Grodent, D.; Badman, S. V.; Dougherty, M. K.; Pryor, W.

2012-09-01

367

Effect of Dynamic Rolling Oscillations on Twin Tail Buffet Response  

NASA Technical Reports Server (NTRS)

The effect of dynamic rolling oscillations of delta-wing/twin-tail configuration on twin-tail buffet response is investigated. The computational model consists of a sharp-edged delta wing of aspect ratio one and swept-back flexible twin tail with taper ratio of 0.23. The configuration model is statically pitched at 30 deg. angle of attack and then forced to oscillate in roll around the symmetry axis at a constant amplitude of 4 deg. and reduced frequency of pi and 2(pi). The freestream Mach number and Reynolds number are 0.3 and 1.25 million, respectively. This multidisciplinary problem is solved using three sets of equations on a dynamic multi-block grid structure. The first set is the unsteady, full Navier-Stokes equations, the second set is the aeroelastic equations for coupled bending and torsion vibrations of the tails, and the third set is the grid-displacement equations. The configuration is investigated for inboard position of the twin tails which corresponds to a separation distance between the twin tails of 33% wing span. The computed results are compared with the results of stationary configuration, which previously have been validated using experimental data. The results conclusively showed that the rolling oscillations of the configuration have led to higher loads, higher deflections, and higher excitation peaks than those of the stationary configuration. Moreover, increasing the reduced frequency has led to higher loads and excitation peaks and lower bending and torsion deflections and acceleration.

Sheta, Essam F.; Kandil, Osama A.

1999-01-01

368

Arsenic bioaccessibility in gold mine tailings of Delita, Cuba.  

PubMed

A bioaccessibility test was carried out in four tailings collected at a former mining area in Delita, Cuba. A previous risk assessment study identified arsenic (As) as the main critical contaminant in this area and showed that the tailings had high As concentrations (up to 3.5%). This study aimed at: (i) evaluating As bioaccessibility in four tailings (R1, R2, R3 and R4) from a gold mining area to obtain a better health risk estimate; and, (ii) identifying the mineral phases responsible for most of the bioaccessible As using XRD, SEM-EDS, and XAS. The results showed that bioaccessible As in the tailings ranged from 0.65 to 40.5%. The main factors influencing As bioaccessibility were a high occurrence of amorphous iron arsenate; occurrence, even at low content, of iron oxyhydroxides and stability of mineral phases in the environment of the gastrointestinal tract. Although arsenopyrite, arsenates and goethite were confirmed by mineralogical methods such as optical microscopy, XRD, and SEM-EDS, XAS showed that scorodite-oxidation state As(+V)-was dominant in most of the tailings. This confirms that the low bioaccessibility of As in most of the tailings is due to the slow kinetics of As release from scorodite. PMID:23428178

Toujaguez, R; Ono, F B; Martins, V; Cabrera, P P; Blanco, A V; Bundschuh, J; Guilherme, L R G

2013-11-15

369

Rare-earth occurrences in the Pea Ridge tailings  

SciTech Connect

Tailings from the Pea Ridge iron mine contain significant amounts of apatite, which has rare-earth element values associated with it. In association with the recovery of rare-earth minerals as a secondary resource, the US Bureau of Mines conducted an investigation on the recoverability of the rare-earth minerals from the tailings. The mill tailings were subjected to a phosphate flotation to separate the apatite from other constituents. More than 70-pct recovery of the rare-earth values was achieved. Based on mineralogical characterization and prior analysis of rare-earth-bearing breccia pipe material at Pea Ridge, it is proposed that processing this phosphate concentrate on a vanner table would yield up to a 95-pct recovery of the rare earths in the concentrate, with the apatite reporting to the tailings. Intensive ore microscopy studies of the original tailings to the flotation products led to the identification of monazite, xenotime, and rare-earth-enriched apatite as the major rare-earth-bearing minerals in the tailings.

Vierrether, C.W.; Cornell, W.I.

1993-01-01

370

Survival of Columbian white-tailed deer in western Oregon  

USGS Publications Warehouse

Columbian white-tailed deer (Odocoileus virginianus leucurus; CWTD) are an endangered subspecies on which little demographic information exists. We determined survival rates and causes of mortality for 64 radiocollared adults from 1996 to 1998, and for 63 radiocollared neonatal fawns during the summer and fall months of 1996-2001 in Douglas County, Oregon, USA. Annual adult survival rates averaged 0.74 over 3 years, and most mortality (73%) occurred between fall and winter. Seasonal survival was lowest (0.75) for the fall-winter 1997-1998, and was ???0.90 during all spring-summer periods. Annual and seasonal survival rates did not differ by gender. Average annual survival was 0.77 for deer in wildland areas compared with 0.66 for deer in suburban areas, but these differences were not consistent between years and seasons. Survival over the entire 3-year study was low (0.38). Eight deer died from a combination of emaciation and disease, and almost all (92%) necropsied deer were in poor body condition. Fawn survival to 7 months was low (0.14, 95% CI = 0.02-0.26) and declined most rapidly during the first 1.5 months of life. Predation (n = 21) and abandonment (n = 6) were the most frequent known causes of death for fawns. Our results suggest that CWTD may have responded to density-dependent factors during this short-term study, although the effects of other environmental or intrinsic factors cannot be ignored. Fawn survival may be insufficient to produce enough recruits for population growth and eventual range expansion.

Ricca, M. A.; Anthony, R. G.; Jackson, D. H.; Wolfe, S. A.

2002-01-01

371

Tailward propagating cross-tail current disruption and dynamics of near-earth tail - A multi-point measurement analysis  

Microsoft Academic Search

Plasma and magnetic field data taken simultaneously in the near-earth plasma sheet aboard GEOS-2, ISEE-1, and ISEE-2, are used to infer directly the location and tailward propagation velocity of the partial cross-tail current disruption associated with a well-defined substorm. This study shows that the disruption starts at 6-9 earth radii and propagates down the tail with a velocity of the

C. Jacquey; J. A. Sauvaud; J. Dandouras; A. Korth

1993-01-01

372

Tailward propagating cross-tail current disruption and dynamics of near-Earth Tail: A multi-point measurement analysis  

Microsoft Academic Search

Plasma and magnetic field data taken simultaneously in the near-Earth plasma sheet (6.6–13 RE) aboard three satellites, GEOS-2, ISEE-1, and ISEE-2, are used to infer directly the location and tailward propagation velocity of the partial cross-tail current disruption associated with a well-defined substorm. This study shows that the disruption starts at 6–9 RE and propagates down the tail with a

C. Jacquey; J. A. Sauvaud; J. Dandouras; A. Korth

1993-01-01

373

Revegetation of coarse taconite iron ore tailing using municipal solid waste compost  

Microsoft Academic Search

On Minnesota's Mesabi Iron Range, coarse taconite iron ore tailing is often used as the principal material in the construction of dams for large tailing impoundments. Mineland reclamation rules in Minnesota require that tailing dams be vegetated to control erosion for dam stability and safety. Coarse taconite iron ore tailing is characterized chemically by an alkaline pH, low organic matter

Michael R. Norland; David L. Veith

1995-01-01

374

Evaluation of chemical stabilizers and windscreens for wind erosion control of uranium mill tailings  

Microsoft Academic Search

Potential wind erosion of uranium mill tailings is a concern for the surface disposal of tailings at uranium mills. Wind-blown tailings may subsequently be redeposited on areas outside the impoundment. Pacific Northwest Laboratory (PNL) is investigating techniques for fugitive dust control at uranium mill tailings piles. Laboratory tests, including wind tunnel studies, were conducted to evaluate the relative effectiveness of

M. R. Elmore; J. N. Hartley

1984-01-01

375

Stability analysis of a copper tailings dam via laboratory model tests: A Chinese case study  

Microsoft Academic Search

The upstream method is a popular method for raising tailings dams. Currently in China there are more than 12,000 tailings impoundments and almost 95% of them use the upstream method for the construction of the dam. Statistical data has shown that the tailings impoundment is one of the main sources of risk in the mining industry. Failures of tailings impoundments

Guangzhi Yin; Guangzhi Li; Zuoan Wei; Ling Wan; Guohong Shui; Xiaofei Jing

2011-01-01

376

Energetic cost of tail streamers in the barn swallow ( Hirundo rustica )  

Microsoft Academic Search

Different hypotheses stress the importance of natural or sexual selection to explain the evolution and maintenance of long outermost tail feathers in the barn swallow (Hirundo rustica). Since energy costs are predicted to arise from tail length manipulation, we measured the daily energy expenditure in three experimental groups (tail-shortened, tail-elongated, and control birds) with the doubly labelled water technique. Though

José Javier Cuervo; Florentino Lope; Anders Pape Møller; Juan Moreno

1996-01-01

377

Pedological characteristics of Mn mine tailings and metal accumulation by native plants  

Microsoft Academic Search

In southern China revegetation and ecological restoration of many abandoned Mn tailings has become a major concern. To determine the major constraints for plant establishment and evaluate the feasibility of remediation, a comparative study was conducted on Mn tailings and rhizosphere soils at the boundary of the tailings pond. Both tailings and rhizosphere soils had neutral to slightly alkaline pH

Xin Wang; Yunguo Liu; Guangming Zeng; Liyuan Chai; Xin Xiao; Xiaochen Song; Zongyi Min

2008-01-01

378

Safety Comprehensive Assessment of Tailing Reservior Based on Information Entropy and Fuzzy Mathematics  

Microsoft Academic Search

The tailing reservoir is a large dangerous source of man-made mud-rock flow with high potential energy, and the loss caused by tailing disaster is considerably serious. Some basic theories of fuzzy mathematics are illustrated in this paper. In allusion to the present situation of tailing reservoir assessment, this method is tried to apply in safety comprehensive assessment of tailing reservoir.

Chundi Si; Enli Chen; Lv Peng

2008-01-01

379

Uranium mill tailings management: cover systems, containment migration and long-term stability  

Microsoft Academic Search

Uranium mill tailings, waste products of uranium extraction, contain hazardous constituents that if released into the atmosphere and groundwater could threaten our health and environment. To provide for safe disposal and control of these tailings, Congress enacted the Uranium Mill Tailings Radiation Control Act of 1978 (Public Law 95-604). Subsequently, the Environmental Protection Agency (EPA) established standards for tailings disposal

J. N. Hartley; M. G. Fluey; G. W. Gee

1984-01-01

380

Experimental Infection of Rhesus and Pig-Tailed Macaques with Macaque Rhadinoviruses  

PubMed Central

The recognition of naturally occurring rhadinoviruses in macaque monkeys has spurred interest in their use as models for human infection with Kaposi sarcoma-associated herpesvirus (human herpesvirus 8). Rhesus macaques (Macaca mulatta) and pig-tailed macaques (Macaca nemestrina) were inoculated intravenously with rhadinovirus isolates derived from these species (rhesus rhadinovirus [RRV] and pig-tailed rhadinovirus [PRV]). Nine rhadinovirus antibody-negative and two rhadinovirus antibody-positive monkeys were used for these experimental inoculations. Antibody-negative animals clearly became infected following virus inoculation since they developed persisting antibody responses to virus and virus was isolated from peripheral blood on repeated occasions following inoculation. Viral sequences were also detected by PCR in lymph node, oral mucosa, skin, and peripheral blood mononuclear cells following inoculation. Experimentally infected animals developed peripheral lymphadenopathy which resolved by 12 weeks following inoculation, and these animals have subsequently remained free of disease. No increased pathogenicity was apparent from cross-species infection, i.e., inoculation of rhesus macaques with PRV or of pig-tailed macaques with RRV, whether the animals were antibody positive or negative at the time of virus inoculation. Coinoculation of additional rhesus monkeys with simian immunodeficiency virus (SIV) isolate SIVmac251 and macaque-derived rhadinovirus resulted in an attenuated antibody response to both agents and shorter mean survival compared to SIVmac251-inoculated controls (155.5 days versus 560.1 days; P < 0.019). Coinfected and immunodeficient macaques died of a variety of opportunistic infections characteristic of simian AIDS. PCR analysis of sorted peripheral blood mononuclear cells indicated a preferential tropism of RRV for CD20+ B lymphocytes. Our results demonstrate persistent infection of macaque monkeys with RRV and PRV following experimental inoculation, but no specific disease was readily apparent from these infections even in the context of concurrent SIV infection.

Mansfield, Keith G.; Westmoreland, Susan V.; DeBakker, Colin D.; Czajak, Susan; Lackner, Andrew A.; Desrosiers, Ronald C.

1999-01-01

381

Longitudinal assessment of in vivo bone dynamics in a mouse tail model of postmenopausal osteoporosis.  

PubMed

Recently, it has been shown that transient bone biology can be observed in vivo using time-lapse micro-computed tomography (?CT) in the mouse tail bone. Nevertheless, in order for the mouse tail bone to be a model for human disease, the hallmarks of any disease must be mimicked. The aim of this study was to investigate whether postmenopausal osteoporosis could be modeled in caudal vertebrae of C57Bl/6 mice, considering static and dynamic bone morphometry as well as mechanical properties, and to describe temporal changes in bone remodeling rates. Twenty C57Bl/6 mice were ovariectomized (OVX, n = 11) or sham-operated (SHM, n = 9) and monitored with in vivo ?CT on the day of surgery and every 2 weeks after, up to 12 weeks. There was a significant decrease in bone volume fraction for OVX (-35%) compared to SHM (+16%) in trabecular bone (P < 0.001). For OVX, high-turnover bone loss was observed, with the bone resorption rate exceeding the bone formation rate (P < 0.001). Furthermore there was a significant decrease in whole-bone stiffness for OVX (-16%) compared to SHM (+11%, P < 0.001). From these results we conclude that the mouse tail vertebra mimics postmenopausal bone loss with respect to these parameters and therefore might be a suitable model for postmenopausal osteoporosis. When evaluating temporal changes in remodeling rates, we found that OVX caused an immediate increase in bone resorption rate (P < 0.001) and a delayed increase in bone formation rate (P < 0.001). Monitoring transient bone biology is a promising method for future research. PMID:22159822

Lambers, Floor M; Kuhn, Gisela; Schulte, Friederike A; Koch, Kathleen; Müller, Ralph

2012-02-01

382

Disease control operations  

USGS Publications Warehouse

Individual disease outbreaks have killed many thousands of animals on numerous occasions. Tens of thousands of migratory birds have died in single die-offs with as many as 1,000 birds succumbing in 1 day. In mammals, individual disease outbreaks have killed hundreds to thousands of animals with, for example, hemorrhagic disease in white-tailed deer, distemper in raccoon, Errington's disease in muskrat, and sylvatic plague in wild rodents. The ability to successfully combat such explosive situations is highly dependent n the readiness of field personnel to deal with them. Because many disease agents can spread though wildlife populations very fast, advance preparation is essential in preventing infected animals from spreading disease to additional species and locations. Carefully though-out disease contingency plans should be developed as practical working documents for field personnel and updated as necessary. Such well-designed plans can prove invaluable in minimizing wildlife losses and costs associated with disease control activities. Although requirements for disease control operations vary and must be tailored to each situation, all disease contingency planning involved general concepts and basic biological information. This chapter, intended as a practical guide, identifies the major activities and needs of disease control operations, and relates them to disease contingency planning.

Friend, Milton; Franson, J. Christian

1987-01-01

383

Effects of aerodynamic interaction between main and tail rotors on helicopter hover performance and noise  

NASA Technical Reports Server (NTRS)

A model test was conducted to determine the effects of aerodynamic interaction between main rotor, tail rotor, and vertical fin on helicopter performance and noise in hover out of ground effect. The experimental data were obtained from hover tests performed with a .151 scale Model 222 main rotor, tail rotor and vertical fin. Of primary interest was the effect of location of the tail rotor with respect to the main rotor. Penalties on main rotor power due to interaction with the tail rotor ranged up to 3% depending upon tail rotor location and orientation. Penalties on tail rotor power due to fin blockage alone ranged up to 10% for pusher tail rotors and up to 50% for tractor tail rotors. The main rotor wake had only a second order effect on these tail rotor/fin interactions. Design charts are presented showing the penalties on main rotor power as a function of the relative location of the tail rotor.

Menger, R. P.; Wood, T. L.; Brieger, J. T.

1983-01-01

384

Salmonid Whirling Disease  

USGS Publications Warehouse

Whirling disease is a parasitic infection of trout and salmon by the myxosporean protozoan Myxobolus cerebralis (Syn. Myxosoma cerebralis). This parasite has selective tropism for cartilage; infection can cause deformities of the axial skeleton and neural damage that results in 'blacktail.' The disease is named for the erratic, tail-chasing, 'whirling' in young fish that are startled or fed. Heavy infection of young fish can result in high mortalities or unmarketable, deformed individuals. Although the parasite was first reported in 1903 in central Europe (Hofer 1903), its complete life cycle was not described until the early 1980's.

Markiw, Maria E.

1992-01-01

385

Slow inward tail currents in rabbit cardiac cells.  

PubMed Central

1. A whole-cell gigaseal suction microelectrode voltage-clamp technique has been used to study slow inward tail currents in single myocytes obtained by enzymatic dispersion of rabbit ventricle and atrium. A variety of stimulation protocols, Tyrode solutions and pharmacological agents have been used to test three hypotheses: (a) that the slow inward tail current is generated by an electrogenic Na(+)-Ca2+ exchanger; (b) that a rise in [Ca2+]i, due to release from the sarcoplasmic reticulum can modulate the activity of this exchanger; and (c) that the uptake of calcium by the sarcoplasmic reticulum is a major determinant of the time course of the tail current. 2. As shown previously in amphibian atrium and guinea-pig ventricle, slow inward tail currents can be observed consistently under conditions in which action potentials and ionic currents are recorded using microelectrode constituents which only minimally disturb the intracellular milieu. 3. In ventricular cells, the envelope of these tail currents obtained by varying the duration of the preceding depolarizations shows that (a) the tail currents are activated by pulses as short as 10 ms, and reach a maximum for pulse durations of 100-200 ms, (b) the rate of decay of the tail current gradually increases as the activating depolarizations are prolonged, and (c) the tails cannot be due to deactivation of calcium currents, in agreement with other studies in frog heart. 4. When the mean level of [Ca2+]i is raised following inhibition of the Na(+)-K+ pump by strophanthidin (10(-5) M) or reductions in [K+]o (0.5 mM), the slow inward tail grows in size prior to the onset of a contracture or other signs of calcium-induced toxicity. 5. In a number of different preparations, replacement of [Ca2+]o with BaCl2 markedly or completely inhibits the Na(+)-Ca2+ exchanger, whereas Sr2+ replacement does not have this effect. In myocytes from rabbit ventricle the slow inward tails are reduced significantly and decay more slowly in 0.5-2.2 mM-BaCl2 Tyrode solution, while in 2.2 mM SrCl2 these tails are not altered. 6. The slow inward tail also shows a dependence on [K+]o, corresponding to previous data on Na(+)-Ca2+ exchange in other tissues. Increasing [K+]o in the Tyrode solution to a final concentration of 10-15 mM results in a marked inhibition of the slow tails. This effect cannot be accounted for by changes in the inwardly rectifying potassium current, IK1. 7. The slow tail currents were changed significantly by increasing the temperature of the superfusing Tyrode solution.(ABSTRACT TRUNCATED AT 400 WORDS)

Giles, W; Shimoni, Y

1989-01-01

386

Research on the Characterization and Conditioning of Uranium Mill Tailings. Volume 1. I. Characterization and Leaching Behavior of Uranium Mill Tailings.  

National Technical Information Service (NTIS)

The goal of these studies on tailings characterization was to determine the mineralogical and elemental composition of various tailings materials, as well as to evaluate their contaminant leachability and radon emanation properties. Extreme variability wi...

D. R. Dreesen M. E. Bunker E. J. Cokal M. M. Denton J. W. Starner

1983-01-01

387

The Tail-Elicited Tail Withdrawal Reflex of "Aplysia" Is Mediated Centrally at Tail Sensory-Motor Synapses and Exhibits Sensitization across Multiple Temporal Domains  

ERIC Educational Resources Information Center

The defensive withdrawal reflexes of "Aplysia californica" have provided powerful behavioral systems for studying the cellular and molecular basis of memory formation. Among these reflexes the (T-TWR) has been especially useful. In vitro studies examining the monosynaptic circuit for the T-TWR, the tail sensory-motor (SN-MN) synapses, have…

Philips, Gary T.; Sherff, Carolyn M.; Menges, Steven A.; Carew, Thomas J.

2011-01-01

388

On near-tail bubble penetration into geosynchronous altitude  

NASA Astrophysics Data System (ADS)

Dipolarization of the magnetic field at the near-Earth tail is usually associated with the local reduction of pV5/3 compared to that of the background, where p is the plasma pressure and V is the volume of the unit magnetic flux tube. This can be interpreted as a bubble, which can propagate earthward by the interchange process. How deep such a bubble can penetrate earthward, and what is the critical factor are critical questions that need to be answered. In this paper, we examine these issues by comparing near-tail observations by inner probes of THEMIS with geosynchronous magnetic observations by GOES. We identified a number of bubble events associated with near-tail dipolarization, which we call “tail bubble,” and checked geosynchronous disturbances. We find a statistical trend that geosynchronous disturbance is more likely to occur when associated with (or when hit by) an earthward moving tail bubble with a more-depleted pV5/3. We estimated the background pV5/3 profile statistically and used it to determine expected equilibrium (or stop) positions for earthward moving bubbles where the bubble's pV5/3 is equal to that of the background. Statistically, we find that the equilibrium position is more inward for tail bubbles with a lower pV5/3, for which the probability of causing geosynchronous disturbance is higher. For example, the probability of a tail bubble being associated with geosynchronous disturbance is 75% if the bubble's equilibrium position is <8 RE. However, for all the events studied here, the bubble equilibrium positions are still outside the geosynchronous altitude. Although this result may be subject to change due to the uncertainty in estimating pV5/3 and the limited number of the events identified near geosynchronous altitude, we suggest that an overshooting of the penetrating bubbles beyond equilibrium positions is a possible explanation.

Kim, H.-S.; Lee, D.-Y.; Ohtani, S.; Park, M.-Y.; Ahn, B.-H.

2012-07-01

389

Structural cooperativity in histone H3 tail modifications  

PubMed Central

Post-translational modifications of histone H3 tails have crucial roles in regulation of cellular processes. There is cross-regulation between the modifications of K4, K9, and K14 residues. The modifications on these residues drastically promote or inhibit each other. In this work, we studied the structural changes of the histone H3 tail originating from the three most important modifications; tri-methylation of K4 and K9, and acetylation of K14. We performed extensive molecular dynamics simulations of four types of H3 tails: (i) the unmodified H3 tail having no chemical modification on the residues, (ii) the tri-methylated lysine 4 and lysine 9 H3 tail (K4me3K9me3), (iii) the tri-methylated lysine 4 and acetylated lysine 14 H3 tail (K4me3K14ace), and (iv) tri-methylated lysine 9 and acetylated lysine 14 H3 tail (K9me3K14ace). Here, we report the effects of K4, K9, and K14 modifications on the backbone torsion angles and relate these changes to the recognition and binding of histone modifying enzymes. According to the Ramachandran plot analysis; (i) the dihedral angles of K4 residue are significantly affected by the addition of three methyl groups on this residue regardless of the second modification, (ii) the dihedral angle values of K9 residue are similarly altered majorly by the tri-methylation of K4 residue, (iii) different combinations of modifications (tri-methylation of K4 and K9, and acetylation of K14) have different influences on phi and psi values of K14 residue. Finally, we discuss the consequences of these results on the binding modes and specificity of the histone modifying enzymes such as DIM-5, GCN5, and JMJD2A.

Sanli, Deniz; Keskin, Ozlem; Gursoy, Attila; Erman, Burak

2011-01-01

390

Structural cooperativity in histone H3 tail modifications.  

PubMed

Post-translational modifications of histone H3 tails have crucial roles in regulation of cellular processes. There is cross-regulation between the modifications of K4, K9, and K14 residues. The modifications on these residues drastically promote or inhibit each other. In this work, we studied the structural changes of the histone H3 tail originating from the three most important modifications; tri-methylation of K4 and K9, and acetylation of K14. We performed extensive molecular dynamics simulations of four types of H3 tails: (i) the unmodified H3 tail having no chemical modification on the residues, (ii) the tri-methylated lysine 4 and lysine 9 H3 tail (K4me3K9me3), (iii) the tri-methylated lysine 4 and acetylated lysine 14 H3 tail (K4me3K14ace), and (iv) tri-methylated lysine 9 and acetylated lysine 14 H3 tail (K9me3K14ace). Here, we report the effects of K4, K9, and K14 modifications on the backbone torsion angles and relate these changes to the recognition and binding of histone modifying enzymes. According to the Ramachandran plot analysis; (i) the dihedral angles of K4 residue are significantly affected by the addition of three methyl groups on this residue regardless of the second modification, (ii) the dihedral angle values of K9 residue are similarly altered majorly by the tri-methylation of K4 residue, (iii) different combinations of modifications (tri-methylation of K4 and K9, and acetylation of K14) have different influences on phi and psi values of K14 residue. Finally, we discuss the consequences of these results on the binding modes and specificity of the histone modifying enzymes such as DIM-5, GCN5, and JMJD2A. PMID:21956975

Sanli, Deniz; Keskin, Ozlem; Gursoy, Attila; Erman, Burak

2011-12-01

391

Auroral counterpart of magnetic field dipolarizations in Saturn's tail  

NASA Astrophysics Data System (ADS)

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations can be initially identified in magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially stretched configuration to a more dipolar field topology. The highly stretched geometry of the kronian magnetotail lobes gives rise to a tail current which flows eastward (dusk to dawn) in the near equatorial plane across the centre of the tail. During reconnection and associated dipolarization of the field, the inner edge of this tail current can be diverted through the ionosphere, in a situation analogous to the substorm current wedge picture at Earth. We present a picture of the current circuit arising from this tail reconfiguration, and outline the equations which govern the field-current relationship. We show an example of a dipolarization identified in the Cassini magnetometer data and use this formalism to constrain the ionospheric current density that would arise for this example and the implications for auroral electron acceleration in regions of upward directed field-aligned current. We then present a separate example of data from the Cassini UVIS instrument where we observe small 'spots' of auroral emission lying near the main oval; features thought to be associated with dipolarizations in the tail. In the example shown, such auroral spots are the precursor to more intense activity associated with recurrent energisation via particle injections from the tail following reconnection. We conclude that dipolarizations in Saturn's magnetotail have an observable auroral counterpart, opening up the possibility to search for further examples and to use this auroral property as a remote proxy for tail reconnection.

Jackman, C. M.; Badman, S. V.; Achilleos, N.; Bunce, E. J.; Cowley, S. W. H.; Radioti, A.; Grodent, D.; Dougherty, M. K.; Pryor, W.

2012-04-01

392

Auroral counterpart of magnetic field dipolarizations in Saturn's tail  

NASA Astrophysics Data System (ADS)

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations are initially identified in magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially stretched configuration to a more dipolar field topology. The highly stretched geometry of the kronian magnetotail lobes gives rise to a tail current which flows eastward (dusk to dawn) in the near equatorial plane across the centre of the tail. During reconnection and associated dipolarization of the field, the inner edge of this tail current can be diverted through the ionosphere, in a situation analogous to the substorm current wedge picture at Earth. We present a picture of the current circuit arising from this tail reconfiguration, and outline the equations which describe the field-current relationship. We show a new in situ example of a dipolarization identified in the Cassini magnetometer data and use this formalism to estimate the ionospheric current density that would arise based on in situ tail measurements of the magnetic field and the implications for corresponding auroral electron acceleration in regions of upward directed field-aligned current. We then present a separate example of data from the Cassini UVIS instrument where we observe small 'spots' of auroral emission lying near the main oval; features suggested to be associated with dipolarizations in the tail. In the example shown, such auroral features are the precursor to more intense activity associated with recurrent energisation via particle injections from the tail following reconnection.

Jackman, Caitriona M.; Achilleos, Nick; Cowley, Stanley W. H.; Bunce, Emma J.; Radioti, Aikaterini; Grodent, Denis; Badman, Sarah V.; Dougherty, Michele K.; Pryor, Wayne

2013-07-01

393

Atomic Structure of Bacteriophage Sf6 Tail Needle Knob*  

PubMed Central

Podoviridae are double-stranded DNA bacteriophages that use short, non-contractile tails to adsorb to the host cell surface. Within the tail apparatus of P22-like phages, a dedicated fiber known as the “tail needle” likely functions as a cell envelope-penetrating device to promote ejection of viral DNA inside the host. In Sf6, a P22-like phage that infects Shigella flexneri, the tail needle presents a C-terminal globular knob. This knob, absent in phage P22 but shared in other members of the P22-like genus, represents the outermost exposed tip of the virion that contacts the host cell surface. Here, we report a crystal structure of the Sf6 tail needle knob determined at 1.0 ? resolution. The structure reveals a trimeric globular domain of the TNF fold structurally superimposable with that of the tail-less phage PRD1 spike protein P5 and the adenovirus knob, domains that in both viruses function in receptor binding. However, P22-like phages are not known to utilize a protein receptor and are thought to directly penetrate the host surface. At 1.0 ? resolution, we identified three equivalents of l-glutamic acid (l-Glu) bound to each subunit interface. Although intimately bound to the protein, l-Glu does not increase the structural stability of the trimer nor it affects its ability to self-trimerize in vitro. In analogy to P22 gp26, we suggest the tail needle of phage Sf6 is ejected through the bacterial cell envelope during infection and its C-terminal knob is threaded through peptidoglycan pores formed by glycan strands.

Bhardwaj, Anshul; Molineux, Ian J.; Casjens, Sherwood R.; Cingolani, Gino

2011-01-01

394

Effect of Horizontal-Tail Chord on the Calculated Subsonic Span Loads and Stability Derivatives of Isolated Unswept Tail Assemblies in Sideslip and Steady Roll  

NASA Technical Reports Server (NTRS)

Subsonic span loads and the resulting stability derivatives have been calculated using the discrete-horseshoe-vortex method for a systematic series of horizontal tails in combination with a vertical tail of aspect ratio 1.0 in order to provide information on the effect of varying the chord of the horizontal tail for isolated tail assemblies performing sideslip and steady-roll motions. In addition, the effects of horizontal-tail dihedral angle for the sideslip case were obtained. Each tail surface considered had a taper ratio of 0.5 and an unswept quarter-chord line. The investigation covered variations in horizontal-tail chord, horizontal-tail span, and vertical location of the horizontal tail. The span loads and the resulting total stability derivatives as well as the vertical- and horizontal-tail contributions to these tail-assembly derivatives are presented in the figures for the purpose of showing the influence of the geometric variables. The results of this investigation showed trends that were in agreement with the results of previous investigations for variations in horizontal-tail span and vertical location of the horizontal tail. Variations in horizontal-tail chord expressed herein in terms of the root-chord ratio, that is, the ratio of horizontal-tail root chord to vertical-tail root chord, were found to have a pronounced influence on most of the span loads and the resulting stability derivatives. For most of the cases considered, the rate of change of the span load coefficients and the stability derivatives with the root-chord ratio was found to be a maximum for small values of root-chord ratio and to decrease as root-chord ratio increased.

Booth, Katherine W.

1959-01-01

395

Long-Term Performance of Uranium Tailings Disposal Cells - 13340  

SciTech Connect

Recently, there has been interest in the performance and evolution of Uranium Mill Tailings Remedial Action (UMTRA) Project disposal cell covers because some sites are not compliant with groundwater standards. Field observations of UMTRA disposal cells indicate that rock covers tend to become vegetated and that saturated conductivities in the upper portion of radon barriers may increase due to freeze/thaw cycles and biointrusion. This paper describes the results of modeling that addresses whether these potential changes and transient drainage of moisture in the tailings affect overall performance of the disposal cells. A numerical unsaturated/saturated 3-dimensional flow model was used to simulate whether increases in saturated conductivities in radon barriers with rock covers affect the overall performance of the disposal cells using field data from the Shiprock, NM, UMTRA site. A unique modeling approach allowed simulation with daily climatic conditions to determine changes in moisture and moisture flux from the disposal cell. Modeling results indicated that increases in the saturated conductivity at the top of radon barrier do not influence flux from the tailings with time because the tailings behave similar hydraulically to the radon barrier. The presence of a thin layer of low conductivity material anywhere in the cover or tailings restricts flux in the worst case to the saturated conductivity of that material. Where materials are unsaturated at depth within the radon barrier of tailings slimes, conductivities are typically less than 10{sup -8} centimeters per second. If the low conductivity layer is deep within the disposal cell, its saturated properties are less likely to change with time. The significance of this modeling is that operation and maintenance of the disposal cells can be minimized if they are allowed to progress to a natural condition with some vegetation and soil genesis. Because the covers and underlying tailings have a very low saturated hydraulic conductivity after transient drainage, eventually the amount of moisture leaving the tailings has a negligible effect on groundwater quality. Although some of the UMTRA sites are not in compliance with the groundwater standards, the explanation may be legacy contamination from mining, or earlier higher fluxes from the tailings or unlined processing ponds. Investigation of other legacy sources at the UMTRA sites may help explain persistent groundwater contamination. (authors)

Bostick, Kent; Daniel, Anamary; Pill, Ken [Professional Project Services, Inc., 1100 Bethel Valley Road, Oak Ridge, TN, 37922 (United States)] [Professional Project Services, Inc., 1100 Bethel Valley Road, Oak Ridge, TN, 37922 (United States); Tachiev, Georgio; Noosai, Nantaporn; Villamizar, Viviana [Florida International University, 10555 W. Flagler St., EC 2100, Miami FL, 33174 (United States)] [Florida International University, 10555 W. Flagler St., EC 2100, Miami FL, 33174 (United States)

2013-07-01

396

Discovery of the Dust Tail of Asteroid (3200) Phaethon  

NASA Astrophysics Data System (ADS)

We report the discovery of a comet-like tail on asteroid (3200) Phaethon when imaged at optical wavelengths near perihelion. In both 2009 and 2012, the tail appears about 350?? (2.5 × 10^8 m) in length and extends approximately in the projected anti-solar direction. We interpret the tail as being caused by dust particles accelerated by solar radiation pressure. The sudden appearance and the morphology of the tail indicate that the dust particles are small, with an effective radius of 1 micron and a combined mass about 3 × 10^5 kg. These particles are likely products of thermal fracture and/or desiccation cracking under the very high (1000K) surface temperatures experienced by Phaethon at perihelion. The existence of the tail confirms our earlier inferences about activity in this body based on the detection of anomalous brightening. Phaethon, the presumed source of the Geminid meteoroids, is still active. The relation between the observed particles and those constituting the Geminid meteoroid stream will be discussed.

Jewitt, David; Li, J.; Agarwal, J.

2013-10-01

397

Design plans for an inexpensive tail flick analgesia meter.  

PubMed

While the pedagogical benefits of incorporating inquiry driven labs into an undergraduate curriculum are well established, often the prohibitive costs of providing equipment for such labs limits the types of experiences that can be offered. For example, the lab portion of Advanced Neuroscience at Centenary College of Louisiana consists of a semester-long research project developed by the students. Frequently, these junior- and senior-level students generate interesting research questions that must be culled or scaled back simply due to a lack of appropriate equipment. In the most recent iteration of the class, the students wanted to examine analgesia using the tail flick test, a measure of spinal nociception. In this test a rodent subject is restrained; its tail is exposed to a heat source; and the latency to flick its tail away from the noxious stimuli is recorded. As commercial devices were far beyond the lab budget, we sought to develop an inexpensive tail flick analgesia meter that was easy to use and generated reliable data. The prototype device was tested by students in the above-mentioned class and was found to consistently produce reliable data in agreement with the literature. Here we present plans for a tail flick analgesia meter that can be constructed for $50-75, roughly 100 times cheaper than commercial devices. PMID:23626497

Otto, Aaron; Butcher, Greg Q; Messina, Troy C

2011-01-01

398

Liner evaluation for uranium mill tailings. Final report  

SciTech Connect

The Liner Evaluation for Uranium Mill Tailings Program was conducted to evaluate the need for and performance of prospective lining materials for the long-term management of inactive uranium mill tailings piles. On the basis of program results, two materials have been identified: natural foundation soil amended with 10% sodium bentonite; catalytic airblown asphalt membrane. The study showed that, for most situations, calcareous soils typical of Western US sites adequately buffer tailings leachates and prevent groundwater contamination without additional liner materials or amendments. Although mathematical modeling of disposal sites is recommended on a site-specific basis, there appears to be no reason to expect significant infiltration through the cover for most Western sites. The major water source through the tailings would be groundwater movement at sites with shallow groundwater tables. Even so column leaching studies showed that contaminant source terms were reduced to near maximum contaminant levels (MCL's) for drinking water within one or two pore volumes; thus, a limited source term for groundwater contamination exists. At sites where significant groundwater movement or infiltration is expected and the tailings leachates are alkaline, however, the sodium bentonite or asphalt membrane may be necessary.

Buelt, J.L. (comp.)

1983-09-01

399

Auroral counterpart of magnetic field dipolarizations in Saturn's tail  

NASA Astrophysics Data System (ADS)

Following magnetic reconnection in a planetary magnetotail, newly closed field lines can be rapidly accelerated back towards the planet, becoming "dipolarized" in the process. At Saturn, dipolarizations can be initially identified from the magnetometer data by looking for a southward turning of the magnetic field, indicating the transition from a radially stretched configuration to a more dipolar field topology. The highly stretched geometry of the kronian magnetotail lobes gives rise to a tail current which flows eastward (dusk to dawn) in the near equatorial plane across the centre of the tail. During reconnection and associated dipolarization of the field, the inner edge of this tail current can be diverted through the ionosphere, in a situation analogous to the substorm current wedge picture at Earth [McPherron et al. 1973]. We present a picture of the current circuit arising from this tail reconfiguration, and outline the equations which govern the field-current relationship. We show a number of examples of dipolarizations as identified in the Cassini magnetometer data and use this formalism to calculate limits for the ionospheric current density that would arise for these examples. In addition to the magnetometer data, we also present data from the Cassini VIMS and UVIS instruments which have observed small 'spots' of auroral emission lying near the main oval - features thought to be associated with dipolarizations in the tail. We compare the auroral intensities as predicted from our calculation with the observed spot sizes and intensities.

Jackman, C. M.; Achilleos, N.; Bunce, E. J.; Cowley, S. W.; Radioti, A.; Grodent, D. C.; Badman, S. V.; Dougherty, M. K.; Melin, H.; Stallard, T.; Gustin, J.; Pryor, W. R.; Baines, K. H.; Cassini MAG-VIMS Team

2011-12-01

400

Characterization of Emergent Data Networks Among Long-Tail Data  

NASA Astrophysics Data System (ADS)

Data curation underpins data-driven scientific advancements. It manages the information flux across multiple users throughout data life cycle as well as increases data sustainability and reusability. The exponential growth in data production spanning across the Earth Science involving individual and small research groups, which is termed as log-tail data, increases the data-knowledge latency among related domains. It has become clear that an advanced framework-agnostic metadata and ontologies for long-tail data is required to increase their visibility to each other, and provide concise and meaningful descriptions that reveal their connectivity. Despite the advancement that has been achieved by various sophisticated data management models in different Earth Science disciplines, it is not always straightforward to derive relationships among long-tail data. Semantic data clustering algorithms and pre-defined logic rules that are oriented toward prediction of possible data relationships, is one method to address these challenges. Our work advances the connectivity of related long-tail data by introducing the design for an ontology-based knowledge management system. In this work, we present the system architecture, its components, and illustrate how it can be used to scrutinize the connectivity among datasets. To demonstrate the capabilities of this "data network" prototype, we implemented this approach within the Sustainable Environment Actionable Data (SEAD) environment, an open-source semantic content repository that provides a RDF database for long-tail data, and show how emergent relationships among datasets can be identified.

Elag, Mostafa; Kumar, Praveen; Hedstrom, Margaret; Myers, James; Plale, Beth; Marini, Luigi; McDonald, Robert

2014-05-01

401

Lightning location using the slow tails of sferics  

NASA Astrophysics Data System (ADS)

Electromagnetic waves produced by lightning strikes, known as sferics, and their extremely low frequency components, known as slow tails, propagate across the Earth-ionosphere waveguide. The properties of the recorded time domain slow tail vary with the causative lightning strike's current moment, the waveguide's characteristics, and the distance of propagation. These variations allow us to approximate the location of a causal lightning strike by examining the corresponding sferic. Many methods require measurements from multiple stations; however, the goal of this work is to approximate the distance a sferic propagated using measurements from a single station. J. R. Wait developed an analytical model that describes the propagation of the slow tail along a uniform path in the Earth-ionosphere waveguide. We examine different source functions and apply them to Wait's propagation model in order to ascertain a new and more accurate method for modeling slow tails while improving the accuracy of locating lightning using a single station. Further, we expand the model to include sferics propagating in a nonuniform ionosphere, i.e., crossing the day-night terminator. This new method provides improved correlation of computed slow tails to recorded ones, leading to a more accurate distance approximation for a larger set of sferics.

Mackay, C.; Fraser-Smith, A. C.

2010-10-01

402

Tail tip necrosis in Ontario beef feedlot cattle  

PubMed Central

Studies were performed to establish the prevalence and importance of tail tip necrosis in the southern Ontario beef feedlot industry and to characterize the gross appearance and histopathology of the condition. In a mail survey, 96% of 71 feedlots with slatted floors, but only 5% of 184 feedlots with solid floors, reported a problem with tail tip necrosis from 1982-1986. Treatments reported included antibiotics, amputation of the tail (therapeutic or preventive), and slaughter. Lameness was associated with tail tip necrosis. A scoring system for severity of necrosis was developed. Repeated inspections revealed that mild lesions were unlikely to progress to more severe stages. Histological alterations such as perivascular edema and hemorrhage, dermal scarring, follicular atrophy, and paucity of leukocytes were compatible with cutaneous ischemia. Of 441 tails inspected at slaughter plants, 34.5% were affected, with 3.4% involving skin lacerations and infection, and 4.3% amputated before slaughter. ImagesFigure 1.Figure 2.Figure 3.Figure 4.Figure 5.Figure 6.Figure 7.Figure 8.

Drolia, Helen; Luescher, U. Andrew; Meek, Alan H.; Wilcock, Brian P.

1991-01-01

403

OVERVIEW OF CYANIDE PLANT REMAINS, TAILINGS PILES, PARKING LOT, AND ...  

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

OVERVIEW OF CYANIDE PLANT REMAINS, TAILINGS PILES, PARKING LOT, AND MINE MANAGER'S HOME, LOOKING SOUTH SOUTHEAST. RIGHT, TAILINGS PILES ARE AT CENTER WITH CYANIDE PLANT FOUNDATIONS TO THE LEFT OF THE PILES. PARKING LOT IS AT UPPER LEFT. THE AREA BETWEEN THE COLLAPSED TANK AT CENTER LEFT AND THE REMAINS OF THE MANAGER'S HOUSE AT LOWER RIGHT IS A TAILINGS HOLDING AREA. TAILINGS FROM THE MILL WERE HELD HERE. THE LARGE SETTLING TANKS WERE CHARGED FROM THIS HOLDING AREA BY A TRAM ON RAILS AND BY A SLUICEWAY SEEN AS THE DARK SPOT ON THE CENTER LEFT EDGE OF THE FRAME. AFTER THE TAILINGS WERE LEACHED, THEY WERE DEPOSITED ON THE LARGE WASTE PILE AT CENTER RIGHT. THE TANK AT CENTER RIGHT EDGE IS WHERE THE WATER PIPELINE ENTERED THE WORKS. A STRAIGHT LINE OF POSTS IN THE GROUND GO ACROSS THE CENTER FROM LEFT TO RIGHT, WHICH ORIGINALLY SUSPENDED THE WATER PIPELINE GOING FROM THE WATER HOLDING TANK AT RIGHT UP TO THE SECONDARY WATER TANKS ABOVE THE MILL. - Keane Wonder Mine, Park Route 4 (Daylight Pass Cutoff), Death Valley Junction, Inyo County, CA

404

Plant Growth-Promoting Bacteria for Phytostabilization of Mine Tailings  

SciTech Connect

Eolian dispersion of mine tailings in arid and semiarid environments is an emerging global issue for which economical remediation alternatives are needed. Phytostabilization, the revegetation of these sites with native plants, is one such alternative. Revegetation often requires the addition of bulky amendments such as compost which greatly increases cost. We report the use of plant growth-promoting bacteria (PGPB) to enhance the revegetation of mine tailings and minimize the need for compost amendment. Twenty promising PGPB isolates were used as seed inoculants in a series of greenhouse studies to examine revegetation of an extremely acidic, high metal content tailings sample previously shown to require 15% compost amendment for normal plant growth. Several isolates significantly enhanced growth of two native species, quailbush and buffalo grass, in tailings. In this study, PGPB/compost outcomes were plant specific; for quailbush, PGPB were most effective in combination with 10% compost addition while for buffalo grass, PGPB enhanced growth in the complete absence of compost. Results indicate that selected PGPB can improve plant establishment and reduce the need for compost amendment. Further, PGPB activities necessary for aiding plant growth in mine tailings likely include tolerance to acidic pH and metals.

Grandlic, C.J.; Mendez, M.O.; Chorover, J.; Machado, B.; Maier, R.M.

2009-05-19

405

Nonideal Sorption-Desorption and Extensive Elution Tailing  

NASA Astrophysics Data System (ADS)

Contamination of subsurface environments by organic compounds continues to pose a risk to the environment. Sorption is a critical process that influences the transport and fate of organic contaminants. Contaminant mobility, bioavailability, and the effectiveness of remediation efforts are mediated in part by sorption/desorption processes. Miscible-displacement experiments were conducted to characterize long-term, low-concentration elution tailing associated with sorption/desorption processes. A variety of soils and aquifer sediments, representing a range of particle-size distributions and organic-carbon contents, were employed, and trichloroethene (TCE) was used as the model organic compound. Trichloroethene transport exhibited extensive elution tailing for all media, with several hundred to several thousand pore volumes of water flushing required to reach the detection limit (~0.1 ?g/L). The elution tailing was more extensive for the media with higher organic-carbon contents and associated retardation factors. However, when normalized by retardation, the extent of tailing did not correlate directly to organic-carbon content. These latter results suggest that differences in the geochemical nature of organic carbon (e.g., composition, structure) among the various media influenced observed behavior. A mathematical model incorporating nonlinear, rate-limited sorption/desorption described by a continuous-distribution function was used to successfully simulate trichloroethene transport, including the extensive elution tailing.

Russo, A. E.; Akyol, N. H.; Schnaar, G. A.; Johnson, G. R.; Yolcubal, I.; Brusseau, M. L.

2011-12-01

406

Uranium Mill Tailings Remedial Action (UMTRA) Project. [UMTRA project  

SciTech Connect

The mission of the Uranium Mill Tailings Remedial Action (UMTRA) Project is explicitly stated and directed in the Uranium Mill Tailings Radiation Control Act of 1978, hereinafter referred to as the Act.'' Title I of the Act authorizes the Department of Energy (DOE) to undertake remedial action at designated inactive uranium processing sites (Attachment 1 and 2) and associated vicinity properties containing uranium mill tailings and other residual radioactive materials derived from the processing site. The purpose of the remedial actions is to stabilize and control such uranium mill tailings and other residual radioactive materials in a safe and environmentally sound manner to minimize radiation health hazards to the public. The principal health hazards and environmental concerns are: the inhalation of air particulates contaminated as a result of the emanation of radon from the tailings piles and the subsequent decay of radon daughters; and the contamination of surface and groundwaters with radionuclides or other chemically toxic materials. This UMTRA Project Plan identifies the mission and objectives of the project, outlines the technical and managerial approach for achieving them, and summarizes the performance, cost, and schedule baselines which have been established to guide operational activity. Estimated cost increases by 15 percent, or if the schedule slips by six months. 4 refs.

Not Available

1989-09-01

407

Curved tails in polymerization-based bacterial motility  

NASA Astrophysics Data System (ADS)

The curved actin ``comet-tail'' of the bacterium Listeria monocytogenes is a visually striking signature of actin polymerization-based motility. Similar actin tails are associated with Shigella flexneri, spotted-fever Rickettsiae, the Vaccinia virus, and vesicles and microspheres in related in vitro systems. We show that the torque required to produce the curvature in the tail can arise from randomly placed actin filaments pushing the bacterium or particle. We find that the curvature magnitude determines the number of actively pushing filaments, independent of viscosity and of the molecular details of force generation. The variation of the curvature with time can be used to infer the dynamics of actin filaments at the bacterial surface.

Rutenberg, Andrew D.; Grant, Martin

2001-08-01

408

Empirical study of the tails of mutual fund size  

NASA Astrophysics Data System (ADS)

The mutual fund industry manages about a quarter of the assets in the U.S. stock market and thus plays an important role in the U.S. economy. The question of how much control is concentrated in the hands of the largest players is best quantitatively discussed in terms of the tail behavior of the mutual fund size distribution. We study the distribution empirically and show that the tail is much better described by a log-normal than a power law, indicating less concentration than, for example, personal income. The results are highly statistically significant and are consistent across fifteen years. This contradicts a recent theory concerning the origin of the power law tails of the trading volume distribution. Based on the analysis in a companion paper, the log-normality is to be expected, and indicates that the distribution of mutual funds remains perpetually out of equilibrium.

Schwarzkopf, Yonathan; Farmer, J. Doyne

2010-06-01

409

Recent radiochemistry observations at the Riverton and Maybell tailings piles  

SciTech Connect

Preliminary results are presented from the radiochemistry effort of the Lawrence Berkeley Laboratory integrated study of the inactive uranium mill tailings sites at Riverton, Wyoming and Maybell, Colorado. These results were obtained primarily by use of ..gamma..-ray spectrometric techniques, and included both field and laboratory application of NaI(Tl) crystal and Ge-semiconductor detector systems. Current interpretation of this evidence indicated there has been downward migration of uranium within the tailings column since its emplacement, and upward movement of several radionuclides from the tailings into the overlying cover material. The mechanisms responsible for these migrations are believed to involve fluid transport, and are further believed to be active at the present time.

Smith, A.R.; Moed, B.A.

1982-09-01

410

Movements of flightless long-tailed ducks during wing molt  

USGS Publications Warehouse

We examined the movements of flightless Long-tailed Ducks (Clangula hyemalis) during the wing molt in the near-shore lagoons of the Beaufort Sea in Alaska. Estimates of site fidelity during the 21-day flightless period ranged from 1-100%, with considerable variation among locations and within locations among years. There was no effect of low-level experimental disturbance or an underwater seismic survey on site fidelity of molting Long-tailed Ducks. Birds molting along a relatively consistent habitat gradient were more likely to move than those molting in a fragmented habitat. While flocks of birds are consistently observed in the same locations, these data suggest considerable turnover within these aggregations. These results, in conjunction with other studies, suggest that forage is relatively uniformly distributed within lagoons. We conclude that habitat selection by molting Long-tailed Ducks is likely influenced by protection from wind and associated waves.

Flint, P. L.; Lacroix, D. L.; Reed, J. A.; Lanctot, R. B.

2004-01-01

411

Extreme values and fat tails of multifractal fluctuations  

NASA Astrophysics Data System (ADS)

In this paper we discuss the problem of the estimation of extreme event occurrence probability for data drawn from some multifractal process. We also study the heavy (power-law) tail behavior of probability density function associated with such data. We show that because of strong correlations, the standard extreme value approach is not valid and classical tail exponent estimators should be interpreted cautiously. Extreme statistics associated with multifractal random processes turn out to be characterized by non-self-averaging properties. Our considerations rely upon some analogy between random multiplicative cascades and the physics of disordered systems and also on recent mathematical results about the so-called multifractal formalism. Applied to financial time series, our findings allow us to propose an unified framework that accounts for the observed multiscaling properties of return fluctuations, the volatility clustering phenomenon and the observed “inverse cubic law” of the return pdf tails.

Muzy, J. F.; Bacry, E.; Kozhemyak, A.

2006-06-01

412

Radon diffusion in candidate soils for covering uranium mill tailings  

SciTech Connect

Diffusion coefficients were measured for radon in 34 soils that had been identified by mill personnel as candidate covers for their tailings piles in order to reduce radon emission. These coefficients referred to diffusion in the total pore space of the soils. They were measured in the laboratory by a steady-state method using soil columns compacted to greater than 80% of their Proctor maximum packing densities but with moisture contents generally less than would be expected at a tailings site. An empirical equation was used to extrapolate measured coefficients to value expected at soil-moisture contents representative of tailings sites in the western United States. Extrapolated values for silty sands and clayey sands ranged from 0.004 to 0.06 cm/sup 2//s. Values for inorganic silts and clays ranged from 0.001 to 0.02 cm/sup 2//s.

Silker, W.B.; Kalkwarf, D.R.

1983-04-01

413

[Leaching kinetics of josephinite tailings with sulfuric acid].  

PubMed

Leaching is the most important step of josephinite tailing recycle technology. This step can separate the valuable metal Mg from Si and other impure metal. Effects of sulfuric acid on leaching Mg efficiency from josephinite tailings were investigated. To obtain the leaching behavior, a modified unreacted shrinking core model that based on the experimental data was used to determine the dissolution kinetic parameters. The model was significant and showed that the dissolution of Mg2+ in josephinite tailing was controlled by the produce layer diffusion, apparent activation reaction energy E = 34.04 kJ x mol(-1). The produce layers obstruct the forward reaction of the dissolution of Mg2+. PMID:24028005

Chen, An-An; Zhou, Shao-Qi; Huang, Peng-Fei

2013-07-01

414

Investigating the heliospheric ion suprathermal tail with Voyager LECP data  

NASA Astrophysics Data System (ADS)

Using publicly available data from the Voyager Low Energy Charged Particle (LECP) instruments, we investigate the form of the solar wind ion suprathermal tail in the outer heliosphere inside the termination shock. This tail has a commonly observed form in the inner heliosphere, that is, a power law with a particular spectral index. The Voyager spacecraft have taken data beyond 100 AU, farther than any other spacecraft. However, during extended periods of time, the data appears to be mostly background. We have developed a technique to self-consistently estimate the background seen by LECP due to cosmic rays using data from the Voyager cosmic ray instruments and a model of the LECP instruments. In this presentation, we discuss the development of our background removal technique and results of applying it to studying the suprathermal ion tail in the solar wind.

Randol, B. M.; Christian, E. R.; Decker, R. B.

2013-12-01

415

Helicopter Tail Boom With Venting for Alleviation and Control of Tail Boom Aerodynamic Loads and Method Thereof  

NASA Technical Reports Server (NTRS)

In at least one embodiment, the apparatus of the invention is a flight vehicle tail assembly having an exterior surface, at least one first vent in the exterior surface, at least one second vent in the exterior surface, and an air passage connecting the at least one first vent to the at least one second vent allowing air to flow there between. Where the at least one first vent is located near a high air pressure area acting on the exterior surface during a range of predefined flight conditions, Further, the at least one second vent is located near a low air pressure area acting on the exterior surface during the predefined flight conditions. So that at the predefined flight conditions adverse loads on the tail assembly are reduced by venting air from the high pressure area, through the tail assembly, to the low pressure area. The method of the present invention includes the steps of: receiving air through the at least one first vent in the exterior surface, passing the air through the tail assembly from the at least one first vent to at least one second vent in the exterior surface. and ejecting the air out of the tail assembly at the at least one second vent.

Banks, Daniel W. (Inventor); Kelley, Henry L. (Inventor)

2002-01-01

416

The fish tail motion forms an attached leading edge vortex  

PubMed Central

The tail (caudal fin) is one of the most prominent characteristics of fishes, and the analysis of the flow pattern it creates is fundamental to understanding how its motion generates locomotor forces. A mechanism that is known to greatly enhance locomotor forces in insect and bird flight is the leading edge vortex (LEV) reattachment, i.e. a vortex (separation bubble) that stays attached at the leading edge of a wing. However, this mechanism has not been reported in fish-like swimming probably owing to the overemphasis on the trailing wake, and the fact that the flow does not separate along the body of undulating swimmers. We provide, to our knowledge, the first evidence of the vortex reattachment at the leading edge of the fish tail using three-dimensional high-resolution numerical simulations of self-propelled virtual swimmers with different tail shapes. We show that at Strouhal numbers (a measure of lateral velocity to the axial velocity) at which most fish swim in nature (approx. 0.25) an attached LEV is formed, whereas at a higher Strouhal number of approximately 0.6 the LEV does not reattach. We show that the evolution of the LEV drastically alters the pressure distribution on the tail and the force it generates. We also show that the tail's delta shape is not necessary for the LEV reattachment and fish-like kinematics is capable of stabilising the LEV. Our results suggest the need for a paradigm shift in fish-like swimming research to turn the focus from the trailing edge to the leading edge of the tail.

Borazjani, Iman; Daghooghi, Mohsen

2013-01-01

417

Grasping convergent evolution in syngnathids: a unique tale of tails.  

PubMed

Seahorses and pipehorses both possess a prehensile tail, a unique characteristic among teleost fishes, allowing them to grasp and hold onto substrates such as sea grasses. Although studies have focused on tail grasping, the pattern of evolutionary transformations that made this possible is poorly understood. Recent phylogenetic studies show that the prehensile tail evolved independently in different syngnathid lineages, including seahorses, Haliichthys taeniophorus and several types of so-called pipehorses. This study explores the pattern that characterizes this convergent evolution towards a prehensile tail, by comparing the caudal musculoskeletal organization, as well as passive bending capacities in pipefish (representing the ancestral state), pipehorse, seahorse and H. taeniophorus. To study the complex musculoskeletal morphology, histological sectioning, ?CT-scanning and phase contrast synchrotron scanning were combined with virtual 3D-reconstructions. Results suggest that the independent evolution towards tail grasping in syngnathids reflects at least two quite different strategies in which the ancestral condition of a heavy plated and rigid system became modified into a highly flexible one. Intermediate skeletal morphologies (between the ancestral condition and seahorses) could be found in the pygmy pipehorses and H. taeniophorus, which are phylogenetically closely affiliated with seahorses. This study suggests that the characteristic parallel myoseptal organization as already described in seahorse (compared with a conical organization in pipefish and pipehorse) may not be a necessity for grasping, but represents an apomorphy for seahorses, as this pattern is not found in other syngnathid species possessing a prehensile tail. One could suggest that the functionality of grasping evolved before the specialized, parallel myoseptal organization seen in seahorses. However, as the grasping system in pipehorses is a totally different one, this cannot be concluded from this study. PMID:24697519

Neutens, C; Adriaens, D; Christiaens, J; De Kegel, B; Dierick, M; Boistel, R; Van Hoorebeke, L

2014-06-01

418

The fish tail motion forms an attached leading edge vortex.  

PubMed

The tail (caudal fin) is one of the most prominent characteristics of fishes, and the analysis of the flow pattern it creates is fundamental to understanding how its motion generates locomotor forces. A mechanism that is known to greatly enhance locomotor forces in insect and bird flight is the leading edge vortex (LEV) reattachment, i.e. a vortex (separation bubble) that stays attached at the leading edge of a wing. However, this mechanism has not been reported in fish-like swimming probably owing to the overemphasis on the trailing wake, and the fact that the flow does not separate along the body of undulating swimmers. We provide, to our knowledge, the first evidence of the vortex reattachment at the leading edge of the fish tail using three-dimensional high-resolution numerical simulations of self-propelled virtual swimmers with different tail shapes. We show that at Strouhal numbers (a measure of lateral velocity to the axial velocity) at which most fish swim in nature (approx. 0.25) an attached LEV is formed, whereas at a higher Strouhal number of approximately 0.6 the LEV does not reattach. We show that the evolution of the LEV drastically alters the pressure distribution on the tail and the force it generates. We also show that the tail's delta shape is not necessary for the LEV reattachment and fish-like kinematics is capable of stabilising the LEV. Our results suggest the need for a paradigm shift in fish-like swimming research to turn the focus from the trailing edge to the leading edge of the tail. PMID:23407826

Borazjani, Iman; Daghooghi, Mohsen

2013-04-01

419

Heavy metal leaching from mine tailings as affected by plants  

SciTech Connect

A column experiment was conducted to determine the impact of soil cover and plants on heavy metal leaching from mine tailings and heavy metal contaminated soil. Columns made of PVC were constructed with 30 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm subsoil covered by 30 cm of mine tailings followed by 0, 30, or 60 cm of clean topsoil. Two grasses, tall fescue (Festuca arundinacea Schreb.) and big bluestem (Andropogon gerardii), were grown in the columns. The columns were leached at a slow rate for 1 yr with a 0.001 M CaCl{sub 2} solution under unsaturated conditions. The presence of both tall fescue and big bluestem increased Zn and Cd concentrations in the leachate. Lead concentrations in leachates were not affected by the presence of plants. Although plants generally reduced the total amount of water leached, total mass of Zn and Cd leached generally was not impacted by plants. Total mass of Pb leached was positively correlated with total leachate collected from each column. Covering the mine tailings with 60 cm of topsoil increased the mass of Zn and Cd leached relative to no topsoil. When the subsoil was absent, Zn and Cd leaching increased by as much as 20-fold, verifying the ability of soil to act as a sink for metals. Mine tailing remediation by establishing vegetation can reduce Pb movement but may enhance short-term Cd and Zn leaching. However, the changes were relatively small and do not outweigh the benefits of using vegetation in mine tailings reclamation.

Zhu, D.; Schwab, A.P.; Banks, M.K.

1999-12-01

420

Ion acceleration in the Martian tail - PHOBOS observations  

NASA Astrophysics Data System (ADS)

The measurements carried out on the spacecraft Phobos-2 have revealed that the plasma sheet of the Martian magnetosphere consists mainly of ions of planetary origin, accelerated up to about 1 keV/q. Such an acceleration may result from the action of magnetic shear stresses of the draped field, the ion energy increasing toward the center of the tail where magnetic stresses are stronger. The energy gained by heavy ions does not depend on their mass and are proportional to the ion charge. The mechanism of the ion acceleration is related with the generation of a charge separation electric field, which extracts ions from 'ray' structures in the Martian tail.

Dubinin, E.; Lundin, R.; Norberg, O.; Pissarenko, N.

1993-03-01

421

The taxonomic status of the white-tailed kite  

USGS Publications Warehouse

The White-tailed Kite (Elanus leucurus) of the Americas has been merged with the Black-shouldered (or Black-winged) Kite (E. caeruleus) of the Old World and the Australian Black-shouldered Kite (E. axillaris) by North American authorities (but not elsewhere), primarily because of similarity in plumage. However, American kites differ from Old World kites in greater size and weight, in proportions (relatively longer tail and smaller bill and feet), plumage pattern (particularly of juveniles), and in behavior. Here we argue that these characters are sufficiently distinctive to warrant recognition of E. leucurus at the species level.

Clark, W.S.; Banks, R.C.

1992-01-01

422

Materials selection for pipelines handling abrasive tailings. Part 2  

SciTech Connect

Critical appraisal is made of concrete, polyurethane, other non-ferrous materials such as pvc, polypropylene and acrylonitrile/butadiene/styrene, and internally lined steel for use for tailings pipelines. In long distance lines, some form of internal lining is strongly recommended. In a tabulated list showing the life expectancy of different materials, polyurethane-lined steel is shown to be the best. Various test methods for predicting wear rates under given operating conditions are discussed, and their advantages and disadvantages are tabulated. Thermoplastic linings give superior life expectancy in tailings service, but their performance varies with type and grade.

Snoek, P.E.; Carney, J.

1981-07-01

423

Adoption in rock and white-tailed ptarmigan  

USGS Publications Warehouse

Reports of adoption in birds are widespread, but few studies report rates of adoption or possible mechanisms for this phenomenon, particularly in the Order Galliformes. We report incidents of adoption in Rock Ptarmigan (Lagopus muta) and White-tailed Ptarmigan (L. leucura) from two sites in western Canada. Adoption rates for White-tailed Ptarmigan on Vancouver Island, British Columbia, and the Ruby Ranges, Yukon Territory were 13% (n = 16 broods) and 4% (n = 27), respectively, while rates for Rock Ptarmigan were 14% (n = 29) in the Ruby Ranges. Low brood densities may result in lower rates of adoption for ptarmigan. ?? 2009 The Wilson Ornithological Society.

Wong, M. M. L.; Fedy, B. C.; Wilson, S.; Martin, K. M.

2009-01-01

424

Weighted Kolmogorov-Smirnov test: Accounting for the tails  

NASA Astrophysics Data System (ADS)

Accurate goodness-of-fit tests for the extreme tails of empirical distributions is a very important issue, relevant in many contexts, including geophysics, insurance, and finance. We have derived exact asymptotic results for a generalization of the large-sample Kolmogorov-Smirnov test, well suited to testing these extreme tails. In passing, we have rederived and made more precise the approximate limit solutions found originally in unrelated fields, first in [L. Turban, J. Phys. A1361-644710.1088/0305-4470/25/3/008 25, 127 (1992)] and later in [P. L. Krapivsky and S. Redner, Am. J. Phys.AJPIAS0002-950510.1119/1.18152 64, 546 (1996)].

Chicheportiche, Rémy; Bouchaud, Jean-Philippe

2012-10-01

425

Late-time tails of self-gravitating massless fields  

NASA Astrophysics Data System (ADS)

In this talk I summarize briefly recent results of joint work with P. Bizo?, T. Chmaj and S. Zajaç, on the nonlinear origin of the power-law tails in the long-time evolution of self-gravitating massless fields. We focus on a spherically symmetric massless scalar field and wave map matter coupled to gravity. Using third-order perturbation method we derive explicit expressions for the tail (the decay rate and the amplitude) for solutions starting from small initial data and we verify this prediction via numerical integration of the full system of Einstein field equations. Our results show that the nonlinear effects can dominate the late time asymptotics.

Rostworowski, Andrzej

2010-05-01

426

Wake patterns of the wings and tail of hovering hummingbirds  

NASA Astrophysics Data System (ADS)

The flow fields of slowly flying bats and fasterflying birds differ in that bats produce two vortex loops during each stroke, one per wing, and birds produce a single vortex loop per stroke. In addition, the circulation at stroke transition approaches zero in bats but remains strong in birds. It is unknown if these difference derive from fundamental differences in wing morphology or are a consequence of flight speed. Here, we present an analysis of the horizontal flow field underneath hovering Anna's hummingbirds (Calypte anna) to describe the wake of a bird flying at zero forward velocity. We also consider how the hummingbird tail interacts with the wake generated by the wings. High-speed image recording and analysis from three orthogonal perspectives revealed that the wing tips reach peak velocities in the middle of each stroke and approach zero velocity at stroke transition. Hummingbirds use complex tail kinematic patterns ranging from in phase to antiphase cycling with respect to the wings, covering several phase shifted patterns. We employed particle image velocimetry to attain detailed horizontal flow measurements at three levels with respect to the tail: in the tail, at the tail tip, and just below the tail. The velocity patterns underneath the wings indicate that flow oscillates along the ventral-dorsal axis in response to the down- and up-strokes and that the sideways flows with respect to the bird are consistently from the lateral to medial. The region around the tail is dominated by axial flows in dorsal to ventral direction. We propose that these flows are generated by interaction between the wakes of the two wings at the end of the upstroke, and that the tail actively defects flows to generate moments that contribute to pitch stability. The flow fields images also revealed distinct vortex loops underneath each wing, which were generated during each stroke. From these data, we propose a model for the primary flow structures of hummingbirds that more strongly resembles the bat model. Thus, pairs of unconnected vortex loops may be shared features of different animals during hovering and slow forward flight.

Altshuler, Douglas L.; Princevac, Marko; Pan, Hansheng; Lozano, Jesse

427

Wake patterns of the wings and tail of hovering hummingbirds  

NASA Astrophysics Data System (ADS)

The flow fields of slowly flying bats and faster-flying birds differ in that bats produce two vortex loops during each stroke, one per wing, and birds produce a single vortex loop per stroke. In addition, the circulation at stroke transition approaches zero in bats but remains strong in birds. It is unknown if these difference derive from fundamental differences in wing morphology or are a consequence of flight speed. Here, we present an analysis of the horizontal flow field underneath hovering Anna’s hummingbirds ( Calypte anna) to describe the wake of a bird flying at zero forward velocity. We also consider how the hummingbird tail interacts with the wake generated by the wings. High-speed image recording and analysis from three orthogonal perspectives revealed that the wing tips reach peak velocities in the middle of each stroke and approach zero velocity at stroke transition. Hummingbirds use complex tail kinematic patterns ranging from in phase to antiphase cycling with respect to the wings, covering several phase shifted patterns. We employed particle image velocimetry to attain detailed horizontal flow measurements at three levels with respect to the tail: in the tail, at the tail tip, and just below the tail. The velocity patterns underneath the wings indicate that flow oscillates along the ventral-dorsal axis in response to the down- and up-strokes and that the sideways flows with respect to the bird are consistently from the lateral to medial. The region around the tail is dominated by axial flows in dorsal to ventral direction. We propose that these flows are generated by interaction between the wakes of the two wings at the end of the upstroke, and that the tail actively defects flows to generate moments that contribute to pitch stability. The flow fields images also revealed distinct vortex loops underneath each wing, which were generated during each stroke. From these data, we propose a model for the primary flow structures of hummingbirds that more strongly resembles the bat model. Thus, pairs of unconnected vortex loops may be shared features of different animals during hovering and slow forward flight.

Altshuler, Douglas L.; Princevac, Marko; Pan, Hansheng; Lozano, Jesse

2009-05-01

428

Hybrid redox polyether melts based on polyether-tailed counterions  

SciTech Connect

Interesting ionic materials can be transformed into room temperature molten salts by combining them with polyether-tailed counterions such as polyether-tailed 2-sulfobenzoate (MePEG-BzSO{sub 3}{sup {minus}}) and polyethertailed triethylammonium (MePEG-Et{sub 3}N{sup +}). Melts containing ruthenium hexamine, metal trisbipyridines, metal trisphenanthrolines, and ionic forms of aluminum quinolate, anthraquinone, phthalocyanine, and porphyrins are described. These melts exhibit ionic conductivities in the 7 x 10{sup {minus}5} to 7 x 10{sup {minus}10} {Omega}{sup {minus}1} cm{sup {minus}1} range, which permit microelectrode voltammetry in the undiluted materials, examples of which are presented.

Dickinson, E. V; Williams, M.E.; Hendrickson, S.M.; Masui, Hitoshi; Murray, R.W.

1999-02-03

429

Endosonography and cytology in diagnosing and staging pancreatic body and tail carcinoma: Preliminary results of endosonographic guided puncture  

SciTech Connect

Endosonography was performed in diagnosing and staging pancreatic body and tail carcinoma in two patients. In the first case endoscopy, abdominal ultrasound, and computed tomography were nondiagnostic in diagnosing the origin of submucosal gastric abnormalities. Endosonography diagnosed a pancreatic tail carcinoma with submucosal gastric involvement, and this was confirmed by endosonographic-guided cytology. Fundus varices due to segmented splenic vein involvement were found. Surgery was not recommended due to the advanced disease. In the second case pancreatic body carcinoma was diagnosed by ERCP and computed tomography. Transcutaneous ultrasonographic-guided cytological puncture confirmed the diagnosis. Endosonography revealed additional information of segmental portal hypertension with fundic varices due to splenic vein involvement. Autopsy confirmed the endosonographic diagnosis. 18 refs., 5 figs.

Tio, T.L.; Sie, L.H.; Tytgat, G.N.J. (Georgetown Univ. Medical Center, Washington, DC (United States) Academic Medical Center, Amsterdam (Netherlands))

1993-01-01

430

A cross-sectional study of the causes of morbidity and mortality in farmed white-tailed deer  

PubMed Central

Abstract Two questionnaires were designed and administered. The first was to a random sample of 340 farmers of white-tailed deer (Odocoileus virginianus) in Canada and the United States. The second was a 10-year retrospective survey of deer submissions to veterinary diagnostic pathology laboratories in Canada and the United States. One-year rates of mortality and common causes of morbidity and mortality for the deer are reported. The primary diagnosis for each record was used to classify diseases into categories, such as parasitic, infectious, toxicological, and neoplastic. Submissions were further classified according to the anatomical location, the pathological change, and the etiology associated with each lesion. Trauma was the most important reported cause of farmed white-tailed deer mortality; necrobacillosis was a major cause of morbidity and mortality, especially in fawns.

2005-01-01

431

Evaluation of the antipsoriatic activity of Aloe vera leaf extract using a mouse tail model of psoriasis.  

PubMed

Aloe vera gel is used traditionally for the treatment of skin diseases, including psoriasis. An ethanolic extract of the gel was assessed for antipsoriatic activity using a mouse tail model of psoriasis. The extract produced a significant differentiation in the epidermis, as seen from its degree of orthokeratosis (85.07 ± 3.36%) when compared with the negative control (17.30 ± 4.09%). This was equivalent to the effect of the standard positive control, tazarotene (0.1%) gel, which showed a 90.03 ± 2.00% degree of orthokeratosis. The ethanolic extract of Aloe vera leaf gel also produced a significant increase in relative epidermal thickness when compared with the control group, whereas the standard tazarotene showed no change. Taken together, the extract showed an overall antipsoriatic activity of 81.95%, compared with 87.94 for tazarotene, in the mouse tail model for psoriasis. PMID:21915932

Dhanabal, S P; Priyanka Dwarampudi, L; Muruganantham, N; Vadivelan, R

2012-04-01

432

Remote control canard missile with a free-rolling tail brake torque system  

NASA Technical Reports Server (NTRS)

An experimental wind-tunnel investigation has been conducted at supersonic Mach numbers to determine the static aerodynamic characteristics of a cruciform canard-controlled missile with fixed and free-rolling tail-fin afterbodies. Mechanical coupling effects of the free-rolling tail afterbody were investigated using an electronic/electromagnetic brake system that provides arbitrary tail-fin brake torques with continuous measurements of tail-to-mainframe torque and tail-roll rate. Results are summarized to show the effects of fixed and free-rolling tail-fin afterbodies that include simulated measured bearing friction torques on the longitudinal and lateral-directional aerodynamic characteristics.

Blair, A. B., Jr.

1981-01-01

433

Interpretation of the break in Comet Halley's tail  

SciTech Connect

Photographs of the broken tail of Comet Halley taken in January 1986 suggest that the comet had crossed a tangential discontinuity in the solar-wind velocity field. The velocity jump amounts to about 20 percent of the wind velocity itself, one of several properties analogous to fronts in the terrestrial atmosphere.

Obukhov, A.M.; Danilov, A.V.; Kurganskii, M.V.

1986-12-01