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1

Increased transcription of Glutathione S-transferases in acaricide exposed scabies mites  

PubMed Central

Background Recent evidence suggests that Sarcoptes scabiei var. hominis mites collected from scabies endemic communities in northern Australia show increasing tolerance to 5% permethrin and oral ivermectin. Previous findings have implicated detoxification pathways in developing resistance to these acaricides. We investigated the contribution of Glutathione S-transferase (GST) enzymes to permethrin and ivermectin tolerance in scabies mites using biochemical and molecular approaches. Results Increased in vitro survival following permethrin exposure was observed in S. scabiei var. hominis compared to acaricide naïve mites (p < 0.0001). The addition of the GST inhibitor diethyl maleate restored in vitro permethrin susceptibility, confirming GST involvement in permethrin detoxification. Assay of GST enzymatic activity in mites demonstrated that S. scabiei var. hominis mites showed a two-fold increase in activity compared to naïve mites (p < 0.0001). Increased transcription of three different GST molecules was observed in permethrin resistant S. scabiei var. canis- mu 1 (p < 0.0001), delta 1 (p < 0.001), and delta 3 (p < 0.0001). mRNA levels of GST mu 1, delta 3 and P-glycoprotein also significantly increased in S. scabiei var. hominis mites collected from a recurrent crusted scabies patient over the course of ivermectin treatment. Conclusions These findings provide further support for the hypothesis that increased drug metabolism and efflux mediate permethrin and ivermectin resistance in scabies mites and highlight the threat of emerging acaricide resistance to the treatment of scabies worldwide. This is one of the first attempts to define specific genes involved in GST mediated acaricide resistance at the transcriptional level, and the first application of such studies to S. scabiei, a historically challenging ectoparasite. PMID:20482766

2010-01-01

2

Acaricidal Activity of Eugenol Based Compounds against Scabies Mites  

Microsoft Academic Search

BackgoundHuman scabies is a debilitating skin disease caused by the “itch mite” Sarcoptes scabiei. Ordinary scabies is commonly treated with topical creams such as permethrin, while crusted scabies is treated with topical creams in combination with oral ivermectin. Recent reports of acaricide tolerance in scabies endemic communities in Northern Australia have prompted efforts to better understand resistance mechanisms and to

Cielo Pasay; Kate Mounsey; Graeme Stevenson; Rohan Davis; Larry Arlian; Marjorie Morgan; Diann Vyszenski-Moher; Kathy Andrews; James McCarthy; Cesar V. Munayco

2010-01-01

3

Acaricidal Activity of Eugenol Based Compounds against Scabies Mites  

PubMed Central

Backgound Human scabies is a debilitating skin disease caused by the “itch mite” Sarcoptes scabiei. Ordinary scabies is commonly treated with topical creams such as permethrin, while crusted scabies is treated with topical creams in combination with oral ivermectin. Recent reports of acaricide tolerance in scabies endemic communities in Northern Australia have prompted efforts to better understand resistance mechanisms and to identify potential new acaricides. In this study, we screened three essential oils and four pure compounds based on eugenol for acaricidal properties. Methodology/Principal Findings Contact bioassays were performed using live permethrin-sensitive S. scabiei var suis mites harvested from pigs and permethrin-resistant S. scabiei var canis mites harvested from rabbits. Results of bioassays showed that clove oil was highly toxic against scabies mites. Nutmeg oil had moderate toxicity and ylang ylang oil was the least toxic. Eugenol, a major component of clove oil and its analogues –acetyleugenol and isoeugenol, demonstrated levels of toxicity comparable to benzyl benzoate, the positive control acaricide, killing mites within an hour of contact. Conclusions The acaricidal properties demonstrated by eugenol and its analogues show promise as leads for future development of alternative topical acaricides to treat scabies. PMID:20711455

Pasay, Cielo; Mounsey, Kate; Stevenson, Graeme; Davis, Rohan; Arlian, Larry; Morgan, Marjorie; Vyszenski-Moher, DiAnn; Andrews, Kathy; McCarthy, James

2010-01-01

4

Scabies  

MedlinePLUS

... Apply once daily for 5 consecutive days. Precipitated sulfur (5% or 10%) – This is prepared with petroleum ... Scabies. http://www.cdc.gov/scabies/index.html. Modified November 10, 2008. Accessed March 11, 2009. Bolognia, ...

5

Scabies  

MedlinePLUS

... Epidemiology & Risk Factors Who gets it and how... Biology Stages of parasite development... Disease Signs and symptoms ... Information Scabies FAQs Workplace FAQs Epidemiology & Risk Factors Biology Disease Diagnosis Treatment Prevention & Control Resources for Health ...

6

Scabies: Treatment  

MedlinePLUS

... sexual and close personal contacts who have had direct prolonged skin-to-skin contact with an infested person within the preceding month should be examined and treated. All persons should be treated at the same time to prevent reinfestation. Products used to treat scabies are called ...

7

Scabies: Diagnosis, Treatment, and Outcome  

MedlinePLUS

... treatments Q - T Scabies Diagnosis, treatment Scabies: Diagnosis, treatment, and outcome How do dermatologists diagnose scabies? A ... only available with a doctor’s prescription. Who needs treatment? The person diagnosed with scabies and everyone who ...

8

Scabies: Who Gets and Causes  

MedlinePLUS

... live for as long as 1 week without human contact. Scabies among people in nursing homes and extended- ... scabies from an animal that has mites. Only humans get this type of scabies. Most people will not get scabies from a handshake or hug. The skin-to-skin contact must be longer for a mite to crawl ...

9

Management of scabies.  

PubMed

Scabies is a common contagious parasitic dermatosis. Transmission of the mite Sarcoptes scabiei var hominis generally occurs by skin-to-skin contact, but with crusted scabies it may also occur through fomites, such as infected clothing or bedding. Diagnosis is usually clinical. A 2010 updated Cochrane review concluded that management of scabies is based on topical scabicides, mainly 5% permethrin. However, oral ivermectin, although not licensed in many countries, may be useful, particularly for patients who cannot tolerate or comply with topical therapy and in institutional scabies epidemics. Patients should also receive detailed information about the infestation to limit further spreading. Cases resulting from close physical or sexual contact, even without symptoms, should be systematically treated. Hygienic measures should be taken after treatment is completed. Patients should be followed to confirm cure, including resolution of itching, which may take up to 4 weeks or longer. PMID:22446818

Monsel, Gentiane; Chosidow, Olivier

2012-03-01

10

[Canine scabies in man].  

PubMed

Parasitic prurigo caused by scabies mites from recently acquired puppies is described in two patients and their family members. Because Sarcoptes scabiei var. canis (dog) occasionally survives in man, patients with persisting complaints despite treatment of their dogs should be treated with the topical scabicide lindane for one night. PMID:1702882

Meijer, P; van Voorst Vader, P C

1990-12-22

11

[Scabies among the Zoo mammals].  

PubMed

Scabies was observed in 9 species of mammals at the Zoological Garden of Lód? in years 1957-1989. Sarcoptes scabiei spp. was found in capybaras, tapirs and camelids. Notoedres cati was recorded from the siberian tiger, but Notoedres sp. from the Erinaceus europaeus. Scabies was also found in a wild dead Tapla europaea at the Zoo area. PMID:1823472

Zuchowska, E

1991-01-01

12

Scabies Mites Alter the Skin Microbiome and Promote Growth of Opportunistic Pathogens in a Porcine Model  

PubMed Central

Background The resident skin microbiota plays an important role in restricting pathogenic bacteria, thereby protecting the host. Scabies mites (Sarcoptes scabiei) are thought to promote bacterial infections by breaching the skin barrier and excreting molecules that inhibit host innate immune responses. Epidemiological studies in humans confirm increased incidence of impetigo, generally caused by Staphylococcus aureus and Streptococcus pyogenes, secondary to the epidermal infestation with the parasitic mite. It is therefore possible that mite infestation could alter the healthy skin microbiota making way for the opportunistic pathogens. A longitudinal study to test this hypothesis in humans is near impossible due to ethical reasons. In a porcine model we generated scabies infestations closely resembling the disease manifestation in humans and investigated the scabies associated changes in the skin microbiota over the course of a mite infestation. Methodology/Principal Findings In a 21 week trial, skin scrapings were collected from pigs infected with S. scabies var. suis and scabies-free control animals. A total of 96 skin scrapings were collected before, during infection and after acaricide treatment, and analyzed by bacterial 16S rDNA tag-encoded FLX-titanium amplicon pyrosequencing. We found significant changes in the epidermal microbiota, in particular a dramatic increase in Staphylococcus correlating with the onset of mite infestation in animals challenged with scabies mites. This increase persisted beyond treatment from mite infection and healing of skin. Furthermore, the staphylococci population shifted from the commensal S. hominis on the healthy skin prior to scabies mite challenge to S. chromogenes, which is increasingly recognized as being pathogenic, coinciding with scabies infection in pigs. In contrast, all animals in the scabies-free cohort remained relatively free of Staphylococcus throughout the trial. Conclusions/Significance This is the first experimental in vivo evidence supporting previous assumptions that establishment of pathogens follow scabies infection. Our findings provide an explanation for a biologically important aspect of the disease pathogenesis. The methods developed from this pig trial will serve as a guide to analyze human clinical samples. Studies building on this will offer implications for development of novel intervention strategies against the mites and the secondary infections. PMID:24875186

Swe, Pearl M.; Zakrzewski, Martha; Kelly, Andrew; Krause, Lutz; Fischer, Katja

2014-01-01

13

Scabies - Multiple Languages: MedlinePlus  

MedlinePLUS

... please enable JavaScript. Scabies - Multiple Languages Amharic (amarunya) Oromo (Afaan Oromo) Spanish (español) Amharic (amarunya) Pubic Lice ("Crabs") and ... English amarunya (Amharic) PDF Minnesota Department of Health Oromo (Afaan Oromo) Pubic Lice ("Crabs") and Scabies English ...

14

Acaricide mode of action.  

PubMed

The last few years have seen the introduction of an unprecedented number of new classes of acaricides with novel or under-exploited modes of action, discovered by traditional screening. Acaricide research has uncovered several unrelated compounds that possess improved properties. Pyridaben, acequinocyl, diafenthiuron, etoxazole, spirodiclofen and bifenazate, in particular, are acaricides that are safe to beneficials, have low mammalian toxicity and short environmental persistence. Many of the new acaricides appear to affect mitochondrial respiration, and previously unknown targets affecting mite growth and development have been identified, offering new opportunities for mite control. PMID:15625668

Dekeyser, Mark A

2005-02-01

15

Pediculosis and scabies: treatment update.  

PubMed

Pediculosis and scabies are caused by ectoparasites. Pruritus is the most common presenting symptom. Head and pubic lice infestations are diagnosed by visualization of live lice. Finding nits (louse egg shells) alone indicates a historical infestation. A "no nit" policy for schools and day care centers no longer is recommended because nits can persist after successful treatment with no risk of transmission. First-line pharmacologic treatment of pediculosis is permethrin 1% lotion or shampoo. Multiple novel treatments have shown limited evidence of effectiveness superior to permethrin. Wet combing is an effective nonpharmacologic treatment option. Finding pubic lice should prompt an evaluation for other sexually transmitted infections. Body lice infestation should be suspected when a patient with poor hygiene presents with pruritus. Washing affected clothing and bedding is essential if lice infestation is found, but no other environmental decontamination is necessary. Scabies in adults is recognized as a pruritic, papular rash with excoriations in a typical distribution pattern. In infants, children, and immunocompromised adults, the rash also can be vesicular, pustular, or nodular. First-line treatment of scabies is topical permethrin 5% cream. Clothing and bedding of persons with scabies should be washed in hot water and dried in a hot dryer. PMID:23062045

Gunning, Karen; Pippitt, Karly; Kiraly, Bernadette; Sayler, Morgan

2012-09-15

16

What's eating you? Canine scabies.  

PubMed

Infestation with Sarcoptes scabiei var canis, the causative strain of canine scabies, can produce a pruritic rash in humans. The rash generally manifests within 24 to 96 hours of contact with the affected pet. Scrapings are generally negative, and the correct diagnosis requires a high index of suspicion. PMID:12953932

Burroughs, Richard F; Elston, Dirk M

2003-08-01

17

Experimental canine scabies in humans.  

PubMed

Adult female Sarcoptes scabiei var. canis mites were applied to human skin for 96 hours in an experimental chamber. Clinical lesions produced during this period were studied histologically. The organisms burrowed, defecated, and laid up to nine eggs that developed normally. Two eggs hatched after removal from the host. A life cycle was not completed during this short experiment, but these results suggest canine scabies are capable of such activities on human skin. PMID:6415133

Estes, S A; Kummel, B; Arlian, L

1983-09-01

18

High-resolution melt analysis for the detection of a mutation associated with permethrin resistance in a population of scabies mites.  

PubMed

Permethrin as a topical acaricide cream is widely used to treat scabies. The neuronal voltage-sensitive sodium channel (Vssc), necessary for the generation of action potentials in excitable cells, is the target of pyrethroid acaricides such as permethrin. Pyrethroid resistance has been linked to specific mutations in the Vssc gene. Following the partial sequencing of the Vssc gene in the scabies mite Sarcoptes scabiei (L.) (Astigmata: Sarcoptidae), we compared Vssc gene sequences from permethrin-sensitive and -tolerant S. scabiei var. canis Gerlach mites, and identified a G to A single nucleotide polymorphism (SNP) in permethrin-tolerant mites resulting in an amino acid change from glycine to aspartic acid in domain III S6. The mutation is in a region of the gene where mutations have been identified in a range of pyrethroid-resistant arthropods. Results of in vitro permethrin exposure assays showed that survival rates for mites bearing the mutation were similar to those previously reported for mites from human subjects where clinical tolerance to permethrin had been observed. A real-time polymerase chain reaction-high-resolution melt (PCR-HRM) assay was developed to detect this SNP. This assay provides a useful methodology for screening for this and other mutations associated with permethrin resistance in scabies mite populations and thus facilitates surveillance for acaricide resistance. PMID:18380658

Pasay, C; Arlian, L; Morgan, M; Vyszenski-Moher, D; Rose, A; Holt, D; Walton, S; McCarthy, J

2008-03-01

19

Scabies and bedbugs in hospital outbreaks.  

PubMed

Scabies and bedbugs are two emerging ectoparasitic infections reported in crowded areas, including hospitals. Skin involvement is the main presenting initial manifestation for both infections, and the diagnosis is yet challenging for both. Topical permethrin is considered the first-line therapy for scabies except for crusted scabies which is mainly treated with oral ivermectin. To the contrary, treatment of bedbugs is mainly symptomatic. Avoiding close contact, early diagnosis and treatment of infected persons as well as decontamination of the involved environment play an essential role in controlling outbreaks in healthcare settings. PMID:24897948

Sfeir, Maroun; Munoz-Price, L Silvia

2014-08-01

20

Scabies  

MedlinePLUS

... I have a terrible, itchy rash around my anal area. ACK, help! I’m having itching and peeling around my vagina? Should I be worried? Tweets by @CYWH The Center for Young Women’s Health (CYWH) is a collaboration between the Division of Adolescent and Young Adult Medicine and the Division of ...

21

Atypical Presentation of Scabies Among Nursing Home Residents  

Microsoft Academic Search

Background. Scabies epidemics are not uncommon in nursing homes. Effective treatment is enhanced by prompt clinical diagnosis and early intervention. The clinical presentation of scabies may vary in older, immunocompromised or cognitively impaired persons. Methods. We performed a retrospective study of all residents diagnosed with scabies in a multilevel long-term care geriatric facility. The duration of the outbreak was from

Margaret-Mary G. Wilson; Carolyn D. Philpott; Wayne A. Breer

2001-01-01

22

The diagnosis and treatment of scabies and pubic lice  

Microsoft Academic Search

Scabies and pediculosis pubis (infestation with pubic lice) are examples of infections caused by human parasites. The most common mode of transmission for both infections is through sexual contact. Scabies may affect multiple sites of the body and usually presents with severe pruritus accompanied by dirty-appearing burrows beneath the skin. The diagnosis is confirmed by demonstrating the presence of the

Barbara M. Faber

1996-01-01

23

[Pseudo-scabies transmitted by red fox].  

PubMed

Pseudoscabies, i.e. infestation of human skin with animal mites may occasionally occur and should be considered in the differential diagnosis of pruritic and papular skin disease. We report here on a 52-year-old woman with pseudoscabies or canine scabies (Sarcoptes scabiei var. canis), transmitted by indirect contact with a red fox in the urban area of Berlin. Red foxes may live in unhabited areas of metropolitan large cities, i.e. in garages, car wrecks and cellars. Full remission of the prolonged and pruritic rush was seen after topical administration of lindane together with systemic corticosteroids. PMID:10097956

Birk, R W; Tebbe, B; Schein, E; Zouboulis, C C; Orfanos, C E

1999-02-01

24

Efficacy and application considerations of selected residual acaricides against the mold mite Tyrophagus putrescentiae (Acari: Acaridae) in simulated retail habitats.  

PubMed

The mold mite, Tyrophagus putrescentiae (Schrank), is a stored product pest of economic significance that commonly infests many types of food and animal feed products. There is limited information regarding pest management tactics, including residual acaricides for managing this pest in retail store habitats. The purpose of this study was to assess the potential of commercially available acaricides that could provide a protective barrier near susceptible food packages destined for consumer use. Mite mortality at 24 and 48 h was measured after exposing mites to acaricide residues applied to a nonporous surface. Two additional factors included in the study were humidity and the presence of an adjuvant to facilitate spread of acaricide on nonporous surfaces. Increasing humidity levels generally decreased acaricide efficacy. Use of the adjuvant itself did not appear to affect efficacy, but the type of application (wet or slurry, or dry) of dust acaricides significantly affected efficacy. The potential for residual acaricides to act as a barrier (within 24-48 h) against dispersal of this mite was discussed. PMID:24020311

Freitag, Jessica A; Kells, Stephen A

2013-08-01

25

9 CFR 73.4 - Interstate shipment of exposed but not visibly diseased cattle from a quarantined or...  

Code of Federal Regulations, 2010 CFR

...shipment of exposed but not visibly diseased cattle from a quarantined or nonquarantined...POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.4 Interstate shipment of exposed but not visibly diseased cattle from a quarantined or...

2010-01-01

26

9 CFR 73.4 - Interstate shipment of exposed but not visibly diseased cattle from a quarantined or...  

Code of Federal Regulations, 2011 CFR

...shipment of exposed but not visibly diseased cattle from a quarantined or nonquarantined...POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.4 Interstate shipment of exposed but not visibly diseased cattle from a quarantined or...

2011-01-01

27

Modulation of cytokine expression in human keratinocytes and fibroblasts by extracts of scabies mites.  

PubMed

Sarcoptes scabiei lives in the stratum corneum of its mammalian host. Keratinocytes and fibroblasts are among the first cells to encounter the burrowing mite and its products. The aim of this study was to determine if molecules in an extract of S. scabiei modulate the expression of cytokines by keratinocytes and fibroblasts. Human keratinocytes and fibroblasts were exposed to an extract of S. scabiei var. canis in the absence or presence of Escherichia coli lipopolysaccharide. Cytokine expression was measured by an enzyme-linked immunosorbent assay. Components in the S. scabiei extract induced marked increases in secretion of interleukin-6 (IL-6) and vascular endothelial growth factor (VEGF) and slight increases in production of granulocyte-colony-stimulating factor (G-CSF) by keratinocytes. The scabies extract down-regulated keratinocyte secretion of IL-1 receptor antagonist, but did not influence the production of IL-1alpha or IL-1beta. In comparison, components in the scabies extract induced marked increases in the elaboration of IL-6, IL-8, G-CSF, and VEGF by fibroblasts. Neither cell type produced eotaxin, stem cell factor, or tumor necrosis factor-alpha under any of the conditions tested. This study demonstrates that components in an extract of the mite S. scabiei are able to influence cytokine expression by human keratinocytes and fibroblasts. PMID:14740884

Arlian, Larry G; Morgan, Marjorie S; Neal, Jacqueline S

2003-12-01

28

Increased Allergic Immune Response to Sarcoptes scabiei Antigens in Crusted versus Ordinary Scabies?  

PubMed Central

Scabies, a parasitic skin infestation by the burrowing “itch” mite Sarcoptes scabiei, causes significant health problems for children and adults worldwide. Crusted scabies is a particularly severe form of scabies in which mites multiply into the millions, causing extensive skin crusting. The symptoms and signs of scabies suggest host immunity to the scabies mite, but the specific resistant response in humans remains largely uncharacterized. We used 4 scabies mite recombinant proteins with sequence homology to extensively studied house dust mite allergens to investigate a differential immune response between ordinary scabies and the debilitating crusted form of the disease. Subjects with either disease form showed serum IgE against recombinant S. scabiei cysteine and serine proteases and apolipoprotein, whereas naive subjects showed minimal IgE reactivity. Significantly (P < 0.05) greater serum IgE and IgG4 binding to mite apolipoprotein occurred in subjects with crusted scabies than in those with ordinary scabies. Both subject groups showed strong proliferative responses (peripheral blood mononuclear cells) to the scabies antigens, but the crusted scabies group showed increased secretion of the Th2 cytokines interleukin 5 (IL-5) and IL-13 and decreased Th1 cytokine gamma interferon (IFN-?) in response to the active cysteine protease. These data confirm that a nonprotective allergic response occurs in the crusted disease form and demonstrate that clinical severity is associated with differences in the type and magnitude of the antibody and cellular responses to scabies proteins. A quantitative IgE inhibition assay identified IgE immunoreactivity of scabies mite antigens distinct from that of house dust mite antigens, which is potentially important for specific scabies diagnosis and therapy. PMID:20631334

Walton, Shelley F.; Pizzutto, Susan; Slender, Amy; Viberg, Linda; Holt, Deborah; Hales, Belinda J.; Kemp, David J.; Currie, Bart J.; Rolland, Jennifer M.; O'Hehir, Robyn

2010-01-01

29

The epidemiology of head lice and scabies in the UK.  

PubMed Central

Anecdotal evidence suggests that the prevalence of both scabies and head lice is increasing and also that both conditions are becoming refractory to pesticide treatment. Using information obtained from the Office of National Statistics, Royal College of General Practitioners Weekly Returns Service, Department of Health, local surveys of school children from Bristol and drug sales of insecticides, we have confirmed that there has been a rise in the prevalence of both conditions. We have shown that scabies is significantly more prevalent in urbanized areas (P < 0.00001), north of the country (P < 0.000001), in children and women (P < 0.000001) and commoner in the winter compared to the summer. Scabies was also shown to have a cyclical rise in incidence roughly every 20 years. Head lice were shown to be significantly more prevalent in children and mothers (P < 0.000001) though both conditions were seen in all age groups. Head lice were also less common during the summer. Host behaviour patterns, asymptomatic carriage, drug resistance and tourism from countries or districts with a higher incidence may be important factors in the currently high prevalence of both scabies and head lice. PMID:10459652

Downs, A. M.; Harvey, I.; Kennedy, C. T.

1999-01-01

30

The development of protective immunity in canine scabies.  

PubMed

Seven of eight dogs that had been previously infested with Sarcoptes scabiei var. canis and then cured, expressed protective immunity when experimentally reinfested with scabies. All seven dogs that expressed resistance were spontaneously cleared of scabies by 64 days after they were experimentally reinfested. Five of the eight dogs were free of scabies by 24 days. The sequential changes in the inflammatory/immune cellular infiltrate in the scabietic lesions of each dog were determined during the sensitizing infestation, cure and the subsequent experimental reinfestation (challenge). During the initial infestation and in the subsequent challenge reinfestation, dogs developed mixed cellular infiltrates in their scabietic lesions that contained mononuclear cells, neutrophils, plasma cells and mast cells. Reinfestation induced more rapid increases in the densities of these cells than had occurred during the sensitizing infestation. Mononuclear and mast cells were the most numerous infiltrating cells during the sensitizing phase. During the challenge phase the most numerous infiltrating cells were mononuclear cells and neutrophils. The sensitizing and challenge infestations induced circulating scabies-specific antibody responses, but the response was more rapid during the reinfestation challenge. Both the cell-mediated response in the skin and the circulating antibody response waned in parallel with clearing of the mites following reinfestation. PMID:8638386

Arlian, L G; Morgan, M S; Rapp, C M; Vyszenski-Moher, D L

1996-03-01

31

Streptomyces scabies 87-22 Possesses a Functional Tomatinase?  

PubMed Central

The actinomycete Streptomyces scabies 87-22 is the causal agent of common scab, an economically important disease of potato and taproot crops. Sequencing of the S. scabies 87-22 genome revealed the presence of a gene with high homology to the gene encoding the ?-tomatine-detoxifying enzyme tomatinase found in fungal tomato pathogens. The tomA gene from S. scabies 87-22 was cotranscribed with a putative family 1 glycosyl hydrolase gene, and purified TomA protein was active only on ?-tomatine and not potato glycoalkaloids or xylans. Tomatinase-null mutants were more sensitive to ?-tomatine than the wild-type strain in a disk diffusion assay. Interestingly, tomatine affected only aerial mycelium and not vegetative mycelium, suggesting that the target(s) of ?-tomatine is not present during vegetative growth. Severities of disease for tomato seedlings affected by S. scabies 87-22 wild-type and ?tomA1 strains were indistinguishable, suggesting that tomatinase is not important in pathogenicity on tomato plants. However, conservation of tomA on a pathogenicity island in S. acidiscabies and S. turgidiscabies suggests a role in plant-microbe interaction. PMID:18835993

Seipke, Ryan F.; Loria, Rosemary

2008-01-01

32

Structural Mechanisms of Inactivation in Scabies Mite Serine Protease Paralogues  

SciTech Connect

The scabies mite (Sarcoptes scabiei) is a parasite responsible for major morbidity in disadvantaged communities and immuno-compromised patients worldwide. In addition to the physical discomfort caused by the disease, scabies infestations facilitate infection by Streptococcal species via skin lesions, resulting in a high prevalence of rheumatic fever/heart disease in affected communities. The scabies mite produces 33 proteins that are closely related to those in the dust mite group 3 allergen and belong to the S1-like protease family (chymotrypsin-like). However, all but one of these molecules contain mutations in the conserved active-site catalytic triad that are predicted to render them catalytically inactive. These molecules are thus termed scabies mite inactivated protease paralogues (SMIPPs). The precise function of SMIPPs is unclear; however, it has been suggested that these proteins might function by binding and protecting target substrates from cleavage by host immune proteases, thus preventing the host from mounting an effective immune challenge. In order to begin to understand the structural basis for SMIPP function, we solved the crystal structures of SMIPP-S-I1 and SMIPP-S-D1 at 1.85 {angstrom} and 2.0 {angstrom} resolution, respectively. Both structures adopt the characteristic serine protease fold, albeit with large structural variations over much of the molecule. In both structures, mutations in the catalytic triad together with occlusion of the S1 subsite by a conserved Tyr200 residue is predicted to block substrate ingress. Accordingly, we show that both proteases lack catalytic function. Attempts to restore function (via site-directed mutagenesis of catalytic residues as well as Tyr200) were unsuccessful. Taken together, these data suggest that SMIPPs have lost the ability to bind substrates in a classical 'canonical' fashion, and instead have evolved alternative functions in the lifecycle of the scabies mite.

Fischer, Katja; Langendorf, Christopher G.; Irving, James A.; Reynolds, Simone; Willis, Charlene; Beckham, Simone; Law, Ruby H.P.; Yang, Sundy; Bashtannyk-Puhalovich, Tanya A.; McGowan, Sheena; Whisstock, James C.; Pike, Robert N.; Kemp, David J.; Buckle, Ashley M.; (Monash); (Queensland Inst. of Med. Rsrch.)

2009-08-07

33

Acaricidal activity of alkaloid fractions of Leucas indica Spreng against Rhipicephalus (Boophilus) annulatus tick.  

PubMed

The acaricidal activity from alkaloid and non-alkaloid fractions of Leucas indica were studied against Rhipicephalus (Boophilus) annulatus tick using adult immersion test under laboratory conditions. For this purpose, the engorged female R.(B.) annulatus tick were exposed to two fold serial dilutions of alkaloid extract (50 mg/ml, 25 mg/ml, 12.5 mg/ml, 6 mg/ml and 3 mg/ml) using 'dipping method' in vitro. The efficacy was assessed by measuring the percentage of adult mortality, inhibition of fecundity and hatching rate. The alkaloid fraction of the extract produced concentration dependent delayed adult tick mortality. The extract at a concentration of 50 mg/ml demonstrated 66.67 per cent mortality and 55.16 per cent inhibition of fecundity. Nicotine was identified as one of the compounds of alkaloid fraction. However, it did not reveal any acaricidal activity when tested in vitro at concentrations ranging from 62.5-1000 ?g/mL. Hence, the acaricidal action of L. indica is not due to nicotine. Non alkaloid fraction also did not reveal any acaricidal effects against R. (B.) annulatus tick. PMID:24862044

Divya, T M; Soorya, V C; Amithamol, K K; Juliet, S; Ravindran, R; Nair, S N; Ajithkumar, K G

2014-03-01

34

Recommendation for the conservation of the name Streptomyces scabies. Request for an Opinion.  

PubMed

The primary streptomycete inciting common scab of potato was first legitimately described by Thaxter in 1892 as 'Oospora scabies', preserving the spelling of an epithet in use since 1846. The name Streptomyces scabies, dating to 1948, was revived in 1989, but changed to Streptomyces scabiei in 1997 to follow grammatical convention. Considering the long-established use and general recognition of 'scabies', it is proposed that the original epithet be conserved. PMID:17911322

Lambert, D H; Loria, R; Labeda, D P; Saddler, G S

2007-10-01

35

Risk Factors for Delayed Diagnosis of Scabies in Hospitalized Patients From Long-Term Care Facilities  

PubMed Central

Background Delayed diagnosis of scabies can cause an institutional outbreak, which causes considerably economic burden to control. This study was to find the risk factors for delayed diagnosis of scabies in hospitalized patients from long-term care facilities. Methods We conducted a retrospective analysis of the hospitalized patients from long-term care facilities, diagnosed to have scabies between January 2006 and December 2008. A stepwise logistic regression analysis was performed to determine the risk factors for delayed diagnosis of scabies. Results A total of 706 episodes with scabies were identified retrospectively in 399 hospitalized patients from long-term care facilities. Of these, 44 episodes were considered as delayed diagnosis of scabies. These patients were more associated with chronic usage of steroid (73% vs. 10%, P < 0.001) and had longer duration of hospitalization than the others (30 vs. 13 days, P < 0.001). After logistic regression, steroid therapy was the risk factor of delayed diagnosis of scabies (odds ratio: 23.493). Conclusions In the patients from long-term care facilities, clinical physicians should pay more attention to those with chronic usage of steroid to avoid delayed diagnosis of scabies. Keywords Scabies; Delayed diagnosis; Risk factor; Long-term care facility PMID:21811533

Lay, Chorng-Jang; Wang, Chun-Lung; Chuang, Hui-Ying; Chen, Ya-Lan; Chen, Hsiang-Ling; Tsai, Shu-Juan; Tsai, Chen-Chi

2011-01-01

36

Preliminary study of effectiveness of aloe vera in scabies treatment.  

PubMed

In an open, non-comparative study carried out between August and December 2002 at the Obafemi Awolowo University Teaching Hospitals Complex, Ile-Ife, Nigeria, 5 patients with scabies were successfully treated with crude gel of Aloe vera; thereafter the efficacy of the extract was compared with that of benzoate lotion among 30 patients. Sixteen patients were treated with Aloe vera and 14 patients had benzyl benzoate lotion. Itching was still present in 3 patients in the benzyl benzoate group and in 2 patients in the Aloe vera group after 2 courses of treatment. The scabietic lesions virtually disappeared in all of them. None of these patients had any noticeable side effects. It is concluded that Aloe vera gel is as effective as benzyl benzoate in the treatment of scabies. PMID:19274696

Oyelami, O A; Onayemi, A; Oyedeji, O A; Adeyemi, L A

2009-10-01

37

Elastosis Perforans Serpiginosa in Association with Scabies Mite  

PubMed Central

Elastosis perforans serpiginosa is a form of perforating dermatoses, which has a characteristic clinical presentation of grouped keratotic papules coalescing into serpiginous or annular configurations. The majority of elastosis perforans serpiginosa cases are idiopathic; however, various etiologies have been postulated for the pathogenesis of this syndrome. The authors present a unique case of elastosis perforans serpiginosa that developed focally secondary to a scabies mite. PMID:24155992

Frederickson, Julie; Griffith, Jack; Shitabata, Paul; Horowitz, David

2013-01-01

38

Acaricidal potentials of active properties isolated from Cynanchum paniculatum and acaricidal changes by introducing functional radicals.  

PubMed

This study evaluated the acaricidal activities of acetophenone and its derivatives for their potentials as natural acaricides using an impregnated fumigant bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae . On the basis of the LD50 values against D. farinae, 3'-methoxyacetophenone (0.41 ?g/cm(2)) was 89.9 times more toxic than DEET (36.87 ?g/cm(2)), followed by 4'-methoxyacetophenone (0.52 ?g/cm(2)), 2'-methoxyacetophenone (0.75 ?g/cm(2)), 2'-hydroxy-5'-methoxyacetophenone (1.03 ?g/cm(2)), 2'-hydroxy-4'-methoxyacetophenone (1.29 ?g/cm(2)), acetophenone (1.48 ?g/cm(2)), 2'-hydroxyacetophenone (1.74 ?g/cm(2)), 2',5'-dimethoxyacetophenone (1.87 ?g/cm(2)), 2',4'-dimethoxyacetophenone (2.10 ?g/cm(2)), and benzyl benzoate (9.92 ?g/cm(2)). In regard to structure-activity relationships between acaricidal activity and functional radicals (hydroxyl and methoxy groups) on the acetophenone skeleton, a monomethoxy group (2'-, 3'-, and 4'-methoxyacetone) on the acetophenone skeleton was more toxic than were the other groups (2',4'- and 2',5'-dimethoxyacetophenone, 2'- and 4'-hydroxyacetophenone, 2'-hydroxy-4'-methoxyacetophenone, 2'-hydroxy-5'-methoxyacetophenone, and 4'-hydroxy-3'-methoxyacetophenone). These results indicated that acaricidal activity against three mite species changed with the introduction of functional radicals (hydroxyl and methoxy groups) onto the acetophenone skeleton. PMID:23855621

Kim, Min-Gi; Yang, Ji-Yeon; Lee, Hoi-Seon

2013-08-01

39

COMPARISON OF THE REPORDUCTIVE BIOLOGY BETWEEN ACARICIDE-RESISTANT AND ACARICIDE-SUSCEPTIBLE RHIPICEPHALUS (BOOPLILUS) MICROPLUS (ACARI:IXODIDAE)  

Technology Transfer Automated Retrieval System (TEKTRAN)

The reproductive dynamics of an acaricide-susceptible strain (SUS) of Boophilus microplus were compared to strains of ticks resistant to organophosphate (OP), pyrethroid (P), or formamidine (F) acaricides to determine whether the acquisition of resistance caused a reduction in fitness. The SUS stra...

40

Acaricidal activity of aqueous extracts of camomile flowers, Matricaria chamomilla, against the mite Psoroptes cuniculi.  

PubMed

Arcaricidal properties of decoctions, infusions and macerates of dried flower heads of camomile, Matricaria chamomilla L. (Asterales: Asteraceae) were tested in vitro against the mite Psoroptes cuniculi Delafond (Parasitiformes: Psoroptidae). This mite species is responsible for otoacariasis in domestic animals. Mites were exposed to the extracts for 24, 48 or 72 h. All the extracts tested showed highly significant acaricidal activity when compared with controls. Among them, a decoction of 10% was the only formulation which gave 100% activity at all the three observations times. PMID:15189247

Macchioni, F; Perrucci, S; Cecchi, F; Cioni, P L; Morelli, I; Pampiglione, S

2004-06-01

41

Problems in Diagnosing Scabies, a Global Disease in Human and Animal Populations  

PubMed Central

Scabies is a worldwide disease and a major public health problem in many developing countries, related primarily to poverty and overcrowding. In remote Aboriginal communities in northern Australia, prevalences of up to 50% among children have been described, despite the availability of effective chemotherapy. Sarcoptic mange is also an important veterinary disease engendering significant morbidity and mortality in wild, domestic, and farmed animals. Scabies is caused by the ectoparasitic mite Sarcoptes scabiei burrowing into the host epidermis. Clinical symptoms include intensely itchy lesions that often are a precursor to secondary bacterial pyoderma, septicemia, and, in humans, poststreptococcal glomerulonephritis. Although diagnosed scabies cases can be successfully treated, the rash of the primary infestation takes 4 to 6 weeks to develop, and thus, transmission to others often occurs prior to therapy. In humans, the symptoms of scabies infestations can mimic other dermatological skin diseases, and traditional tests to diagnose scabies are less than 50% accurate. To aid early identification of disease and thus treatment, a simple, cheap, sensitive, and specific test for routine diagnosis of active scabies is essential. Recent developments leading to the expression and purification of S. scabiei recombinant antigens have identified a number of molecules with diagnostic potential, and current studies include the investigation and assessment of the accuracy of these recombinant proteins in identifying antibodies in individuals with active scabies and in differentiating those with past exposure. Early identification of disease will enable selective treatment of those affected, reduce transmission and the requirement for mass treatment, limit the potential for escalating mite resistance, and provide another means of controlling scabies in populations in areas of endemicity. PMID:17428886

Walton, Shelley F.; Currie, Bart J.

2007-01-01

42

Acaricidal effects of fenvalerate and cypermethrin against Rhipicephalus (Boophilus) annulatus.  

PubMed

The acaricidal effects of two most commonly used acaricides viz., fenvalerate and cypermethrin against Rhipicephalus (Boophilus) annulatus were studied using Adult Immersion Test (AIT). The LC50 values observed for fenvalerate and cypermethrin were 1570 ppm and 184 ppm respectively. The death of ticks was not an immediate process. Fenvalerate caused death only after 7 days while cypermethrin after 5 days of treatment. The eggs laid by treated ticks did not hatch at all concentrations tested. PMID:25382471

Ravindran, R; Ajith Kumar, K G; Suresh, N N; Amithamol, K K; Sunil, A R; Adarshkrishna, T P; Chithra, N D; Jyothimol, G; Ghosh, S; Juliet, S

2014-09-01

43

Chemistry and toxicology of quinoxaline, organotin, organofluorine, and formamidine acaricides.  

PubMed

Quinoxaline, organotin, organofluorine, and formamidine compounds are among the newer pesticide chemicals used for acarine control. Included in these four classes are some of the most selective synthetic organic toxicants currently in the acaricide/insecticide arsenal. Oxythioquinox, Plictran (tricyclohexylhydroxytin), Nissol [2-fluoro-N-methyl-N-(1-naphthyl)acetamide], and chlordimeform are examples of quinoxaline, organotin, organofluorine, and formamidine acaricides, respectively. The chemistry and toxicology of these and related compounds are discussed. PMID:789072

Knowles, C O

1976-04-01

44

Detection of living Sarcoptes scabiei larvae by reflectance mode confocal microscopy in the skin of a patient with crusted scabies  

NASA Astrophysics Data System (ADS)

Scabies is an intensely pruritic disorder induced by a delayed type hypersensitivity reaction to infestation of the skin by the mite Sarcoptes scabiei. The diagnosis of scabies is established clinically and confirmed by identifying mites or eggs by microscopic examination of scrapings from the skin or by surface microscopy using a dermatoscope. Reflectance-mode confocal microscopy is a novel technique used for noninvasive imaging of skin structures and lesions at a resolution compatible to that of conventional histology. Recently, the technique was employed for the confirmation of the clinical diagnosis of scabies. We demonstrate the first ever documentation of a larva moving freely inside the skin of a patient infected with scabies.

Levi, Assi; Mumcuoglu, Kosta Y.; Ingber, Arieh; Enk, Claes D.

2012-06-01

45

Resistance and immune response in scabies-infested hosts immunized with Dermatophagoides mites.  

PubMed

Seventy-one percent of rabbits immunized with a mixed (50:50) Dermatophagoides farinae and D. pteronyssinus house dust mite extract were resistant to infestation by Sarcoptes scabiei var. canis. The resistance was evidenced by a marked reduction in parasite load. All immunized hosts developed similar immunogen-specific antibody titers that were independent of the levels of scabies infestation that developed when the hosts were infested with scabies. Resistant hosts exhibited significantly lower scabies-specific immunoglobulin titers and produced antibody to fewer scabies antigens than did nonresistant hosts. All infested hosts (resistant and nonresistant) showed a cellular infiltrate in the scabietic lesions that was composed of neutrophils, plasma cells, macrophages, and mononuclear cells. Resistant hosts were characterized by fewer plasma cells in the infiltrate than were observed for non-resistant hosts. Resistant hosts exhibited a gradual increase in the number of infiltrating neutrophils, followed by a decrease that correlated with a decrease in the mite burden. Nonresistant hosts exhibited an early rapid increase, a decrease, and then a gradual increase in the concentration of neutrophils as the mite load increased. These results clearly showed that D. farinae/D. pteronyssinus antigens/epitopes can sensitize the hosts to scabies mites and induce protective immunity. The lower circulating antibody levels and generally stronger inflammatory cell-mediated response of resistant hosts compared with nonresistant hosts suggested that the mechanism by which immunization with Dermatophagoides mites induces immunity to scabies mites involved a down-regulated T helper cell type 2 (Th2) response with reduced antibody production but an up-regulated and stronger Th1 (inflammatory cell-mediated) response to scabies. PMID:7611562

Arlian, L G; Rapp, C M; Morgan, M S

1995-06-01

46

Scabies community prevalence and mass drug administration in two Fijian villages  

PubMed Central

Background Scabies has been estimated to affect approximately 300 million people worldwide each year. Scabies rates are high and pose a significant public health problem in Fiji. Community-based comparison treatment trials have not been undertaken. We estimated scabies prevalence and compared the efficacy and tolerability of mass drug administration (MDA) of benzyl benzoate lotion (BB) or oral ivermectin (IVM) in two villages in Fiji. Methods A prospective MDA trial was undertaken in two Fijian villages, comparing three daily applications of BB with single dose IVM or permethrin cream for those aged under two years. The therapies were offered to all community members regardless of the presence of scabies or its symptoms. The difference in prevalence was measured before and after the intervention and absolute risk reduction (ARR) and relative risk (RR) calculated. Results In the BB group, there were 572 eligible participants, of whom 435 (76%) enrolled and 201 (46%) returned for follow-up. In the IVM group, there were 667 eligible participants, of whom 325 (49%) enrolled and 126 (39%) returned. Scabies prevalence was lower after the intervention in both groups. It fell from 37.9 to 20.0% (ARR 18.0%; RR 0.52) in the BB group and from 23.7 to 9.5% (ARR 14.2%; RR 0.40) in the IVM group. Conclusions Our study provides proof of principle that MDA for scabies can reduce scabies prevalence at the community level, and that there was no significant difference in this trial between BB and oral IVM. PMID:24168177

Haar, Karin; Romani, Lucia; Filimone, Raikanikoda; Kishore, Kamal; Tuicakau, Meciusela; Koroivueta, Josefa; Kaldor, John M; Wand, Handan; Steer, Andrew; Whitfeld, Margot

2014-01-01

47

Topical (pour-on) ivermectin in the treatment of canine scabies.  

PubMed Central

The efficacy of a pour-on formulation of ivermectin at 500 micrograms/kg body weight applied on the dorsum on days 1 and 15 was evaluated in 90 dogs from a shelter, naturally infested with Sarcoptes scabiei. This very practical form of treatment was successful in eradicating scabies from this shelter. PMID:9187806

Paradis, M; de Jaham, C; Pagé, N

1997-01-01

48

Thaxtomin A production and virulence are controlled by several bld gene global regulators in Streptomyces scabies.  

PubMed

Streptomyces scabies is the main causative agent of common scab disease, which leads to significant annual losses to potato growers worldwide. The main virulence factor produced by S. scabies is a phytotoxic secondary metabolite called thaxtomin A, which functions as a cellulose synthesis inhibitor. Thaxtomin A production is controlled by the cluster-situated regulator TxtR, which activates expression of the thaxtomin biosynthetic genes in response to cello-oligosaccharides. Here, we demonstrate that at least five additional regulatory genes are required for wild-type levels of thaxtomin A production and plant pathogenicity in S. scabies. These regulatory genes belong to the bld gene family of global regulators that control secondary metabolism or morphological differentiation in Streptomyces spp. Quantitative reverse-transcriptase polymerase chain reaction showed that expression of the thaxtomin biosynthetic genes was significantly downregulated in all five bld mutants and, in four of these mutants, this downregulation was attributed to the reduction in expression of txtR. Furthermore, all of the mutants displayed reduced expression of other known or predicted virulence genes, suggesting that the bld genes may function as global regulators of virulence gene expression in S. scabies. PMID:24678834

Bignell, Dawn R D; Francis, Isolde M; Fyans, Joanna K; Loria, Rosemary

2014-08-01

49

Effect of owner-controlled acaricidal treatment on tick infestation and immune response to tick-borne pathogens in naturally infested dogs from Eastern Austria  

PubMed Central

Background Tick-borne infections resulting from regular tick infestation in dogs are a common veterinary health problem all over the world. The application of repellent and acaricidal agents to prevent transmission of pathogens is a major protection strategy and has been proven to be highly effective in several trials under laboratory and natural conditions in dogs. Despite such promising results, many dog owners still report tick infestation in their dogs although acaricidal agents are used. Information about the current infection status and changes of the infection status regarding tick-borne diseases (TBD) in dogs treated by the owner’s controlled acaricide application is lacking. Methods In this study 30 dogs were each treated with permethrin, fipronil + S-methoprene, or served as untreated controls. Application of the acaricide was performed by the owner who decided when and how often to use the spot on preparation. Over a period of 11 months, dogs were clinically examined and sampled for antibody responses against Babesia canis, Anaplasma phagocytophilum, Borrelia burgdorferi s. l., and TBE virus before the study started, 6 months later and at the end of the investigation period. Results The permethrin acaricide was applied on average 3.40 times within the examination period, whereas the fipronil + S-methoprene medication was applied 3.03 times. Approximately 2/3 of all dogs, independent of the group, had a positive immune response to one or more pathogens. Three dogs developed clinical symptoms of canine babesiosis, all other dogs remained healthy. Individual number of ticks per dog or number of infections per dog did not correlate with the application rate, and the number of ticks per dog did not influence the number of infections per dog. As owners did not apply the acaricides regularly no influence on the number of infections could be documented although the number of ticks was clearly reduced by the application of the spot-on drugs. Conclusions Clinical disease in dogs exposed to tick-borne pathogens is rare, although a humoral immune response reflecting infection is common. More educational training for dog owners is necessary to make the application of acaricides effective regarding the prevention of tick-borne diseases. PMID:23497548

2013-01-01

50

Monitoring of resistance or susceptibility of adults and larvae of Amblyomma cajennense (Acari: Ixodidae) to synthetic acaricides in Goiás, Brazil.  

PubMed

Amblyomma cajennense or the Cayenne tick is a three-host ixodid tick species of low parasitic specificity that is the principal vector of Brazilian spotted fever. The primary objective of this study was to evaluate the possible development of resistance by adult specimens of A. cajennense to deltamethrin, a synthetic pyrethroid insecticide and the principal miticide/acaricide commercially available in the region. The second objective was to monitor the susceptibility and/or resistance of larvae of this species to 12 synthetic acaricide formulations selected from the principal pesticides available in Goiás for the control of ticks. Unfed male and female adult specimens of A. cajennense were collected from leaves of bushes along a nature trail in the municipality of Caldas Novas, Goiás, Brazil. They were submitted to immersion in the highest recommended dose of deltamethrin and subsequently, were placed in contact with filter paper impregnated with the substance. The toxicological effects caused by the insecticide were observed every 6 h over a 36 h period. To obtain larvae, engorged females of A. cajennense were collected from naturally infested horses that had been free of acaricidal residue for at least 45 days, in farms situated in five different municipalities in the state (Caldas Novas, Hidrolândia, Goiás, Terezópolis and Goiânia). The larvae were exposed to different concentrations of 12 commercially available acaricidal formulations using the larval packet test (LPT) method. The control groups were treated with distilled water alone. The bioassays were performed in quadruplicate at a temperature of 27 °C, relative air humidity > 80% and 12 h light/dark cycles. The mean percentage of mortality MX was 72.6% in the adult specimens after 24 h of exposure to the dose of deltamethrin recommended by the manufacturer, characterizing a status of resistance. MX of 82, 89, 89.6 and 90% of the larvae were obtained, respectively, for deltamethrin, cypermethrin + piperonyl butoxide (PBO), amitraz and permethrin, characterizing a status of probable resistance of the larvae to these acaricides. No significant mortality was found in the control groups. PMID:20976616

Freitas, Edméia de Paula e Souza; Zapata, Marco Túlio Antônio Garcia; Fernandes, Fernando de Freitas

2011-02-01

51

[Pyrethrin and pyrethroid (permethrin) in the treatment of scabies and pediculosis].  

PubMed

The history and development of pyrethrum, the natural pyrethrins and synthetic pyrethroids and their insecticidal properties, chemical structure and toxic and allergic side-effects are reported. Permethrin is stressed as a photostable insecticide that is very effective against a large variety of insects and mites with low mammalian toxicity and virtually no allergic side-effects. Only 10-20 min after application, permethrin (1% cream rinse or 0.5% in ethanol) proved to be safe, reliable and cosmetically acceptable in the treatment of infestations with head lice and the prevention of reinfestations, and also in failures with lindane owing to the development of tolerance in the lice. The same was true of 5% permethrin cream (2.5% in children below 5 years of age) used in the treatment of scabies. Permethrin is absorbed percutaneously in only small amounts, is metabolized rapidly in the skin and excreted in the urine. A single "head to toe" application is ideal for eradication programmes allowing lice to be targetted and the prevalence of secondary bacterial infections decreased at the same time. Benzyl benzoate has an irritant potential, and lindane has been reported to exert CNS toxicity in a few anecdotal cases, in particular in small children or after repeated applications in patients with scabies crustosa, and permethrin was distinctly superior to both of these. This is documented by the results obtained in the treatment of 48 children and 56 adults suffering from scabies. Permethrin is recommended in scabies therapy in premature infants, small children, patients with seizures and neurological complications, in treatment failures with lindane entailing the need to repeat the therapy, in scabies crustosa and in pregnant women and nursing mothers. PMID:2010292

Haustein, U F

1991-01-01

52

Acaricide resistance in cattle ticks and approaches to its management: the state of play.  

PubMed

Cattle ticks are an important constraint on livestock production, particularly in tropical and subtropical areas. Use of synthetic acaricides is the primary method of tick control; therefore, it would be imperative to develop strategies to preserve the efficacy of existing acaricides. This paper summarizes the status of acaricide resistance in cattle ticks from different parts of the world and reviews modes of action of currently used acaricides, mechanism of resistance development, contributory factors for the development and spread of resistance, management of resistant strains and strategies to prolong the effect of the available acaricides. Use of vaccines, synthetic and botanical acaricides and educating farmers about recommended tick control practices are discussed, along with the integration of currently available options for the management of drug resistance and, ultimately, the control of cattle ticks. PMID:24709006

Abbas, Rao Z; Zaman, Muhammad Arfan; Colwell, Douglas D; Gilleard, John; Iqbal, Zafar

2014-06-16

53

Scabies Mite Peritrophins Are Potential Targets of Human Host Innate Immunity  

PubMed Central

Background Pruritic scabies lesions caused by Sarcoptes scabiei burrowing in the stratum corneum of human skin facilitate opportunistic bacterial infections. Emerging resistance to current therapeutics emphasizes the need to identify novel targets for protective intervention. We have characterized several protein families located in the mite gut as crucial factors for host-parasite interactions. Among these multiple proteins inhibit human complement, presumably to avoid complement-mediated damage of gut epithelial cells. Peritrophins are major components of the peritrophic matrix often found in the gut of arthropods. We hypothesized that a peritrophin, if abundant in the scabies mite gut, could be an activator of complement. Methodology/Principal Findings A novel full length scabies mite peritrophin (SsPTP1) was identified in a cDNA library from scabies mites. The amino acid sequence revealed four putative chitin binding domains (CBD). Recombinant expression of one CBD of the highly repetitive SsPTP1 sequence as TSP-hexaHis-fusion protein resulted in soluble protein, which demonstrated chitin binding activity in affinity chromatography assays. Antibodies against a recombinant SsPTP1 fragment were used to immunohistochemically localize native SsPTP1 in the mite gut and in fecal pellets within the upper epidermis, co-localizing with serum components such as host IgG and complement. Enzymatic deglycosylation confirmed strong N- and O-glycosylation of the native peritrophin. Serum incubation followed by immunoblotting with a monoclonal antibody against mannan binding lectin (MBL), the recognition molecule of the lectin pathway of human complement activation, indicated that MBL may specifically bind to glycosylated SsPTP1. Conclusions/Significance This study adds a new aspect to the accumulating evidence that complement plays a major role in scabies mite biology. It identifies a novel peritrophin localized in the mite gut as a potential target of the lectin pathway of the complement cascade. These initial findings indicate a novel role of scabies mite peritrophins in triggering a host innate immune response within the mite gut. PMID:21980545

Holt, Deborah C.; Kemp, Dave J.; Fischer, Katja

2011-01-01

54

Orally active acaricidal peptide toxins from spider venom.  

PubMed

Numerous species of ticks and mites (collectively known as acarines) are serious pests of animals, humans, and crops. There are few commercially available acaricides and major classes of these chemicals continue to be lost from the marketplace due to resistance development or deregistration by regulatory agencies. There is consequently a pressing need to isolate new and safe acaricidal compounds. In this study, we show that two families of peptide neurotoxins isolated from the venom of the Australian funnel-web spider Hadronyche versuta are lethal to the lone star tick Amblyomma americanum. These toxins, which are specific blockers of arthropod voltage-gated calcium channels, induce a pronounced phenotype characterized by an unusual gait that is rapidly followed by paralysis and death. Remarkably, one of these toxins, the calcium channel blocker omega-atracotoxin-Hv1a, is virtually equipotent whether the toxin is injected or fed to A. americanum. PMID:16330063

Mukherjee, Ashis K; Sollod, Brianna L; Wikel, Stephen K; King, Glenn F

2006-02-01

55

Microarray analysis of acaricide inducible gene expression in the southern cattle tick, Rhipicephalus (Boophilus) microplus  

Technology Transfer Automated Retrieval System (TEKTRAN)

Acaricide-inducible differential gene expression was studied in larvae of Rhipicephalus (Boophilus) microplus using a microarray-based approach. The acaricides used were: coumaphos, permethrin, ivermectin, and amitraz. The microarrays contained over 13,000 probes, having been derived from a previous...

56

Acaricidal activity of Cassia alata against Rhipicephalus (Boophilus) annulatus.  

PubMed

Using adult immersion test, the acaricidal activity of ethanolic extracts of leaves of Cassia alata L. was studied against Rhipicephalus (Boophilus) annulatus. The efficacy was assessed by measuring per cent adult mortality, inhibition of fecundity and hatching rate. The ethanolic extract of C. alata produced a concentration dependant increase in the adult tick mortality. The highest mortality (45.8%) and inhibition of fecundity (10.9%) were observed at the highest concentration tested (100 mg/ml). The plant extract did not affect egg hatchability. PMID:21909822

Ravindran, Reghu; Juliet, Sanis; Sunil, Athalathil Ramankutty; Ajith Kumar, Karapparambu Gopalan; Nair, Suresh Narayanan; Amithamol, Krishnan Kavillimakkil; Bandyopadhyay, Amitabh; Rawat, Ajay Kumar Singh; Ghosh, Srikanta

2012-01-01

57

Survival and behavioural response to acaricides of the coconut mite predator Neoseiulus baraki.  

PubMed

The coconut mite, Aceria guerreronis Keifer, is a major pest of coconut palm in the world. The control of this pest species is done through acaricide applications at short time intervals. However, the predators of this pest may also be affected by acaricides. Among the predators of A. guerreronis, Neoseiulus baraki (Athias-Henriot) has potential for biological control. The objective of this study was to assess the effect of acaricides on the survival and behavior of N. baraki. The survivorship of N. baraki was recorded in surface-impregnated arenas. Choice and no-choice behavioral bioassays were carried out using a video tracking system to assess the walking behavior of the predator under acaricide exposure. Although all acaricides negatively affected the survival of N. baraki, chlorfenapyr and azadirachtin caused lower effect than the other acaricides. No significant differences in walking behavior were observed under exposure to fenpyroximate, chlorfenapyr and chlorpyrifos on fully-contaminated arenas. Azadirachtin and chlorpyrifos caused repellence. Irritability was observed for all acaricides, except for abamectin. Chlorfenapyr was the most suitable product for managing the coconut mite because of its low effect on survival and behavior of N. baraki. PMID:23224672

Lima, Debora B; Melo, José W S; Guedes, Raul N C; Siqueira, Herbert A A; Pallini, Angelo; Gondim, Manoel G C

2013-07-01

58

A Scabies Mite Serpin Interferes with Complement-Mediated Neutrophil Functions and Promotes Staphylococcal Growth  

PubMed Central

Background Scabies is a contagious skin disease caused by the parasitic mite Sarcoptes scabiei. The disease is highly prevalent worldwide and known to predispose to secondary bacterial infections, in particular by Streptococcus pyogenes and Staphylococcus aureus. Reports of scabies patients co-infected with methicillin resistant S. aureus (MRSA) pose a major concern for serious down-stream complications. We previously reported that a range of complement inhibitors secreted by the mites promoted the growth of S. pyogenes. Here, we show that a recently characterized mite serine protease inhibitor (SMSB4) inhibits the complement-mediated blood killing of S. aureus. Methodology/Principal Findings Blood killing of S. aureus was measured in whole blood bactericidal assays, counting viable bacteria recovered after treatment in fresh blood containing active complement and phagocytes, treated with recombinant SMSB4. SMSB4 inhibited the blood killing of various strains of S. aureus including methicillin-resistant and methicillin-sensitive isolates. Staphylococcal growth was promoted in a dose-dependent manner. We investigated the effect of SMSB4 on the complement-mediated neutrophil functions, namely phagocytosis, opsonization and anaphylatoxin release, by flow cytometry and in enzyme linked immuno sorbent assays (ELISA). SMSB4 reduced phagocytosis of S. aureus by neutrophils. It inhibited the deposition of C3b, C4b and properdin on the bacteria surface, but did not affect the depositions of C1q and MBL. SMSB4 also inhibited C5 cleavage as indicated by a reduced C5b-9 deposition. Conclusions/Significance We postulate that SMSB4 interferes with the activation of all three complement pathways by reducing the amount of C3 convertase formed. We conclude that SMSB4 interferes with the complement-dependent killing function of neutrophils, thereby reducing opsonization, phagocytosis and further recruitment of neutrophils to the site of infection. As a consequence secreted scabies mites complement inhibitors, such as SMSB4, provide favorable conditions for the onset of S. aureus co-infection in the scabies-infected microenvironment by suppressing the immediate host immune response. PMID:24945501

Swe, Pearl M.; Fischer, Katja

2014-01-01

59

Novel Scabies Mite Serpins Inhibit the Three Pathways of the Human Complement System  

PubMed Central

Scabies is a parasitic infestation of the skin by the mite Sarcoptes scabiei that causes significant morbidity worldwide, in particular within socially disadvantaged populations. In order to identify mechanisms that enable the scabies mite to evade human immune defenses, we have studied molecules associated with proteolytic systems in the mite, including two novel scabies mite serine protease inhibitors (SMSs) of the serpin superfamily. Immunohistochemical studies revealed that within mite-infected human skin SMSB4 (54 kDa) and SMSB3 (47 kDa) were both localized in the mite gut and feces. Recombinant purified SMSB3 and SMSB4 did not inhibit mite serine and cysteine proteases, but did inhibit mammalian serine proteases, such as chymotrypsin, albeit inefficiently. Detailed functional analysis revealed that both serpins interfered with all three pathways of the human complement system at different stages of their activation. SMSB4 inhibited mostly the initial and progressing steps of the cascades, while SMSB3 showed the strongest effects at the C9 level in the terminal pathway. Additive effects of both serpins were shown at the C9 level in the lectin pathway. Both SMSs were able to interfere with complement factors without protease function. A range of binding assays showed direct binding between SMSB4 and seven complement proteins (C1, properdin, MBL, C4, C3, C6 and C8), while significant binding of SMSB3 occurred exclusively to complement factors without protease function (C4, C3, C8). Direct binding was observed between SMSB4 and the complement proteases C1s and C1r. However no complex formation was observed between either mite serpin and the complement serine proteases C1r, C1s, MASP-1, MASP-2 and MASP-3. No catalytic inhibition by either serpin was observed for any of these enzymes. In summary, the SMSs were acting at several levels mediating overall inhibition of the complement system and thus we propose that they may protect scabies mites from complement-mediated gut damage. PMID:22792350

Mika, Angela; Reynolds, Simone L.; Mohlin, Frida C.; Willis, Charlene; Swe, Pearl M.; Pickering, Darren A.; Halilovic, Vanja; Wijeyewickrema, Lakshmi C.; Pike, Robert N.; Blom, Anna M.; Kemp, David J.; Fischer, Katja

2012-01-01

60

Topically applied myco-acaricides for the control of cattle ticks: overcoming the challenges  

Microsoft Academic Search

In the absence of commercially viable and environmentally friendly options, the management of cattle ticks is heavily dependent\\u000a on the use of chemical acaricides. Due to recent advances in production, formulation and application technology, commercial\\u000a fungus-based biological pesticides (myco-insecticides, myco-acaricides) are becoming increasingly popular for the control\\u000a of plant pests; however, they have not been used against animal ectoparasites. The

Perry Polar; Dave Moore; Moses T. K. Kairo; Adash Ramsubhag

2008-01-01

61

Composition and Acaricidal Activity of Laurus novocanariensis and Laurus nobilis Essential Oils Against Psoroptes cuniculi  

Microsoft Academic Search

The major components of Laurus nobilis and L. novocanariensis leaf oils were identified and their acaricidal activity against Psoroptes cuniculi evaluated. Monoterpenes were predominant in L. nobilis oil (91.8%), while sesquiterpenes were only 1.4%. The main components of this oil were 1,8-cineole (39.2%), ?-terpinyl acetate (11.3%), sabinene (10.6%) and linalool (7.4%). The acaricidal activity of L. nobilis oil, at a

Fabio Macchioni; Stefania Perrucci; Pierluigi Cioni; Ivano Morelli; Paula Castilho; Francesca Cecchi

2006-01-01

62

Studies in vitro on the relative efficacy of current acaricides for Sarcoptes scabiei var. hominis  

Microsoft Academic Search

Resistance of Sarcoptes scabiei to various topical therapies has been described, but clinical assessment of treatment failure is problematic and in-vitro assays are generally not available. We describe a simple in-vitro analysis used to evaluate the relative efficacy of a range of topical, oral, and herbal treatments available in Australia for the treatment of scabies. S. scabiei var. hominis mites

S. F. Walton; M. R. Myerscough; B. J. Currie

2000-01-01

63

[Treatment of scabies and Ascabiol(®) supply disruption: what about the pediatric population?].  

PubMed

Scabies is a disease in steady increase in Île-de-France region. Standard treatment, Ascabiol(®) (benzyl benzoate/sulfiram), is back-order for several months and its return remains uncertain. Facing this drug shortage, French Drug Agency (ANSM) has imported a drug from Germany, Antiscabiosum 10 % (benzyl benzoate), to treat patients having contraindications for other scabicides available in France (ivermectin, esdepallethrine). However, infants less than 1 year (<15 kg) and asthmatics infants have no alternative treatment. A multidisciplinary workgroup explored the various existing therapeutic alternatives in France and worldwide. From ANSM's recommendations and group's experience, a decision algorithm was proposed for treating patients. However, pediatric context implied the use of off-label drugs. Proposed treatments widely known by practitioners, prescriptions-types, dose, modalities of use and dispensation, and flyers to patients were realized to optimize treatment efficacy. PMID:24768069

Berthe-Aucejo, A; Prot-Labarthe, S; Pull, L; Lorrot, M; Touratier, S; Trout, H; Bourdon, O; Dehen, L; Bourrat, E

2014-06-01

64

[Preliminary analysis of the incidence rate of scabies in Lód? population].  

PubMed

We have analysed all the reported and diagnosed cases of scabies in the years 1999-2000 per 100 000 inhabitants in the Lód? voivodeship. The data was obtained from the Regional Administration Unit for the Control of Epidemics and Hygiene Promotion in Lód?. The incidence in Lód? voivodeship was found to be twice as high (89,0) as that in Poland (44,0). The highest incidence in Lód? voivodeship was found in Radomsko (268,0), Pabianice (149,0) and Kutno (148.5) districts. The number of new cases registered in 1999-2000 did not increase in the districts: Leczyca, Radomsko, Lowicz and Be?chatów. PMID:16894748

Mamos, A R; Osi?ska, E

2001-01-01

65

Acaricide resistance status in Indian isolates of Hyalomma anatolicum.  

PubMed

The multi host tick, Hyalomma anatolicum, is the commonest Hyalomma species in India and cattle serves as the main host of this species. A study to evaluate the acaricide resistance of H. anatolicum to deltamethrin, cypermethrin and diazinon was conducted in 20 areas located in three agro climatic regions known to have abundance of the species. Results obtained by the "larval packet test" (LPT) showed a low grade resistance (level-I, RF <5) in the tick species to both deltamethrin and cypermethrin in 10 areas and higher grade resistance (level-II, RF <25) to deltamethrin in one area, where intensive use of synthetic pyrethroids are practiced for tick control. Low grade resistance to diazinon (level I) was recorded in six areas where organophosphates compounds are extensively used for agricultural practices allowing increased exposure of the moulting instars of the ticks to these chemicals. Biochemical analysis of the samples suggested involvement of esterase and alterations of acetylcholinesterase in the resistance mechanisms. PMID:22760859

Shyma, K P; Kumar, Sachin; Sharma, Anil Kumar; Ray, D D; Ghosh, S

2012-12-01

66

Ovicidal activity of topically applied acaricides against eggs of the southern cattle tick (Acari: Ixodidae).  

PubMed

Ovicidal activity of coumaphos, diazinon, dioxathion, chlorpyrifos, and crotoxyphos applied topically at 0.125, 0.25, and 0.5% (AI) to 1-d-old, 10-d-old, and 20-d-old eggs of southern cattle tick, Boophilus microplus (Canestrini), was determined. All acaricides produced some disruption of hatching of eggs in all age classes. Coumaphos, diazinon, dioxathion, and chlorpyrifos were most effective in reducing egg hatch of 1-d-old eggs but had little effect against 10- or 20-d-old eggs. Although crotoxyphos was comparable with other acaricides in reducing hatch in 1-d-old eggs, it caused significantly greater mortality (greater than or equal to 94.6%) in 20-d-old eggs than other compounds tested. Crotoxyphos applied at 0.5% (AI) is the only acaricide tested that provided sufficient ovicidal activity in all three egg age classes (greater than or equal to 85% reduction of hatch). PMID:2708632

Davey, R B; Ahrens, E H; George, J E

1989-04-01

67

Structure/activity relationship of some natural monoterpenes as acaricides against Psoroptes cuniculi.  

PubMed

The pharmacological activity of many essential oils on a large number of human and animal pathogens, as used in folk medicine, has been confirmed world-wide by several laboratory investigations. Unfortunately, the biological properties of essential oils can be extremely inconsistent because of the variability of their chemical composition. The acaricidal activities of some natural terpenoids, which are the main constitutents of several essential oils, were evaluated in vitro against the mange mite (Psoroptes cuniculi) of the rabbit, by direct contact and by inhalation. Because the test components represent different chemical classes (hydrocarbons, alcohols, and phenols, with free and esterified or etherified functional groups), it was also possible to discern in a preliminary fashion a correlation between chemical structure and acaricidal activity. The results obtained suggest that molecules possessing free alcoholic or phenolic groups showed the most potent acaricidal activity. PMID:7595592

Perrucci, S; Macchioni, G; Cioni, P L; Flamini, G; Morelli, I

1995-08-01

68

Acaricidal activity of five essential oils of Ocimum species on Rhipicephalus (Boophilus) microplus larvae.  

PubMed

The aim of this study was to evaluate the acaricidal activity on the cattle tick Rhipicephalus (Boophilus) microplus of essential oils from three Ocimum species. Acaricidal activity of five essential oils extracted from Ocimum gratissimum L. (three samples), O. urticaefolium Roth, and O. canum Sims was evaluated on 14- to 21-day-old Rhipicephalus microplus tick larvae using larval packet test bioassay. These essential oils were analyzed by gas chromatography (GC) and gas chromatography-mass spectrometry (GC/MS) showing great variations of their chemical compositions according to the botanical species and even within the O. gratissimum species; the acaricidal activity of their main compounds was also evaluated. The essential oils of O. urticaefolium and O. gratissimum collected in Cameroon were the most efficient with respective LC50 values of 0.90 and 0.98 %. The two essential oils obtained from O. gratissimum collected in New Caledonia were partially active at a dilution of 5 % while the essential oil of O. canum collected in Cameroon showed no acaricidal activity. The chemical analysis shows five different profiles. Whereas the essential oils of O. urticaefolium from Cameroon and O. gratissimum from New Caledonia contain high amounts of eugenol (33.0 and 22.3-61.0 %, respectively), 1,8-cineole was the main component of the oil of an O. canum sample from Cameroon (70.2 %); the samples of O. gratissimum oils from New Caledonia are also characterized by their high content of (Z)-?-ocimene (17.1-49.8 %) while the essential oil of O. gratissimum collected in Cameroon is mainly constituted by two p-menthane derivatives: thymol (30.5 %) and ?-terpinene (33.0 %). Moreover, the essential oil of O. urticaefolium showed the presence of elemicin (18.1 %) as original compound. The tests achieved with the main compounds confirmed the acaricidal activity of eugenol and thymol with residual activity until 0.50 and 1 %, respectively, and revealed the acaricidal property of elemicin, which was the most efficient compound with 100 % of acaricidal activity at a dilution of 0.25 % and could be a valuable acaricide for the control of the cattle tick R. microplus. PMID:25300420

Hüe, T; Cauquil, L; Fokou, J B Hzounda; Dongmo, P M Jazet; Bakarnga-Via, I; Menut, C

2015-01-01

69

Influence of long-term exposure to simulated acid rain on development, reproduction and acaricide susceptibility of the carmine spider mite, Tetranychus cinnabarinus.  

PubMed

Development, reproduction and acaricide susceptibility of Tetranychus cinnabarinus (Boisduvals) (Acari: Tetranychidae) were investigated after long-term (about 40 generations) exposure to various levels of acid rain; pH 2.5, 3.0, 4.0, and 5.6. Deionized water (pH 6.8) served as a control. The mites were reared on eggplant leaves at 28 degrees C, 80%RH and a photoperiod of 14:10 (L:D) in the laboratory. The results showed that the duration of the immature stage was significantly affected by acid rain exposure. The shortest duration (8.90 days) was recorded for populations exposed to pH 5.6 acid rain, while the longest duration (9.37 days) occurred after exposure to pH 2.5 acid rain. Compared with the control population, adult longevity was shortened with an increase in acidity. Similarly, the oviposition duration was also shortened by an increase in acidity. Statistically, female fecundity did not differ significantly between pH 5.6, pH 4.0 and control populations, but did differ significantly between the control population and those exposed to pH 2.5 and pH 3.0 acid rain. This suggested that the mite suffered reproductive defects after long-term exposure to acid rain with higher acidity (pH 2.5 and 3.0). The intrinsic rate of increase among different populations was not significantly affected, but the net reproductive rate of populations exposed to pH 2.5 and 3.0 acid rain was significantly less than pH 4.0, 5.6, and control populations. Bioassay results showed that after long-term exposure to acid rain, susceptibility of the mites to two acaricides, dichlorvos and fenpropathrin, did not change significantly. PMID:19537978

Wang, Jin-Jun; Zhang, Jian-Ping; He, Lin; Zhao, Zhi-Mo

2006-01-01

70

Acaricidal activity of 31 essential oils extracted from plants collected in Tunisia  

Microsoft Academic Search

The two-spotted spider mite Tetranychus urticae Koch is a worldwide pest, feeding on a large variety of plant families. As its resistance to acaricides spreads rapidly, it is crucial to develop new biological control tactics to manage its populations. In this respect, essential oils may be a good alternative, as they are currently considered minimum-risk pesticides. In this paper, we

Sabrine Attia; Kaouthar L. Grissa; Zeineb G. Ghrabi; Anne C. Mailleux; Georges Lognay; Thierry Hance

2012-01-01

71

Residual bioassay to assess the toxicity of Acaricides against Aceria guerreronis (Acari: Eriophyidae) under laboratory conditions.  

PubMed

Aceria guerreronis Keifer (Acari: Eriophyidae) is considered a major pest of the coconut (Cocos nucifera L.), and the use of pesticides is the current method to control it. However, no standard toxicological tests exist to select and assess the efficiency of molecules against the coconut mite. The aim of this study was to develop a methodology that allows for the evaluation of the relative toxicity of acaricides to A. guerreronis through rapid laboratory procedures. We confined A. guerreronis on arenas made out of coconut leaflets and tested two application methods: immersing the leaf fragments in acaricides and spraying acaricides on the leaf fragments under a Potter spray tower. In the latter application method, we sprayed leaf fragments both populated with and devoid of mites. We evaluated the comparative toxicity of two populations (Itamaracá and Petrolina, Pernambuco, Brazil) by spraying on leaflets without mites and submitted the mortality data to probit analysis after 24 h of exposure. No difference was observed in the LC50, regardless of whether the leaflets were immersed or sprayed with acaricide (abamectin, chlorfenapyr or fenpyroximate). The toxicity of chlorfenapyr and fenpyroximate did not differ, irrespective of whether it was applied directly to the leaflet or to the mite; however, the toxicity of abamectin was higher when applied directly to the mite. Chlorpyrifos and abamectin toxicities were lower for the Petrolina population than for the Itamaracá population. Immersing and spraying coconut leaflets can be used to assess the mortality of A. guerreronis under laboratory conditions. PMID:22928324

Monteiro, Vaneska B; Lima, Debora B; Gondim, Manoel G C; Siqueira, Herbert A A

2012-08-01

72

Effect of various acaricides on hatchability of eggs of Rhipicephalus (Boophilus) microplus.  

PubMed

The effect of commonly used acaricides (amitraz, cypermethrin, deltamethrin, fenvalerate, and flumethrin) on the eggs of Rhipicephalus (Boophilus) microplus collected from Ludhiana, Punjab, was evaluated by egg hatch assay (EHA). The regression graph of probit hatchability and per cent inhibition of hatching (IH%) of eggs was plotted against log values of concentration of various acaricides. All concentrations of flumethrin and amitraz caused complete inhibition of hatching, whereas a hatchability of 31.0 ± 6.1, 40.0 ± 5.2 and 19.3 ± 1.7% was only recorded at the highest concentration of cypermethrin, deltamethrin, and fenvalerate, respectively. An increase in the concentration of the acaricide showed a significant effect on the IH% of eggs for cypermethrin (P < 0.01) and deltamethrin (P < 0.05) but was nonsignificant for fenvalerate. The slope of the regression curve of IH% was utilized for the calculation of the dose of various acaricides causing inhibition of hatching for 95% eggs (LC95) and the discriminating dose (DD). Results indicated that maximum DD was recorded for fenvalerate (2.136%), followed by cypermethrin (0.214%) and deltamethrin (0.118%). The results of the current study will be helpful in formulating effective control strategies against ticks. PMID:25057486

Haque, M; Jyoti; Singh, N K; Rath, S S

2014-01-01

73

Acaricidal activity of active constituent isolated in Chamaecyparis obtusa leaves against Dermatophagoides spp.  

PubMed

Acaricidal activities of materials derived from Chamaecyparis obtusa leaves against Dermatophagoides farinae and Dermatophagoides pteronyssinus were examined using the dry film method and compared with that of commercial benzyl benzoate and N,N-diethyl-m-toluamide (DEET). The active constituent of the C. obtusa leaves was identified as beta-thujaplicin (C10H12(O2)) by spectroscopic analyses. Responses varied with dose. On the basis of a 24 h LC50 value, acaricidal activity against D. farinaewas more pronounced with beta-thujaplicin (72.2 mg/m2) than benzyl benzoate (89.9 mg/m2) and DEET (377 mg/m2). Acaricidal activity against D. pteronyssinus was more pronounced in beta-thujaplicin (62.1 mg/m2) than benzyl benzoate (72.4 mg/m2) and DEET (193 mg/m2). These results indicate that acaricidal activity of C. obtusa leaves likely results from by beta-thujaplicin. Beta-thujaplicin merits further study as potential house dust mite control agents or lead compounds. PMID:15769116

Jang, Young-Su; Lee, Chi-Hoon; Kim, Moo-Key; Kim, Jeong-Hak; Lee, Sang-Hyun; Lee, Hoi-Seon

2005-03-23

74

Plant essential oils and formamidines as insecticides/ acaricides: what are the molecular targets?  

E-print Network

to combat Varroa mites. Nowadays, mainly plant essential oils and organic acids are applied becausePlant essential oils and formamidines as insecticides/ acaricides: what are the molecular targets protein-coupled receptor / octopamine / thymol / tyramine 1. PLANT ESSENTIAL OILS-- AN INTRODUCTION

75

Acaricidal activity of constituents derived from peppermint oil against Tyrophagus putrescentiae.  

PubMed

The acaricidal activities of peppermint oil and menthol isomers against mites in stored food were evaluated using fumigant and contact bioassays and were compared with the activity of benzyl benzoate as a synthetic acaricide. Based on the 50% lethal dose (LD50) values against Tyrophagus putrescentiae in the fumigant bioassay, menthol (0.96 ?g/cm(2)) was approximately 12.18 times more effective than benzyl benzoate (11.70 ?g/cm(2)), followed by (+)-neomenthol (1.33 ?g/cm(2)), (-)-menthol (1.60 ?g/cm(2)), and (+)-menthol (1.90 ?g/cm(2)). In the filter paper bioassay, menthol (0.55 ?g/cm(2)) was about 15.18 times more active than benzyl benzoate (8.35 ?g/cm(2)), followed by (-)-menthol (0.84 ?g/cm(2)), (+)-menthol (0.92 ?g/cm(2)), and (+)-neomenthol (1.72 ?g/cm(2)). However, (+)-isomenthol did not exhibit any acaricidal activity against T. putrescentiae in the fumigant and filter paper bioassays. These results indicate that peppermint oil and menthol isomers could be effective natural acaricides for managing mites in stored food. PMID:25285505

Park, Jun-Hwan; Yang, Ji-Yeon; Lee, Hoi-Seon

2014-10-01

76

Acaricidal activities of materials derived from Pyrus ussuriensis fruits against stored food mites.  

PubMed

The acaricidal activities of materials derived from Pyrus ussuriensis fruits were evaluated against Tyrophagus putrescentiae and compared with that of commercial acaricide (benzyl benzoate). On the basis of the 50 % lethal dose (LD(50)) values, the ethyl acetate fraction of the fractions obtained from an aqueous extract of P. ussuriensis fruits had the highest acaricidal activity (16.32 ?g/cm(2)) against T. putrescentiae. The acaricidal constituent of P. ussuriensis fruits was isolated by chromatographic techniques and identified as 1,4-benzoquinone. On the basis of the LD(50) values, 1,4-benzoquinone (1.98 ?g/cm(2)) was 5.9 times more toxic than benzyl benzoate (11.69 ?g/cm(2)), followed by 2-isopropyl-5-methyl-1,4-benzoquinone (3.29 ?g/cm(2)), and 2,3-dimethoxy-5-methyl-1,4-benzoquinone (5.03 ?g/cm(2)) against T. putrescentiae in the fumigant bioassay. In a filter paper bioassay, the acaricidal activity of 1,4-benzoquinone (0.07 ?g/cm(2)) was 120.1 times more effective than that of benzyl benzoate (8.41 ?g/cm(2)), followed by 2-isopropyl-5-methyl-1,4-benzoquinone (0.11 ?g/cm(2)) and 2,3-dimethoxy-5-methyl-1,4-benzoquinone (0.30 ?g/cm(2)) against T. putrescentiae. These results demonstrate that P. ussuriensis fruit-derived material and its derivatives have potential as new preventive agents for the control of stored food mites. PMID:22980009

Jeon, Ju-Hyun; Yang, Ji-Yeon; Lee, Hoi-Seon

2012-07-01

77

Potential role of ATP-binding cassette transporters against acaricides in the brown dog tick Rhipicephalus sanguineus sensu lato.  

PubMed

ATP-binding cassette (ABC) transporters have been shown to be involved in pesticide detoxification in arthropod vectors and are thought to contribute to the development of drug resistance. Little is currently known about the role they play in ticks, which are among the more important vectors of human and animal pathogens. Here, the role of ABC transporters in the transport of fipronil and ivermectin acaricides in the tick Rhipicephalus sanguineus (Ixodida: Ixodidae) was investigated. Larvae were treated with acaricide alone and acaricide in combination with a sub-lethal dose of the ABC transporter inhibitor cyclosporine A. The LC50 doses and 95% confidence intervals (CIs) estimated by mortality data using probit analysis were 67.930?p.p.m. (95% CI 53.780-90.861) for fipronil and 3741?p.p.m. (95% CI 2857-4647) for ivermectin. The pre-exposure of larvae to a sub-lethal dose of cyclosporine A reduced the LC50 dose of fipronil to 4.808?p.p.m. (95% CI 0.715-9.527) and that of ivermectin to 167?p.p.m. (95% CI 15-449), which increased toxicity by about 14- and 22-fold, respectively. The comparison of mortality data for each separate acaricide concentration showed the synergic effect of cyclosporine A to be reduced at higher concentrations of acaricide. These results show for the first time a strong association between ABC transporters and acaricide detoxification in R.sanguineus s.l. PMID:25530472

Cafarchia, C; Porretta, D; Mastrantonio, V; Epis, S; Sassera, D; Iatta, R; Immediato, D; Ramos, R A N; Lia, R P; Dantas-Torres, F; Kramer, L; Urbanelli, S; Otranto, D

2015-03-01

78

Acaricidal activities of apiol and its derivatives from Petroselinum sativum seeds against Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Tyrophagus putrescentiae.  

PubMed

The acaricidal effects of an active constituent derived from Petroselinum sativum seeds and its derivatives were determined using impregnated fabric disk bioassay against Dermatophagoides farinae , Dermatophagoides pteronyssinus , and Tyrophagus putrescentiae and compared with that of synthetic acaricide. The acaricidal constituent of P. sativum was isolated by various chromatographic techniques and identified as apiol. On the basis of LD(50) values against D. farinae and D. pteronyssinus, apiol (0.81 and 0.94 ?g/cm(2)) was 12.4 and 10.2 times more toxic than benzyl benzoate (10.0 and 9.58 ?g/cm(2)), respectively. In acaricidal studies of apiol derivatives, 3,4-methylenedioxybenzonitrile (0.04, 0.03, and 0.59 ?g/cm(2)) was 250, 319, and 20.7 times more toxic than benzyl benzoate (10.0, 9.58, and 12.2 ?g/cm(2)) against D. farinae, D. pteronyssinus, and T. putrescentiae. In structure-activity relationships, the acaricidal activities of apiol derivatives could be related to allyl (-C(3)H(5)) and methoxy (-OCH(3)) functional groups. Furthermore, apiol and its derivatives could be useful for natural acaricides against these three mite species. PMID:21688847

Song, Ha Yun; Yang, Ji Yeon; Suh, Joo Won; Lee, Hoi Seon

2011-07-27

79

Integrated control of an acaricide-resistant strain of the cattle tick Rhipicephalus microplus by applying Metarhizium anisopliae associated with cypermethrin and chlorpyriphos under field conditions.  

PubMed

The efficacy of the fungus Metarhizium anisopliae to control ticks has been shown in several in vitro experiments. However, few studies have been undertaken in field conditions in order to demonstrate the applicability of its use as a biological control of ticks and its combination with chemical acaricides. The aim of the present study was to evaluate the efficacy of M. anisopliae to control an acaricide-resistant strain of Rhipicephalus microplus under laboratory and field conditions. First, the compatibility of M. anisopliae strain (TIS-BR03) with commercial acaricides and its potential to control the cattle tick were evaluated in vitro. In general, acaricide treatments had mild effects on fungus viability. In the field experiment, the median of treatment efficacy with acaricide only, M. anisopliae only and combination of M. anisopliae with acaricide were 71.1%, 56.3% and 97.9%, respectively. There is no statistical difference between groups treated with M. anisopliae and acaricide alone. Thus, in this work we have demonstrated the applicability of M. anisopliae use associated or not with chemical acaricides on field conditions in order to control an acaricide-resistant strain of the cattle tick R. microplus. PMID:25577676

Webster, Anelise; Reck, José; Santi, Lucélia; Souza, Ugo A; Dall'Agnol, Bruno; Klafke, Guilherme M; Beys-da-Silva, Walter O; Martins, João Ricardo; Schrank, Augusto

2015-01-30

80

Insecticide/acaricide resistance in fleas and ticks infesting dogs and cats  

PubMed Central

This review defines insecticide/acaricide resistance and describes the history, evolution, types, mechanisms, and detection of resistance as it applies to chemicals currently used against fleas and ticks of dogs and cats and summarizes resistance reported to date. We introduce the concept of refugia as it applies to flea and tick resistance and discuss strategies to minimize the impact and inevitable onset of resistance to newer classes of insecticides. Our purpose is to provide the veterinary practitioner with information needed to investigate suspected lack of efficacy, respond to lack of efficacy complaints from their clients, and evaluate the relative importance of resistance as they strive to relieve their patients and satisfy their clients when faced with flea and tick infestations that are difficult to resolve. We conclude that causality of suspected lack of insecticide/acaricide efficacy is most likely treatment deficiency, not resistance. PMID:24393426

2014-01-01

81

Toxicity and efficacy of selected pesticides and new acaricides to stored product mites (Acari: Acaridida)  

Microsoft Academic Search

Stored product mites can often infest stored products, but currently there is little information regarding the efficacy of\\u000a pesticides that can be used for control. In this study we evaluated several common pesticides formulated from single active\\u000a ingredients (a.i.) or commercially available mixtures (chlorpyrifos, deltamethrin, beta-cyfluthrin, and a combination of deltamethrin\\u000a and S-bioallethrin), plus an acaricide composed of permethrin, pyriproxyfen

Jan Hubert; Vaclav Stejskal; Zuzana Munzbergova; Jana Hajslova; Frank H. Arthur

2007-01-01

82

Acaricide Residues in Laying Hens Naturally Infested by Red Mite Dermanyssus gallinae  

PubMed Central

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides - sometimes in high concentrations - to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS. Ninety-one (40.4%) samples were positive to carbaryl and four samples (1.7%) were positive to permethrin. Concentrations of carbaryl exceeding the detection limit (0.005 ppm) were registered in the skin and fat of birds from two farms (p<0.01), although these concentrations remained below the maximum residue limit (MRLs) (0.05 ppm) (p<0.01). All organs/tissues of hens from a third farm were significantly more contaminated, with skin and muscle samples exceeding the MRL (0.05 ppm) (p<0.01) of carbaryl in force before its use was banned. Out of 45 chickens tested, 37 (82.2%) were found to be contaminated by carbaryl, and 4 (8.8%) by permethrin. The present study is the first report on the presence of pesticides banned by the EU (carbaryl) or not licensed for use (permethrin) in the organs and tissues of laying hens, which have been treated against red mites, and then slaughtered for human consumption at the end of their life cycle. PMID:22363736

Marangi, Marianna; Morelli, Vincenzo; Pati, Sandra; Camarda, Antonio; Cafiero, Maria Assunta; Giangaspero, Annunziata

2012-01-01

83

Acaricide residues in laying hens naturally infested by red mite Dermanyssus gallinae.  

PubMed

In the poultry industry, control of the red mite D. gallinae primarily relies worldwide on acaricides registered for use in agriculture or for livestock, and those most widely used are carbamates, followed by amidines, pyrethroids and organophosphates. Due to the repeated use of acaricides--sometimes in high concentrations--to control infestation, red mites may become resistant, and acaricides may accumulate in chicken organs and tissues, and also in eggs. To highlight some situations of misuse/abuse of chemicals and of risk to human health, we investigated laying hens, destined to the slaughterhouse, for the presence of acaricide residues in their organs and tissues. We used 45 hens from which we collected a total of 225 samples from the following tissues and organs: skin, fat, liver, muscle, hearth, and kidney. In these samples we analyzed the residual contents of carbaryl and permethrin by LC-MS/MS.Ninety-one (40.4%) samples were positive to carbaryl and four samples (1.7%) were positive to permethrin. Concentrations of carbaryl exceeding the detection limit (0.005 ppm) were registered in the skin and fat of birds from two farms (p<0.01), although these concentrations remained below the maximum residue limit (MRLs) (0.05 ppm) (p<0.01). All organs/tissues of hens from a third farm were significantly more contaminated, with skin and muscle samples exceeding the MRL (0.05 ppm) (p<0.01) of carbaryl in force before its use was banned. Out of 45 chickens tested, 37 (82.2%) were found to be contaminated by carbaryl, and 4 (8.8%) by permethrin. The present study is the first report on the presence of pesticides banned by the EU (carbaryl) or not licensed for use (permethrin) in the organs and tissues of laying hens, which have been treated against red mites, and then slaughtered for human consumption at the end of their life cycle. PMID:22363736

Marangi, Marianna; Morelli, Vincenzo; Pati, Sandra; Camarda, Antonio; Cafiero, Maria Assunta; Giangaspero, Annunziata

2012-01-01

84

Acaricidal activity of different extracts from Syzygium cumini L. Skeels (Pomposia) against Tetranychus urticae Koch  

PubMed Central

Objective To investigate the acaricidal activity of different extracts from Syzygium cumini (S. cumini) (Pomposia) againsst Tetranychus urticae Koch (T. urticae) and the biochemical changes in antioxidants enzymes. Methods Six extracts of S. cumini (Pomposia) at concentrations of 75, 150 and 300µg/mL were used to control T. urticae (Koch). Results The ethanol extract showed the most efficient acaricidal activity agent against T. urticae (98.5%) followed by hexane extract (94.0%), ether and ethyl acetate extract (90.0%). The LC50 values of the promising extract were 85.0, 101.0, 102.0 and 98.0µg/mL, respectively. The activities of enzymes including ascorbate peroxidase (APX), peroxidase (POD), superoxide dismutase (SOD) and catalase (CAT) in susceptible mites were increased. The activities of all antioxidant enzymes reach the maximum value in mites at LC50 with ethanol and ethyl acetate extracts, respectively. Conclusions The extract of S. cumini has acaricidal acivity against T. urticae, and the ethanol extract is the most efficient. PMID:23569793

Afify, Abd El-Moneim MR; El-Beltagi, Hossam S; Fayed, Sayed A; Shalaby, Emad A

2011-01-01

85

Acaricidal activities against house dust mites of spearmint oil and its constituents.  

PubMed

The aim of this study was to evaluate the acaricidal activities of spearmint oil and carvone derivatives against house dust mites using contact and fumigant toxicity bioassays to replace benzyl benzoate as a synthetic acaricide. Based on the LD50 values, the contact toxicity bioassay revealed that dihydrocarvone (0.95 and 0.88?µg/cm2) was 7.7 and 6.8 times more toxic than benzyl benzoate (7.33 and 6.01?µg/cm2) against Dermatophagoides farinae and Dermatophagoides pteronyssinus, respectively, followed by carvone (3.78 and 3.23?µg/cm2), spearmint oil (5.16 and 4.64?µg/cm2), carveol (6.00 and 5.80?µg/cm2), and dihydrocarveol (8.23 and 7.10?µg/cm2). Results of the fumigant toxicity bioassay showed that dihydrocarvone (2.73 and 2.16?µg/cm2) was approximately 4.0 and 4.8 times more effective than benzyl benzoate (11.00 and 10.27?µg/cm2), followed by carvone (6.63 and 5.78?µg/cm2), carveol (7.58 and 7.24?µg/cm2), spearmint oil (9.55 and 8.10?µg/cm2), and dihydrocarveol (9.79 and 8.14?µg/cm2). Taken together, spearmint oil and carvone derivatives are a likely viable alternative to synthetic acaricides for managing house dust mites. PMID:24488719

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Sung-Eun; Lee, Hoi-Seon

2014-02-01

86

Acaricidal effect of Cassia fistula Linn. leaf ethanolic extract against Rhipicephlaus (Boophilus) annulatus.  

PubMed

The present study evaluates the acaricidal properties of crude ethanolic extract of Cassia fistula leaves for controlling Rhipicephalus (Boophilus) annulatus based on adult immersion test (AIT). The percentage of adult mortality, inhibition of fecundity and hatching of ova laid were studied at different concentrations of the extract ranging from 50 to 100 mg / ml. The results were compared using one-way ANOVA. The extract produced complete inhibition of hatching of eggs at concentrations above 80 mg / ml of the extract. Mortality of adult engorged female ticks and inhibition of fecundity were concentration dependent. The LC50 value of extract against R. (B.) annulatus was 97.1 mg / ml. PMID:23959488

Sunil, A R; Amithamol, K K; Juliet, S; Nair, S N; Ajithkumar, K G; Soorya, V C; Divya, T M; Jyothymol, G; Ghosh, S; Ravindran, R

2013-06-01

87

In vitro evaluation of acaricidal activity of fipronil against Haemaphysalis bispinosa based on adult immersion test.  

PubMed

Fipronil is a phenylpyrazole family insecticide which mainly affects the nervous system of insects. In the present study, the in vitro acaricidal effects of the compound against the widely prevalent multihost tick, Haemaphysalis bispinosa was assessed. The lowest concentration at which complete adult tick mortality was observed was at 25 ppm while complete absence of egg mass observed at 10 ppm. Hundred per cent inhibition of fecundity was observed at 1 ppm while complete blocking of hatching of the laid ova was observed even at 500 ppb. PMID:22543603

Ravindran, R; Ajith Kumar, K G; Amithamol, K K; Sunil, A R; Juliet, S; Nair, S N; Chandrasekhar, L; Sujith, S; Varghese, S; Aparna, M; Bandyapadhyay, A; Rawat, A K S; Ghosh, S

2012-03-01

88

A model to test how ticks and louping ill virus can be controlled by treating red grouse with acaricide.  

PubMed

Ticks are the most important vectors of disease-causing pathogens in Europe. In the U.K., Ixodes ricinus L. (Ixodida: Ixodidae) transmits louping ill virus (LIV; Flaviviridae), which kills livestock and red grouse, Lagopus lagopus scoticus Lath. (Galliformes: Phasianidae), a valuable game bird. Tick burdens on grouse have been increasing. One novel method to reduce ticks and LIV in grouse may be acaricide treatment. Here, we use a mathematical model parameterized with empirical data to investigate how the acaricide treatment of grouse might theoretically control ticks and LIV in grouse. Assuming a situation in which ticks and LIV impact on the grouse population, the model predicts that grouse density will depend on deer density because deer maintain the tick population. In low deer densities, no acaricide treatment is predicted to be necessary because abundances of grouse will be high. However, at higher deer densities, the model predicts that grouse densities will increase only if high numbers of grouse are treated, and the efficacy of acaricide is high and lasts 20 weeks. The qualitative model predictions may help to guide decisions on whether to treat grouse or cull deer depending on deer densities and how many grouse can be treated. The model is discussed in terms of practical management implications. PMID:23088727

Porter, R; Norman, R A; Gilbert, L

2013-09-01

89

Impact of kaolin particle film, spirodiclofen acaricide, harpin protein, and an organic biostimulant on pear psylla Cacopsylla pyri (Hemiptera: Psyllidae)  

Microsoft Academic Search

Pear psylla Cacopsylla pyri (L.) is among the most serious pests in pear orchards. Field studies were conducted in 2005 and 2006 on pear trees (Pyrus communis L.) to assess the effect of kaolin-based particle film, spirodiclofen acaricide, harpin protein, and an organic biostimulant on C. pyri infestations. Pear psylla nymph densities were effectively suppressed over the entire season by

G. Saour; H. Ismail; A. Hashem

2010-01-01

90

In vitro acaricidal efficacy of plant extracts from Brazilian flora and isolated substances against Rhipicephalus microplus (Acari: Ixodidae).  

PubMed

The tick Rhipicephalus microplus causes significant losses in livestock cattle and has developed increasing resistance to the primary acaricides that are used to treat these infections. The objective of this study was to identify new biomolecules or isolated substances showing acaricidal activity from plants. Larval packet tests were conducted to evaluate the effects of 11 species of plants and three isolated substances (betulinic acid, eugenol, and nerolidol) on R. microplus. An adult female immersion test was performed with the substance that showed the highest larvicidal activity, which was evaluated for inhibition of reproduction. Tests using Licania tomentosa, Hymenaea stigonocarpa, Hymenaea courbaril, Stryphnodendron obovatum, Jacaranda cuspidifolia, Jacaranda ulei, Struthanthus polyrhizus, Chrysobalanus icaco, Vernonia phosphorea, Duguetia furfuracea, and Simarouba versicolor extracts as well as the isolated substance betulinic acid indicated lower acaricidal effects on R. microplus larvae. The extract displaying the best larvicidal activity was the ethanolic extract from L. tomentosa at a concentration of 60%, resulting in a mortality rate of 40.3%. However, nerolidol and eugenol showed larvicidal activity, which was highest for eugenol. Nerolidol caused a 96.5% mortality rate in the R. microplus larvae at a high concentration of 30%, and eugenol caused 100% mortality at a concentration of 0.3%. In the adult immersion test, 5% eugenol was identified as a good biomolecule for controlling R. microplus, as demonstrated by its high acaricidal activity and inhibition of oviposition. PMID:24221889

Valente, Paula Pimentel; Amorim, Juliana Mendes; Castilho, Rachel Oliveira; Leite, Romário Cerqueira; Ribeiro, Múcio Flávio Barbosa

2014-01-01

91

Determination of acaricide residues in saudi arabian honey and beeswax using solid phase extraction and gas chromatography.  

PubMed

Determination of acaricide residues of flumethrin, tau-fluvalinate, coumaphos, and amitraz in honey and beeswax was carried out using a rapid extraction method utilizing C-18 SPE cartridges and an analytical method utilizing GC with ECD, NPD, and MSD detectors for the four acaricides. Recovery percentages from the extraction method ranged from 90-102%, while the minimum detection levels ranged from 0.01-0.05 mg/kg for the acaricides. Nine of the 21 analyzed samples were found to be contaminated with the acaricides tau-fluvalinate and coumaphos. Neither flumethrin nor amitraz was detected in any of the honey or wax samples. Coumaphos was found only in honey samples in which two samples exceeded the tolerance levels set by EPA and EC regulations. It has not been detected in beeswax. Five honey samples and eight beeswax samples were found to be contaminated with tau-fluvalinate. One of the wax samples was contaminated with a relatively high residue of tau-fluvalinate and contained above 10 mg/kg. PMID:16393903

Kamel, Alaa; Al-Ghamdi, Ahmad

2006-01-01

92

First report of fluazuron resistance in Rhipicephalus microplus: a field tick population resistant to six classes of acaricides.  

PubMed

The control of the cattle tick Rhipicephalus microplus is based mainly on the use of chemical acaricides, which has contributed to the emerging problem of selection of resistant tick populations. Currently, there are six main classes of acaricides commercially available in Brazil to control cattle ticks, with fluazuron, a tick growth regulator with acaricidal properties, being the only active ingredient with no previous reports of resistance. Ticks (designated the Jaguar strain) were collected in a beef cattle ranch located at Rio Grande do Sul state, Southern Brazil, after a complaint of fluazuron treatment failure. To characterise the resistance of this strain against acaricides, larval tests were performed and showed that the Jaguar strain was resistant to all of the drugs tested: cypermethrin (resistance ratio, RR=31.242), chlorpyriphos (RR=103.926), fipronil (RR=4.441), amitraz (RR=11.907) and ivermectin (3.081). A field trial was conducted to evaluate the efficacy of fluazuron treatment in heifers that had been experimentally infested with the Jaguar or a susceptible strain. Between 14 and 28 days after treatment, the average efficacy in cattle experimentally infested with the susceptible strain was 96%, while for the Jaguar strain the efficacy was zero. Additionally, the Jaguar strain response to fluazuron was evaluated in vitro using a modified adult immersion test (AIT) and the artificial feeding assay (AFA). With the AIT, 50 ppm of fluazuron inhibited 99% of larvae hatching in the susceptible strain (POA) and less than 50% in the Jaguar strain. Results of the AFA showed a larval hatching rate of 67% at 2.5 ppm of fluazuron with the Jaguar strain; conversely, only 3% of larvae of the susceptible strain hatched at the same fluazuron concentration. The results showed here demonstrated the first case of fluazuron resistance in R. microplus and the first tick population resistant to six classes of acaricides in Brazil. PMID:24560364

Reck, José; Klafke, Guilherme Marcondes; Webster, Anelise; Dall'Agnol, Bruno; Scheffer, Ramon; Souza, Ugo Araújo; Corassini, Vivian Bamberg; Vargas, Rafael; dos Santos, Julsan Silveira; Martins, João Ricardo de Souza

2014-03-17

93

Efficacy of pheromone-acaricide-impregnated tail-tag decoys for controlling the bont tick,Amblyomma hebraeum (Acari: Ixodidae), on cattle in Zimbabwe  

Microsoft Academic Search

A large-scale field test using pheromone-acaricide-impregnated plastic tail-tag decoys demonstrated excellent efficacy of these devices for control of the bont tick,Amblyomma hebraeum, on cattle in Zimbabwe. The tail tags were impregnated with a mixture containingo-nitrophenol, methyl salicylate, 2,6-dichlorophenol and phenylacetaldehyde and one of three different acaricides (cyfluthrin, flumethrin or alphacypermethrin).o-Nitrophenol and methyl salicylate are components of theA. hebraeum attraction-aggregation-attachment pheromone,

R. A. I. Norval; Daniel E. Sonenshine; Sandra A. Allan; Michael J. Burridge

1996-01-01

94

Acaricidal properties of the essential oil from Zanthoxylum caribaeum against Rhipicephalus microplus.  

PubMed

Zanthoxylum caribaeum Lamarck (Rutaceae) is plant species with a variety of medical applications, including insecticidal activity. This study determined the bioacaricidal activity of the essential oil from Z. caribaeum leaves against engorged Rhipicephalus (Boophilus) microplus (Canestrini, 1887) females using the adult immersion test. For this purpose, three serial concentrations (5.0, 2.5, and 1.25%, vol:vol, in 1% dimetilsulfoxide) of the essential oil were used. Essential oil 5% caused 65% mortality on the first day after treatment, 85% on the second day, and 100% mortality by the fifth day. To our knowledge, this is the first demonstration of the acaricidal activity of the essential oil from Z. caribaeum leaves against cattle ticks. PMID:25276925

Nogueira, Jeane; Vinturelle, Rafaelle; Mattos, Camila; Tietbohl, Luis Armando Candido; Santos, Marcelo Guerra; Junior, Itabajara Silva Vaz; Mourão, Samanta Cardozo; Rocha, Leandro; Folly, Evelize

2014-09-01

95

Acaricidal effect of herbal extracts against cattle tick Rhipicephalus (Boophilus) microplus using in vitro studies.  

PubMed

The crude methanolic extract of Datura stramonium, Azadirachta indica, and Calotropis procera leaves, Allium sativum (AS) cloves, and Carica papaya (CP) seeds collected from Banaskanta, Gujarat (India) was tested for its acaricidal properties against Rhipicephalus (Boophilus) microplus. The percent adult mortality within 15 days, reproductive index, percentage inhibition of oviposition, hatching of laid ova, and percentage larval mortality were studied at concentrations of 12.5, 25, 50, and 100 mg/ml. At the highest concentration (100 mg/ml), the adult tick mortality was 66.67, 73.33, 80.00, and 93.33% for C. procera, D. stramonium, A. sativum, and C. papaya extracts, respectively, and it was statistically significant (P?acaricidal properties and could be a potential component of alternative R. (B.) microplus tick control strategy. PMID:24633906

Shyma, K P; Gupta, J P; Ghosh, S; Patel, K K; Singh, Veer

2014-05-01

96

Acaricidal properties of the formulations based on essential oils from Cymbopogon winterianus and Syzygium aromaticum plants.  

PubMed

The cattle tick, Rhipicephalus (Boophilus) microplus, has caused serious harm to livestock raising in Brazil, considering the costs of controlling it, loss of revenue due to smaller production of milk and meat, and damage to leather, in addition to transmitting diseases. The use of medicinal plants is considered an alternative to the recurring resistance to chemicals. Due to the need for efficient alternatives with less environmental impact, this study aimed to develop contact formulations with essential oils from the Java citronella (Cymbopogon winterianus) and clove (Syzygium aromaticum) plants and to assess in vitro the effects in different stages of the tick cycle. In the present study, concentrations from 0.5-15.0 % of the essential oils incorporated in the formulations were used. The ticks from different geographical areas were treated with those formulations, and their effects on the production levels of eggs, on the larvae hatching, and their efficiency on ticks were assessed. The obtained results were compared with other commercial acaricidal products. After the 20th day of treatment, the formulations with citronella essential oil had 2.09-55.51 % efficiency, depending on the concentration of the oil incorporated. The efficiency of the treatment with formulations containing clove essential oil was higher, from 92.47-100 %. The results showed the acaricidal effects of the formulations tested when compared to commercial chemical products. In vivo studies should be performed in order to assess the efficiency of those formulations in the fields, aiming to use these products as an alternative for controlling cattle ticks. PMID:25199555

de Mello, Valéria; Prata, Márcia Cristina de Azevedo; da Silva, Márcio Roberto; Daemon, Erik; da Silva, Luciane Santos; Guimarães, Flávia Del Gaudio; de Mendonça, Alessandra Esther; Folly, Evelize; Vilela, Fernanda Maria Pinto; do Amaral, Lilian Henriques; Cabral, Lucio Mendes; do Amaral, Maria da Penha Henriques

2014-12-01

97

Acaricidal properties of the essential oil of Melaleuca alternifolia Cheel (tea tree oil) against nymphs of Ixodes ricinus.  

PubMed

The aim of the study was to examine the acaricidal effect of essential oil of Melaleuca alternifolia (tea tree oil, TTO) at different doses (4, 6, 8 and 10 microl) and for different exposure times (30, 60, 90 and 120 min) on nymphs of Ixodes ricinus. A dose of 8 microl TTO was lethal for more than 70% of ticks when inhaled and this effect was enhanced when the dose was increased to 10 microl (> 80%). The effect was correlated with the duration of exposure of ticks to TTO, with a significant effect being observed after 90 min exposure. The findings show that TTO has acaricidal properties and could be extremely useful in controlling ticks that are efficient vectors of pathogens. PMID:15817219

Iori, A; Grazioli, D; Gentile, E; Marano, G; Salvatore, G

2005-04-20

98

Acaricidal activities of some essential oils and their monoterpenoidal constituents against house dust mite, Dermatophagoides pteronyssinus (Acari: Pyroglyphidae)  

PubMed Central

The acaricidal activities of fourteen essential oils and fourteen of their major monoterpenoids were tested against house dust mites Dermatophagoides pteronyssinus. Five concentrations were used over two different time intervals 24 and 48 h under laboratory conditions. In general, it was noticed that the acaricidal effect based on LC 50 of either essential oils or monoterpenoids against the mite was time dependant. The LC 50 values were decreased by increasing of exposure time. Clove, matrecary, chenopodium, rosemary, eucalyptus and caraway oils were shown to have high activity. As for the monoterpenoids, cinnamaldehyde and chlorothymol were found to be the most effective followed by citronellol. This study suggests the use of the essential oils and their major constituents as ecofriendly biodegradable agents for the control of house dust mite, D. pteronyssinus. PMID:17111463

Saad, El-Zemity; Hussien, Rezk; Saher, Farok; Ahmed, Zaitoon

2006-01-01

99

Determination of synthetic acaricides residues in beeswax by high-performance liquid chromatography with photodiode array detector.  

PubMed

A multiresidue HPLC method for identification and quantification of the synthetic acaricides fluvalinate, coumaphos, bromopropylate and its metabolite 4,4'-dibromobenzophenone in beeswax has been developed. Different techniques were tested and modified. The method consists of a sample preparation with isooctane followed by solid phase extraction using Florisil columns. Determination of the synthetic acaricides is achieved by HPLC with a photodiode array detector. Analytical performance of the proposed method, including sensitivity, accuracy and precision was satisfactory. The LOD for the analytes varied between 0.1 and 0.2 microg g(-1) wax and the recoveries between 70 and 110%. Relative standard deviation of the repeatability of the method is <15% and reproducibility is <31%. PMID:17386431

Adamczyk, Sabine; Lázaro, Regina; Pérez-Arquillué, Consuelo; Herrera, Antonio

2007-01-01

100

Effect of plant essential oils as acaricides against the poultry red mite, Dermanyssus gallinae, with special focus on exposure time  

Microsoft Academic Search

Essential oils from thyme and cade have been shown to be effective acaricides against the poultry red mite, Dermanyssus gallinae (De Geer) when tested over a 24h period. Data on the actual rate of knock-down achieved with these products is lacking and potentially important as essential oils are likely to display only short-term toxicity.When tested over periods of less than

D. R. George; G. Olatunji; J. H. Guy; O. A. E. Sparagano

2010-01-01

101

Acaricidal toxicity of 2'-hydroxy-4'-methylacetophenone isolated from Angelicae koreana roots and structure-activity relationships of its derivatives.  

PubMed

The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derived from Angelica koreana roots and its derivatives against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae were examined by vapor phase and contact toxicity bioassays. In the vapor phase toxicity bioassay, 2'-methylacetophenone (1.25 ?g/cm(2)) was 8.0 times more toxic against D. farinae than benzyl benzoate (10.00 ?g/cm(2)), followed by 3'-methylacetophenone (1.26 ?g/cm(2)), 4'-methylacetophenone (1.29 ?g/cm(2)), 2'-hydroxy-4'-methylacetophenone (1.75 ?g/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.96 ?g/cm(2)). In the contact toxicity bioassay, 3'-methylacetophenone (0.58 ?g/cm(2)) was 17.24 times more effective against D. farinae than benzyl benzoate (7.52 ?g/cm(2)), followed by 2'-methylacetophenone (0.64 ?g/cm(2)), 2'-hydroxy-4'-methylacetophenone (0.76 ?g/cm(2)), 4'-methylacetophenone (0.77 ?g/cm(2)), and 2'-hydroxy-5'-methylacetophenone (1.16 ?g/cm(2)). The acaricidal activities of 2'-hydroxy-4'-methylacetophenone derivatives against D. pteronyssinus and T. putrescentiae were similar to those against D. farinae. In terms of structure-activity relationships, acaricidal activity against the three mite species changed with the introduction of hydroxyl and methyl functional groups onto the acetophenone skeleton. Furthermore, some of 2'-hydroxy-4'-methylacetophenone derivatives could be useful for natural acaricides against three mite species. PMID:22429095

Oh, Min Seok; Yang, Ji-Yeon; Lee, Hoi Seon

2012-04-11

102

Acaricide Treatment Affects Viral Dynamics in Varroa destructor-Infested Honey Bee Colonies via both Host Physiology and Mite Control  

PubMed Central

Honey bee (Apis mellifera) colonies are declining, and a number of stressors have been identified that affect, alone or in combination, the health of honey bees. The ectoparasitic mite Varroa destructor, honey bee viruses that are often closely associated with the mite, and pesticides used to control the mite population form a complex system of stressors that may affect honey bee health in different ways. During an acaricide treatment using Apistan (plastic strips coated with tau-fluvalinate), we analyzed the infection dynamics of deformed wing virus (DWV), sacbrood virus (SBV), and black queen cell virus (BQCV) in adult bees, mite-infested pupae, their associated Varroa mites, and uninfested pupae, comparing these to similar samples from untreated control colonies. Titers of DWV increased initially with the onset of the acaricide application and then slightly decreased progressively coinciding with the removal of the Varroa mite infestation. This initial increase in DWV titers suggests a physiological effect of tau-fluvalinate on the host's susceptibility to viral infection. DWV titers in adult bees and uninfested pupae remained higher in treated colonies than in untreated colonies. The titers of SBV and BQCV did not show any direct relationship with mite infestation and showed a variety of possible effects of the acaricide treatment. The results indicate that other factors besides Varroa mite infestation may be important to the development and maintenance of damaging DWV titers in colonies. Possible biochemical explanations for the observed synergistic effects between tau-fluvalinate and virus infections are discussed. PMID:22020517

Forsgren, Eva; Fries, Ingemar; de Miranda, Joachim R.

2012-01-01

103

Acaricidal Activity of Petroleum Ether Extract of Leaves of Tetrastigma leucostaphylum (Dennst.) Alston against Rhipicephalus (Boophilus) annulatus  

PubMed Central

The acaricidal activity of the petroleum ether extract of leaves of Tetrastigma leucostaphylum (Dennst.) Alston (family: Vitaceae) against Rhipicephalus (Boophilus) annulatus was assessed using adult immersion test (AIT). The per cent of adult mortality, inhibition of fecundity, and blocking of hatching of eggs were studied at different concentrations. The extract at 10% concentration showed 88.96% inhibition of fecundity, 58.32% of adult tick mortality, and 50% inhibition of hatching. Peak mortality rate was observed after day 5 of treatment. Mortality of engorged female ticks, inhibition of fecundity, and hatching of eggs were concentration dependent. The LC50 value of the extract against R. (B.) annulatus was 10.46%. The HPTLC profiling of the petroleum ether extract revealed the presence of at least seven polyvalent components. In the petroleum ether extract, nicotine was identified as one of the components up to a concentration of 5.4%. However, nicotine did not reveal any acaricidal activity up to 20000 ppm (2%). Coconut oil, used as diluent for dissolving the extract, did not reveal any acaricidal effects. The results are indicative of the involvement of synergistic or additive action of the bioactive components in the tick mortality and inhibition of the oviposition. PMID:25436226

Krishna, T. P. Adarsh; Krishna, T. P. Ajeesh; Chithra, N. D.; Deepa, P. E.; Darsana, U.; Sreelekha, K. P.; Juliet, Sanis; Nair, Suresh N.; Ajith Kumar, K. G.; Ghosh, Srikanta

2014-01-01

104

Studies on the acaricidal mechanism of the active components from neem (Azadirachta indica) oil against Sarcoptes scabiei var. cuniculi.  

PubMed

Octadecanoic acid-3,4-tetrahydrofuran diester, isolated from neem (Azadirachta indica) oil, exhibited potent acaricidal activity against Sarcoptes scabiei var. cuniculi. In this paper, the acaricidal mechanism of octadecanoic acid-3,4-tetrahydrofuran diester against Sarcoptes scabiei var. cuniculi was evaluated based on pathologic histology and enzyme activities. The results showed that after compound treatment for 24h at a concentration of 20mg/mL, the lesions of mites were prominent under transmission electron microscopy. The lesions consisted of the lysis of dermis cell membranes and cell nuclear membranes, mitochondrial morphological abnormalities, the drop of spinal disorders, and mitochondrial vacuolization. The activity of superoxide dismutase (SOD), peroxidase (POD), glutathione-s-transferases (GSTs), and Ca(2+)-ATPase of mites significantly changed after treatment with octadecanoic acid-3,4-tetrahydrofuran diester compared with the control group. The activities of SOD, POD, and Ca(2+)-ATPase were significantly suppressed, whereas that of GSTs was activated. These results indicated that the mechanism of the acaricidal activity of octadecanoic acid-3,4-tetrahydrofuran diester was mainly achieved through interference with the energy metabolism of mites, thus resulting in insect death. PMID:24974121

Chen, Zhen-zhen; Deng, Yun-xia; Yin, Zhong-qiong; Wei, Qin; Li, Mei; Jia, Ren-yong; Xu, Jiao; Li, Li; Song, Xu; Liang, Xiao-xia; Shu, Gang; He, Chang-liang; Gu, Xiao-bin; Lv, Cheng; Yin, Lizi

2014-08-29

105

Window contamination on Expose-R  

NASA Astrophysics Data System (ADS)

Expose is a multi-user instrument for astrobiological and astrochemical experiments in space. Installed at the outer surface of the International Space Station, it enables investigators to study the impact of the open space environment on biological and biochemical test samples. Two Expose missions have been completed so far, designated as Expose-E (Rabbow et al. 2012) and Expose-R (Rabbow et al. this issue). One of the space-unique environmental factors offered by Expose is full-spectrum, ultraviolet (UV)-rich electromagnetic radiation from the Sun. This paper describes and analyses how on Expose-R, access of the test samples to Solar radiation degraded during space exposure in an unpredicted way. Several windows in front of the Sun-exposed test samples acquired a brown shade, resulting in a reduced transparency in visible light, UV and vacuum UV (VUV). Post-flight investigations revealed the discolouration to be caused by a homogenous film of cross-linked organic polymers at the inside of the windows. The chemical signature varied per sample carrier. No such films were found on windows from sealed, pressurized compartments, or on windows that had been kept out of the Sun. This suggests that volatile compounds originating from the interior of the Expose facility were cross-linked and photo-fixed by Solar irradiation at the rear side of the windows. The origin of the volatiles was not fully identified; most probably there was a variety of sources involved including the biological test samples, adhesives, plastics and printed circuit boards. The outer surface of the windows (pointing into space) was chemically impacted as well, with a probable effect on the transparency in VUV. The reported analysis of the window contamination on Expose-R is expected to help the interpretation of the scientific results and offers possibilities to mitigate this problem on future missions - in particular Expose-R2, the direct successor of Expose-R.

Demets, R.; Bertrand, M.; Bolkhovitinov, A.; Bryson, K.; Colas, C.; Cottin, H.; Dettmann, J.; Ehrenfreund, P.; Elsaesser, A.; Jaramillo, E.; Lebert, M.; van Papendrecht, G.; Pereira, C.; Rohr, T.; Saiagh, K.

2015-01-01

106

Linkage and dominance characteristics of genes for resistance to organophosphorus acaricides and allelic inheritance of decreased brain cholinesterase activity in three strains of the cattle tick, Boophilus microplus.  

PubMed

Resistance to the organophosphorus acaricides diazinon, dimethoate and formothion in the Biarra (B), Mackay (M) and Ridgelands (R) strains respectively of the cattle tick B. microplus has been shown previously to be controlled in each strain by a single incompletely dominant autosomal genetic factor. A very similar mode of inheritance of fenthion resistance in strain B has now been demonstrated with no departure in degree of dominance of resistance from the mean value of +0-57 common to these strains exposed to these chemicals. No F1 larval progeny from the following crossings were appreciably more resistant than their parents to these chemicals: R x B--bromophos ethyl and fenthion; B x M--carbaryl, chlorfenvinphos, chlorpyrifos, diazinon, dimethoate, ethion, fenthion and formothion; M x R--chlorfenvinphos, diazinon, dimethoate, ethion, formothion. The field importance of this absence of overdominance is discussed. There were no susceptible double recessive F2 larval progeny of B x M crossings of F2 or F3 larval progeny of R x M crossings when tested against dimethoate to which the three parental types were similarly resistant; 1/16 of the larval progeny would be expected to be completely susceptible if the resistance genes were unlinked. F1 adult progeny of B x M and R x M crossings exhibited the incompletely recessive mutant-type decreased brain acetylcholinesterase (AChE) activity common to strains B, M and R, thus satisfying the test for allelism. No ticks with normal levels of brain AChE were detected in F2 adult progeny of B x M or R x M crossings. This evidence was strongly suggestive of a series of closely linked genes or alleles controlling dimethoate resistance and a series of alleles controlling decreased brain AChE activity in strains B, M and R. PMID:985225

Stone, B F; Wilson, J T; Youlton, N J

1976-07-01

107

SUSCEPTIBILIDAD DE Tetranychus urticae Koch (Acari: Tetranychidae) COLECTADA EN Primula obconica Hance Y Convolvulus arvensis L. A ACARICIDAS Susceptibility of Tetranychus urticae Koch (Acari: Tetranychidae) collected in Primula obconica Hance and Convolvulus arvensis L. to acaricides  

Microsoft Academic Search

A B S T R A C T The use of acaricides of high toxicity in the production and handling of ornamental plants should be a matter of consumer concern. The susceptibility of two populations of Tetranychus urticae was assessed: one collected from Primula obconica Hance and the other from Convolvulus arvenis L. as susceptible reference strain to the acaricides

108

Acaricide activity of different extracts from Piper tuberculatum fruits against Rhipicephalus microplus.  

PubMed

Rhipicephalus microplus is the main tick that affects cattle. Plant bioactive molecules can be used to control this ectoparasite. The aim of this study was to evaluate the in vitro efficacy of Piper tuberculatum fruit extracts obtained with different solvents on R. microplus larvae and engorged females. Hexane, ethyl ether, ethanolic, and methanolic extracts of P. tuberculatum fruits were evaluated. After extraction, all of the extracts were dried. Adult immersion tests and larval packet tests were performed with five different concentrations of each of the extracts. The hexane extracts of P. tuberculatum showed the highest larvicidal activity against R. microplus (lethal concentration (LC50 = 0.04 mg/mL), followed by the ethyl ether (LC50 = 0.08 mg/mL), ethanolic (LC50 = 2.73 mg/mL), and methanolic (LC50 = 4.49 mg/mL) extracts. The P. tuberculatum fruit extracts were also effective against R. microplus-engorged females. Ethyl acetate extracts showed the highest efficiency (LC50 = 18.4 mg/mL), followed by the methanolic (LC50 = 105.6 mg/mL), ethanolic (LC50 = 140.0 mg/mL), and hexane (LC50 = 297.4 mg/mL) extracts. All of the extracts showed similar chromatographic profiles containing 24% piperine. The P. tuberculatum fruit extracts contain bioactive compounds with great potential to improve the standard formulations of acaricides for the control of R. microplus. PMID:24221883

Lima, Aldilene da Silva; Sousa Filho, José Gracione do Nascimento; Pereira, Sinval Garcia; Guillon, Giselle Maria Skelding Pinheiro; Santos, Lourivaldo da Silva; Costa Júnior, Livio Martins

2014-01-01

109

Acaricidal efficacy against cattle ticks and acute oral toxicity of Lippia javanica (Burm F.) Spreng.  

PubMed

In search for low-cost, safe and environmentally benign plant-based alternatives to commercial pesticides, the efficacy of Lippia javanica aqueous leaf extracts in controlling ticks on cattle, acute oral toxicity in mice and phytochemistry were evaluated. L. javanica aqueous leaf extracts at 10% and 20% w/v were effective at controlling cattle ticks but not as good as an amitraz-based acaricide Tickbuster. However, they can provide an effective tick control option where synthetic products are unavailable or unaffordable, particularly in remote parts of southern Africa. Peripheral blood samples collected showed no haemoparasites in treated cattle implying that animals did not suffer from clinical tick-borne diseases. The leaf aqueous extracts of L. javanica were tested for toxicity in BALB/c mice. While anecdotal evidence suggests L. javanica has low mammalian toxicity, within 48 h all mice fed with the L. javanica leaf aqueous extract at 12.5-37.5% v/v were lethargic, and overall mortality was 37.5% (n = 24). Thus, despite their apparent safety, water extracts of L. javanica leaves may have deleterious health implications on humans and animals if consumed at very high doses. Many compounds have been identified from L. javanica including an array of phenolic glycosides, flavonoids and essential oils but none of these are known to have acute toxic properties. PMID:20978842

Madzimure, James; Nyahangare, Emmanuel T; Hamudikuwanda, Humphrey; Hove, Thokozani; Stevenson, Philip C; Belmain, Steve R; Mvumi, Brighton M

2011-02-01

110

Acaricidal activity of ethanolic extract of Artemisia absinthium against Hyalomma anatolicum ticks.  

PubMed

The aim of the study was to evaluate the in vitro efficacy of different concentrations of ethanolic extract obtained from the aerial parts of Artemisia absinthium in comparison to amitraz on adults, eggs and larvae of Hyalomma anatolicum using the adult immersion test (AIT), egg hatchability test and larval packet test (LPT), respectively. Four concentrations of the extract (2.5, 5, 10 and 20%) with three replications for each concentration were used in all the bioassays. In AIT, the mortality rates at 2.5, 5 and 10% were significantly different (p < 0.05) in comparison to the control group; however, at 20%, it was similar to the positive control group. Maximum mortality of 86.7% was recorded at 20%. The LC50 and LC95 values were calculated as 6.51 and 55.43%, respectively. The oviposition was reduced significantly by 36.8 and 59.1% at concentrations of 10 and 20%, respectively. Egg hatchability was reduced significantly at all concentrations (2.5-20%) in comparison to the control. In LPT, the extract caused 100% mortality of larvae at all the concentrations after 24 h. The results show that ethanolic extract obtained from the aerial parts of A. absinthium has acaricidal properties and could be useful in controlling H. anatolicum. PMID:25039005

Godara, R; Parveen, S; Katoch, R; Yadav, A; Katoch, M; Khajuria, J K; Kaur, D; Ganai, A; Verma, P K; Khajuria, Varun; Singh, N K

2015-01-01

111

Acaricidal activity of Cymbopogon citratus and Azadirachta indica against house dust mites  

PubMed Central

Objective To examine the acaricidal effects of the essential oil of Cymbopogon citratus leaf extract (lemongrass) and ethanolic Azadirachta indica leaf extract (neem) against house dust mites Dermatophagoides farinae (D. farinae) and Dermatophagoides pteronyssinus (D. pteronyssinus). Methods Twenty-five adults mites were placed onto treated filter paper that is soaked with plant extract and been tested at different concentrations (50.00%, 25.00%, 12.50%, 6.25% and 3.13%) and exposure times (24hrs, 48hrs, 72hrs and 96 hrs). All treatments were replicated 7 times, and the experiment repeated once. The topical and contact activities of the two herbs were investigated. Results Mortalities from lemongrass extract were higher than neem for both topical and contact activities. At 50 % concentration, both 24 hrs topical and contact exposures to lemongrass resulted in more than 91% mortalities for both species of mites. At the same concentration and exposure time, neem resulted in topical mortalities of 40.3% and 15.7% against D. pteronyssinus and D. farinae respectively; contact mortalities were 8.0% and 8.9% against the 2 mites, respectively. There was no difference in topical mortalities of D. pteronyssinus from exposure to concentrations of lemongrass and neem up to 12.50%; lemongrass was more effective than neem at the higher concentrations. Conclusions Generally, topical mortalities of D. farinae due to lemongrass are higher than that due to neem. Contact mortalities of lemongrass are always higher that neem against both species of mites. PMID:23569794

Hanifah, Azima Laili; Awang, Siti Hazar; Ming, Ho Tze; Abidin, Suhaili Zainal; Omar, Maizatul Hashima

2011-01-01

112

EXPOSE-R cosmic radiation time profile  

NASA Astrophysics Data System (ADS)

The aim of the paper is to present the time profile of cosmic radiation exposure obtained by the radiation risks radiometer-dosimeter (R3DR) during the ESA exposition facility for EXPOSE-R mission (EXPOSE-R) in the EXPOSE-R facility outside the Russian Zvezda module of the International Space Station (ISS). Another aim is to make the obtained results available to other EXPOSE-R teams for use in their data analysis. R3DR is a low mass and small dimensions automated device, which measures solar radiation in four channels and in addition cosmic ionizing radiation. The main results of cosmic ionizing radiation measurements are: three different radiation sources were detected and quantified: galactic cosmic rays (GCR), energetic protons from the inner radiation belt (IRB) in the region of the South Atlantic anomaly and energetic electrons from the outer radiation belt (ORB). The highest daily averaged absorbed dose rate of 506 ?Gy day-1 came from IRB protons; GCR delivered much smaller daily absorbed dose rates of 81.4 ?Gy day-1 on average, and ORB source delivered on average a dose rate of 89 ?Gy day-1. The IRB and ORB daily averaged absorbed dose rates were higher than those observed during the ESA exposition facility for EXPOSE-E mission (EXPOSE-E), whereas the GCR rate was smaller than that measured during the EXPOSE-E mission. The reason for this difference is much less surrounding constructions shielding of the R3DR instrument in comparison with the R3DE instrument.

Dachev, Tsvetan; Horneck, Gerda; Häder, Donat-Peter; Schuster, Martin

2015-01-01

113

Acaricidal toxicities of 1-hydroxynaphthalene from Scutellaria barbata and its derivatives against house dust and storage mites.  

PubMed

The essential oil of Scutellaria barbata was extracted using a steam distillation and then evaluated via fumigant and contact toxicity bioassays against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and Tyrophagus putrescentiae. The acaricidal toxicities of 1-hydroxynaphthalene from S. barbata oil and its derivatives were determined and compared with those of benzyl benzoate. Based on the LD50 values of 1-hydroxynaphthalene derivatives against D. farinae, D. pteronyssinus, and T. putrescentiae, obtained using a fumigant toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (2.11, 2.37, and 4.50 µg/cm2) was 4.76, 6.00, and 2.68 times higher than that of benzyl benzoate (10.05, 9.50, and 12.50 µg/cm2) in the corresponding order, which was followed by that of 2-hydroxynaphthalene (9.50, 9.00, and 11.50 µg/cm2). On the contact toxicity bioassay, the acaricidal activity of 1-hydroxynaphthalene (0.79, 0.92, and 2.50 µg/cm2) was 9.49, 6.52, and 3.76 times higher than that of benzyl benzoate (7.50, 6.00, and 9.41 µg/cm2), which was followed by that of 2-hydroxynaphthalene (4.21, 4.80, and 6.50 µg/cm2). In conclusion, our results indicate that S. barbata oil and 1-hydroxynaphthalene derivatives might be effective natural agents for the management of house dust and storage mites. PMID:23757178

Yang, Ji-Yeon; Kim, Min-Gi; Lee, Hoi-Seon

2013-07-01

114

Acaricidal activities of major constituents of essential oil of Juniperus chinensis leaves against house dust and stored food mites.  

PubMed

The acaricidal activities of major constituents from the oil of Juniperus chinensis (var. globosa) leaves were compared with those of DEET (N,N-diethyl-m-toluamide) by using impregnated fabric disk bioassay against Dermatophagoides spp. and Tyrophagus putrescentiae. Toxicity varied with doses as well as chemical composition. The 50% lethal doses (LD50) of J. chinensis oil against Dermatophagoides farinae, Dermatophagoides pteronyssinus, and T. putrescentiae were 21.60, 19.89, and 38.10 microg/cm2, respectively. The active constituent was purified using silica gel chromatography and high-performance liquid chromatography. The acaricidal component was identified as bomyl acetate through gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C-NMR, 1H-13C shift correlation spectrum-NMR, and distortionless enhancement by polarization transfer-NMR. The LD50 of bornyl acetate (2.94 microg/cm2) against D. farinae was significantly lower than those of DEET (37.13 microg/cm2) and alpha-eudesmol (29.72 microg/cm2). Similar results were observed when bomyl acetate and alpha-eudesmol were tested against D. pteronyssinus and T. putrescentiae. The lower LD50 of bornyl acetate indicates that it may be responsible for the major acaricidal activity against house dust and stored food mites, even though it constitutes only 19.5% of J. chinensis oil. Overall, these findings indicated that bornyl acetate and c-eudesmol have potential for use as control agents against house dust and stored food mites. PMID:19722401

Lee, Chi-Hoon; Park, Joon-Moh; Song, Ha-Yun; Jeong, Eun-Young; Lee, Hoi-Seon

2009-08-01

115

Acaricidal activity of Thymus vulgaris oil and its main components against Tyrophagus putrescentiae, a stored food mite.  

PubMed

The acaricidal activities of compounds derived from Thymus vulgaris (thyme) oil against Tyrophagus putrescentiae were assessed using an impregnated fabric disk bioassay, and were compared with those of the synthetic acaricides, benzyl benzoate and N,N-diethyl-m-toluamide. The observed responses differed according to dosage and chemical components. The 50% lethal dose (LD50) value of the T. vulgaris oil against T. putrescentiae was 10.2 microg/cm2. Biologically active constituents derived from T. vulgaris oil were purified by using silica gel chromatography and high-performance liquid chromatography. The structures of acaricidal components were analyzed by gas chromatography-mass spectrometry, 1H nuclear magnetic resonance (NMR), 13C NMR, 1H-13C COSY-NMR, and DEPT-NMR spectra, and were subsequently identified as carvacrol and thymol. Carvacrol was the most toxic compound with LD50 values (4.5 microg/cm2) significantly different from thymol (11.1 microg/cm2), benzyl benzoate (11.3 microg/cm2), and N,N-diethyl-m-toluamide (13.9 microg/cm2). Linalool was as toxic as was N,N-diethyl-m-toluamide. The lower LD50 of carvacrol indicates that it may be the major contributor of the toxicity of T. vulagaris oil against the stored food mite, although it only constitutes 14.2% of the oil. From this point of view, carvacrol and thymol can be very useful as potential control agents against stored food mite. PMID:18326186

Jeong, E Y; Lim, J H; Kim, H G; Lee, H S

2008-02-01

116

Acaricidal activity of the essential oils from three Lamiaceae plant species on Rhipicephalus turanicus Pom. (Acari: Ixodidae).  

PubMed

Acaricidal effects of three Labiatae essential oils extracted from ariel parts of Thymus sipyleus Boiss. subsp. sipyleus, Mentha longifolia L., and Dorystoechas hastata Boiss. & Heldr. ex Bentham on 10-day-old Rhipicephalus turanicus Pom. (Acari: Ixodidae) larvae were evaluated by using the larval packet test bioassay. Serial dilutions of the three essential oils were tested from a starting concentration of 1-0.1% (1.0, 0.5, 0.25, and 0.1% w/v). Results showed that all essential oils had very similar activity, producing complete mortality (100%) in all tested concentrations on 10-day-old R. turanicus tick larvae. PMID:22581297

Koc, Samed; Oz, Emre; Ayd?n, Levent; Cetin, Huseyin

2012-10-01

117

Verbenone structural analogues isolated from Artemesia aucheri as natural acaricides against Dermatophagoides spp. and Tyrophagus putrescentiae.  

PubMed

The acaricidal activities of Artemisia aucheri oil and (1S)-(-)-verbenone structural analogues were evaluated using a fumigant method against Dermatophagoides farinae , Dermatophagoides pteronyssinus , and Tyrophagus putrescentiae and then compared to those of benzyl benzoate. On the basis of the LD50 values against D. farinae , (1S)-(-)-verbenone (1.38 ?g/cm(2)) was about 7.4 times more active than benzyl benzoate (10.15 ?g/cm(2)), followed by (+)-trans-myrtanol (2.27 ?g/cm(2)), (-)-trans-myrtanol (2.30 ?g/cm(2)), and A. aucheri oil (8.75 ?g/cm(2)). (1S)-(-)-Verbenone (1.25 ?g/cm(2)) was approximately 7.8 times more effective against D. pteronyssinus than benzyl benzoate (9.80 ?g/cm(2)), followed by (+)-trans-myrtanol (2.18 ?g/cm(2)), (-)-trans-myrtanol (2.22 ?g/cm(2)), and A. aucheri oil (8.46 ?g/cm(2)). In the case of T. putrescentiae , (1S)-(-)-verbenone (3.75 ?g/cm(2)) was roughly 3.5 times more toxic than benzyl benzoate (13.25 ?g/cm(2)), followed by (+)-trans-myrtanol (12.57 ?g/cm(2)), (-)-trans-myrtanol (12.95 ?g/cm(2)), and A. aucheri oil (11.55 ?g/cm(2)). These results indicate that A. aucheri oil and (1S)-(-)-verbenone structural analogues may be effective natural agents to control house dust and storage mites. PMID:24295367

Yang, Ji-Yeon; Lee, Hoi-Seon

2013-12-18

118

Acaricide resistance in northern fowl mite (Ornithonyssus sylviarum) populations on caged layer operations in Southern California.  

PubMed

Southern California caged layer operations were visited over 3 yr. Northern fowl mites from 26 field populations were tested for acaricide resistance using a capillary pipette and glass dish bioassay. One was a susceptible field population with no pesticide exposure for over 30 yr (reference site for resistance ratio calculation). Technical and commercial formulations of malathion, carbaryl (Sevin), permethrin, and a commercial formulation of tetrachlorvinphos/dichlorvos (Ravap) were tested. Malathion did not have high activity for mites relative to other materials, but resistance to both technical and commercial formulations was low (< 5x). Resistance to other materials was moderate to extreme. Frequency of carbaryl resistance (> 10x) was higher with the commercial (88%) than the technical material (41%); 19% of the populations had resistance > 100x to commercial carbaryl. Frequency of Ravap resistance (> 10x) was 68%; 8% of populations had resistance > 100x. Frequency of permethrin resistance (> 10x) was 72% for the technical material and 88% for the commercial formulation. Extreme permethrin resistance (> 1,000x) was observed in 56 and 50% of mite populations assayed using the technical and commercial formulations, respectively. Among sites, resistance to permethrin was uncorrelated with resistance to other chemicals, suggesting a different resistance mechanism. Resistance to carbaryl and Ravap was highly correlated [r = 0.76 at the LC50 level (concentrations estimated to be lethal to 50% of the test population) and r = 0.99 at the LC95 level], suggesting a common resistance mechanism. Producers currently depend completely on pesticides to control mite infestations. Mite resistance to registered materials emphasizes the need for integrated control measures. PMID:15049488

Mullens, B A; Velten, R K; Hinkle, N C; Kuney, D R; Szijj, C E

2004-03-01

119

CYP9Q-mediated detoxification of acaricides in the honey bee (Apis mellifera)  

PubMed Central

Although Apis mellifera, the western honey bee, has long encountered pesticides when foraging in agricultural fields, for two decades it has encountered pesticides in-hive in the form of acaricides to control Varroa destructor, a devastating parasitic mite. The pyrethroid tau-fluvalinate and the organophosphate coumaphos have been used for Varroa control, with little knowledge of honey bee detoxification mechanisms. Cytochrome P450-mediated detoxification contributes to pyrethroid tolerance in many insects, but specific P450s responsible for pesticide detoxification in honey bees (indeed, in any hymenopteran pollinator) have not been defined. We expressed and assayed CYP3 clan midgut P450s and demonstrated that CYP9Q1, CYP9Q2, and CYP9Q3 metabolize tau-fluvalinate to a form suitable for further cleavage by the carboxylesterases that also contribute to tau-fluvalinate tolerance. These in vitro assays indicated that all of the three CYP9Q enzymes also detoxify coumaphos. Molecular models demonstrate that coumaphos and tau-fluvalinate fit into the same catalytic pocket, providing a possible explanation for the synergism observed between these two compounds. Induction of CYP9Q2 and CYP9Q3 transcripts by honey extracts suggested that diet-derived phytochemicals may be natural substrates and heterologous expression of CYP9Q3 confirmed activity against quercetin, a flavonoid ubiquitous in honey. Up-regulation by honey constituents suggests that diet may influence the ability of honey bees to detoxify pesticides. Quantitative RT-PCR assays demonstrated that tau-fluvalinate enhances CYP9Q3 transcripts, whereas the pyrethroid bifenthrin enhances CYP9Q1 and CYP9Q2 transcripts and represses CYP9Q3 transcripts. The independent regulation of these P450s can be useful for monitoring and differentiating between pesticide exposures in-hive and in agricultural fields. PMID:21775671

Mao, Wenfu; Schuler, Mary A.; Berenbaum, May R.

2011-01-01

120

Scabies: Prevention and Control  

MedlinePLUS

... Related Links For Health Care Providers and Institutional Staff Institutional Settings Print page Get email updates Listen to audio/Podcast Contact Us: Centers for Disease Control and Prevention 1600 Clifton Rd. Atlanta, GA 30333 1-800-CDC-INFO (1-800-232-4636) TTY: 1-888-232- ...

121

Travelers' Health: Scabies  

MedlinePLUS

... Travel Safe, Travel Smart Share Compartir Chapter 3 Infectious Diseases Related To Travel Chapter 3 - Salmonellosis (Nontyphoidal) Chapter ... Red Book: 2012 Report of the Committee on Infectious Diseases. 29th ed. Elk Grove Village, IL: American Academy ...

122

Scabies: Tips for Managing  

MedlinePLUS

... About dermatology A to Z: The video series Classroom activities Media Media resources Media contacts Public service ... About dermatology A to Z: The video series Classroom activities Home Dermatology A to Z Diseases and ...

123

Biofunctional constituent isolated from Citrullus colocynthis fruits and structure-activity relationships of its analogues show acaricidal and insecticidal efficacy.  

PubMed

The acaricidal and insecticidal potential of the active constituent isolated from Citrullus colocynthis fruits and its structurally related analogues was evaluated by performing leaf disk, contact toxicity, and fumigant toxicity bioassays against Tetranychus urticae, Sitophilus oryzae, and Sitophilus zeamais adults. The active constituent of C. colocynthis fruits was isolated by chromatographic techniques and was identified as 4-methylquinoline on the basis of spectroscopic analyses. To investigate the structure-activity relationships, 4-methylquinoline and its structural analogues were tested against mites and two insect pests. On the basis of the LC50 values, 7,8-benzoquinoline was the most effective against T. urticae. Quinoline, 8-hydroxyquinoline, 2-methylquinoline, 4-methylquinoline, 6-methylquinoline, 8-methylquinoline, and 7,8-benzoquinoline showed high insecticidal activities against S. oryzae and S. zeamais regardless of the application method. These results indicate that introduction of a functional group into the quinoline skeleton and changing the position of the group have an important influence on the acaricidal and insecticidal activities. Furthermore, 4-methylquinoline isolated from C. colocynthis fruits, along with its structural analogues, could be effective natural pesticides for managing spider mites and stored grain weevils. PMID:25110971

Jeon, Ju-Hyun; Lee, Hoi-Seon

2014-08-27

124

Laboratory assessment of acaricidal activity of Cymbopogon winterianus, Vitex negundo and Withania somnifera extracts against deltamethrin resistant Hyalomma anatolicum.  

PubMed

Larval packet test was used for detection of resistance levels against cypermethrin and deltamethrin, the most commonly used synthetic pyrethroids, in the multi-host tick Hyalomma anatolicum collected from district Moga, Punjab (India). Results indicated the presence of level I resistance against deltamethrin (RF = 2.81), whereas the tick isolate was susceptible to cypermethrin (RF = 0.2). The aqueous and ethanolic extracts of leaves of Cymbopogon winterianus, Vitex negundo and Withania somnifera along with roots of Vitex negundo were assessed for their acaricidal activity against the larvae of deltamethrin resistant H. anatolicum. The efficacy was assessed by measuring per cent larval mortality and determination of LC50 values. The various ethanolic extracts produced a concentration dependent increase in larval tick mortality, whereas the aqueous extracts exhibited a much lower mortality. The highest mortality (93.7 ± 0.66 %) was observed at the 5.0 % concentration of ethanolic extract of leaves of C. winterianus and the lowest LC50 value (0.011 %) was recorded for ethanolic extracts of leaves of V. negundo. The results indicated that these plant extracts have potential to be developed as herbal acaricides. PMID:24647800

Singh, Nirbhay Kumar; Jyoti; Vemu, Bhaskar; Nandi, Abhijit; Singh, Harkirat; Kumar, Rajender; Dumka, V K

2014-07-01

125

Effect of plant essential oils as acaricides against the poultry red mite, Dermanyssus gallinae, with special focus on exposure time.  

PubMed

Essential oils from thyme and cade have been shown to be effective acaricides against the poultry red mite, Dermanyssus gallinae (De Geer) when tested over a 24h period. Data on the actual rate of knock-down achieved with these products is lacking and potentially important as essential oils are likely to display only short-term toxicity. When tested over periods of less than 24h, thyme essential oil killed D. gallinae relatively quickly and so may make for an effective acaricide even if the residual toxicity of this product is low. However, cade essential oil did not display such a high level of mite knock-down, suggesting it may hold less promise in D. gallinae management. Comparison of the results with those obtained elsewhere using alternative D. gallinae products further confirms the possibility that thyme essential may be useful in control of this pest. This might be especially true if thyme essential oil were employed as part of an integrated pest management approach. PMID:20071087

George, D R; Olatunji, G; Guy, J H; Sparagano, O A E

2010-04-19

126

Acaricidal properties of Artemisia absinthium and Tanacetum vulgare (Asteraceae) essential oils obtained by three methods of extraction.  

PubMed

Essential oils of Artemisia absinthium L. and Tanacetum vulgare L. were extracted by three methods, a microwave assisted process (MAP), distillation in water (DW) and direct steam distillation (DSD), and tested for their relative toxicity as contact acaricides to the two spotted spider mite, Tetranychus urticae Koch. All three extracts of A. absinthium and of T. vulgare were lethal to the spider mite but to variable degrees. The LC50 obtained from the DSD oil of A. absinthium was significantly lower (0.04 mg/cm2) than that of the MAP (0.13 mg/cm2) and DW (0.13 mg/cm2) oil of this plant species. DSD and DW extracts of T. vulgare were more toxic (75.6 and 60.4% mite mortality, respectively, at 4% concentration) to the spider mite than the MAP extract (16.7% mite mortality at 4% concentration). Chromatographic analysis indicated differences in composition between the more toxic DSD oil of A. absinthium and the other two extracts of this plant, indicating that a sesquiterpene (C15H24) compound present in the DSD oil and absent in the other two may enhance the toxicity of the DSD oil. Chemical analysis of the T. vulgare extracts indicated that beta-thujone is by far the major compound of the oil (>87.6%) and probably contributes significantly to the acaricidal activity of the oil. PMID:11233109

Chiasson, H; Bélanger, A; Bostanian, N; Vincent, C; Poliquin, A

2001-02-01

127

Topical Treatment of White-Tailed Deer with an Acaricide for the Control of Ixodes Scapularis (Acari: Ixodidae) in a Connecticut Lyme Borreliosis Hyperendemic Community  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann), against ticks using the acaricide amitraz, was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21–24 of the 4-Posters were distrib...

128

In vitro assessment of the acaricidal activity of computer-selected analogues of carvacrol and salicylic acid on Rhipicephalus (Boophilus) microplus.  

PubMed

Rhipicephalus (Boophilus) microplus is a tick that causes huge economic losses in cattle. The indiscriminate use of acaricides has generated resistance to most compounds present on the market. This makes further investigation on other potential acaricides necessary, the in silico assay being an alternative to the design of new compounds. In the present study a biosilico assay was performed using TOMOCOMD-CARDD (TOpological MOlecular COMputer Design-Computer-Aided Rational Drug Design) and WEKA (Waikato Environment for Knowledge Analysis) software. Two carvacrol and four salicylic acid derivatives, synthesized by conventional methods and evaluated with the larval packet test on larvae of R. (B.) microplus were selected. All evaluated compounds presented acaricidal activity; however, ethyl 2-methoxybenzoate (91.8 ± 1.7 % mortality) and ethyl 2,5-dihydroxybenzoate (89.1 ± 1.6 % mortality) showed greater activity than salicylic acid. With regard to the carvacrol analogues, carvacrol acetate (67.8 ± 2.1 % mortality) and carvacrol methyl ether (71.7 ± 1.6 % mortality) also showed greater activity than carvacrol (35.9 ± 3.2 % mortality). TOMOCOMD-CARDD and WEKA software were helpful tools in the search for alternative structures with potential acaricidal activity on R. (B.) microplus. PMID:23543288

Concepción, Ramírez L; Froylán, Ibarra V; Herminia I, Pérez M; Norberto, Manjarrez A; Héctor J, Salgado Z; Yeniel, González C

2013-10-01

129

Acaricidal effects of herb essential oils against Dermatophagoides farinae and D. pteronyssinus (Acari: Pyroglyphidae) and qualitative analysis of a herb Mentha pulegium (pennyroyal)  

PubMed Central

This experiment was undertaken to screen the acaricidal effects of herb essential oils (pennyroyal, ylang ylang, citronella, lemon grass, tea tree, and rosemary) at different doses (0.1, 0.05, 0.025, 0.0125, and 0.00625 µl/cm2) and exposure times (5, 10, 20, 20, 30 and 60 min) on house dust mites Dermatophgoides farinae and D. pteronyssinus. The most effective acaricidal components of pennyroyal (Mentha pulegium) were analyzed using a gas chromatography-mass spectrometer (GC-MS). Of these essential oils, the most effective was pennyroyal, which is composed essentially of pulegone (> 99%), at a dose of 0.025 µl/cm2 which at an exposure time of 5 min killed more than 98% of house dust mites. In the pennyroyal fumigation test, the closed method was more effective than the open method and maximum acaricidal effect was 100% at 0.025 µl/cm2, 60 min. The results show that herb essential oils, in particular, pennyroyal was proved to have potent acaricidal activity. PMID:16809961

Rim, In-Sook

2006-01-01

130

Acaricidal Treatment of White-Tailed Deer to Control Ixodes Scapularis (Acari: Ixodidae) in a New York Lyme Disease-Endemic Community  

Technology Transfer Automated Retrieval System (TEKTRAN)

The 4-Poster device for the topical treatment of white-tailed deer, Odocoileus virginianus (Zimmermann) against ticks using the acaricide amitraz was evaluated in a Lyme borreliosis endemic community in Connecticut. As part of a 5-year project from 1997 to 2002, 21–24 of the 4-Posters were distribut...

131

Acaricidal activity of extract of Artemisia absinthium against Rhipicephalus sanguineus of dogs.  

PubMed

The objective of the study was to evaluate the in vitro efficacy of different concentrations of chloroform extract obtained from the aerial parts of Artemisia absinthium in comparison to amitraz on adults, eggs and larvae of the dog tick Rhipicephalus sanguineus using the adult immersion test (AIT), egg hatchability test (EHT) and larval packet test (LPT), respectively. Five concentrations of the extract (1.25, 2.5, 5, 10 and 20 %) with three replications for each concentration were used in all the bioassays. A control group was established (water + dimethylsulphoxide) together with a positive control group (amitraz), with three repetitions each. In AIT, the mortality rates were 0.0, 13.3, 16.7, 33.3 and 93.3 % in concentrations of 1.25, 2.5, 5, 10 and 20 %, respectively, and the variation was significant (p=0.0151). The LC50 (CI) and LC95 (CI) values were calculated as 8.793 % (8.217-9.408) and 34.59 % (29.71-40.26), respectively. The egg production was reduced by 6.6, 6.6, 18.3, 42.5 and 85.1 % in the concentrations of 1.25, 2.5, 5, 10 and 20 %, respectively, and it was statistically significant (p=0.0274). In EHT, hatching was completely inhibited at 5, 10 and 20 % displaying 100 % ovicidal action while at the concentrations of 1.25 and 2.5 %, the inhibition rates were 20 and 60 %, respectively. In LPT, the extract caused 100 % mortality of larvae in the concentrations of 5, 10 and 20 % after 24 h while at the concentrations of 1.25 and 2.5 %, the mortality rates were 54.3 and 96.7 %, respectively. The LC50 (CI) and LC95 (CI) values were determined to be 1.11 % (1.099-1.121) and 2.37 % (2.328-2.423), respectively. The results show that the extract of A. absinthium has acaricidal properties and could be useful in controlling R. sanguineus which is an efficient vector of pathogens both in dogs and humans. PMID:24288053

Godara, R; Parveen, S; Katoch, R; Yadav, A; Verma, P K; Katoch, M; Kaur, D; Ganai, A; Raghuvanshi, P; Singh, N K

2014-02-01

132

In-Vitro Assessment of the Acaricidal Properties of Artemisia annua and Zataria multiflora Essential Oils to Control Cattle Ticks  

PubMed Central

Background The aim of this study was to investigate the ‘acaricidal effect’ of Zataria multiflora and Artemisia annua essential oils on Rhipicephalus (Boophilus) annulatus. Methods This study was carried out in 2009 in the Laboratory of Parasitology of the Faculty of Veterinary Medicine of Shahrekord University, west central Iran. Six dilutions (5, 10, 20, 40, 60 and 80 µL/cm3) of both essential oils were used against engorged female R. (Boophilus) annulatus ticks using an in vitro immersion method. The mortality rates for each treatment were recorded 6, 15 and 24 hours post inoculation (hpi). Mortality rate was analyzed using Repeated Measures Analysis of Variance, and comparison of means was carried out using General Linear Models Procedure. Results The mortality rate caused by different dilutions of Z. multiflora essential oil ranged from 26.6% (using 10 µL/cm3) to 100% (using 40 µL/cm3) and for A. annua essential oil it was 33.2 to 100% (using 20 and 80 µL/cm3, respectively) by the end of the experiment (36 hpi). No mortality was recorded for the non-treated control group or for dilutions less than 5 and 10 µL/cm3 using Zataria and Artemisia essential oils, respectively. For Z. multiflora mortality peaked at 15 hpi for all concentrations other than 20 µL/cm3 and took 24 h to achieve its maximum effect while for A. annua the two highest concentrations needed 24 hpi to reach their full effect. In addition, essential oils applied at more than 20 and 60 µL/cm3 caused 100% egg-laying failure in engorged female ticks by Zataria and Artemisia, respectively while no failure was observed for the non-treated control group. The mortality rate in both botanical acaricides was dose-dependent. Conclusion Both these medicinal plants have high potential acaricidal effects on the engorged stage of R. (Boophilus) annulatus in vitro. PMID:22347275

Pirali-Kheirabadi, KH; Teixeira da Silva, JA

2011-01-01

133

Comparison of in vitro acaricidal effects of commercial preparations of cypermethrin and fenvalerate against Rhipicephalus (Boophilus) annulatus.  

PubMed

Commercially available preparations of cypermethrin (Clinar and Ectomin) and fenvalerate (Flytik and Ticomax, 20% E.C) were compared for their acaricidal activity against Rhipicephalus (Boophilus) annulatus using adult immersion test. Adult tick mortality was higher with Ectomin compared to Clinar. Complete eclosion blocking was observed at all the tested concentrations with Ectomin while it was observed only at the highest concentration tested for Clinar. Compared to Flytik, adult tick mortality was higher with Ticomax at the tested concentrations. Complete blocking of hatching of laid ova was observed with Flytik at the highest concentration tested. At the manufacture recommended dosage of 200 ppm Ectomin elicited 93.37 per cent inhibition of fecundity, while it was 91.7 per cent for Clinar. For fenvalerate, the recommended concentration was 1200 ppm at which Ticomax showed 86 per cent and Flytik produced 80.05 per cent inhibition of fecundity respectively. PMID:24570856

Ravindran, Reghu; Ramankutty, Sunil Athalathil; Juliet, Sanis; Palayullaparambil, Adarsh Krishna Thumadath; Gopi, Jyothimol; Gopalan, Ajith Kumar Karapparambu; Nair, Suresh Narayanan; Ghosh, Srikanta

2014-01-01

134

Acaricidal properties of two extracts from Guiera senegalensis J.F. Gmel. (Combrataceae) against Hyalomma anatolicum (Acari: Ixodidae).  

PubMed

Laboratory test were carried out on eggs, larvae, nymphs and adults of Hyalomma anatolicum to determine the acaricidal activities of petroleum ether (PE) and crude ethanolic extracts (EE) from the leaves of Guiera senegalensis J.F. Gmel. (Combrataceae) using immersion method. Stock solutions, of 300 mg/ml (30%) of the each two extract, were prepared. Six two-fold serial dilutions each with three replicates were used. Both extracts, at the highest concentration 150 mg/ml (15%), induced 100% failure of hatching of the treated eggs. The concentrations of PE and EE that induced 50% inhibition of the hatchability (IC50) were 1.71 and 0.508%, respectively. In the larval immersion test (LIT), EE at 15% concentration caused complete mortality while the same concentration of PE resulted in 96% mortality. The mortalities increased with concentrations. There was a correlation between the mortalities and increased concentrations, the values of the linear correlation coefficient (r) for PE and EE were 0.93 and 0.79, and The LC50 and LC99 were 2.08 and 14.09, and 0.787 and 11.054, respectively. At the concentrations of 3.75%, 7.5% and 15%, PE inhibited the molting of the nymphs by 40, 55 and 65%, respectively, while EE induced 46.49, 64.3 and 71.4% inhibition, respectively. The effectiveness of the treatment against unfed adult females was assessed by measuring the feeding performance and egg production using adult immersion test (AIT). Although, there was no mortality in unfed adults, PE and EE inhibited feeding and egg-laying of the survived females by 35-100% and 6.16-100%, respectively. Our results indicated that G. senegalensis is a promising biocontrol candidate as an acaricidal agent against H. anatolicum. PMID:24315188

Osman, Ilham M; Mohammed, A S; Abdalla, A B

2014-01-31

135

Acaricidal effect and chemical composition of essential oils extracted from Cuminum cyminum , Pimenta dioica and Ocimum basilicum against the cattle tick Rhipicephalus (Boophilus) microplus (Acari: Ixodidae)  

Microsoft Academic Search

Acaricidal activity of essential oils extracted from cumin seeds (Cuminum cyminum), allspice berries (Pimenta dioica) and basil leaves (Ocimum basilicum) were tested on 10-day-old Rhipicephalus (Boophilus) microplus tick larvae using the LPT. Two-fold dilutions of the three essential oils were tested from a starting dilution of 20% down\\u000a to 1.25%. Results showed a high toxicological effect for cumin, producing 100%

Moises Martinez-Velazquez; Gustavo Adolfo Castillo-Herrera; Rodrigo Rosario-Cruz; Jose Miguel Flores-Fernandez; Julisa Lopez-Ramirez; Rodolfo Hernandez-Gutierrez; Eugenia del Carmen Lugo-Cervantes

2011-01-01

136

The acaricidal efficacy of aqueous neem extract and ivermectin against Sarcoptes scabiei var. cuniculi in experimentally infested rabbits.  

PubMed

Sarcoptes scabiei var. cuniculi is one of the most important veterinary ectoparasites in rabbits and results in considerable loss of weight, productivity, and wool quality. The acaricidal activity of aqueous leaf extract of neem (CAN) and ivermectin (IVR) were evaluated in vitro and in vivo against S. scabiei var. cuniculi. Rabbits were classified into four groups (ten rabbits each). The first group (group 1) was designated as the negative control group. Each rabbit of the other groups was experimentally infested with 50 mites. One month post-infestation, the second group (group 2) was not treated and taken into account as the positive control group. The third group (group 3) was subcutaneously injected with 1 % IVR (200 ?g/kg body weight, three times within a week interval). The fourth group (group 4) was treated topically with CAN (25 %) every 3 days for three consecutive weeks. Index scoring of lesions was described weekly. The number of live mites (larvae, nymphs, and adults) on each rabbit was counted on the 14th, 28th, and 42th day post-treatment (PT). Blood samples were taken 28 and 42 days PT for estimation of some chemical parameters. The body weight and cumulative body weight gain were recoded 14, 28, and 42 days PT. CAN (40 %) was highly efficacious against larvae of S. scabiei var. cuniculi as 100 % mortality was reached 24 h PT. On the other hand, all treated mites with CAN (20 %) and IVR died 48 h PT. The lethal values of CAN (LC50, LC90, LC95, and LC99) were 7.496, 14.67, 17.75, and 25.37 %, respectively, 48 h PT. Lesion scoring in groups 3 and 4 were significantly decreased (P???0.05), reaching 0.20 and 0.40, respectively, when compared with that of group 2 (4.00), 42 days PT. Twenty-eight days PT, the reduction percentages of mites infesting rabbits were 93.38 and 93.09 % for IVR and CAN, respectively. However, complete mite reduction was reached 42 days PT. Rabbits treated with CAN did not show signs of restlessness or irritation, respiratory signs, or inflammation on the eye and/or skin at the time of application or afterwards. Regarding biochemical analysis, the levels of aspartate aminotransferase, alanine aminotransferase, creatinine, and total cholesterol in rabbits treated with CAN were decreased significantly (P???0.05) than those of rabbits of the positive control group and those treated with IVR. On the other hand, the levels of total protein, albumin, and globulin of rabbits in group 4 were significantly (P???0.05) increased when compared with the corresponding values of groups 2 and 3. The body weight and cumulative body weight gain of rabbits treated with CAN were significantly increased (P???0.05) when compared with such values of groups 2 and 3, 28 and 42 days PT. The present data indicated that CAN had in vitro and in vivo acaricidal efficiency similar to that of IVR and improved the performance of rabbits without inducing adverse effects on treated rabbits; consequently, CAN could be suitable as a promising alternative acaricide for veterinary use. PMID:23572045

Seddiek, Shaker A; Khater, Hanem F; El-Shorbagy, Mohamed M; Ali, Ali M

2013-06-01

137

Acaricide and ivermectin resistance in a field population of Rhipicephalus microplus (Acari: Ixodidae) collected from red deer (Cervus elaphus) in the Mexican tropics.  

PubMed

In the Neotropics the control of tick infestations in red deer (Cervus elaphus) is achieved primarily through the use of acaricides and macrocyclic lactones. In Mexico, resistance to one or multiple classes of acaricides has been reported in Rhipicephalus microplus infesting cattle, but information on acaricide susceptibility in R. microplus infesting red deer is lacking. In this study we report the level of resistance to different classes of acaricides and ivermectin in R. microplus collected from red deer in the Mexican tropics. Engorged R. microplus females were collected from a red deer farm in Yucatan, Mexico. The larval packet test was used to detect resistance to the organophosphates (OPs) chlorpyrifos and coumaphos, synthetic pyrethroids (SPs) cypermethrin and permethrin, and the phenylpyrazol, fipronil. Resistance to the formamidine amitraz (Am), and ivermectin was ascertained using the larval immersion test. Data were subjected to probit analysis to determine lethal concentrations and resistance ratios to kill 50% (RR50) and 99% (RR99) of the tick population under evaluation in relation to susceptible reference strains. Additionally, allele specific polymerase chain reaction was used to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus. The R. microplus population from red deer in Yucatan showed very high resistance to the two SPs evaluated (RRs>72.2 for cypermethrin; RR for permethrin resistance was so high a dose-response curve was not possible). All individual larvae tested to detect the sodium channel F1550I mutation associated with SP resistance in R. microplus were homozygous. The same tick population showed different levels of resistance to OPs (chlorpyrifos: RR50=1.55, RR99=0.63; coumaphos: RR50=6.8, RR99=5.9), fipronil (RR50=1.8, RR99=0.9), and amitraz (RR50=2.3, RR99=4.4). Resistance to ivermectin was regarded as moderate (RR50=7.1, RR99=5.0). This is the first report of R. microplus ticks collected from red deer in Mexico with different levels of resistance to four acaricide groups and ivermectin. PMID:24365245

Rodríguez-Vivas, R I; Miller, R J; Ojeda-Chi, M M; Rosado-Aguilar, J A; Trinidad-Martínez, I C; Pérez de León, A A

2014-02-24

138

Acaricidal activity of Cymbopogon winterianus, Vitex negundo and Withania somnifera against synthetic pyrethroid resistant Rhipicephalus (Boophilus) microplus.  

PubMed

Detection of resistance levels against cypermethrin and deltamethrin, the most commonly used synthetic pyrethroids (SPs) against Rhipicephalus (Boophilus) microplus collected from Moga, Punjab (India) was carried out using larval packet test. Results indicated the presence of resistance of level I and III against cypermethrin (resistance factors (RF) = 4.67) and deltamethrin (RF = 34.2), respectively. Adult immersion test was used to assess the acaricidal activity of aqueous and ethanolic extracts of leaves of Cymbopogon winterianus, Vitex negundo, and Withania somnifera along with roots of V. negundo against the SP resistant engorged females of R. (B.) microplus. The efficacy of various extracts was assessed by estimation of percent adult mortality, reproductive index (RI), percent inhibition of oviposition (%IO), and hatching rate. A concentration dependent increase in tick mortality was recorded which was more marked with various ethanolic extracts, and highest mortality was recorded in ticks treated with ethanolic extract of leaves of C. winterianus. The LC50 values were determined by applying regression equation analysis to the probit transformed data of mortality for various aqueous and ethanolic extracts. Acaricidal property was recorded to be higher in ethanolic extracts, and high activity was found with the ethanolic extract of leaves of C. winterianus with LC50 (95% CL) values of 0.46% (0.35-0.59%), followed by W. somnifera as 5.21% (4.45-6.09%) and V. negundo as 7.02% (4.58-10.74%). The egg mass weight of the live ticks treated with different concentrations of the various extract was significantly (p < 0.01) lower than that of control ticks; consequently, the RI and the %IO value of the treated ticks were reduced. Further, complete inhibition of hatching was recorded in eggs laid by ticks treated with ethanolic extracts of leaves of V. negundo and aqueous extracts of leaves of W. somnifera. The results of the current study indicate that extracts of C. winterianus, V. negundo, and W. somnifera can be used for the control of SP resistant ticks. PMID:24178747

Singh, Nirbhay Kumar; Jyoti; Vemu, Bhaskar; Nandi, Abhijit; Singh, Harkirat; Kumar, Rajender; Dumka, V K

2014-01-01

139

In vitro acaricidal activity of neem (Azadirachta indica) seed extracts with known azadirachtin concentrations against Rhipicephalus microplus.  

PubMed

The effect of four extracts from neem seeds (Azadirachta indica) containing 2000, 5000, 9000 and 10,000 ppm of azadirachtin A (AZA), quantified by high-performance liquid chromatography (HPLC) and diluted to 1.25%; 2.5%; 5.0%; 10.0% and 12.8% was verified by in vitro tests with engorged females and larvae of the cattle tick Rhipicephalus microplus. The results from the bioassays with the engorged females showed that the main toxic effect of the extracts was reduction of the reproductive parameters, with a sharp drop in the number of eggs laid and the hatching rate, mainly when the extracts were diluted to 10.0% and 12.8%. The product effectiveness (PE) calculations for all the solutions tested showed that the AZA solution at 10,000 ppm (N10) was the most effective. However, statistical analysis of the PE data obtained for the proportional AZA concentrations in the different diluted extracts showed significance (P<0.05) of the effects included in the model (extract dilution, principle effect (classificatory) of the assay (extract) and the interaction between the two), indicating significant variations due to the dilution, the test and the interaction between the two factors in the tests with engorged females. For solutions N2, N5, and N9, it was not possible to estimate LC(90) values in the dilution range tested. The lowest LC(50) was observed for extract N5, and although extract N10 was the only extract for which the LC(90) could be estimated within the range tested, the LC(50) was higher than for N5 and N9. These results suggest that substances other than AZA present in the extracts influenced the efficacy, especially up to a certain LC range. In the tests with larvae, no mortality was observed, indicating zero effectiveness of all the extracts tested. The results of the tests with engorged females showed that the neem extracts had acaricide activity, inhibiting egg laying and the larval hatching rate. Complementary studies are necessary to develop new methods to isolate and/or identify other substances besides AZA contained in this plant, to enable using products made from it as acaricides. PMID:21536387

Giglioti, R; Forim, M R; Oliveira, H N; Chagas, A C S; Ferrezini, J; Brito, L G; Falcoski, T O R S; Albuquerque, L G; Oliveira, M C S

2011-09-27

140

Design, synthesis, structure, and acaricidal/insecticidal activity of novel spirocyclic tetronic acid derivatives containing an oxalyl moiety.  

PubMed

A series of novel spirocyclic tetronic acid derivatives containing an oxalyl moiety was designed and synthesized via the key intermediate 3-(2,4,6-trimethyl)-2-oxo-1-oxaspiro[4.4]-decyl-3-en-4-ol. The target compounds were identified by (1)H NMR and elemental analysis or high-resolution mass spectrum (HRMS). The results of bioassays indicated that most of the target compounds possessed excellent acaricidal activities against carmine spider mite larvae and eggs. Especially, diisopropylamino oxalyl compound 7g and piperidine oxalyl compound 7h were 1.4- and 2.3-fold as high as the activities of commercial Spiromesifen, respectively, against spider mite eggs. Moreover, most of the target compounds exhibited insecticidal activities against Lepidoptera pest. Interestingly, compounds containing alkylamino-substituted oxalyl moiety showed obvious selectivity between spider mite larvae and eggs because the activities against spider mite eggs of 7g and 7h were 25-fold those against spider mite larvae, whereas Spiromesifen had no significant differences in these activities. This meant that the introduction of an oxalyl moiety to spirocyclic tetronic acid might lead to novel biological activity characteristics. PMID:22044426

Liu, Zhihui; Lei, Qiong; Li, Yongqiang; Xiong, Lixia; Song, Haibin; Wang, Qingmin

2011-12-14

141

Acaricidal effects of cardiac glycosides, azadirachtin and neem oil against the camel tick, Hyalomma dromedarii (Acari: Ixodidae).  

PubMed

The cardiac glycoside, digitoxin, from Digitalis purpurea L (Scrophulariaceae), a cardiac glycosidal (cardenolide) extract from Calotropis procera (Ait) R Br (Asclepiadaceae), azadirachtin and neem oil from Azadirachta indica A Juss (Meliaceae) were tested for their effects against larvae and adult stages of the camel tick, Hyalomma dromedarii Koch (Acari: Ixodidae). The contact LC50 values of the first three materials against adults were 4.08, 9.63 and >40.7 microg cm(-2), respectively, whereas the dipping LC50 values of the four materials were 409.9, 1096, >5000 and >5000 mg litre(-1), respectively. Contact and dipping LC50 values of the extract and azadirachtin against larvae were 6.16, >20.3 microg cm(-2) and 587.7 and >2500 mg litre(-1), respectively. Azadirachtin had no effects on egg production or feeding of adults up to 5000 mg litre(-1); however at 2500 mg litre(-1), it caused significant reduction in feeding activity of larve, prolonged the period for moulting to nymphal stage, and caused 60% reduction in moultability. Results of the two cardiac glycoside materials are comparable with those of several commercial acaricides. The risks and benefits associated with the use of cardiac glycosides are considered. PMID:14620053

Al-Rajhy, DiefAlla H; Alahmed, Azzam M; Hussein, Hamdy I; Kheir, Salah M

2003-11-01

142

Characterization of acaricide resistance in Rhipicephalus sanguineus (latreille) (Acari: Ixodidae) collected from the Corozal Army Veterinary Quarantine Center, Panama.  

PubMed

Rhipicephalus sanguineus (Latreille) were collected from the Corozal Army Veterinary Quarantine Center in Panama and characterized for resistance to five classes of acaricides. These ticks were highly resistant to permethrin, DDT, and coumaphos; moderately resistant to amitraz; and not resistant to fipronil when compared with susceptible strains. Resistance to both permethrin and DDT may result from a mutation of the sodium channel. However, synergist studies indicate that enzyme activity is involved. The LC50 estimate for permethrin was lowered further in the Panamanian strain then in susceptible strains with the addition of triphenylphosphate (TPP), but not with the addition ofpiperonyl butoxide (PBO). This suggests that esterases and not oxidases are responsible for at least some pyrethroid resistance. Elevated esterase activity and its inhibition by TPP were confirmed by native gel electrophoresis. The LC50 estimate obtained for coumaphos in the Panamanian strain was not lowered further than what was observed for susceptible strains by the addition of TPP or PBO. This indicates that enzyme activity might not be involved in coumaphos resistance. Resistance to amitraz was measured through a modification of the Food and Agriculture Organization Larval Packet Test. All tick strains were found to be susceptible to fipronil. PMID:11296838

Miller, R J; George, J E; Guerrero, F; Carpenter, L; Welch, J B

2001-03-01

143

Acaricidal activity and sublethal effects of an oxymatrine-based biopesticide on two-spotted spider mite (Acari: Tetranychidae).  

PubMed

Lethal and sublethal effects of the biopesticide Kingbo (oxymatrine 0.2 % + psoralen 0.4 %) on the two-spotted spider mite (Tetranychus urticae Koch) were investigated in laboratory bioassays. The biopesticide was applied to bean leaf discs or primary leaves by using a Potter spray tower. Acute toxicity tests showed no significant ovicidal action: toxic effect (LC50 = 55.49 ?l/l) was the result of a residual activity against larvae that hatched from the treated eggs. Preovipositional females and female teleiochrysales showed similar susceptibility (LC50 = 52.68 and 59.03 ?l/l, respectively), whereas larvae, protonymphs and female deutonymphs were the most susceptible stages (LC50 = 6.88, 13.03, and 8.80 ?l/l, respectively). In a choice test, females preferred the untreated halves of leaves over the halves treated with 2,000, 1,000, and 500 ?l/l in the first 24 h, and their oviposition in those treatments was significantly greater on the untreated halves after 24 and 48 h, as well as the summed oviposition over 72 h. Viability and reproduction of survivors, as well as population growth, were strongly affected after the treatments of preovipositional females and female teleiochrysales with 100, 50 and 25 ?l/l. On the other hand, sublethal effects on the females that survived treatment at the egg stage or reached adulthood from the eggs laid on the treated surface (treatments with 50 and 25 ?l/l) were significantly weaker. Acaricidal and sublethal effects of the biopesticide Kingbo were discussed as a starting point for further research aimed to improve management of T. urticae populations. Regulatory issues and safety concerns regarding further commercialization of this biopesticide are addressed as well. PMID:24948329

Mar?i?, Dejan; Me?o, Irena

2014-11-01

144

Evaluation of benzaldehyde derivatives from Morinda officinalis as anti-mite agents with dual function as acaricide and mite indicator  

PubMed Central

Severe fever with thrombocytopenia syndrome (SFTS) is an emerging infectious disease caused by SFTS virus with 12–30% fatality rate. Despite severity of the disease, any medication or treatment for SFTS has not developed yet. One approach to prevent SFTS spreading is to control the arthropod vector carrying SFTS virus. We report that 2–methylbenzaldehyde analogues from M. officinalis have a dual function as acaricide against Dermatophagoides spp. and Haemaphysalis longicornis and indicator (color change) against Dermatophagoides spp. Based on the LD50 values, 2,4,5–trimethylbenzaldehyde (0.21, 0.19, and 0.68??g/cm3) had the highest fumigant activity against D. farinae, D. pteronyssinus, and H. longicornis, followed by 2,3–dimethylbenzaldehyde (0.46, 0.44, and 0.79??g/cm3), 2,4–dimethylbenzaldehyde (0.66, 0.59, and 0.95??g/cm3), 2,5–dimethylbenzaldehyde (0.65, 0.68, and 0.88??g/cm3), 2–methylbenzaldehyde (0.95, 0.87, and 1.28??g/cm3), 3–methylbenzaldehyde (0.99, 0.93, and 1.38??g/cm3), 4–methylbenzaldehyde (1.17, 1.15, and 3.67??g/cm3), and M. officinalis oil (7.05, 7.00, and 19.70??g/cm3). Furthermore, color alteration of Dermatophagoides spp. was shown to be induced, from colorless to dark brown, by the treatment of 2,3–dihydroxybenzaldehyde. These finding indicated that 2–methylbenzaldehyde analogues could be developed as functional agent associated with the arthropod vector of SFTS virus and allergen. PMID:25434408

Yang, Ji-Yeon; Kim, Min-Gi; Park, Jun-Hwan; Hong, Seong-Tshool; Lee, Hoi-Seon

2014-01-01

145

Resistance status of the carmine spider mite, Tetranychus cinnabarinus and the twospotted spider mite, T. urticae to selected acaricides on strawberries.  

PubMed

The carmine spider mite, Tetranychus cinnabarinus (Boisduval) and the twospotted spider mite, T. urticae Koch, are serious pests of strawberries and many other horticultural crops. Control of these pests has been heavily dependent upon chemical acaricides. Objectives of this study were to determine the resistance status of these two pest species to commonly used acaricides on strawberries in a year-round intensive horticultural production region. LC90 of abamectin for adult carmine spider mites was 4% whereas that for adult twospotted spider mites was 24% of the top label rate. LC90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 0.5%, 0.5%, 1.4% and 83% of their respective highest label rates for carmine spider mite eggs, 0.7%, 2.7%, 12.1% and 347% of their respective highest label rates for the nymphs. LC90s of spiromesifen, etoxazole, hexythiazox and bifenazate were 4.6%, 11.1%, 310% and 62% of their respective highest label rates for twospotted spider mite eggs, 3%, 13%, 432,214% and 15% of their respective highest label rates for the nymphs. Our results suggest that T. cinnabarinus have developed resistance to bifenazate and that the T. urticae have developed resistance to hexythiazox. These results strongly emphasize the need to develop resistance management strategies in the region. This article is protected by copyright. All rights reserved. PMID:25409919

Bi, Jian-Long; Niu, Zi-Mian; Yu, Lu; Toscano, Nick C

2014-11-20

146

Acaricide treatment prevents adrenocortical hyperplasia as a long-term stress reaction to psoroptic mange in cattle.  

PubMed

In cattle, infestation with Psoroptes ovis mites may cause severe dermatitis (psoroptic mange) which compromises the health and welfare of the animals and may lead to significant economic losses. To investigate yet undocumented effects of psoroptic mange mite infestations and how successful therapy promotes animal health, the present study examined alterations of the skin, lymph nodes and adrenal glands of P. ovis infested Fleckvieh (Simmental) bulls treated with either ivermectin long-acting injection (IVM LAI; IVOMEC(®) GOLD, Merial; 3.15% ivermectin w/v) or saline (n=16 each). Approximately 8 weeks subsequent to experimental infestation with P. ovis, the bulls had developed mange and were administered either IVM LAI or saline once at 1mL/50kg body weight by subcutaneous injection. Mite counts were conducted in weekly intervals for determination of efficacy of treatment, and following humane euthanasia of the animals 8 weeks after treatment, skin samples from affected (mangy or previously mangy) and unaffected areas, prescapular lymph nodes and adrenal glands were collected for gross and pathohistological examination. In addition, four age-matching, uninfested Simmental bulls were sampled as controls for comparison. No P. ovis mites were detected on any IVM LAI-treated bull after 28 days following treatment whereas saline-treated bulls maintained infestation throughout the study. At sampling (approximately 16 weeks after experimental infestation and 8 weeks following saline or IVM LAI treatment), saline-treated bulls displayed a severe, exsudative dermatitis with significantly increased skin thickness and inflammatory cell infiltration, significantly enlarged, hyperplastic prescapular lymph nodes, as well as significantly increased adrenal gland weights and volumes as compared to P. ovis-infested, IVM LAI-treated bulls and uninfested controls. Quantitative stereological analysis revealed that the adrenal gland enlargement in P. ovis-infested, saline-treated bulls was due to a selective increase of the volume of the zona fasciculata in the adrenal cortex. Compared to uninfested controls and P. ovis-infested, IVM LAI-treated bulls, the number of epithelial cells in the zona fasciculata was significantly increased in P. ovis-infested, saline-treated bulls, while the zona fasciculata cell volumes did not differ between the three groups of cattle. While the single point determination of serum cortisol concentrations did not reveal significant differences between the three groups of cattle at tissue sampling, the hyperplastic growth of the adrenal cortex in the P. ovis-infested, saline-treated bulls provides morphologic evidence that a chronic stress reaction is one consequence of mange mite infestations that can be prevented by efficacious acaricidal treatment. PMID:25468014

Blutke, A; Börjes, P; Herbach, N; Pfister, K; Hamel, D; Rehbein, S; Wanke, R

2015-01-15

147

Acaricidal activity against Tetranychus urticae and essential oil composition of four Croton species from Caatinga biome in northeastern Brazil.  

PubMed

Volatile components of essential oils from the leaves and stems of Croton jacobinensis, C. rhamnifolius, C. muscicapa and C. micans, which are medicinal plants found in the Caatinga biome of northeastern Brazil, were analyzed using GC and GC/MS. The acaricidal activity of these oils against Tetranychus urticae was evaluated using the fumigation method. Oil yields from the Croton species ranged from 1.1 +/- 0.0 to 0.6 +/- 0.0%, w/w, for leaves and 0.7 +/- 0.0 to 0.1 +/- 0.0% for stems. Sesquiterpenoids were dominant in all oils, except the stem oil from C. rhamnifolius, which exhibited a high monoterpene content, and the leaf and stem oils from C. muscicapa, which were rich in phenylpropanoids. The major volatile components of the leaf and stem oils from C. jacobinensis were (Z)-alpha-atlantone (24.3 +/- 0.4%) and trans-isolongifolanone (22.8 +/- 0.5%), respectively. The most abundant constituents detected in C. rhamnifolius were alpha-cedrene epoxide (23.3 +/- 0.1%) and caryophyllene oxide (21.9 +/- 0.0%) in the leaf oil, and camphor (16.6 +/- 0.5%) and tricyclene (12.8 +/- 0.1%) in the stem oil. Foenicolin was the main compound identified in the leaf (50.6 +/- 0.2%) and stem (72.7 +/- 0.6%) oils of C. muscicapa, while alpha-bulnesene (32.9 +/- 0.2%) and guaiol (17.9 +/- 0.7%) were the principal components of C. micans oils. These oils exhibited a high degree of toxicity in the fumigation assay. The stem oils from C. jacobinensis and C. rhamnifolius exhibited high lethality rates, with LC50 values of 0.3 and 0.2 microL/L of air after 24 h, respectively. The results suggest the potential use of stem essential oil, especially from C. rhamnifolius and C. jacobinensis, for the integrated control of Tetranychus urticae. PMID:21815434

Neves, Ilzenayde Araújo; da Camara, Claudio Augusto Gomes

2011-06-01

148

9 CFR 73.6 - Placarding means of conveyance and marking billing of shipments of treated scabby cattle or...  

Code of Federal Regulations, 2010 CFR

...conveyance and marking billing of shipments of treated scabby cattle or cattle exposed to scabies. 73.6 Section 73.6 Animals...INCLUDING POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.6 Placarding means of conveyance and...

2010-01-01

149

9 CFR 73.6 - Placarding means of conveyance and marking billing of shipments of treated scabby cattle or...  

Code of Federal Regulations, 2011 CFR

...conveyance and marking billing of shipments of treated scabby cattle or cattle exposed to scabies. 73.6 Section 73.6 Animals...INCLUDING POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.6 Placarding means of conveyance and...

2011-01-01

150

Molecular analysis of resistance to acaricidal spirocyclic tetronic acids in Tetranychus urticae: CYP392E10 metabolizes spirodiclofen, but not its corresponding enol.  

PubMed

Spirodiclofen is one of the most recently developed acaricides and belongs to the new family of spirocyclic tetronic acids (ketoenols). This new acaricidal family is an important chemical tool in resistance management strategies providing sustainable control of spider mites such as Tetranychus urticae. Spirodiclofen targets lipid biosynthesis mediated by direct inhibition of acetyl coenzyme A carboxylase (ACCase). In this study, we investigated two genetically distant spider mite strains with high resistance to spirodiclofen. Despite the strong resistance levels to spirodiclofen (up to 680-fold), only limited cross-resistance with other members of this group such as spiromesifen and spirotetramat could be detected. Amplification and sequencing of the ACCase gene from resistant and susceptible strains did not reveal common non-synonymous mutations, and expression levels of ACCase were similar in both resistant and susceptible strains, indicating the absence of target-site resistance. Furthermore, we collected genome-wide expression data of susceptible and resistant T. urticae strains using microarray technology. Analysis of differentially expressed genes revealed a broad response, but within the overlap of two resistant strains, several cytochrome P450s were prominent. Quantitative PCR confirmed the constitutive over-expression of CYP392E7 and CYP392E10 in resistant strains, and CYP392E10 expression was highly induced by spirodiclofen. Furthermore, stage specific expression profiling revealed that expression levels were not significantly different between developing stages, but very low in eggs, matching the age-dependent resistance pattern previously observed. Functional expression of CYP392E7 and CYP392E10 confirmed that CYP392E10 (but not CYP392E7) metabolizes spirodiclofen by hydroxylation as identified by LC-MS/MS, and revealed cooperative substrate binding and a Km of 43 ?M spirodiclofen. CYP392E10 also metabolizes spiromesifen, but not spirotetramat. Surprisingly, no metabolism of the hydrolyzed spirodiclofen-enol metabolite could be detected. These findings are discussed in the light of a likely resistance mechanism. PMID:23523619

Demaeght, Peter; Dermauw, Wannes; Tsakireli, Dimitra; Khajehali, Jahangir; Nauen, Ralf; Tirry, Luc; Vontas, John; Lümmen, Peter; Van Leeuwen, Thomas

2013-06-01

151

Welding tritium exposed stainless steel  

NASA Astrophysics Data System (ADS)

Stainless steels that are exposed to tritium become unweldable by conventional methods due to buildup of decay helium within the metal matrix. With longer service lives expected for tritium containment systems, methods for welding on tritium exposed material will become important for repair or modification of the systems. Solid-state resistance welding and low-penetration overlay welding have been shown to mitigate helium embrittlement cracking in tritium exposed 304 stainless steel. These processes can also be used on stainless steel containing helium from neutron irradiation, such as occurs in nuclear reactors.

Kanne, W. R., Jr.

152

9 CFR 73.10 - Permitted dips; substances allowed.  

Code of Federal Regulations, 2011 CFR

...POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.10 Permitted dips; substances...treatment, as required in this part, of cattle affected with or exposed to scabies...dip for the eradication of scabies in cattle, the APHIS 3 will require that...

2011-01-01

153

9 CFR 73.10 - Permitted dips; substances allowed.  

Code of Federal Regulations, 2010 CFR

...POULTRY) AND ANIMAL PRODUCTS SCABIES IN CATTLE § 73.10 Permitted dips; substances...treatment, as required in this part, of cattle affected with or exposed to scabies...dip for the eradication of scabies in cattle, the APHIS 3 will require that...

2010-01-01

154

Chemical characterization and acaricide potential of essential oil from aerial parts of Tagetes patula L. (Asteraceae) against engorged adult females of Rhipicephalus sanguineus (Latreille, 1806).  

PubMed

Rhipicephalus sanguineus, commonly known as the brown dog tick, is one of the most widely distributed species of tick. In dogs, it can cause anemia and provide the transmission of pathogenic microorganisms such as Babesia canis, Ehrlichia canis, Hepatozoon canis, Anaplasma platys, and Mycoplasma haemocanis. To man, it can transmit the intracellular parasites Rickettsia rickettsii and Rickettsia conorii, the causative agents of the Rocky Mountain spotted fever in the Americas and Mediterranean and spotted fever in Europe and North Africa. Its control is performed by applying synthetic formulations composed of pyrethroids; however, continued use of these products results in environmental damage and acquisition of resistance. Alternatively, studies with botanical insecticides have been increasingly recurrent. Therefore, this study aimed to test the efficacy of essential oil of Tagetes patula, a ruderal species widely described in the literature for its insecticidal properties, in engorged females of R. sanguineus by the adults immersion test (AIT) and impregnated paper disk test (IPDT). The essential oil used, through gas chromatography coupled to mass spectrometry, revealed the presence of 55 compounds, being the 4-vinyl guaiacol and gamma terpinene the majority ones. The AIT compared to the IPDT was more efficient in inhibiting oviposition of tick; however, the eggs laid by the females submitted to saturated atmosphere with essential oil, from IPDT, not hatched, interrupted their development cycle. Besides being a pioneer work, the results presented here contributes to new researches, aiming the incorporation of essential oil in an acaricide for use in the environment. PMID:23508761

Politi, Flávio Augusto Sanches; de Souza-Moreira, Tatiana Maria; Rodrigues, Edvânio Ramos; de Queiroz, Geisiany Maria; Figueira, Glyn Mara; Januário, Ana Helena; Berenger, Jean-Michel; Socolovschi, Cristina; Parola, Philippe; Pietro, Rosemeire Cristina Linhari Rodrigues

2013-06-01

155

Acaricidal activities of whole cell suspension, cell-free supernatant, and crude cell extract of Xenorhabdus stokiae against mushroom mite (Luciaphorus sp.)*  

PubMed Central

Xenorhabdus bacterium has been used as a biological control agent against Luciaphorus sp., a mushroom mite endemic in Thailand. To develop an effective formulation of Xenorhabdus stokiae, treatments using different parts of X. stokiae isolate PB09 culture, including whole cell suspension, cell-free supernatant, and crude cell extract, were performed. The results show that different parts of X. stokiae isolate PB09 culture could induce variable effects on mite mortality and fecundity. Application with cell-free supernatant of X. stokiae culture resulted in both the highest mite mortality rate [(89.00±3.60)%] and the lowest mite fecundity [(41.33±23.69) eggs/gravid female]. Whole cell suspension of X. stokiae isolate PB09 culture was found to be slightly less effective than its cell-free supernatant, suggesting that X. stokiae was more likely to release its metabolites with acaricidal activities to the surrounding culture media. Crude cell extract of X. stokiae was not effective against mites. Cell-free supernatant of X. stokiae isolate PB09 was the most effective biological control agent and it could be conveniently used in future formulations instead of live bacteria. PMID:22467367

Bussaman, Prapassorn; Sa-Uth, Chirayu; Rattanasena, Paweena; Chandrapatya, Angsumarn

2012-01-01

156

New method using quantitative PCR to follow the tick blood meal and to assess the anti-feeding effect of topical acaricide against Rhipicephalus sanguineus on dogs.  

PubMed

A 28-day study was conducted to assess the dynamic of blood feeding by Rhipicephalus sanguineus ticks on dogs treated or not with a novel topical combination of fipronil, amitraz and (S)-methoprene. Dogs were infested weekly through exposure to ticks in crates for 4h. Ticks were then counted in the crates at 2h and 4h post dog exposure. Ticks were also counted and removed from the dogs at 2h, 4h, 6h, 12h and 24h post tick exposure. The inhibition of blood feeding was assessed by both tick quantification and designing and performing a quantitative PCR (qPCR) to detect the canine hydroxymethylbilane synthase (HMBS) gene in ticks. The percentage of repellency sensu lato based on the ticks collected in crates at 2h varied from 4.7% at day 28 to 48.3% at day 7. The immediate mortality rate of the ticks expelled at 2h varied from 1.5% at day 21 to 31.7% at day 7. The efficacy calculation showed that the acaricidal combination started to kill ticks in as little as 2h. The average efficacy reached 90.0% at 12h post crate challenges and 100% at 24h post exposure in crates. The inclusion of an internal amplification control was used to ensure that no significant template-derived PCR inhibition (? 6.2%) affected the overall results. The reduction of blood feeding was significant at 4h (>80.0%) and >99.0% at 24h post tick exposure in the crate. The high repellency rate and the lethal efficacy of CERTIFECT(®) resulted in significantly fewer live attached ticks, consequently reducing blood intake and fluid exchanges. PMID:24656063

Fourie, J J; Joubert, A; Labuschagné, M; Beugnet, F

2014-05-01

157

The novel isoxazoline ectoparasiticide fluralaner: selective inhibition of arthropod ?-aminobutyric acid- and L-glutamate-gated chloride channels and insecticidal/acaricidal activity.  

PubMed

Isoxazolines are a novel class of parasiticides that are potent inhibitors of ?-aminobutyric acid (GABA)-gated chloride channels (GABACls) and L-glutamate-gated chloride channels (GluCls). In this study, the effects of the isoxazoline drug fluralaner on insect and acarid GABACl (RDL) and GluCl and its parasiticidal potency were investigated. We report the identification and cDNA cloning of Rhipicephalus (R.) microplus RDL and GluCl genes, and their functional expression in Xenopus laevis oocytes. The generation of six clonal HEK293 cell lines expressing Rhipicephalus microplus RDL and GluCl, Ctenocephalides felis RDL-A285 and RDL-S285, as well as Drosophila melanogaster RDLCl-A302 and RDL-S302, combined with the development of a membrane potential fluorescence dye assay allowed the comparison of ion channel inhibition by fluralaner with that of established insecticides addressing RDL and GluCl as targets. In these assays fluralaner was several orders of magnitude more potent than picrotoxinin and dieldrin, and performed 5-236 fold better than fipronil on the arthropod RDLs, while a rat GABACl remained unaffected. Comparative studies showed that R. microplus RDL is 52-fold more sensitive than R. microplus GluCl to fluralaner inhibition, confirming that the GABA-gated chloride channel is the primary target of this new parasiticide. In agreement with the superior RDL on-target activity, fluralaner outperformed dieldrin and fipronil in insecticidal screens on cat fleas (Ctenocephalides felis), yellow fever mosquito larvae (Aedes aegypti) and sheep blowfly larvae (Lucilia cuprina), as well as in acaricidal screens on cattle tick (R. microplus) adult females, brown dog tick (Rhipicephalus sanguineus) adult females and Ornithodoros moubata nymphs. These findings highlight the potential of fluralaner as a novel ectoparasiticide. PMID:24365472

Gassel, Michael; Wolf, Christian; Noack, Sandra; Williams, Heike; Ilg, Thomas

2014-02-01

158

[Drug Exposed Infants and Their Families.  

ERIC Educational Resources Information Center

This bulletin issue addresses the theme of drug-exposed infants and the services required by these infants and their families. "Cocaine-Exposed Infants: Myths and Misunderstandings" (Barbara J. Myers and others) comments on the negative accounts of drug-exposed babies presented by mass media and reviews the mix of positive and negative findings…

Fenichel, Emily, Ed.

1992-01-01

159

Acaricidal, pediculocidal and larvicidal activity of synthesized ZnO nanoparticles using wet chemical route against blood feeding parasites.  

PubMed

The present study was based on assessments of the anti-parasitic activities to determine the efficacies of synthesized zinc oxide nanoparticles (ZnO NPs) prepared by wet chemical method using zinc nitrate and sodium hydroxide as precursors and soluble starch as stabilizing agent against the larvae of cattle tick Rhipicephalus (Boophilus) microplus, Canestrini (Acari: Ixodidae); head louse Pediculus humanus capitis, De Geer (Phthiraptera: Pediculidae); larvae of malaria vector, Anopheles subpictus, Grassi; and filariasis vector, Culex quinquefasciatus, Say (Diptera: Culicidae). R. microplus larvae were exposed to filter paper envelopes impregnated with different ZnO NP concentrations. Direct contact method was conducted to determine the potential of pediculocidal activity. Parasite larvae were exposed to varying concentrations of synthesized ZnO NPs for 24 h. The results suggested that the mortality effects of synthesized ZnO NPs were 43% at 1 h, 64% at 3 h, 78% at 6 h, and 100% after 12 h against R. microplus activity. In pediculocidal activity, the results showed that the optimal times for measuring mortality effects of synthesized ZnO NPs were 38% at 10 min, 71% at 30 min, 83% at 1 h, and 100% after 6 h against P. humanus capitis. One hundred percent lice mortality was observed at 10 mg/L treated for 6 h. The mortality was confirmed after 24 h of observation period. The larval mortality effects of synthesized ZnO NPs were 37%, 72%, 100% and 43%, 78% and 100% at 6, 12, and 24 h against A. subpictus and C. quinquefasciatus, respectively. It is apparent that the small size and corresponding large specific surface area of small nanometer-scale ZnO particles impose several effects that govern its parasitic action, which are size dependent. ZnO NPs were synthesized by wet chemical process, and it was characterized with the UV showing peak at 361 nm. X-ray diffraction (XRD) spectra clearly shows that the diffraction peaks in the pattern indexed as the zinc oxide with lattice constants a = 3.249 and c = 5.206 Å. The FTIR spectrum showed the range of 400-4,000 cm(-1). The band at 899.56 cm(-1); 1,151.87 cm(-1); 1,396 cm(-1); and these bands showed the complete composition of ZnO NPs. SEM micrograph showed 60-120-nm size and aggregates of spherical shape nanoparticles. EDX showed the complete chemical composition of the synthesized nanoparticles of zinc oxide. The maximum efficacy was observed in zinc oxide against the R. microplus, P. humanus capitis, and the larvae of A. subpictus, C. quinquefasciatus with LC(50) values of 29.14, 11.80, 11.14, and 12.39 mg/L; r (2)?=?0.805, 0.876, 0.894, and 0.904, respectively. The synthesized ZnO NPs showed the LC(50) and r (2) values against the R. microplus (13.41 mg/L; 0.982), P. humanus capitis (11.80 mg/L; 0.966), and the larvae of A. subpictus (3.19; 0.945 mg/L), against C. quinquefasciatus (4.87 mg/L; 0.970), respectively. The control (distilled water) showed nil mortality in the concurrent assay. This is the first report on anti-parasitic activity of the synthesized ZnO NPs. PMID:21340566

Kirthi, Arivarasan Vishnu; Rahuman, Abdul Abdul; Rajakumar, Govindasamy; Marimuthu, Sampath; Santhoshkumar, Thirunavukkarasu; Jayaseelan, Chidambaram; Velayutham, Kanayairam

2011-08-01

160

Layers Exposed at Polar Canyon  

NASA Technical Reports Server (NTRS)

This false-color subframe of an image from the High Resolution Imaging Science Experiment camera on NASA's Mars Reconnaissance Orbiter shows the north polar layered deposits at top and darker materials at bottom, exposed in a scarp at the head of Chasma Boreale, a large canyon eroded into the layered deposits.

The polar layered deposits appear red because of dust mixed within them, but are ice-rich as indicated by previous observations. Water ice in the layered deposits is probably responsible for the pattern of fractures seen near the top of the scarp. The darker material below the layered deposits may have been deposited as sand dunes, as indicated by the crossbedding (truncation of curved lines) seen near the middle of the scarp. It appears that brighter, ice-rich layers were deposited between the dark dunes in places. Exposures such as these are useful in understanding recent climate variations that are likely recorded in the polar layered deposits.

NASA's Jet Propulsion Laboratory, a division of the California Institute of Technology in Pasadena, manages the Mars Reconnaissance Orbiter for NASA's Science Mission Directorate, Washington. Lockheed Martin Space Systems, Denver, is the prime contractor for the project and built the spacecraft. The High Resolution Imaging Science Experiment is operated by the University of Arizona, Tucson, and the instrument was built by Ball Aerospace and Technology Corp., Boulder, Colo.

2006-01-01

161

3 EXPOSE Missions - overview and lessons learned  

NASA Astrophysics Data System (ADS)

The International Space Station ISS provides a variety of external research platforms for experiments aiming at the utilization of space parameters like vacuum, temperature oscillation and in particular extraterrestrial short wavelength UV and ionizing radiation which cannot be simulated accurately in the laboratory. Three Missions, two past and one upcoming, will be presented. A family of astrobiological experimental ESA facilities called "EXPOSE" were and will be accommodated on these outside exposure platforms: on one of the external balconies of the European Columbus Module (EXPOSE-E) and on the URM-D platform on the Russian Zvezda Module (EXPOSE-R and EXPOSE-R2). Exobiological and radiation experiments, exposing chemical, biological and dosimetric samples to the harsh space environment are - and will be - accommodated on these facilities to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigate resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens, plant seeds and small animals like mosquito larvae to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biological specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation are regularly recorded and down linked by telemetry. Two long term missions named according to their facility - EXPOSE-E and EXPOSE-R - are completed and a third mission is planned and currently prepared. Operations of all three missions including sample accommodation are performed by DLR. An overview of the two completed missions will be given including lessons learned as well as an outlook and short introduction to the next mission, EXPSOE-R2

Rabbow, E.; Willnekcer, R.; Reitz, G.; Aman, A.; Bman, B.; Cman, C.

2011-10-01

162

Eryptosis in lead-exposed workers.  

PubMed

Eryptosis is a physiological phenomenon in which old and damaged erythrocytes are removed from circulation. Erythrocytes incubated with lead have exhibited major eryptosis. In the present work we found evidence of high levels of eryptosis in lead exposed workers possibly via oxidation. Blood samples were taken from 40 male workers exposed to lead (mean blood lead concentration 64.8?g/dl) and non-exposed workers (4.2?g/dl). The exposure to lead produced an intoxication characterized by 88.3% less ?-aminolevulinic acid dehydratase (?ALAD) activity in lead exposed workers with respect to non-lead exposed workers. An increment of oxidation in lead exposed workers was characterized by 2.4 times higher thiobarbituric acid-reactive substance (TBARS) concentration and 32.8% lower reduced/oxidized glutathione (GSH/GSSG) ratio. Oxidative stress in erythrocytes of lead exposed workers is expressed in 192% higher free calcium concentration [Ca(2+)]i and 1.6 times higher ?-calpain activity with respect to non-lead exposed workers. The adenosine triphosphate (ATP) concentration was not significantly different between the two worker groups. No externalization of phosphatidylserine (PS) was found in non-lead exposed workers (<0.1%), but lead exposed workers showed 2.82% externalization. Lead intoxication induces eryptosis possibly through a molecular pathway that includes oxidation, depletion of reduced glutathione (GSH), increment of [Ca(2+)], ?-calpain activation and externalization of PS in erythrocytes. Identifying molecular signals that induce eryptosis in lead intoxication is necessary to understand its physiopathology and chronic complications. PMID:25448684

Aguilar-Dorado, Itzel-Citlalli; Hernández, Gerardo; Quintanar-Escorza, Martha-Angelica; Maldonado-Vega, María; Rosas-Flores, Margarita; Calderón-Salinas, José-Víctor

2014-12-01

163

SUIVI MEDICAL DE SALARIES EXPOSES AU BERYLLIUM : Medical follow-up of beryllium -exposed workers  

E-print Network

1 SUIVI MEDICAL DE SALARIES EXPOSES AU BERYLLIUM : Medical follow-up of beryllium - exposed workers-up of beryllium-exposed workers. Method: a medical follow-up of workers from a factory machining beryllium (Be preventive measures. Key words: beryllium, sensitisation, occupational exposure, prevention, Lymphocyte

Boyer, Edmond

164

Chemical composition and acaricidal activity of the essential oil of Baccharis dracunculifolia De Candole (1836) and its constituents nerolidol and limonene on larvae and engorged females of Rhipicephalus microplus (Acari: Ixodidae).  

PubMed

Baccharis dracunculifolia DC (common name "alecrim-do-campo" in Brazil) is a plant with widespread distribution in South America that is the botanical origin of green propolis. The aim of this study was to evaluate the chemical composition and acaricidal activity of the essential oil of B.?dracunculifolia and its constituents nerolidol and limonene on unengorged larvae and engorged females of Rhipicephalus microplus (Acari: Ixodidae). The essential oil yield was 0.8% of dry mass and the major constituents were nerolidol (22.3%), germacrene D (7.2%), limonene (6.9%), ?-pinene (6.7) and bicyclogermacrene (6.5%). The acaricidal activity of the essential oil and the pure compounds nerolidol and (R)-(+)-limonene were assessed in the laboratory through the modified larval packet test (LPT) and the female immersion test (FIT). In the LPT, the essential oil and nerolidol were both active, causing more than 90% mortality at concentrations from 15.0 and 10.0?mg?mL(-1), respectively, whereas (R)-(+)-limonene was not active. In the FIT, the oil and nerolidol caused reduction in the quantity and quality of eggs produced, with control percentages of 96.3% and 90.3% at concentrations of 60.0 and 50.0?mg?mL(-1), respectively. It can be concluded that the essential oil obtained from the aerial parts of B.?dracunculifolia and its major component nerolidol have high activity on R.?microplus larvae and engorged females. PMID:25448290

de Assis Lage, Tiago Coelho; Montanari, Ricardo Marques; Fernandes, Sergio Antonio; de Oliveira Monteiro, Caio Márcio; de Oliveira Souza Senra, Tatiane; Zeringota, Viviane; da Silva Matos, Renata; Daemon, Erik

2015-01-01

165

ERYTHROCYTE SURVIVAL IN SHEEP EXPOSED TO OZONE  

EPA Science Inventory

Ozone has been reported to produce a variety of extrapulmonary effects including changes in the specific activity of some erythrocyte enzymes. Buckley et al. (1975) reported statistically significant extrapulmonary changes in a number of human volunteers experimentally exposed to...

166

The astrobiological mission EXPOSE-R on board of the International Space Station  

NASA Astrophysics Data System (ADS)

EXPOSE-R flew as the second of the European Space Agency (ESA) EXPOSE multi-user facilities on the International Space Station. During the mission on the external URM-D platform of the Zvezda service module, samples of eight international astrobiology experiments selected by ESA and one Russian guest experiment were exposed to low Earth orbit space parameters from March 10th, 2009 to January 21st, 2011. EXPOSE-R accommodated a total of 1220 samples for exposure to selected space conditions and combinations, including space vacuum, temperature cycles through 273 K, cosmic radiation, solar electromagnetic radiation at >110, >170 or >200 nm at various fluences up to GJ m-2. Samples ranged from chemical compounds via unicellular organisms and multicellular mosquito larvae and seeds to passive radiation dosimeters. Additionally, one active radiation measurement instrument was accommodated on EXPOSE-R and commanded from ground in accordance with the facility itself. Data on ultraviolet radiation, cosmic radiation and temperature were measured every 10 s and downlinked by telemetry and data carrier every few months. The EXPOSE-R trays and samples returned to Earth on March 9th, 2011 with Shuttle flight, Space Transportation System (STS)-133/ULF 5, Discovery, after successful total mission duration of 27 months in space. The samples were analysed in the individual investigators laboratories. A parallel Mission Ground Reference experiment was performed on ground with a parallel set of hardware and samples under simulated space conditions following to the data transmitted from the flight mission.

Rabbow, Elke; Rettberg, Petra; Barczyk, Simon; Bohmeier, Maria; Parpart, Andre; Panitz, Corinna; Horneck, Gerda; Burfeindt, Jürgen; Molter, Ferdinand; Jaramillo, Esther; Pereira, Carlos; Weiß, Peter; Willnecker, Rainer; Demets, René; Dettmann, Jan

2015-01-01

167

9 CFR 78.8 - Brucellosis exposed cattle.  

Code of Federal Regulations, 2011 CFR

...2011-01-01 false Brucellosis exposed cattle. 78.8 Section 78.8 Animals... Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis exposed cattle. Brucellosis exposed cattle may...

2011-01-01

168

The Expose-R2 mission: astrobiology and astrochemistry in low Earth orbit  

NASA Astrophysics Data System (ADS)

EXPOSE is an exposure platform developed by ESA which permits scientists to install test samples for 1 to 2 years at the outer surface of the ISS. In that way, the impact of the open space environment on biological and biochemical sample materials can be explored. This environment, featuring full-spectrum solar light, near-vacuum, cosmic radiation, wide temperature variations and near-weightlessness, is impossible to reproduce in its entirety in the lab. As such, EXPOSE offers astrochemists and astrobiologists a chance to acquire novel scientific data. Astrochemists are interested in Low Earth Orbit conditions due to the fact that photochemistry in space is quite different from photochemistry on Earth, where the high-energy UV compounds of the solar spectrum are filtered away by our atmosphere. As for the astro biologists, EXPOSE offers an attractive opportunity to expand earlier results obtained during short-duration LEO flights, which have shown that particular microbes and, amazingly, even some multi-cellular macroscopic organisms were able to cope with a two-week exposure to space. The open space environment, often described as harsh and hostile, can apparently be tolerated by some robust inhabitants of our Earth - unprotected, in the absence of a space suit! The first mission of EXPOSE, as an external payload on the European Columbus module, happened during 2008-2009 with the test samples provided by five separate research teams. Three additional teams were involved in the monitoring of space environment. The results were published collectively in 2012 in a special issue of the monthly journal Astrobiology. Several organisms survived, having spent 1.5 years in space. The second mission was called EXPOSE-R, the R referring to ‘Russian segment’, the location where the EXPOSE instrument was installed this time. The EXPOSE-R mission took place in 2009-2011, ten science teams were involved. The publication of the results, again as a collection, is currently in preparation. A follow-on mission, EXPOSE-R2, is planned for 2014-2016. The upload of the new sample trays to the ISS will have occurred just before COSPAR 2014. In this presentation the new EXPOSE-R2 experiments are introduced, with an overview of the test samples and the scientific goals. The main characteristics of the EXPOSE platform are addressed including the sensors used to monitor the space environment. The envisaged operational flow in flight and on ground are explained. Moreover, a brief overview of the key lessons learnt from the past EXPOSE missions is provided.

Demets, René

169

Anesthetic gases and occupationally exposed workers.  

PubMed

The aim of this study is to estimate whether the occupational exposure to low dose anesthetic gases could cause alterations of blood parameters in health care workers. 119 exposed subjects and 184 not exposed controls were included in the study. Each worker underwent the complete blood count test (CBC), proteinaemia, leukocyte count, serum lipids, liver and kidney blood markers. The liver blood markers show statistically significant differences in health care workers compared with controls (p<0.05), a statistically significant decrease in neutrophils and an increase of lymphocytes in health care workers compared with controls (p<0.05). The prevalence of values outside the range for GPT, GGT, total bilirubin, lymphocytes and neutrophils was statistically significant in health care workers compared with controls (p<0.05). The results suggest that occupational exposure to low dose anesthetic gases could influence some haematochemical hepatic and hematopoietic parameters in exposed health care workers. PMID:24374387

Casale, Teodorico; Caciari, Tiziana; Rosati, Maria Valeria; Gioffrè, Pier Agostino; Schifano, Maria Pia; Capozzella, Assunta; Pimpinella, Benedetta; Tomei, Gianfranco; Tomei, Francesco

2014-01-01

170

SENSORIMOTOR DEVELOPMENT IN COCAINE-EXPOSED INFANTS  

PubMed Central

This study investigated effects of prenatal cocaine exposure on infant sensorimotor development. One hundred and sixty-seven 12-month-olds (74 cocaine-exposed and 93 unexposed) were assessed using the Bayley Scales of Infant Development (BSID). Ninety-seven had previously been evaluated on the Movement Assessment of Infants and the Test of Sensory Functions in Infants at age 4 months. On the BSID, the cocaine-exposed infants performed less well on the Mental portion and were more frequently rated as behaviorally suspect. Cocaine-exposed infants also performed less well at four months on the motor and sensory measures. Early motor performance predicted 12 month BSID mental, motor and behavioral outcomes. Cocaine exposure had an effect independent from confounders on general cognitive and specific motor and behavioral outcomes.

Arendt, Robert; Singer, Lynn; Angelopoulos, Jennifer; Bass-Busdiecker, Orphia; Mascia, JoMarie

2014-01-01

171

An exploratory study to assess the activity of the acarine growth inhibitor, fluazuron, against Sarcoptes scabei infestation in pigs  

PubMed Central

Background The most common treatments for scabies in human and veterinary settings are topical 5% permethrin or systemic treatment with ivermectin. However, these treatments have very little activity against arthropod eggs, and therefore repeated treatment is frequently required. In-vitro, biochemical and molecular studies have demonstrated that human mites are becoming increasingly resistant to both acaricides. To identify alternate acaricides, we undertook a pilot study of the in vivo activity of the benzoylphenyl urea inhibitor of chitin synthesis, fluazuron, in pigs with sarcoptic mange. Findings Pigs (n = 5) were infested with S. scabei var suis, and randomised to treatment at the start of peak infestation with fluazuron at a dose of 10 mg/kg/day per os for 7 days (n = 3) or no treatment (n = 2). Clinical scores, skin scrapings for mite counts and blood sampling for pharmacokinetic analysis were undertaken. Fluazuron was well absorbed in treated pigs with measureable blood levels up to 4 weeks post treatment. No adverse effects were observed. Modest acaricidal activity of the compound was observed, with a reduction in severity of skin lesions in treated pigs, as well as a reduction in number of scabies mite's early life stages. Conclusions The moderate efficacy of fluazuron against scabies mites indicates a lead to the development of alternate treatments for scabies, such as combination therapies that maybe applicable for human use in the future. PMID:22336283

2012-01-01

172

Cosmic radiation exposure of biological test systems during the EXPOSE-R mission  

NASA Astrophysics Data System (ADS)

In the frame of the EXPOSE-R mission outside the Russian Zvezda Module of the International Space Station (ISS) passive thermoluminescence dosimeters were applied to measure the radiation exposure of biological samples. The detectors were located beneath the sample carriers to determine the dose levels for maximum shielding. The dose measured beneath the sample carriers varied between 317 +/- 10 and 230 +/- 2 mGy, which amount to an average dose rate of 381 +/- 12 and 276 +/- 2 ?Gy d-1. These values are close to those assessed for the interior of the ISS and reflect the high shielding of the biological experiments within the EXPOSE-R facility. As a consequence of the high shielding (several g cm-2), the biological samples were predominantly exposed to galactic cosmic heavy ions and trapped protons in the Earth's radiation belts, whereas the trapped electrons did not reach the samples.

Berger, Thomas; Hajek, Michael; Bilski, Pawel

2015-01-01

173

Cocaine Babies: Florida's Substance-Exposed Youth.  

ERIC Educational Resources Information Center

This report is designed to provide Florida's school personnel with assistance in working with students prenatally exposed to cocaine or other toxic substances. The report offers background data, practical strategies for teaching and learning, and resources for networking. The first chapter outlines statistics on the incidence of the problem of…

Harpring, Jayme

174

Interviews with Children Exposed to Violence  

ERIC Educational Resources Information Center

The aim of this article is to show how research practices may simultaneously follow principles of children's citizenship rights to participation and principles of protection and support when children exposed to violence are informants. The article focuses upon organisation of interview processes and interactions between adult researchers and child…

Eriksson, Maria; Nasman, Elisabet

2012-01-01

175

Rural Canadian Youth Exposed to Physical Violence  

ERIC Educational Resources Information Center

Exposure to physical violence is an unfortunate reality for many Canadian youth as it is associated with numerous negative psychosocial effects. The study aims to assist in understanding resilience in rural Canadian youth exposed to physical violence. This is accomplished by identifying the importance of protective factors, as measured by the…

Laye, Adele M.; Mykota, David B.

2014-01-01

176

Exposing the Mathematical Wizard: Approximating Trigonometric Functions  

ERIC Educational Resources Information Center

For almost all students, what happens when they push buttons on their calculators is essentially magic, and the techniques used are seemingly pure wizardry. In this article, the author draws back the curtain to expose some of the mathematics behind computational wizardry and introduces some fundamental ideas that are accessible to precalculus…

Gordon, Sheldon P.

2011-01-01

177

Expose Mechanical Engineering Students to Biomechanics Topics  

ERIC Educational Resources Information Center

To adapt the focus of engineering education to emerging new industries and technologies nationwide and in the local area, a biomechanics module has been developed and incorporated into a mechanical engineering technical elective course to expose mechanical engineering students at ONU (Ohio Northern University) to the biomedical engineering topics.…

Shen, Hui

2011-01-01

178

Children Exposed to War\\/Terrorism  

Microsoft Academic Search

This paper reviews the prevalence of psychological morbidities in children who have been exposed to war-related traumas or terrorism as well as the diversity of war-related casualties and their associated psychological responses. The psychological responses to war-related stressors are categorized as (1) little or no reaction, (2) acute emotional and behavioral effects, and (3) long-term effects. Specific categories of war-related

Jon A. Shaw

2003-01-01

179

Prosocial coping by youth exposed to violence  

Microsoft Academic Search

Chronic exposure to violence encourages youth to cope with challenges via a mixture of asocial, depressive and antisocial,\\u000a aggressive tactics rather than prosocially in ways that benefit self without harming others. Youth exposed to violence are,\\u000a therefore, not only at high risk for posttraumatic stress disorder (PTSD) but also for externalizing and internalizing behavior\\u000a problems, school dropout, teen pregnancy, substance

Elaine A. Blechman; Jean E. Dumas; Ronald J. Prinz

1994-01-01

180

Work ability in vibration-exposed workers  

PubMed Central

Background Hand–arm vibration exposure may cause hand–arm vibration syndrome (HAVS) including sensorineural disturbances. Aims To investigate which factors had the strongest impact on work ability in vibration-exposed workers. Methods A cross-sectional study in which vibration-exposed workers referred to a department of occupational and environmental medicine were compared with a randomized sample of unexposed subjects from the general population of the city of Gothenburg. All participants underwent a structured interview, answered several questionnaires and had a physical examination including measurements of hand and finger muscle strength and vibrotactile and thermal perception thresholds. Results The vibration-exposed group (47 subjects) showed significantly reduced sensitivity to cold and warmth in digit 2 bilaterally (P < 0.01) and in digit 5 in the left hand (P < 0.05) and to warmth in digit 5 in the right hand (P < 0.01), compared with the 18 referents. Similarly, tactilometry showed significantly raised vibration perception thresholds among the workers (P < 0.05). A strong relationship was found for the following multiple regression model: estimated work ability = 11.4 ? 0.1 × age ? 2.3 × current stress level ? 2.5 × current pain in hands/arms (multiple r = 0.68; P < 0.001). Conclusions Vibration-exposed workers showed raised vibrotactile and thermal perception thresholds, compared with unexposed referents. Multiple regression analysis indicated that stress disorders and muscle pain in hands/arms must also be considered when evaluating work ability among subjects with HAVS. PMID:25145484

Hagberg, M.

2014-01-01

181

Aphid acceptance of barley exposed to volatile phytochemicals differs between plants exposed in daylight and darkness.  

PubMed

It is well known that volatile cues from damaged plants may induce resistance in neighboring plants. Much less is known about the effects of volatile interaction between undamaged plants. In this study, barley plants, Hordeum vulgare cv. Kara, were exposed to volatiles from undamaged plants of barley cv. Alva or thistle Cirsium vulgare, and to the volatile phytochemicals, methyl salicylate or methyl jasmonate. Exposures were made either during natural daylight or darkness. Acceptance of exposed plants by the aphid Rhopalosiphum padi was assessed, as well as the expression of putative marker genes for the different treatments. Aphid acceptance of plants exposed to either barley or C. vulgare was significantly reduced, and an effect of the volatiles from undamaged plants was confirmed by the induction of pathogenesis-related protein, PR1a in exposed plants. However the effect on aphid acceptance was seen only when plants were exposed during darkness, whereas PR1a was induced only after treatment during daylight. Aphid acceptance of plants exposed to either methyl salicylate or methyl jasmonate was significantly reduced, but only when plants were exposed to the chemicals during daylight. AOS2 (allene oxide synthase) was induced by methyl jasmonate and BCI-4 (barley chemical inducible gene-4) by methyl salicylate in both daylight and darkness. It is concluded that (a) the effects on aphids of exposing barley to volatile phytochemicals was influenced by the presence or absence of light and (b) the response of barley to methyl salicylate/methyl jasmonate and to volatiles from undamaged plants differed at the gene and herbivore level. PMID:19516995

Glinwood, Robert; Gradin, Therese; Karpinska, Barbara; Ahmed, Elham; Jonsson, Llisbeth; Ninkovic, Velemir

2007-09-01

182

Aphid Acceptance of Barley Exposed to Volatile Phytochemicals Differs Between Plants Exposed in Daylight and Darkness  

PubMed Central

It is well known that volatile cues from damaged plants may induce resistance in neighboring plants. Much less is known about the effects of volatile interaction between undamaged plants. In this study, barley plants, Hordeum vulgare cv. Kara, were exposed to volatiles from undamaged plants of barley cv. Alva or thistle Cirsium vulgare, and to the volatile phytochemicals, methyl salicylate or methyl jasmonate. Exposures were made either during natural daylight or darkness. Acceptance of exposed plants by the aphid Rhopalosiphum padi was assessed, as well as the expression of putative marker genes for the different treatments. Aphid acceptance of plants exposed to either barley or C. vulgare was significantly reduced, and an effect of the volatiles from undamaged plants was confirmed by the induction of pathogenesis-related protein, PR1a in exposed plants. However the effect on aphid acceptance was seen only when plants were exposed during darkness, whereas PR1a was induced only after treatment during daylight. Aphid acceptance of plants exposed to either methyl salicylate or methyl jasmonate was significantly reduced, but only when plants were exposed to the chemicals during daylight. AOS2 (allene oxide synthase) was induced by methyl jasmonate and BCI-4 (barley chemical inducible gene-4) by methyl salicylate in both daylight and darkness. It is concluded that (a) the effects on aphids of exposing barley to volatile phytochemicals was influenced by the presence or absence of light and (b) the response of barley to methyl salicylate/methyl jasmonate and to volatiles from undamaged plants differed at the gene and herbivore level. PMID:19516995

Glinwood, Robert; Gradin, Therese; Karpinska, Barbara; Ahmed, Elham; Jonsson, Llisbeth

2007-01-01

183

The PUR Experiment on the EXPOSE-R facility: biological dosimetry of solar extraterrestrial UV radiation  

NASA Astrophysics Data System (ADS)

The aim of our experiment Phage and Uracil Response was to extend the use of bacteriophage T7 and uracil biological dosimeters for measuring the biologically effective ultraviolet (UV) dose in the harsh extraterrestrial radiation conditions. The biological detectors were exposed in vacuum-tightly cases in the European Space Agency (ESA) astrobiological exposure facility attached to the external platform of Zvezda (EXPOSE-R). EXPOSE-R took off to the International Space Station (ISS) in November 2008 and was installed on the External platform of the Russian module Zvezda of the ISS in March 2009. Our goal was to determine the dose-effect relation for the formation of photoproducts (i.e. damage to phage DNA and uracil, respectively). The extraterrestrial solar UV radiation ranges over the whole spectrum from vacuum-UV (?<200 nm) to UVA (315 nm

Bérces, A.; Egyeki, M.; Fekete, A.; Horneck, G.; Kovács, G.; Panitz, C.

2015-01-01

184

Mortality patterns among workers exposed to acrylamide  

SciTech Connect

A cohort of 8854 men, 2293 of whom were exposed to acrylamide, was examined from 1925 to 1983 for mortality. This cohort consisted of four plant populations in two countries: the United States and The Netherlands. No statistically significant excess of all-cause or cause-specific mortality was found among acrylamide workers. Analysis by acrylamide exposure levels showed no trend of increased risk of mortality from several cancer sites. These results do not support the hypothesis that acrylamide is a human carcinogen.

Collins, J.J.; Swaen, G.M.; Marsh, G.M.; Utidjian, H.M.; Caporossi, J.C.; Lucas, L.J. (American Cyanamid Co., Wayne, NJ (USA))

1989-07-01

185

Experimental investigations on freely exposed ducted radiators  

NASA Technical Reports Server (NTRS)

This report deals with the relation between the open areas, the drag, and the air flow as observed on freely exposed, ducted radiators - the air conductivity being modified from zero to one unit. In conjunction with theoretical results, the individual components of the drag of ducted radiators are discussed and general rules established for low-loss ducts. The influence of the wall thickness of the ducts, of the length ratio of the exit, and the effects of sonic velocity on diffusers are dealt with by special measurement.

Linke, W

1941-01-01

186

The surgical closure of exposed skull.  

PubMed

The closure of scalp defects is still surrounded by many uncertainties. Free skin graft has proved most successful. Thiersch graft, split skin graft and full thickness skin graft have their indication for use. Thiersch skin graft is used as a temporary dressing, in order to achieve aseptic wound conditions, but cannot be looked upon as a lasting solution cosmetically and functionally. Split skin is used only for the closure of smaller defects. Full thickness skin grafts are most suitable, because they offer a lasting coverage, which meets to all demands. If the outer table of the skull is exposed, multiple bur holes could be placed immediately in cases of fresh injuries, and these facilitate the growth of granulation tissues which nourish the outer table adequately, so that it remains viable. Exposure of the outer table of the skull for a long time leads to necrosis of the superficial layer. It must therefore be removed down to the diploe with a chisel, or brought to early sequestration by means of numerous perforations made with a bur. Skin should not, however, be placed on the exposed diploe immediately, but it should be allowed to granulate, so as to produce a layer of fibrous tissue beneath the grafted full thickness skin. Thus a direct adhesion to the bony underlayer is prevented, and the skin remains movable. The danger of pressure ulcer is also prevented. The figures show the surgical procedure. PMID:1100743

Widmaier, W

1975-09-01

187

Endometriosis among Women Exposed to Polybrominated Biphenyls  

PubMed Central

Purpose We examined the association between endometriosis and exposure to polybrominated biphenyls (PBBs) and polychlorinated biphenyls (PCBs) among women inadvertently exposed to PBBs in 1973. Methods Serum PBB and PCB were measured in the late 1970s. Women self-reported endometriosis at interview in 1997. We constructed Cox models to estimate the relative incidence of endometriosis in relation to PBB and PCB levels. Results Seventy-nine of 943 women (9%) reported endometriosis. Compared to women with low PBB exposure (? 1 parts per billion [ppb]), women with moderate PBB (1–4 ppb) (hazard ratio [HR] = 0.72; 95% confidence interval [CI], 0.39–1.31) and high PBB (? 4 ppb) (HR = 0.90; 95% CI, 0.51–1.59) exposure did not have increased incidence of endometriosis. Increased incidence of endometriosis was suggested among women exposed to moderate PCB (5–8 ppb) (HR = 1.67; 95% CI, 0.91–3.10) and high PCB (? 8 ppb) (HR = 1.68; 95% CI, 0.95–2.98) levels compared to low PCB exposure (? 5 ppb). Conclusions Our study does not support an association between PBB exposure and endometriosis. Findings for serum PCB level are consistent with an emerging body of literature suggesting an association between PCB exposure and endometriosis. PMID:17448678

Hoffman, Caroline S.; Small, Chanley M.; Blanck, Heidi Michels; Tolbert, Paige; Rubin, Carol; Marcus, Michele

2007-01-01

188

First results of the ORGANIC experiment on EXPOSE-R on the ISS  

NASA Astrophysics Data System (ADS)

The ORGANIC experiment on EXPOSE-R spent 682 days outside the International Space Station, providing continuous exposure to the cosmic-, solar- and trapped-particle radiation background for fourteen samples: 11 polycyclic aromatic hydrocarbons (PAHs) and three fullerenes. The thin films of the ORGANIC experiment received, during space exposure, an irradiation dose of the order of 14 000 MJ m-2 over 2900 h of unshadowed solar illumination. Extensive analyses were performed on the returned samples and the results compared to ground control measurements. Analytical studies of the returned samples included spectral measurements from the vacuum ultraviolet to the infrared range and time-of-flight secondary ion mass spectrometry. Limited spectral changes were observed in most cases pointing to the stability of PAHs and fullerenes under space exposure conditions. Furthermore, the results of these experiments confirm the known trend in the stability of PAH species according to molecular structure: compact PAHs are more stable than non-compact PAHs, which are themselves more stable than PAHs containing heteroatoms, the last category being the most prone to degradation in the space environment. We estimate a depletion rate of the order of 85 +/- 5% over the 17 equivalent weeks of continuous unshadowed solar exposure in the most extreme case tetracene (smallest, non-compact PAH sample). The insignificant spectral changes (below 10%) measured for solid films of large or compact PAHs and fullerenes indicate a high stability under the range of space exposure conditions investigated on EXPOSE-R.

Bryson, K. L.; Salama, F.; Elsaesser, A.; Peeters, Z.; Ricco, A. J.; Foing, B. H.

2015-01-01

189

Dust release from surfaces exposed to plasma  

NASA Astrophysics Data System (ADS)

Micrometer-sized particles adhered to a surface can be released when exposed to plasma. In an experiment with a glass surface coated with lunar-simulant dust, it was found that particle release requires exposure to both plasma and an electron beam. The dust release rate diminishes almost exponentially in time, which is consistent with a random process. As proposed here, charges of particles adhered to the surface fluctuate. These charges experience a fluctuating electric force that occasionally overcomes the adhesive van der Waals force, causing particle release. The release rate increases with plasma density, so that plasma cleaning is feasible at high plasma densities. Applications of this cleaning include controlling particulate contamination in semiconductor manufacturing, dust mitigation in the exploration of the moon and Mars, and dusty plasmas.

Flanagan, T. M.; Goree, J.

2006-12-01

190

Immune Response among Patients Exposed to Molds  

PubMed Central

Macrocyclic trichothecenes, mycotoxins produced by Stachybotrys chartarum, have been implicated in adverse reactions in individuals exposed to mold-contaminated environments. Cellular and humoral immune responses and the presence of trichothecenes were evaluated in patients with mold-related health complaints. Patients underwent history, physical examination, skin prick/puncture tests with mold extracts, immunological evaluations and their sera were analyzed for trichothecenes. T-cell proliferation, macrocyclic trichothecenes, and mold specific IgG and IgA levels were not significantly different than controls; however 70% of the patients had positive skin tests to molds. Thus, IgE mediated or other non-immune mechanisms could be the cause of their symptoms. PMID:20054481

Edmondson, David A.; Barrios, Christy S.; Brasel, Trevor L.; Straus, David C.; Kurup, Viswanath P.; Fink, Jordan N.

2009-01-01

191

Mortality among industrial workers exposed to formaldehyde.  

PubMed

A historical cohort study evaluated the mortality experience of 26,561 workers employed in 10 formaldehyde-producing or -using facilities. Approximately 600,000 person-years of follow-up accrued as workers were followed to January 1, 1980. Estimates of historical exposure to formaldehyde by job were developed by project industrial hygienists using monitoring data available from participating plants, comments from long-term workers, and comprehensive monitoring data specifically collected for this study. Mortality from all causes combined was about as expected [standardized mortality ratio (SMR) = 96] based on mortality rates of the general U.S. population. Significantly fewer deaths occurred from infective and parasitic diseases (SMR = 51) and from accidents (SMR = 72) than expected. Cancer overall was not related to formaldehyde exposure. Workers exposed to formaldehyde had slight excesses for Hodgkin's disease and cancers of the lung and prostate gland, but these excesses were not consistently related to duration of or average, cumulative, or peak formaldehyde exposure levels. Recent animal studies found nasal cancer among rats exposed to formaldehyde, but no excess of this tumor occurred in this study. Mortality from brain cancer and leukemia among these industrial workers was not excessive in contrast to reported excesses among professional groups (e.g., anatomists, embalmers, and pathologists) with exposure to formaldehyde. Although there was a deficit for cancer of the buccal cavity and pharynx, mortality from certain subsites, i.e., the nasopharynx and oropharynx, was elevated. These subsites did not, however, show a consistently rising risk with level of exposure. These data provide little evidence that mortality from cancer is associated with formaldehyde exposure at levels experienced by workers in this study. PMID:3458945

Blair, A; Stewart, P; O'Berg, M; Gaffey, W; Walrath, J; Ward, J; Bales, R; Kaplan, S; Cubit, D

1986-06-01

192

Population exposed to landslide risk in Italy  

NASA Astrophysics Data System (ADS)

Italy is one of the European countries most affected by landslides counting over 486,000 mass movements with a total area of 20,700 square kilometres equal to 6.9% of the national territory. Moreover Italy is a densely urbanized country: 8101 municipalities, about 200 inhabitants per sq. km, 16,000 km of rail network and 180,000 km of road network. Landslides caused more than 5000 fatalities in the last century and considerable damage to urban areas, transport infrastructure and facilities, environmental and cultural heritage. The aim of this work is to estimate the population exposed to landslide risk in Italy. The input data are: the Italian Landslide Inventory, the Italian Population Census data and the high-resolution Artificial surfaces-Imperviousness Layer (Geoland2). The Italian Landslide Inventory (Progetto IFFI) realised by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-governing Provinces, identifies landslides occurred in the national territory in accordance with standardized methods and using a detailed landslide mapping (1:10,000 scale). The 14th Population Census, made by ISTAT (Italian National Institute of Statistics) in 2001, contains data of resident population for the 382,534 census tracts in which Italy is divided. The pan-European high-resolution (HR) Artificial surfaces-Imperviousness Layer, realized using remote sensing data within the GMES initiative (Global Monitoring for Environment and Security) by European Commission and European Space Agency, contains the degree of imperviousness (between 0 and 100%). GIS overlay of this information layer (20 x 20 m grid) with census tracts has allowed the spatialization of population within urban settlements of each census tract. This methodology has been particularly useful in the case of rural census tracts characterized by large surface area and low population density. The methodology could be also applied to estimate the population exposed to other natural, environmental or technological risks.

Trigila, Alessandro; Iadanza, Carla; Munafò, Michele; Baiocco, Fabio; Marinosci, Ines; Chiocchini, Raffaella; Mugnoli, Stefano

2013-04-01

193

Acaricidal effect of a diatomaceous earth formulation against Tyrophagus putrescentiae (Astigmata: Acaridae) and its predator Cheyletus malaccensis (Prostigmata: Cheyletidae) in four grain commodities.  

PubMed

Laboratory bioassays were conducted to evaluate the effect of the diatomaceous earth (DE) formulation SilicoSec (Biofa GmbH, Münsingen, Germany), against two stored-product mite species, Tyrophagus putrescentiae (Shrank) and the predator Cheyletus malaccensis Oudemans. For this purpose, DE was applied in wheat, oat, rye, and maize, at the dose rates 0, 0.5, 1, and 2 g/kg grain. The mortality of the exposed mites was assessed after 24 h, 48 h, 7 d, and 14 d of exposure in the treated substrate. After this interval, the treated grains were checked for oviposition or progeny. The tests were conducted at 80% RH and at two temperatures, 20 and 25 degrees C. Generally, for both species, mortality was higher at 25 degrees C than at 20 degrees C. For T. putrescentiae, at both temperatures, the mortality in grains treated with the highest DE rate was 100% after only 24 h of exposure, with the exception of maize at 20 degrees C, where mortality was 91.7%. The mortality of C. malaccensis after 24 h of exposure to the treated grains, in the absence of prey, did not exceed 29% at any of the temperature- grain-dose combinations, whereas no mites were dead in rye and maize treated with 0.5 and 1 g of DE. Even after 14 d of exposure at the highest DE rate, mite mortality did not reach 100%. The presence of T. putrescentiae individuals as prey in the treated substrate enhanced C. malaccensis survival. Hence, after 14 d of exposure, the mortality of C. malaccensis, in wheat, oat, rye, and maize treated with the highest DE rate was 51.7, 59.7, 70, and 36.9, respectively. No progeny production was recorded in the treated substrate for T. putrescentiae; in contrast, oviposition and F1 progeny were recorded for C. malaccensis. Our results suggest that the use of C. malaccensis with low doses of DE may be an appealing integrated pest management (IPM) approach against T. putrescentiae, and probably against other stored-grain mite species. PMID:16573344

Palyvos, Nickolas E; Athanassiou, Christos G; Kavallieratos, Nickolas G

2006-02-01

194

The SPORES experiment of the EXPOSE-R mission: Bacillus subtilis spores in artificial meteorites  

NASA Astrophysics Data System (ADS)

The experiment SPORES `Spores in artificial meteorites' was part of European Space Agency's EXPOSE-R mission, which exposed chemical and biological samples for nearly 2 years (March 10, 2009 to February 21, 2011) to outer space, when attached to the outside of the Russian Zvezda module of the International Space Station. The overall objective of the SPORES experiment was to address the question whether the meteorite material offers enough protection against the harsh environment of space for spores to survive a long-term journey in space by experimentally mimicking the hypothetical scenario of Lithopanspermia, which assumes interplanetary transfer of life via impact-ejected rocks. For this purpose, spores of Bacillus subtilis 168 were exposed to selected parameters of outer space (solar ultraviolet (UV) radiation at ?>110 or >200 nm, space vacuum, galactic cosmic radiation and temperature fluctuations) either as a pure spore monolayer or mixed with different concentrations of artificial meteorite powder. Total fluence of solar UV radiation (100-400 nm) during the mission was 859 MJ m-2. After retrieval the viability of the samples was analysed. A Mission Ground Reference program was performed in parallel to the flight experiment. The results of SPORES demonstrate the high inactivating potential of extraterrestrial UV radiation as one of the most harmful factors of space, especially UV at ?>110 nm. The UV-induced inactivation is mainly caused by photodamaging of the DNA, as documented by the identification of the spore photoproduct 5,6-dihydro-5(?-thyminyl)thymine. The data disclose the limits of Lithopanspermia for spores located in the upper layers of impact-ejected rocks due to access of harmful extraterrestrial solar UV radiation.

Panitz, Corinna; Horneck, Gerda; Rabbow, Elke; Rettberg, Petra; Moeller, Ralf; Cadet, Jean; Douki, Thierry

2015-01-01

195

Neurotoxicity of Acrylamide in Exposed Workers  

PubMed Central

Acrylamide (ACR) is a water-soluble chemical used in different industrial and laboratory processes. ACR monomer is neurotoxic in humans and laboratory animals. Subchronic exposure to this chemical causes neuropathies, hands and feet numbness, gait abnormalities, muscle weakness, ataxia, skin and in some cases, cerebellar alterations. ACR neurotoxicity involves mostly the peripheral but also the central nervous system, because of damage to the nerve terminal through membrane fusion mechanisms and tubulovescicular alterations. Nevertheless, the exact action mechanism is not completely elucidated. In this paper we have reviewed the current literature on its neurotoxicity connected to work-related ACR exposure. We have analyzed not only the different pathogenetic hypotheses focusing on possible neuropathological targets, but also the critical behavior of ACR poisoning. In addition we have evaluated the ACR-exposed workers case studies. Despite all the amount of work which have being carried out on this topic more studies are necessary to fully understand the pathogenetic mechanisms, in order to propose suitable therapies. PMID:23985770

Pennisi, Manuela; Malaguarnera, Giulia; Puglisi, Valentina; Vinciguerra, Luisa; Vacante, Marco; Malaguarnera, Mariano

2013-01-01

196

Post-exposed fiber Bragg gratings  

NASA Astrophysics Data System (ADS)

This thesis explains the development and characterization of a novel technique to fabricate weak fiber Bragg gratings for highly specific multi-element sensor arrays. This method, termed the "rescan technique," involves re-exposing a local region of a grating to fringeless ultraviolet light to "trim" unwanted portions of the reflection spectrum. The spectral effects that result from a rescan can only be adequately described by inventing the concept of a three-dimensional index growth surface, where induced index is a function of both the writing intensity and the exposure time. Using this information, it is possible to predict the spectral response of a rescanned grating using a numerical model. For our model, we have modified the piecewise-uniform approach to include coefficients within the coupled-mode formulism that imitate the same scattering properties as the actual grating. By taking high accuracy measurements of the refractive index change in germanosilicate fiber, we have created the necessary 3D map of photoinduced index to accurately model gratings and their post-exposure spectra. We will also demonstrate that optical fiber exhibits what we call "exposure history"; the final index change in a region depends on the previous exposures conditions.

Miller, Gary A.

197

Thyroid hormones in chronic heat exposed men  

NASA Astrophysics Data System (ADS)

Previous reports have indicated that thyroid gland activity, is depressed in the heat. Total thyroxine (T4) and triiodothyronine (T3) serum levels in 17 workers of the metal work shop at a plant near the Dead Sea and 8 workers in Beer Sheva, Israel were examined. The metal workshop of the plant near the Dead Sea is part of a large chemical plant. The one in Beer Sheva is part of a large construction company. Maintenance work, as well as metal work projects are performed in both workshops. During the work shifts, the workers of the Dead Sea plant were exposed to temperatures ranging from 30 36°C (May Oct.) and 14 21°C (Dec. Feb). In Beer Sheva the range was 25 32°C (June Sept.) and 10 17°C (Dec. Feb.). Total T4 was measured by competitive protein binding and total T3 by radioimmunoassay in blood drawn before work (0700) in July and January. In summer. T4 was higher and T3 was lower for both groups than in winter. The observed summer T3 decrease may result from depressed extrathyroidal conversion of T4 to T3. We conclude that the regulation of energy metabolism in hot climates may be related to extrathyroidal conversion of T4 to T3.

Gertner, A.; Israeli, R.; Lev, A.; Cassuto, Y.

1983-03-01

198

In vitro and in vivo acaricide action of juvenoid analogs produced from the chemical modification of Cymbopogon spp. and Corymbia citriodora essential oil on the cattle tick Rhipicephalus (Boophilus) microplus.  

PubMed

The present study aimed to evaluate the acaricidal action of the chemically modified essential oil of Cymbopogon spp. and Corymbia citriodora on Rhipicephalus (Boophilus) microplus. Citronellal was converted into N-butylcitronellylamine and in N-prop-2-inylcitronellylamine, analogs of juvenoids, by reductive amination using butylamine (N1 to N3) and propargylamine (N4 to N7). In vitro assays included the adult immersion, and larval packet tests. Engorged females were weighed in groups of 10 and tested in three replicates for six concentrations. They were immersed in the modified oils or control solution and incubated. In the larval packet test, the same substances and concentrations were evaluated in three replicates. In the in vivo test, six pastured heifers naturally infested with R. (B.) microplus were used per treatment: negative control, positive control (amitraz, Triatox(®)), original oil of C. citriodora at 1.5%, and modified oil containing 0.9% N-prop-2-inylcitronellylamine (N7). Ticks were counted in the right side of the body in 24 animals from day D-3 to D21. LC50 and LC90 were obtained by Probit analysis, while the in vivo results were log transformed and compared using the Tukey test. Among the nitrocellylamines tested in vitro, N6 was most effective on the engorged females (100% efficacy at 50mg/mL) and N7 on the larvae (100% efficacy at 6.25mg/mL). In the test with larvae, the original oil of C. citriodora was less effective than the counterpart modified oil (N7), proving that the chemical modification optimized its effect. In the in vivo test, no significant difference was observed between N7 and the negative control. The average numbers of ticks on the animals' right side were 32.8, 8.1, 37.9 and 35.4 for the negative control, positive control, original oil and N7, respectively. The chemical modification improved the efficacy in vitro, but it was not observed in vivo, perhaps due to the low stability of the amines under field conditions. The evaluation carried out here has not been previously studied, so this concept expands the horizon for research into chemically modified substances for parasite control and shed light on the challenges to find effective formulations and application methods. PMID:25085774

Chagas, Ana Carolina S; Domingues, Luciana F; Fantatto, Rafaela R; Giglioti, Rodrigo; Oliveira, Márcia C S; Oliveira, Daniela H; Mano, Renata A; Jacob, Raquel G

2014-09-15

199

Children Exposed to Community Violence: The Rationale for Early Intervention  

Microsoft Academic Search

Children are exposed to violence in their homes and communities at extraordinarily high rates. Given the alarming rates of exposure and its known impact on child developmental outcomes, crisis intervention geared at interrupting the negative effects of violence exposure are increasingly important. This review provides a rationale for the implementation of early and crisis intervention strategies for children exposed to

Steven J. Berkowitz

2003-01-01

200

31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD ...  

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

31. VIEW OF ROOM 212 LOOKING NORTHWEST TOWARDS EXPOSED STUD WALL THAT SERVES AS DIVIDER TO ROOM 211. EXPOSED TRUSSWORK VISIBLE THROUGH TO NEXT ROOM. WOOD PANELED WALLS ARE PAINTED; FLOORS ARE WOOD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

201

Exposing Image Forgery with Blind Noise Estimation Computer Science  

E-print Network

to expose such image forgeries by detecting the noise variance differences between original and tam- pered. In this work, we propose a new detection method to effectively locate image forgeries based on iExposing Image Forgery with Blind Noise Estimation Xunyu Pan Computer Science Department University

Lyu, Siwei

202

EXPOSING IMAGE FORGERY THROUGH THE DETECTION OF CONTRAST ENHANCEMENT  

E-print Network

EXPOSING IMAGE FORGERY THROUGH THE DETECTION OF CONTRAST ENHANCEMENT Xufeng Lin1 , Chang-Tsun Li1- age forgery through detecting contrast enhancement is proposed. We reveal the inter, which introduce some statisti- cal traces. Therefore, we can expose cut-and-paste image forgery

Li, Chang-Tsun

203

The Psychobiology of Children Exposed to Marital Violence  

ERIC Educational Resources Information Center

We examined the psychological and physiological functioning of a community sample of children exposed to marital violence, comparing them to a clinical comparison group without marital violence exposure. Results replicated past findings of elevated levels of trauma symptomatology in this population. Further, children exposed to marital violence…

Saltzman, Kasey M.; Holden, George W.; Holahan, Charles J.

2005-01-01

204

The perception of briefly exposed point-sources of light  

Microsoft Academic Search

Point-sources of light (dots) were exposed for 10 to 50 msec, before five dark-adapted subjects in a dimly illuminated room. During voluntary fixation with one eye, the target was exposed some 10° on the nasal side of the optic axis. The intensity X duration of all targets was 2 X threshold and they consisted of either a single dot, or

B. Delisle Burns; G. Mandl; R. Pritchard; Cordelia Webb

1969-01-01

205

Reactivity and Regulation in Children Prenatally Exposed to Cocaine  

ERIC Educational Resources Information Center

Children prenatally exposed to cocaine may be at elevated risk for adjustment problems in early development because of greater reactivity and reduced regulation during challenging tasks. Few studies have examined whether cocaine-exposed children show such difficulties during the preschool years, a period marked by increased social and cognitive…

Dennis, Tracy; Bendersky, Margaret; Ramsay, Douglas; Lewis, Michael

2006-01-01

206

Dust release from surfaces exposed to plasma T. M. Flanagana  

E-print Network

Dust release from surfaces exposed to plasma T. M. Flanagana and J. Goree Department of Physics exposed to plasma. In an experiment with a glass surface coated with lunar-simulant dust, it was found that particle release requires exposure to both plasma and an electron beam. The dust release rate diminishes

Goree, John

207

CEREBELLAR HISTOGENESIS IN RATS EXPOSED TO 2450 MHZ MICROWAVE RADIATION  

EPA Science Inventory

Pregnant rats were either exposed or sham exposed from day 13 of gestation until birth to 2450 MHz linearly polarized microwaves at 10 mW/sq cm. A third matching group served as cage control. After birth, the pups were kept with their mothers for 21 days without any treatment, an...

208

Follow-up of children of depressed mothers exposed or not exposed to antidepressant drugs during pregnancy  

Microsoft Academic Search

Objective To compare the structural growth and developmental outcome of children born to mothers diagnosed with major depressive disorder during pregnancy who were exposed or not exposed to selective serotonin reuptake inhibitors (SSRIs) in utero. Study design Children whose mothers were diagnosed with major depressive disorder in pregnancy and elected not to take medication (n = 13) were compared with

Regina C. Casper; Barry E. Fleisher; Julie C. Lee-Ancajas; Allyson Gilles; Erika Gaylor; Anne DeBattista; H. Eugene Hoyme

2003-01-01

209

The AMINO experiment: RNA stability under solar radiation studied on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

Careful examination of the present metabolism and in vitro selection of various catalytic RNAs strongly support the RNA world hypothesis as a crucial step of the origins and early life evolution. Small functional RNAs were exposed from 10 March 2009 to 21 January 2011 to space conditions on board the International Space Station in the EXPOSE-R mission. The aim of this study was to investigate the preservation or modification properties such as integrity of RNAs after space exposition. The exposition to the solar radiation has a strong degradation effect on the size distribution of RNA. Moreover, the comparison between the in-flight samples, exposed to the Sun and not exposed, indicates that the solar radiation degrades RNA bases.

Vergne, Jacques; Cottin, Hervé; da Silva, Laura; Brack, André; Chaput, Didier

2015-01-01

210

Aluminium in the blood and urine of industrially exposed workers.  

PubMed Central

Blood and urine aluminium concentrations were studied in industrially exposed workers using electrothermal atomic absorption spectrometry. Welders and workers making aluminium powder and aluminium sulphate had higher concentrations in blood and urine than non-exposed referents. Workers in the electrolytic production of aluminium had higher urine but not blood concentrations than the referents. Thus aluminium was found to be absorbed by all industrially exposed workers. Blood concentrations were lower than those presumably associated with aluminium induced encephalopathy in patients receiving dialysis. PMID:6871119

Sjögren, B; Lundberg, I; Lidums, V

1983-01-01

211

Outdoor polymeric insulators long-term exposed to HVDC  

SciTech Connect

Field experience from outdoor polymeric insulators exposed to HVDC under natural contamination conditions is presented. This paper summarizes the peak leakage current statistics, the hydrophobicity and the surface material conditions studied by electron spectroscopy for chemical analysis (ESCA) and attenuated total reflection Fourier transform infrared (ATR-FTIR) spectroscopy. The results show a strong interrelation between the surface conditions and the performance with respect to leakage currents. Moreover, the results show that the surface conditions and the performance of the insulators exposed to HVDC are rather similar to those of the insulators exposed to HVAC.

Soerqvist, T.; Vlastos, A.E. [Chalmers Univ. of Technology, Gothenburg (Sweden)] [Chalmers Univ. of Technology, Gothenburg (Sweden)

1997-04-01

212

Isolation and characterisation of acaricidal and larvicidal novel compound (2S,5R,6R)-2-hydroxy-3,5,6-trimethyloctan-4-one from Streptomyces sp. against blood-sucking parasites.  

PubMed

The aim of the present study was to assess the acaricidal and larvicidal property of marine actinobacterial compound (2S,5R,6R)-2-hydroxy-3,5,6-trimethyloctan-4-one extracted and isolated from Streptomyces sp. VITDDK3 tested against the larvae of Rhipicephalus (Boophilus) microplus Canestrini (Acari: Ixodidae), Anopheles subpictus Grassi and Culex quinquefasciatus Say (Diptera: Culicidae). The isolate was taxonomically characterised, identified and designated as Streptomyces sp. VITDDK3. The crude compound was loaded on silica gel column and eluted with chloroform-methanol-water. The purity of the compound isolated was analysed by thin layer chromatography using chloroform and methanol as the solvent system and confirmed by high-performance liquid chromatography. The structure of the purified compound was established from infrared, ultraviolet, (1)H-nuclear magnetic resonance (NMR), (13)C-NMR and mass spectral data. The chemical shift assignments obtained for the aliphatic compound from (1)H-NMR corresponding to the molecular formula C(11)H(22)O(2). Bioassay-guided fractionation led to the isolation of compound, which was identified as (2S,5R,6R)-2-hydroxy-3,5,6-trimethyloctan-4-one. In the present study, Streptomyces sp. VITDDK3 crude extract and different fractions were tested against the larvae of parasites at a concentration of 1,000 ppm. Those fractions showing 100% mortality in 24 h alone was selected for further column chromatographic separation. The purified compound (2S,5R,6R)-2-hydroxy-3,5,6-trimethyloctan-4-one was tested in the concentrations of 250, 200, 150, 100 and 50 ppm and observed the per cent mortality of 100, 88, 62, 50 and 36 against R. microplus; 100, 100, 87, 62 and 39 against A. subpitcus; and 100, 94, 79, 51 and 33 against C. quinquefasciatus, respectively. The crude extract showed parasitic effects after 24 h of exposure at 1,000 ppm, and parasite mortality was observed against the larvae of R. microplus (LC(50) = 88.74 ppm; r (2) = 0.865) against the larvae of A. subpictus (LC(50) = 162.59 ppm; r (2) = 0.817) and against C. quinquefasciatus (LC(50) = 120.15 ppm; r (2) = 0.782), respectively. The maximum efficacy was observed in purified marine actinobacterial compound (2S,5R,6R)-2-hydroxy-3,5,6-trimethyloctan-4-one with LC(50) and r (2) values against the larvae of R. microplus (94.49 ppm; 0.982) and A. subpictus (69.65 ppm; 0.906) and against C. quinquefasciatus (82.82 ppm; 0.957), respectively. The control (distilled water) showed nil mortality in the concurrent assay. PMID:21698506

Deepika, Thimiri Lakshmipathi; Kannabiran, Krishnan; Khanna, Venkatesan Gopiesh; Rajakumar, Govindasamy; Jayaseelan, Chidambaram; Santhoshkumar, Thirunavukkarasu; Rahuman, Abdul Abdul

2012-09-01

213

9 CFR 78.23 - Brucellosis exposed bison.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Brucellosis exposed bison. 78.23 Section...INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Bison Because of Brucellosis § 78.23 Brucellosis...

2010-01-01

214

9 CFR 78.8 - Brucellosis exposed cattle.  

Code of Federal Regulations, 2010 CFR

...2010-01-01 2010-01-01 false Brucellosis exposed cattle. 78.8 Section...INCLUDING POULTRY) AND ANIMAL PRODUCTS BRUCELLOSIS Restrictions on Interstate Movement of Cattle Because of Brucellosis § 78.8 Brucellosis...

2010-01-01

215

TRANSCRIPTIONAL RESPONSES OF MOUSE EMBRYO CULTURES EXPOSED TO BROMOCHLOROACETIC ACID  

EPA Science Inventory

Transcriptional responses of mouse embryo cultures exposed to bromochloroacetic acid Edward D. Karoly?*, Judith E. Schmid* and E. Sidney Hunter III* ?Curriculum in Toxicology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina and *Reproductive Tox...

216

VERTEBRAL DYSPLASIA IN YOUNG FISH EXPOSED TO THE HERBICIDE TRIFLURALIN  

EPA Science Inventory

Sheepshead minnows, Cyprinodon variegatus Lacepede, exposed to 5-5 to 31 micrograms/l of the herbicide trifluralin, throughout their first 28 days of life, developed a heretofore, undescribed vertebral dysplasia. This dysplasia consisted of semisymmetrical hypertrophy of vertebra...

217

10. CLOSEUP VIEW OF SEGMENT OF DETERIORATING CURB SHOWING EXPOSED ...  

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

10. CLOSE-UP VIEW OF SEGMENT OF DETERIORATING CURB SHOWING EXPOSED REBAR, LOOKING NORTHEAST - Escalante River Bridge, Spanning Escalante River at State Route 12, 9.5 miles East of Escalante, Escalante, Garfield County, UT

218

RESPIRATORY DAMAGE IN CHILDREN EXPOSED TO URBAN POLLUTION  

EPA Science Inventory

Southwest Metropolitan Mexico City (SWMMC) children are chronically exposed to complex mixtures of air pollutants. In a cross-sectional arm of our study, we investigated the association between exposure to SWMMC atmosphere and nasal abnormalities, hyperinflation, and intersti...

219

Possible Crustal Boundary Exposed at Lunar Copernicus Crater  

NASA Astrophysics Data System (ADS)

Mineral distribution and geology of lunar Copernicus Crater studied with VIS-NIR reflectance spectra of Kaguya Multiband Imager (MI) indicate that a crustal boundary may be exposed at the Copernicus Crater.

Arai, T.; Ohtake, M.; Yamamoto, A.; Sugihara, T.; Hiroi, T.; Nakamura, R.; Namiki, N.; Wada, K.; Yamamoto, S.; Matsunaga, T.; Haruyama, J.

2011-03-01

220

TERATOGENESIS, TOXICITY, AND BIOCONCENTRATION IN FROGS EXPOSED TO DIELDRIN  

EPA Science Inventory

Teratogenesis, acute and chronic toxicity, and bioconcentration were investigated in various like stages of African clawed frogs (Xenopus laevis), bullfrogs (Rana catesbeiana) and leopard frogs (Rana pipiens) exposed to aqueous dieldrin in static-renewal and continuous-flow tests...

221

Mortality patterns among men exposed to methyl methacrylate  

SciTech Connect

A cohort of 2,671 men, 1561 of whom were exposed to methyl methacrylate, was observed from 1951 to 1983 for mortality. This cohort consisted of men from two plants. This study utilizes detailed exposure estimates and smoking status to evaluate mortality patterns. We find no statistically significant excess all-cause or cause-specific mortality. Analysis of dose of methyl methacrylate with several cancer sites showed no trend. Men exposed to high levels of methyl methacrylate had cancer rates similar to those for men not exposed in the workplace, as well as for other men in the US population. An earlier epidemiology study reported a significant excess of colorectal cancer among persons exposed to several substances including methyl methacrylate. Our study results and results from animal studies do not support the hypothesis that methyl methacrylate is a human carcinogen.

Collins, J.J.; Page, L.C.; Caporossi, J.C.; Utidjian, H.M.; Saipher, J.N.

1989-01-01

222

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2012 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2012-10-01

223

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2011 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2011-10-01

224

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2014 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2014-10-01

225

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2010 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2010-10-01

226

46 CFR 108.223 - Guards on exposed equipment.  

Code of Federal Regulations, 2013 CFR

...Guards on exposed equipment. Each unit must have hand covers, guards, or rails installed on all belts, gears, shafts, pulleys, sprockets, spindles, flywheels or other reciprocating, rotating or moving parts of machinery or equipment normally...

2013-10-01

227

46 CFR 28.215 - Guards for exposed hazards.  

Code of Federal Regulations, 2012 CFR

...Fish Tender Vessels Engaged in the Aleutian Trade § 28.215 Guards for exposed hazards. (a...space on board a vessel must meet the requirements of this section. (b) Suitable hand covers, guards, or railing must be...

2012-10-01

228

46 CFR 28.215 - Guards for exposed hazards.  

Code of Federal Regulations, 2011 CFR

...Fish Tender Vessels Engaged in the Aleutian Trade § 28.215 Guards for exposed hazards. (a...space on board a vessel must meet the requirements of this section. (b) Suitable hand covers, guards, or railing must be...

2011-10-01

229

46 CFR 28.215 - Guards for exposed hazards.  

Code of Federal Regulations, 2010 CFR

...Fish Tender Vessels Engaged in the Aleutian Trade § 28.215 Guards for exposed hazards. (a...space on board a vessel must meet the requirements of this section. (b) Suitable hand covers, guards, or railing must be...

2010-10-01

230

46 CFR 28.215 - Guards for exposed hazards.  

Code of Federal Regulations, 2013 CFR

...Fish Tender Vessels Engaged in the Aleutian Trade § 28.215 Guards for exposed hazards. (a...space on board a vessel must meet the requirements of this section. (b) Suitable hand covers, guards, or railing must be...

2013-10-01

231

46 CFR 28.215 - Guards for exposed hazards.  

Code of Federal Regulations, 2014 CFR

...Fish Tender Vessels Engaged in the Aleutian Trade § 28.215 Guards for exposed hazards. (a...space on board a vessel must meet the requirements of this section. (b) Suitable hand covers, guards, or railing must be...

2014-10-01

232

Symptom Patterns among Youth Exposed to Intimate Partner Violence  

Microsoft Academic Search

Children and adolescents exposed to intimate partner violence display a broad range of symptoms. We sought to differentiate\\u000a symptom patterns and predictors of these patterns using a person-oriented approach. Previous cluster analysis research of\\u000a exposed youth was extended to include youth PTSD symptoms and trauma history. Participants were 74 mothers who had received\\u000a a police call for domestic violence, and

Jason M. Lang; Carla Smith Stover

2008-01-01

233

Construction of virus-like particles exposing HIV1 epitopes  

Microsoft Academic Search

An original method was elaborated to construct artificial immunogens in the form of spherical particles with yeast dsRNA in\\u000a the center and hybrid proteins exposing epitopes of an infectious agent on the surface. The dsRNA and the proteins were linked\\u000a with spermidine-polyglucin-glutathione conjugates. Particles exposing HIV-1 epitopes were constructed, and their immunogenicity\\u000a tested.

L. R. Lebedev; L. I. Karpenko; V. A. Poryvaeva; M. Sh. Azaev; E. I. Ryabchikova; I. P. Gileva; A. A. Il’ichev

2000-01-01

234

Risk management among benzene-exposed oil refinery workers  

Microsoft Academic Search

Ten benzene-exposed oil refinery workers were genotoxicologically monitored in an annual follow-up study between 1990 and 2003 and compared with 87 industrial and 26 matched controls. Each of the exposed subjects suffered from several intercurrent non-infectious diseases such as joint, rheumatic, gastric and dental problems, as well as kidney and liver dysfunctions. The structural chromosome aberration (CA) yields of the

Anna Tompa; Mátyás G. Jakab

2005-01-01

235

The AMINO experiment: methane photolysis under Solar VUV irradiation on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

The scientific aim of the present campaign is to study the whole chain of methane photo-degradation, as initiated by Solar vacuum-ultraviolet irradiation in Titan's atmosphere. For this purpose, the AMINO experiment on the EXPOSE-R mission has loaded closed cells for gas-phase photochemistry in space conditions. Two different gas mixtures have been exposed, named Titan 1 and Titan 2, involving both N2-CH4 gas mixtures, without and with CO2, respectively. CO2 is added as a source of reactive oxygen in the cells. The cell contents were analysed thanks to infrared absorption spectroscopy, gas chromatography and mass spectrometry. Methane consumption leads to the formation of saturated hydrocarbons, with no detectable influence of CO2. This successful campaign provides a first benchmark for characterizing the whole methane photochemical system in space conditions. A thin film of tholin-like compounds appears to form on the cell walls of the exposed cells.

Carrasco, Nathalie; Cottin, Hervé; Cloix, Mégane; Jérome, Murielle; Bénilan, Yves; Coll, Patrice; Gazeau, Marie-Claire; Raulin, François; Saiagh, Kafila; Chaput, Didier

2015-01-01

236

Neurodevelopmental outcomes in HIV-exposed-uninfected children versus those not exposed to HIV.  

PubMed

Human immunodeficiency virus (HIV)-negative children born to HIV-infected mothers may exhibit differences in neurodevelopment (ND) compared to age- and gender-matched controls whose lives have not been affected by HIV. This could occur due to exposure to HIV and antiretroviral agents in utero and perinatally, or differences in the environment in which they grow up. This study assessed neurodevelopmental outcomes in HIV-exposed uninfected (HEU) and HIV-unexposed uninfected (HUU) children enrolled as controls in a multicenter ND study from Thailand and Cambodia. One hundred sixty HEU and 167 HUU children completed a neurodevelopmental assessment using the Beery Visual Motor Integration (VMI) test, Color Trails, Perdue Pegboard, and Child Behavior Checklist (CBCL). Thai children (n = 202) also completed the Wechsler Intelligence Scale (IQ) and Stanford-Binet II memory tests. In analyses adjusted for caregiver education, parent as caregiver, household income, age, and ethnicity, statistically significant lower scores were seen on verbal IQ (VIQ), full-scale IQ (FSIQ), and Binet Bead Memory among HEU compared to HUU. The mean (95% CI) differences were -6.13 (-10.3 to -1.96), p = 0.004; -4.57 (-8.80 to -0.35), p = 0.03; and -3.72 (-6.57 to -0.88), p = 0.01 for VIQ, FSIQ, and Binet Bead Memory, respectively. We observed no significant differences in performance IQ, other Binet memory domains, Color Trail, Perdue Pegboard, Beery VMI, or CBCL test scores. We conclude that HEU children evidence reductions in some neurodevelopmental outcomes compared to HUU; however, these differences are small and it remains unclear to what extent they have immediate and long-term clinical significance. PMID:24878112

Kerr, Stephen J; Puthanakit, Thanyawee; Vibol, Ung; Aurpibul, Linda; Vonthanak, Sophan; Kosalaraksa, Pope; Kanjanavanit, Suparat; Hansudewechakul, Rawiwan; Wongsawat, Jurai; Luesomboon, Wicharn; Ratanadilok, Kattiya; Prasitsuebsai, Wasana; Pruksakaew, Kanchana; van der Lugt, Jasper; Paul, Robert; Ananworanich, Jintanat; Valcour, Victor

2014-01-01

237

Epidemiological survey of workers exposed to inorganic germanium compounds  

PubMed Central

OBJECTIVES—To assess occupational exposure to inorganic germanium (Ge) in workers from a producing plant, and to assess the health of these workers, with a special focus on respiratory, kidney, and liver functions.?METHODS—Cross sectional study of 75 workers exposed to Ge and 79 matched referents. Exposure was characterised by measuring air and urine concentrations of the element during a typical working week, and health was assessed by a questionnaire, clinical examination, lung function testing, chest radiography, and clinical chemistry in serum and urine, including high and low molecular weight urinary proteins.?RESULTS—Airborne concentrations of Ge (inhalable fraction) ranged from 0.03 to 300 µg/m, which was reflected by increased urinary excretion of Ge (0.12-200 µg/g creatinine, after the shift at the end of the working week). Lung, liver, and haematological variables were not significantly different between referents and workers exposed to Ge. A slightly higher urinary concentration of high molecular weight proteins (albumin and transferrin) was found in workers exposed to Ge, possibly reflecting subclinical glomerular changes. No relation was found between the intensity or duration of exposure and the urinary concentration of albumin. No difference between referents and workers exposed to Ge was found for other renal variables.?CONCLUSIONS—Measurement of urinary Ge can detect occupational exposure to inorganic Ge and its compounds. It is prudent to recommend the monitoring of renal variables in workers exposed to Ge.???Keywords: inorganic germanium; occupational exposure; biological monitoring PMID:10810110

Swennen, B; Mallants, A; Roels, H; Buchet, J; Bernard, A; Lauwerys, R; Lison, D

2000-01-01

238

Whole DNA methylome profiling in mice exposed to secondhand smoke.  

PubMed

Aberration of DNA methylation is a prime epigenetic mechanism of carcinogenesis. Aberrant DNA methylation occurs frequently in lung cancer, with exposure to secondhand smoke (SHS) being an established risk factor. The causal role of SHS in the genesis of lung cancer, however, remains elusive. To investigate whether SHS can cause aberrant DNA methylation in vivo, we have constructed the whole DNA methylome in mice exposed to SHS for a duration of 4 mo, both after the termination of exposure and at ensuing intervals post-exposure (up to 10 mo). Our genome-wide and gene-specific profiling of DNA methylation in the lung of SHS-exposed mice revealed that all groups of SHS-exposed mice and controls share a similar pattern of DNA methylation. Furthermore, the methylation status of major repetitive DNA elements, including long-interspersed nuclear elements (LINE L1), intracisternal A particle long-terminal repeat retrotransposons (IAP-LTR), and short-interspersed nuclear elements (SINE B1), in the lung of all groups of SHS-exposed mice and controls remains comparable. The absence of locus-specific gain of DNA methylation and global loss of DNA methylation in the lung of SHS-exposed mice within a timeframe that precedes neoplastic-lesion formation underscore the challenges of lung cancer biomarker development. Identifying the initiating events that cause aberrant DNA methylation in lung carcinogenesis may help improve future strategies for prevention, early detection and treatment of this highly lethal disease. PMID:23051858

Tommasi, Stella; Zheng, Albert; Yoon, Jae-In; Li, Arthur Xuejun; Wu, Xiwei; Besaratinia, Ahmad

2012-11-01

239

Effects on LDEF exposed copper film and bulk  

NASA Technical Reports Server (NTRS)

Two forms of copper were exposed to the Long Duration Exposure Facility (LDEF) Mission 1 environment: a copper film, initially 74.2 plus or minus 1.1 nm thick sputter coated on a fused silica flat and a bulk piece of oxygen-free, high conductivity (OFHC) copper. The optical density of the copper film changed from 1.33 to 0.70 where exposed, and the film thickness increased to 106.7 plus or minus 0.5 nm where exposed. The exposed area appears purple by reflection and green by transmission for the thin film and maroon color for the bulk copper piece. The exposed areas increased in thickness, but only increase in the thickness of the thin film sample could be readily measured. The increase in film thickness is consistent with the density changes occurring during conversion of copper to an oxide. However, we have not been able to confirm appreciable conversion to an oxide by x-ray diffraction studies. We have not yet subjected the sample to e-beams or more abusive investigations out of concern that the film might be modified.

Peters, Palmer N.; Gregory, John C.; Christl, Ligia C.; Raikar, Ganesh N.

1991-01-01

240

42 CFR 84.86 - Component parts exposed to oxygen pressures; minimum requirements.  

Code of Federal Regulations, 2014 CFR

...2014-10-01 false Component parts exposed to oxygen pressures; minimum requirements. 84...84.86 Component parts exposed to oxygen pressures; minimum requirements...construction of component parts exposed to oxygen pressures above atmospheric pressure...

2014-10-01

241

Occupational dermatitis in workers exposed to detergents, disinfectants, and antiseptics.  

PubMed

Anti-infective prevention has led to a significant use of disinfectants, detergents, and antiseptics in various areas of activities. Most of these products are skin irritants and allergens, which can cause skin disorders in exposed workers. The authors conducted a descriptive and retrospective study on occupational dermatitis diagnosed at an occupational dermatology hospital consultation service, targeting exposed workers in the health, food, and cleaning industries. These included 20.9% (61 of 291) of the patients seen at this consultation. An occupational origin was proven for 50 of these 61 patients. The most frequent dermatoses were irritant contact dermatitis (42%) and allergic contact dermatitis (26.3%). The main allergens were disinfectants and antiseptics (26.3%), especially quaternary ammoniums, aldehydes, and nickel. Patients exposed to disinfectants, detergents, and antiseptics in the workplace represent an important part (about 1 of 5) of occupational dermatology consultations, although factors may be contributory. Prevention and knowledge are necessary for this increasing issue. PMID:22783559

Loddé, Brice; Paul, Marianne; Roguedas-Contios, Anne-Marie; Eniafe-Eveillard, Moriamo Ola Bisi; Misery, Laurent; Dewitte, Jean-Dominique

2012-01-01

242

Study of the lipoprotein pattern among workers exposed to lead.  

PubMed

Occupational exposure to lead fumes constitutes a serious problem in Egypt, since a considerable number of workers might be involved in its deleterious effect. The present study aimed to elucidate the effect of lead exposure on the lipoprotein pattern of exposed workers. The study has been carried out in a plant manufacturing lead batteries. It consists of 89 workers exposed to lead and 25 control subjects. Fasting blood samples were collected for the determination of serum lipoprotein pattern and their cholesterol and phospholipid content. Levels of lead in blood and delta amino levulinic acid in urine have been determined as biological indices of lead exposure. Lead exposure caused mainly a cumulative effect on the cholesterol and phospholipid content of lipoproteins since only workers exposed for more than 10 years showed significant changes. These changes might be referred to the effect of lead exposure on liver and/or on trace metal metabolism. PMID:2519975

el-Gazzar, R M; el-Hefny, S A; Noweir, K H; Shamy, M Y

1989-01-01

243

Cytogenetic investigation of subjects professionally exposed to radiofrequency radiation.  

PubMed

Nowadays, virtually everybody is exposed to radiofrequency radiation (RFR) from mobile phone base station antennas or other sources. At least according to some scientists, this exposure can have detrimental health effects. We investigated cytogenetic effects in peripheral blood lymphocytes from subjects who were professionally exposed to mobile phone electromagnetic fields in an attempt to demonstrate possible RFR-induced genetic effects. These subjects can be considered well suited for this purpose as their RFR exposure is 'normal' though rather high, and definitely higher than that of the 'general population'. The alkaline comet assay, sister chromatid exchange (SCE) and chromosome aberration tests revealed no evidence of RFR-induced genetic effects. Blood cells were also exposed to the well known chemical mutagen mitomycin C in order to investigate possible combined effects of RFR and the chemical. No cooperative action was found between the electromagnetic field exposure and the mutagen using either the comet assay or SCE test. PMID:16481348

Maes, Annemarie; Van Gorp, Urbain; Verschaeve, Luc

2006-03-01

244

Cytogenetic damage in female Pakistani agricultural workers exposed to pesticides.  

PubMed

Bhawalpur is a major cotton-growing area in Pakistan. Cotton picking in Pakistan is carried out by females and as a result of the intensive use of pesticides during the growing season these females are exposed to pesticide residues in the picking season. In the present study, peripheral blood was obtained from 69 cotton pickers and 69 unexposed females and used to assess the effect of pesticide exposure on genetic damage as well as on hepatic enzymes and serum cholinesterase. The subjects were of similar average age in workers and control groups (37.55 +/- 12.75 vs. 37.52 +/- 13.47, P > 0.05). Average exposure time of the picker females was 10.26 +/- 6.14 years. Subjects from the exposed group did not use any protective measures during their work activities. Levels of serum cholinesterase were lower, and levels of alkaline phosphatase, alanine aminotransferase, and aspartate aminotransferase were higher in the exposed workers as compared with the control group (P < 0.001). The exposed group exhibited significantly increased frequencies of binucleated cells with micronuclei (12.72 +/- 3.48 vs. 4.35 +/- 2.44, P < 0.001) and total number of micronuclei in binucleated lymphocytes (16.51 +/- 4.27 vs. 5.86 +/- 3.09, P < 0.001) in comparison with subjects of the control group. The binucleated cells with micronuclei frequency also seemed to increase with age in both the groups, however, the magnitude of increase was greater in exposed group than the control. Results from the present study indicate that occupational exposure to pesticide mixtures results in cytogenetic damage in exposed females. PMID:18418870

Ali, Tayyaba; Bhalli, Javed A; Rana, Shahid M; Khan, Qaiser M

2008-06-01

245

The EXPOSE-E Mission on the ISS  

NASA Astrophysics Data System (ADS)

The International Space Station ISS provides a variety of external research platforms for ex-periments aiming at the utilization of space parameters like vacuum, temperature oscillation, extraterrestrial UV and ionizing radiation. For 1.5 years the astrobiological experimental ESA facility EXPOSE-E was accommodated on the EuTEF Platform on one of the external balconies of the Columbus Module with 5 exobio-logical and 3 radiation experiments, exposing the chemical, biological and dosimetric samples to the harsh space environment. The main interest of the experiments was to increase our knowledge on the origin, evolution and distribution of life, on Earth and possibly beyond. The biological experiments investigated resistance and adaptation of organisms like bacteria, Achaea, fungi, lichens and plant seeds to extreme environmental conditions and underlying mechanisms like DNA repair. The organic chemical experiments analyse chemical reactions triggered by the extraterrestrial environment, especially short wavelength UV radiation, to better understand prebiotic chemistry. The facility is optimized to allow exposure of biologi-cal specimen and material samples under a variety of conditions, using optical filter systems. Environmental parameters like temperature and radiation were regularly recorded and down linked by telemetry. The exposure facility EXPOSE-E itself and the accommodated experiments and samples are introduced. A complete Mission overview of this recent long term astrobiological experiment is presented: from the sample preparation and launch to the landing and sample retrieval. Mission data and an assessment of the impacting space parameters during the mission are given. After EXPOSE-E, the sister facility EXPOSE-R was launched and still is in space. A short status information and outlook on this second astrobiological Mission will be included.

Rabbow, Elke; Rettberg, Petra; Panitz, Corinna; Reitz, Guenther

246

Semen quality in workers exposed to 2-ethoxyethanol.  

PubMed Central

To evaluate whether long term exposure to 2-ethoxyethanol (2EE) may affect semen quality, a cross sectional study was conducted among men exposed to 2EE used as a binder slurry in a metal castings process. Full shift breathing zone exposures to 2EE ranged from non-detectable to 24 ppm (geometric mean 6.6 ppm). Because of the potential for substantial absorption of 2EE through skin exposure, urine measurements of the metabolite of 2EE, 2-ethoxyacetic acid (2EAA) were conducted, showing levels of 2EAA ranging from non-detectable to 163 mg 2EAA/g creatinine. Only 37 exposed men (50% participation) and 39 non-exposed comparison (26% participation) from elsewhere in the plant provided a sperm sample. A questionnaire to determine personal habits, and medical and work histories, and a physical examination of the urogenital tract were also administered. The average sperm count per ejaculate among the workers exposed to 2EE was significantly lower than that of the unexposed group (113 v 154 million sperm per ejaculate respectively; p = 0.05) after consideration of abstinence, sample age, subjects' age, tobacco, alcohol and caffeine use, urogenital disorders, fever, and other illnesses. The mean sperm concentrations of the exposed and unexposed groups did not significantly differ from each other (44 and 53 million/ml respectively). No effect of exposure to 2EE on semen volume, sperm viability, motility, velocity, and normal morphology or testicular volume was detected, although some differences in the proportion of abnormal sperm shapes were observed. These data suggest that there may be an effect of 2EE on sperm count among these workers, although the possibility that other factors may be affecting the semen quality in both exposed and unexposed men in this population or that the results reflect bias introduced by the low participation rates cannot be excluded. PMID:2818974

Ratcliffe, J M; Schrader, S M; Clapp, D E; Halperin, W E; Turner, T W; Hornung, R W

1989-01-01

247

Preparation of the Biochip experiment on the EXPOSE-R2 mission outside the International Space Station  

NASA Astrophysics Data System (ADS)

Biochips might be suited for planetary exploration. Indeed, they present great potential for the search for biomarkers - molecules that are the sign of past or present life in space - thanks to their size (miniaturized devices) and sensitivity. Their detection principle is based on the recognition of a target molecule by affinity receptors fixed on a solid surface. Consequently, one of the main concerns when developing such a system is the behavior of the biological receptors in a space environment. In this paper, we describe the preparation of an experiment planned to be part of the EXPOSE-R2 mission, which will be conducted on the EXPOSE-R facility, outside the International Space Station (ISS), in order to study the resistance of biochip models to space constraints (especially cosmic radiation and thermal cycling). This experiment overcomes the limits of ground tests which do not reproduce exactly the space parameters. Indeed, contrary to ground experiments where constraints are applied individually and in a limited time, the biochip models on the ISS will be exposed to cumulated constraints during several months. Finally, this ISS experiment is a necessary step towards planetary exploration as it will help assessing whether a biochip can be used for future exploration missions.

Vigier, F.; Le Postollec, A.; Coussot, G.; Chaput, D.; Cottin, H.; Berger, T.; Incerti, S.; Triqueneaux, S.; Dobrijevic, M.; Vandenabeele-Trambouze, O.

2013-12-01

248

Survival of Spores of Trichoderma longibrachiatum in Space: data from the Space Experiment SPORES on EXPOSE-R  

NASA Astrophysics Data System (ADS)

In the space experiment `Spores in artificial meteorites' (SPORES), spores of the fungus Trichoderma longibrachiatum were exposed to low-Earth orbit for nearly 2 years on board the EXPOSE-R facility outside of the International Space Station. The environmental conditions tested in space were: space vacuum at 10-7-10-4 Pa or argon atmosphere at 105 Pa as inert gas atmosphere, solar extraterrestrial ultraviolet (UV) radiation at ? > 110 nm or ? > 200 nm with fluences up to 5.8 × 108 J m-2, cosmic radiation of a total dose range from 225 to 320 mGy, and temperature fluctuations from -25 to +50°C, applied isolated or in combination. Comparable control experiments were performed on ground. After retrieval, viability of spores was analysed by two methods: (i) ethidium bromide staining and (ii) test of germination capability. About 30% of the spores in vacuum survived the space travel, if shielded against insolation. However, in most cases no significant decrease was observed for spores exposed in addition to the full spectrum of solar UV irradiation. As the spores were exposed in clusters, the outer layers of spores may have shielded the inner part. The results give some information about the likelihood of lithopanspermia, the natural transfer of micro-organisms between planets. In addition to the parameters of outer space, sojourn time in space seems to be one of the limiting parameters.

Neuberger, Katja; Lux-Endrich, Astrid; Panitz, Corinna

2015-01-01

249

Lung cancer in rats exposed to fibrogenic dusts  

SciTech Connect

Fischer-344 rats were exposed to quartz dusts and to quartz-bearing oil shale dusts in long-term inhalation studies. Aerosol concentrations of 12 mg/m/sup 3/ and 152-176 mg/m/sup 3/ for quartz and shale dusts, respectively, were used in exposure regimens lasting up to two years. Pulmonary fibrosis was observed in most animals surviving beyond 400 days. Adenocarcinomas and epidermoid carcinomas of the lung were observed in animals from all exposure groups, including those exposed to quartz alone. The pulmonary tumors were a late effect, with the earliest lung tumor being observed after 651 days. 13 references, 10 figures, 4 tables.

Holland, L.M.; Wilson, J.S.; Tillery, M.I.; Smith, D.M.

1984-01-01

250

Fibrin Sealant-Assisted Revision of the Exposed Ahmed Tube  

PubMed Central

Tube exposure is a known complication of Ahmed glaucoma valve (AGV) implantation. Repair of the exposed tube is not easy. A 42-year-old monocular aphakic male had undergone retinal detachment repair with placement of an episcleral-encircling band followed by implantation of AGV. He presented to the clinic on routine review with exposure of the shunt tube. The complication was managed by placing scleral and conjunctival grafts over the exposed tube using a fibrin adhesive (Tisseel kit; Baxter AG, Vienna, Austria). The novel use of the fibrin sealant in the repair of AGV tube exposure was for better graft-integration.

Choudhari, Nikhil S.; Neog, Aditya; Latka, Supriya; Srinivasan, Bhaskar

2015-01-01

251

BEHAVIORAL AND AUTONOMIC THERMOREGULATION IN MICE EXPOSED TO MICROWAVE RADIATION  

EPA Science Inventory

Preferred ambient temperature (T) and breathing rate were measured in free-moving mice exposed to 2,450-MHz microwaves. A waveguide-exposure system was imposed with a longitudinal temperature gradient that permitted mice to select their preferred T. Breathing rate was determined ...

252

Fate of graphene in polymer nanocomposite exposed to UV radiation  

Microsoft Academic Search

Graphene is increasingly incorporated in polymers to enhance their mechanical, thermal and electrical properties. However, organic polymers are prone to degrade when exposed to UV radiation. Therefore, graphene in polymer nanocomposites could eventually be released into the environment during their life cycle, which might have a negative impact on the environment and thus presents a roadblock to their use. This

C. Bernard; T. Nguyen; B. Pellegrin; R. D. Holbrook; M. Zhao; J. Chin

2011-01-01

253

Genetic Predisposition for Dermal Problems in Hexavalent Chromium Exposed Population  

PubMed Central

We studied the effect of genetic susceptibility on hexavalent chromium induced dermal adversities. The health status of population was examined from the areas of Kanpur (India) having the elevated hexavalent chromium levels in groundwater. Blood samples were collected for DNA isolation to conduct polymorphic determination of genes, namely: NQO1 (C609T), hOGG1 (C1245G), GSTT1, and GSTM1 (deletion). Symptomatic exposed subjects (n = 38) were compared with asymptomatic exposed subjects (n = 108) along with asymptomatic controls (n = 148) from a non contaminated reference community. Exposed symptomatic group consisted of 36.8% subjects who were GSTM1 null genotyped as compared to asymptomatic where only 19.4% subjects were null. The exposed subjects with GSTM1 null genotype were more susceptible to dermal adversities in comparison with wild genotyped subjects (OR?=?2.42; 95% CI?=?1.071–5.451). Age, smoking, gender or duration of residence were not found to have any confounding effect towards this association. Association with other genes was not statistically significant, nonetheless, possible contribution by these genes cannot be ruled out. In conclusion, variation in the polymorphic status of GSTM1 gene may influence dermal outcomes among residents from Cr(VI) contaminated areas. Further studies are therefore, needed to examine these observations among different population groups. PMID:22919465

Sharma, Priti; Bihari, Vipin; Agarwal, Sudhir K.; Goel, Sudhir K.

2012-01-01

254

EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ...  

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

EXPOSED BEAM AND VINYL VENTED SOFFIT MATERIAL IN THE CARPORT ON THE SOUTHEAST SIDE OF THE UNIT - Camp H.M. Smith and Navy Public Works Center Manana Title VII (Capehart) Housing, U-Shaped Two-Bedroom Single-Family Type 6, Birch Circle, Elm Drive, Elm Circle, and Date Drive, Pearl City, Honolulu County, HI

255

Exposing Digital Forgeries in Scientific Images Department of Computer Science  

E-print Network

Exposing Digital Forgeries in Scientific Images Hany Farid Department of Computer Science Dartmouth community. By some measures, however, this case is not isolated ­ in at least one journal, it is estimated Tampering, Digital Forensics 1. INTRODUCTION In 2004, Professor Hwang Woo-Suk and colleagues pub- lished

Farid, Hany

256

CYTOGENETIC STUDIES OF MICE EXPOSED TO STYRENE BY INHALATION  

EPA Science Inventory

The published data for the in vivo genotoxicity of styrene (STY) are equivocal. o evaluate the clastogenicity and sister chromatid exchange (SCE)-inducing potential of STY in vivo under carefully controlled conditions, 36C3F1 female mice were exposed by inhalation for 6 hours/day...

257

Performance and haematological indices in rats exposed to monocrotophos contamination  

Microsoft Academic Search

Monocrotophos is an organophosphate pesticide used in agriculture to control insect pests. Changes in performance and haematological parameters (such as packed cell volume, white blood cells, neutrophils, eosinophils and lymphocytes) were used to assess the effect of the pesticide on rats chronically exposed to 12.5 parts per million (ppm), 25 ppm, 50 ppm, 100 ppm and 200 ppm for 10

T. O. Sunmonu; O. B. Oloyede

2010-01-01

258

CUTICULAR LESIONS INDUCED IN GRASS SHRIMP EXPOSED TO HEXAVALENT CHROMIUM  

EPA Science Inventory

Adult grass shrimp were exposed to four concentrations (0.5, 1.0, 2.0 and 4.0 ppm) of hexavalent chromium for 38 days. At the end of the exposure period, over 50% of the surviving shrimp possessed cuticular lesions that had many of the gross characteristics of 'shell disease.' Th...

259

INTRODUCTION Coastal ecosystems have been exposed to serious pollution for  

E-print Network

4010 INTRODUCTION Coastal ecosystems have been exposed to serious pollution for several decades because of increased human activity. Modern agriculture is a major contributor to coastal pollution levels of pollution and potentially harming marine organisms (Banerjee et al., 1996). Some organisms

Alvarez, Nadir

260

FLOW CYTOMETRY ANALYSIS OF WHITE TAILED DEER EXPOSED TO BVDV  

Technology Transfer Automated Retrieval System (TEKTRAN)

Two groups of four deer each, 2 to 4 weeks in age, were exposed to one of two bovine viral diarrhea virus (BVDV) strains: type 1b or type 2a, originally isolated from two different whitetail deer in southeast South Dakota in the fall of 2003. Two control age-matched deer were also used. Flow cytomet...

261

Fetal, neonatal and developmental outcomes of lithium-exposed pregnancies  

Microsoft Academic Search

IntroductionMany women with a bipolar disorder are of reproductive age and will need to continue lithium treatment during pregnancy. The teratogenic and perinatal effects of lithium are known, but not the long-term effects of lithium on neurodevelopment of the children. This study investigates growth, neurological, cognitive and behavioral development of children exposed to lithium in utero.

N. Margreth van der Lugt; Josephine S. van de Maat; Inge L. van Kamp; Elise A. M. Knoppert-van der Klein; Jacqueline G. F. M. Hovens; Frans J. Walther

262

Embryo- and fetotoxicity of chromium in pregestationally exposed mice  

SciTech Connect

Chromium, an essential element in the human body required for proper carbohydrate, protein, and fat metabolism, is reported to impair gestational development of offspring of workers chronically exposed to this metal in the work place. Workers in chromium based industries can be exposed to concentrations two orders of magnitude higher than the general population. Among the general population, residents living near chromate production sites may be exposed to high levels of chromium (VI) in air or to elevated levels (40 - 50,000 ppm) of chromium in effluents. Shmitova reported afterbirth and puerperal hemorrhages in women industrially exposed to this metal and observed high chromium levels in blood and urine of pregnant women and in fetal and cord blood. Chromium readily passes the placental barrier and reaches the growing fetus. Exposure of mice to chromium during various gestational periods resulted in embryo and fetotoxic effects. This study looks at the role of body chromium accumulated pregestationally on embryo and fetal development and its subsequent transfer to feto-placental sites. 25 refs., 3 tabs.

Junaid, M.; Murthy, R.C.; Saxena, D.K. [Industrial Toxicology Research Centre, Lucknow (India)] [Industrial Toxicology Research Centre, Lucknow (India)

1996-10-01

263

Silicon solar cells exposed to electron bombardment: Thermovoltaic properties  

Microsoft Academic Search

The thermovoltaic effect has been discovered for the first time in single-crystal silicon n\\u000a +-p structures consisting of an intermediate product for conventional solar cells exposed to 1-meV electron bombardment at a\\u000a dose D = 1015 cm?2.

B. M. Abdurakhmanov; L. O. Olimov; F. S. Abdurazzakov; Z. N. Alad’ina

2010-01-01

264

Neurobehavioural effects among workers occupationally exposed to organophosphorous pesticides  

PubMed Central

Aims: To identify neurobehavioural deficits among workers exposed to organophosphorous (OP) pesticides in their occupation. Methods: This study was conducted during the period when pesticides were applied to cotton crops in the fields in Menoufiya Governorate, Egypt. Fifty two occupationally exposed male workers were compared to 50 unexposed male controls who were similar in age, socioeconomic class, and years of education (?12 years). All participants completed a questionnaire (assessing personal, occupational, and medical histories), general and neurological clinical examination, neurobehavioural test battery (including tests for verbal abstraction, problem solving, attention, memory, and visuomotor speed), personality assessment, and serological analysis for serum acetylcholinesterase. Results: After correcting for confounders of age and education, the exposed participants exhibited significantly lower performance than controls on six neurobehavioural tests (Similarities, Digit Symbol, Trailmaking part A and B, Letter Cancellation, Digit Span, and Benton Visual Retention). A longer duration of work with pesticides was associated with lower performance on most neurobehavioural tests after adjusting for multiple comparisons. Although serum acetylcholinesterase was significantly lower in the exposed than the control participants, it was not significantly correlated with either neurobehavioural performance or neurological abnormalities. Conclusions: Occupational exposure to OP pesticides was associated with deficits in a wider array of neurobehavioural functions than previously reported, perhaps because of higher exposure in this population. Moderate chronic OP exposure may not only affect visuomotor speed as reported previously, but also verbal abstraction, attention, and memory. PMID:12660376

Farahat, T; Abdelrasoul, G; Amr, M; Shebl, M; Farahat, F; Anger, W

2003-01-01

265

Many Kids Exposed to Unneeded X-Rays, Study Finds  

MedlinePLUS

... enable JavaScript. Many Kids Exposed to Unneeded X-Rays, Study Finds Limiting radiation, costs should be objectives, researcher says (*this news ... 3, 2014 Related MedlinePlus Pages Children's Health X-Rays WEDNESDAY, Dec. 3, 2014 (HealthDay News) -- Many American ...

266

WATER RELATIONS OF DIFFERENTIALLY IRRIGATED COTTON EXPOSED TO OZONE  

EPA Science Inventory

This field study was conducted to test the hypothesis that plants chronically exposed to be sore susceptible to drought because typically inhibits root growth and increases shoot-root ratios implants. otton was grown in open-top chambers on Hanford coarse sandy loam in Riverside,...

267

26. ROOM 210, VIEW TO THE SOUTHEAST. EXPOSED TIE BEAMS ...  

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

26. ROOM 210, VIEW TO THE SOUTHEAST. EXPOSED TIE BEAMS AT CEILING ARE BOXED IN PLYWOOD. WAINSCOTING IS PLYWOOD PANELING. CEILING AND UPPER WALL TREATMENT IS GYPSUM BOARD. CLERESTORY WINDOWS LINE BOTH LONG SIDES OF ROOM. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

268

Detail, oblique view to northeast atop building 935 showing exposed ...  

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

Detail, oblique view to northeast atop building 935 showing exposed roof sections of buildings 934 (center) and 933 (left), 90 mm lens. - Travis Air Force Base, Nuclear Weapons Assembly Plant 3, W Street, Armed Forces Special Weapons Project Q Area, Fairfield, Solano County, CA

269

Exposing Pliocene Lignite Bed Near a BEN Village  

USGS Multimedia Gallery

Nikola Pavlovic, a kidney specialist and a USGS collaborator on Balkan endemic nephropathy (BEN) studies from Serbia, is shown exposing a small Pliocene lignite bed near a BEN village in the Vratza area of Bulgaria. The Pliocene lignite seams vary greatly in size and extent. BEN villages are always ...

2009-09-10

270

CHEMICAL CONTAMINANTS IN NONOCCUPATIONALLY EXPOSED U.S. RESIDENTS  

EPA Science Inventory

The report reviews the manner in which chemical contaminants found in nonoccupationally exposed U.S. residents enter the environment and subsequently human tissue. Approximately 100 contaminants are treated. Sources of literature used in the survey covered a 30-year period, the b...

271

Exposing Digital Forgeries in Video by Detecting Double MPEG Compression  

E-print Network

Exposing Digital Forgeries in Video by Detecting Double MPEG Compression Weihong Wang Department similar approaches to detect- ing traces of tampering in digital images (e.g., [5, 3, 10, 9, 2, 7, 8 considerable challenges. Here we begin to explore techniques for detecting traces of tam- pering in digital

Farid, Hany

272

Exposing Digital Forgeries in Video by Detecting Duplication  

E-print Network

Exposing Digital Forgeries in Video by Detecting Duplication Weihong Wang Department of Computer for detecting this form of tampering. Categories and Subject Descriptors I.4 [Image Processing]: Miscellaneous. Techniques for detecting image duplication have previ- ously been proposed [2, 5]. These techniques, however

Farid, Hany

273

Exposing Digital Forgeries in Interlaced and De-Interlaced Video  

E-print Network

1 Exposing Digital Forgeries in Interlaced and De-Interlaced Video Weihong Wang, Student Member two techniques for detecting traces of tampering in de-interlaced and interlaced video. For de considerable progress in the area of digital image forensics (e.g., [1], [2], [3], [4], [5], [6], [7]), less

Farid, Hany

274

Exposing Digital Forgeries in Color Filter Array Interpolated Images  

E-print Network

1 Exposing Digital Forgeries in Color Filter Array Interpolated Images Alin C. Popescu and Hany editing software, digital images can be easily manipulated and altered. Although good forgeries may leave, or lack thereof, can be automatically detected in any portion of an image. We show the efficacy

Farid, Hany

275

Exposing Digital Forgeries by Detecting Traces of Re-sampling  

E-print Network

1 Exposing Digital Forgeries by Detecting Traces of Re-sampling Alin C. Popescu and Hany Farid, in part, to the ease with which digital images can be manipulated and altered. Although good forgeries may editing software, digital images can be easily manipulated and altered. Digital forgeries, often leaving

Farid, Hany

276

Exposing Digital Forgeries by Detecting Inconsistencies in Lighting  

E-print Network

Exposing Digital Forgeries by Detecting Inconsistencies in Lighting Micah K. Johnson Department a single image. We show the efficacy of this approach in real-world settings. Categories and Subject Descriptors I.4 [Image Processing]: Miscellaneous Keywords Digital Tampering, Digital Forensics 1

Farid, Hany

277

Exposing Digital Forgeries Through Chromatic Aberration Micah K. Johnson  

E-print Network

of this approach for detecting digital tampering in synthetic and real images. This work provides another toolExposing Digital Forgeries Through Chromatic Aberration Micah K. Johnson Department of Computer Science Dartmouth College Hanover, NH 03755 farid@cs.dartmouth.edu ABSTRACT Virtually all optical imaging

Farid, Hany

278

Urologic cancer risks for veterans exposed to Agent Orange.  

PubMed

Agent Orange, an herbicide widely used during the Vietnam War, has been linked to various health risks, including urologic malignancy. Exposed veterans are at risk for prostate cancer and may be entitled to compensation if diagnosed with prostate cancer. Current research studies are aimed at mitigating prostate dysplasia and prostate cancer PMID:23734554

Hoenemeyer, Lori A

2013-01-01

279

VIEW OF STATION BARLOW SHOWING EXPOSED EXTERIOR FRONT AND LEFT ...  

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

VIEW OF STATION BARLOW SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT WITH SANDSTONE FLANK-WALL FRAGMENT, FACING NORTHWEST - White's Point Reservation, Base End Stations, B"1, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

280

3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR ...  

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

3. VIEW OF STATION PARLEY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

281

VIEW OF STATION BARLOW FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION BARLOW FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALL FRAGMENT VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"1, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

282

VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION LEARY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

283

VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION OSGOOD FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT INCLUDING POST 1920 DOORWAY ALTERATIONS, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

284

VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION LEARY FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"3, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

285

VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION SAXTON FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES - White's Point Reservation, Base End Stations, B"2, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

286

2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR ...  

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

2. VIEW OF STATION FARLEY FACING NORTH SHOWING EXPOSED EXTERIOR FRONT OF THE CONCRETE CONCEALMENT, SANDSTONE FLANK-WALLS ARE VISIBLE AT REAR SIDES. - White's Point Reservation, Base End Stations, B"6, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

287

VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT ...  

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

VIEW OF STATION OSGOOD FACING NORTHWEST, SHOWING EXPOSED EXTERIOR FRONT AND LEFT SIDE OF THE CONCRETE CONCEALMENT, SANDSTONE FLANKWALL IS VISIBLE AT LEFT REAR - White's Point Reservation, Base End Stations, B"5, Bounded by Voyager Circle & Mariner Drive, San Pedro, Los Angeles County, CA

288

Gibraltar: Exposing Hardware Devices to Web Pages Using AJAX  

Microsoft Academic Search

Gibraltar is a new framework for exposing hardware devices to web pages. Gibraltar's fundamental insight is that JavaScript's AJAX facility can be used as a hardware access protocol. Instead of relying on the browser to mediate device interactions, Gibraltar sandboxes the browser and uses a small device server to handle hardware requests. The server uses native code to interact with

Kaisen Lin; David Chu; James Mickens; Li Zhuang; Feng Zhao; Jian Qiu

2012-01-01

289

RESPONSE OF BUSH BEAN EXPOSED TO ACID MIST  

EPA Science Inventory

Bush bean plants (Phaseolus vulgaris L. cv. Contender) were treated once a week for six weeks with simulated acid mist at five pH ranging from 5.5 to 2.0. Leaf injury developed on plants exposed to acid concentrations below pH 3 and many leaves developed a flecking symptom simila...

290

In vitro methemoglobin formation in human blood exposed to NOâ  

Microsoft Academic Search

The in vitro formation of methemoglobin in human blood was determined for various NOâ concentrations and exposure times. Blood was exposed either to measured amounts of NOâ in air or to a continuous flow of known concentrations of NOâ in air. COâ was added to the gas phase to maintain pH and PCOâ in a normal range. Exposure of 45

H. Chiodi; C. R. Collier; J. G. Mohler

1983-01-01

291

Semen study of papaya workers exposed to ethylene dibromide  

SciTech Connect

A cross sectional semen and cytogenetic study was performed on male workers exposed to ethylene-dibromide (EDB) in the papaya fumigation industry in Hawaii. Semen analyses were conducted on 46 men in six fumigation facilities with an average length of employment of 5 years and airborne exposures to EDB ranging from 16 to 213 parts per billion. Statistically significant decreases in sperm count per ejaculate and the percentage of viable and motile sperm and increases in the proportion of specific morphological abnormalities were observed among exposed men when compared with controls. Semen volume and sperm concentration were also lower in the exposed group. No effect of exposure to EDB on sperm velocity, the overall proportion of sperm with normal morphology or YFF bodies was noted. The authors conclude that based on the decreases in sperm count, viability and motility and increases in certain types of morphological abnormalities among workers exposed to EDB, EDB may increase the risk of reproductive impairment in workers at exposure levels near the NIOSH recommended limit of 45 parts per billion and far below the current OSHA standard of 20 parts per million.

Ratcliffe, J.M.; Schrader, S.M.; Steenland, K.; Clapp, D.; Turner, T.

1984-01-01

292

Exterior building details of Building A; west façade: exposed common ...  

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

Exterior building details of Building A; west façade: exposed common bond brick wall, arched brick lintels over a two single-light casement window with brick sills, arched brick lintel over door cornice; easterly view - San Quentin State Prison, Building 22, Point San Quentin, San Quentin, Marin County, CA

293

18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT ...  

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

18. INTERIOR OF ROOM 106 LOOKING SOUTHEAST. EXPOSED BEAM AT CEILING IS PAINTED. FLOOR IS VINYL COMPOSITION TILE. WALLS AND CEILING ARE PAINTED GYPSUM BOARD. - Presidio of San Francisco, Cavalry Stables, Cowles Street, between Lincoln Boulevard & McDowell Street, San Francisco, San Francisco County, CA

294

Author's personal copy Reactivity of lithium exposed graphite surface  

E-print Network

Author's personal copy Reactivity of lithium exposed graphite surface S.S. Harilal a, *, J (NSTX) magnetic fusion device, a lithium coating was introduced on graphite tiles and produced applications in fusion devices, lithium­graphite intercalation compounds (LGIC) have been extensively used

Harilal, S. S.

295

12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING ...  

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

12. A LONG RUN OF EXPOSED TOP SURFACE, NORTH TRAINING WALL, ABOUT 1,500 FEET EAST OF THE FEDERAL CHANNEL MOUTH. VIEW TO WEST, TOWARD SAN FRANCISCO. - Oakland Harbor Training Walls, Mouth of Federal Channel to Inner Harbor, Oakland, Alameda County, CA

296

Profiles of Reactivity in Cocaine-Exposed Children  

ERIC Educational Resources Information Center

This study explored the possibility that specific, theoretically consistent profiles of reactivity could be identified in a sample of cocaine-exposed infants and whether these profiles were associated with a range of infant and/or maternal characteristics. Cluster analysis was used to identify distinct groups of infants based on physiological,…

Schuetze, Pamela; Molnar, Danielle S.; Eiden, Rina D.

2012-01-01

297

Biological responses of marine flatfish exposed to municipal wastewater effluent.  

PubMed

There is increasing concern over the presence of pharmaceutical compounds, personal care products, and other chemicals collectively known as contaminants of emerging concern (CECs) in municipal effluents, yet knowledge of potential environmental impacts related to these compounds is still limited. The present study used laboratory exposures to examine estrogenic, androgenic, and thyroid-related endocrine responses in marine hornyhead turbot (Pleuronichthys verticalis) exposed to CECs from municipal effluents with 2 degrees of treatment. Fish were exposed for 14 d to environmentally realistic concentrations of effluent (0.5%) and to a higher concentration (5%) to investigate dose responses. Plasma concentrations of estradiol (E2), vitellogenin (VTG), 11-keto testosterone, and thyroxine were measured to assess endocrine responses. Contaminants of emerging concern were analyzed to characterize the effluents. Diverse types of effluent CECs were detected. Statistically significant responses were not observed in fish exposed to environmentally realistic concentrations of effluent. Elevated plasma E2 concentrations were observed in males exposed to ammonia concentrations similar to those found in effluents. However, exposure to ammonia did not induce VTG production in male fish. The results of the present study highlight the importance of conducting research with sentinel organisms in laboratory studies to understand the environmental significance of the presence of CECs in aquatic systems. PMID:24273037

Vidal-Dorsch, Doris E; Bay, Steven M; Greenstein, Darrin J; Baker, Michael E; Hardiman, Gary; Reyes, Jesus A; Kelley, Kevin M; Schlenk, Daniel

2014-03-01

298

Immunological changes among workers occupationally exposed to styrene  

Microsoft Academic Search

The functional status of the immune system was investigated in a group of 71 workers exposed to styrene and in 65 control subjects, recruited according to the same selection criteria and comparable as to sex, age, and confounding variables. Air and biological monitoring were used to characterize styrene exposure (median of the main urinary metabolites in the “next-morning” spot samples:

Enrico Bergamaschi; Audrey Smargiassi; Antonio Mutti; Innocente Franchini; Roberto Lucchini; L. Alessio

1995-01-01

299

Neuropsychiatric Evaluation in Subjects Chronically Exposed to Organophosphate Pesticides  

Microsoft Academic Search

Long-term exposure to low levels of organophosphate pesticides (OP) may produce neuropsychiatric symptoms. We performed clinical, neuropsychiatric, and laboratory evaluations of 37 work- ers involved in family agriculture of tobacco from southern Brazil who had been exposed to OP for 3 months, and in 25 of these workers, after 3 months without exposure to OP. Plasma acetyl- cholinesterase activity levels

Rosane Maria Salvi; Diogo R. Lara; Eduardo S. Ghisolfi; Luis V. Portela; Renato D. Dias; Diogo O. Souza

2003-01-01

300

Dust release from surfaces exposed to plasma T. M. Flanagana)  

E-print Network

1 Dust release from surfaces exposed to plasma T. M. Flanagana) and J. Goree Department of Physics-simulant dust, it was found that particle release requires exposure to both plasma and an electron beam. The dust release rate diminishes almost exponentially in time, indicating a random process. As proposed

Goree, John

301

Increased Medication Use in a Community Environmentally Exposed to Chemicals  

Microsoft Academic Search

An epidemiological health study compared the health status of residents of a town exposed to an accidental Catacarb chemical release from an adjacent oil refinery, with the health status of demographically similar residents of an unexposed town in the region. Few studies of Catacarb's effects on humans exist; however, animal studies have shown it to be a respiratory, gastro-intestinal, dermatological

Rosemarie M. BOWLER; Sabine GYSENS; Christopher HARTNEY; Long NGO; Stephen S. RAUCH; John MIDTLING

2002-01-01

302

Damage assessment in CFRP laminates exposed to impact fatigue loading  

Microsoft Academic Search

Demand for advanced engineering composites in the aerospace industry is increasing continuously. Lately, carbon fibre reinforced polymers (CFRPs) became one of the most important structural materials in the industry due to a combination of characteristics such as: excellent stiffness, high strength-to-weight ratio, and ease of manufacture according to application. In service, aerospace composite components and structures are exposed to various

George Tsigkourakos; Vadim V. Silberschmidt; I. A. Ashcroft

2011-01-01

303

Communication no. 33 Protein metabolism in heat-exposed  

E-print Network

depression of tissue protein synthesis rates, especially in skeletal muscle. This was mainly relatedCommunication no. 33 Protein metabolism in heat-exposed chickens. S. Temim, F. Alleman, A.M. Chag, a lower growth rate and also a depressed protein gain, which suggests an alteration in protein metabolism

Paris-Sud XI, Université de

304

18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF ...  

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

18. William E. Barrett, Photographer, August 1975. EXPOSED VIEW OF LOWER PULLEYS OF LEFT-HAND MILL. LOWER LEFT IS BAND SAW PULLEY. UPPER LEFT IS TENSION WHEEL. LARGE PULLEY ON RIGHT IS DRIVE WHEEL FROM POWER SOURCE. - Meadow River Lumber Company, Highway 60, Rainelle, Greenbrier County, WV

305

Hind-leg heat losses in cold-exposed rats  

Microsoft Academic Search

Wistar rats, reared at 22°C, were exposed to 4°C for up to 2 h. During this period, the temperatures of aortic blood (core), thigh muscle and skin were recorded; the blood flow into the skin and muscle of the hind leg was determined with radioactive microspheres; and the arterio-venous balances of oxygen and carbon dioxide, as well as those of

Cristina Adán; Anna Ardévol; Daniel Closa; Xavier Remesar; Marià Alemany; José-Antonio Fernández-López

1995-01-01

306

Enhanced Natural Carbon Sequestration in Tectonically Exposed Mantle Peridotites  

Microsoft Academic Search

Carbon sequestration via mineral carbonation of calcium and magnesium silicates has been proposed but efficient carbonation is limited by the cost and energy requirement associated with mineral pretreatment (grinding, heating). Weathering of tectonically exposed mantle peridotite (rich in olivine and minor pyroxene) forms solid carbonate minerals (magnesite, hydrated magnesite, and calcite) during interaction between ground water and either olivine and

J. M. Matter; P. Kelemen

2007-01-01

307

29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER ...  

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

29. VIEW WEST TOWARDS KALAWAO OF PIPELINE, EXPOSED AT LOWER LEFT. CAT TRACKS, MADE BY THE CONSTRUCTION/MAINTENANCE VEHICLES, CAN BE SEEN ALONG BOULDER BEACH - Kalaupapa Water Supply System, Waikolu Valley to Kalaupapa Settlement, Island of Molokai, Kalaupapa, Kalawao County, HI

308

A pill to treat people exposed to radioactive materials  

ScienceCinema

Berkeley Lab's Rebecca Abergel discusses "A pill to treat people exposed to radioactive materials" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers:

Abergel, Rebecca

2014-06-24

309

Health Effects of Depleted Uranium on Exposed Gulf War Veterans  

Microsoft Academic Search

A small group of Gulf War veterans possess retained fragments of depleted uranium (DU) shrapnel, the long-term health consequences of which are undetermined. We evaluated the clinical health effects of DU exposure in Gulf War veterans compared with nonexposed Gulf War veterans. History and follow-up medical examination were performed on 29 exposed veterans and 38 nonexposed veterans. Outcome measures employed

Melissa A. McDiarmid; James P. Keogh; Frank J. Hooper; Kathleen McPhaul; Katherine Squibb; Robert Kane; Raymond DiPino; Michael Kabat; Bruce Kaup; Larry Anderson; Dennis Hoover; Lawrence Brown; Matthew Hamilton; David Jacobson-Kram; Belton Burrows; Mark Walsh

2000-01-01

310

Nutritional Status among the Children of Age Group 5-14 Years in Selected Arsenic Exposed and Non-Exposed Areas of Bangladesh  

PubMed Central

Objective: To assess and compare the nutritional status of children aged 5-14 years in arsenic exposed and non- exposed areas. Materials and methods: It was a cross sectional study conducted on 600 children of age 5-14 years from arsenic exposed and non-exposed areas in Bangladesh. Designed questionnaire and check list were used for collection of data. To estimate BMI necessary anthropometric measurements of the studied children were done. Dietary intakes of the study children were assessed using 24-hours recall method. Results: The difference of socio-economic conditions between the children of exposed area and non-exposed area was not significant. On an average the body mass index was found to be significantly (p < 0.01) lower among the children of arsenic exposed area (49%) in comparison to that of children in non-exposed area (38%). Stunting (p < 0.01), wasting (p < 0.05) and underweight (p < 0.05) were significantly higher in exposed group in comparison to non-exposed group. No significant difference of nutrition intake was found between exposed and non-exposed children as well as thin and normal children. Conclusion: In this study children exposed to arsenic contaminated water were found to be suffered from lower nutritional status. PMID:25530768

Rezaul Karim, Mohammad; Ahmad, Sk. Akhtar

2014-01-01

311

Exposed Ice in the Northern Mid-Latitudes of Mars  

NASA Technical Reports Server (NTRS)

Ice-Rich Layer: Polygonal features with dimensions of approximately 100 meters, bounded by cracks, are commonly observed on the martian northern plains. These features are generally attributed to thermal cracking of ice-rich sediments, in direct analogy to polygons in terrestrial polar regions. We mapped polygons in the northern mid-latitudes (30 to 65 N) using MOC and HiRISE images. Polygons are scattered across the northern plains, with a particular concentration in western Utopia Planitia. This region largely overlaps the Late Amazonian Astapus Colles unit, characterized by polygonal terrain and nested pits consistent with periglacial and thermokarst origins. Bright and Dark Polygonal Cracks: An examination of all MOC images (1997 through 2003) covering the study area demonstrated that, at latitudes of 55 to 65 N, most of the imaged polygons show bright bounding cracks. We interpret these bright cracks as exposed ice. Between 40 and 55 N, most of the imaged polygons show dark bounding cracks. These are interpreted as polygons from which the exposed ice has been removed by sublimation. The long-term stability limit for exposed ice, even in deep cracks, apparently lies near 55 N. Bright and Dark Spots: Many HiRISE and MOC frames showing polygons in the northern plains also show small numbers of bright and dark spots, particularly in western Utopia Planitia. Many of the spots are closely associated with collapse features suggestive of thermokarst. The spots range from tens to approximately 100 meters in diameter. The bright spots are interpreted as exposed ice, due to their prevalence on terrain mapped as ice rich. The dark spots are interpreted as former bright spots, which have darkened as the exposed ice is lost by sublimation. The bright spots may be the martian equivalents of pingos, ice-cored mounds found in periglacial regions on Earth. Terrestrial pingos from which the ice core has melted often collapse to form depressions similar to the martian dark spots. Future Observations: The SHARAD radar should be able to confirm the presence and measure the depth of the interpreted ice-rich layer that forms the Astapus Colles unit. If this layer is confirmed it will strengthen the interpretation of bright polygon cracks and bright spots as exposed ice. HiRISE images of the northern plains are showing unprecedented details of the polygonal cracks. Future HiRISE images that include bright spots, compared to MOC images taken years earlier, will illustrate the temporal stability of the spots. The CRISM spectrometer, with multiple spectral bands and a spatial resolution around 20 meters, should allow mineralogical identification of the material exposed in the polygonal bounding cracks and in the bright spots.

Allen, Carlton C.

2007-01-01

312

Measurement of DNA repair deficiency in workers exposed to benzene.  

PubMed Central

We hypothesize that chronic exposure to environmental toxicants can induce genetic damage causing DNA repair deficiencies and leading to the postulated mutator phenotype of carcinogenesis. To test our hypothesis, a host cell reactivation (HCR) assay was used in which pCMVcat plasmids were damaged with UV light (175, 350 J/m2 UV light), inactivating the chloramphenicol acetyltransferase reporter gene, and then transfected into lymphocytes. Transfected lymphocytes were therefore challenged to repair the damaged plasmids, reactivating the reporter gene. Xeroderma pigmentosum (XP) and Gaucher cell lines were used as positive and negative controls for the HCR assay. The Gaucher cell line repaired normally but XP cell lines demonstrated lower repair activity. Additionally, the repair activity of the XP heterozygous cell line showed intermediate repair compared to the homozygous XP and Gaucher cells. We used HCR to measure the effects of benzene exposure on 12 exposed and 8 nonexposed workers from a local benzene plant. Plasmids 175 J/m2 and 350 J/m2 were repaired with a mean frequency of 66% and 58%, respectively, in control workers compared to 71% and 62% in exposed workers. Conversely, more of the exposed workers were grouped into the reduced repair category than controls. These differences in repair capacity between exposed and control workers were, however, not statistically significant. The lack of significant differences between the exposed and control groups may be due to extremely low exposure to benzene (< 0.3 ppm), small population size, or a lack of benzene genotoxicity at these concentrations. These results are consistent with a parallel hprt gene mutation assay. PMID:8781377

Hallberg, L M; el Zein, R; Grossman, L; Au, W W

1996-01-01

313

Immunomodulatory effects of mineral fibres in occupationally exposed workers.  

PubMed

In the context of a large-scale molecular epidemiology study, the possible immunomodulatory effects of mineral fibres, in workers occupationally exposed to asbestos, rockwool and glass fibres, were examined. In each plant, 61, 98 and 80 exposed workers and 21, 43 or 36 control clerical subjects, respectively, were recruited. In the case of the asbestos-exposed subjects, an additional town-control group of 49 people was included. Evidence of pulmonary fibrosis was found in 42% of the asbestos-exposed workers, while evidence of pleural fibrosis was found in 24%. The asbestos-exposed cohort had significantly decreased forced vital capacity of lungs as well as forced expiratory volume per first second. Our findings indicate that exposure to all three types of fibres examined modulates to different degrees the immune response. Suppression of T-cell immunity and to a lesser extent, B-cell immunity was found in the case of workers from a former asbestos cement plant, while stimulation of T-cell response was observed in rockwool workers, and stimulation of T- and B-cell response was seen in glass fibre workers. Depression of the percentage of lymphocyte subpopulation of CD 16+56 (natural killer cells) in peripheral blood was found in glass fibre workers. Statistical analysis showed increased levels of proinflammatory cytokines (IL-6 asbestos; IL-8 all three fibres), expression of adhesion molecule L-selectin on granulocytes and monocytes (asbestos), levels of soluble adhesion molecules (SAMs) in sera (ICAM-1 all three fibres; E-selectin glass fibres), increased levels of immunoglobulin E (asbestos and rockwool) and elevated expression of activation markers on eosinophils (CD66b asbestos, glass fibres; CD69 asbestos). Significant correlations were observed between lymphocyte proliferation and markers of DNA damage and repair. Increased levels of proinflammatory cytokines, SAMs, immunoglobulin E and elevated expression of activation markers on eosinophils was found in people with symptoms of hypersensitivity and an elevated inflammatory status. PMID:15288538

Tulinska, Jana; Jahnova, Eva; Dusinska, Maria; Kuricova, Miroslava; Liskova, Aurelia; Ilavska, Silvia; Horvathova, Mira; Wsolova, Ladislava; Kyrtopoulos, Soterios A; Collins, Andrew; Harrington, Vikki; Fuortes, Laurence

2004-09-01

314

The AMINO experiment: a laboratory for astrochemistry and astrobiology on the EXPOSE-R facility of the International Space Station  

NASA Astrophysics Data System (ADS)

The study of the evolution of organic matter subjected to space conditions, and more specifically to Solar photons in the vacuum ultraviolet range (120-200 nm) has been undertaken in low-Earth orbit since the 1990s, and implemented on various space platforms. This paper describes a photochemistry experiment called AMINO, conducted during 22 months between 2009 and 2011 on the EXPOSE-R ESA facility, outside the International Space Station. Samples with relevance to astrobiology (connected to comets, carbonaceous meteorites and micrometeorites, the atmosphere of Titan and RNA world hypothesis) have been selected and exposed to space environment. They have been analysed after return to the Earth. This paper is not discussing the results of the experiment, but rather gives a general overview of the project, the details of the hardware used, its configuration and recent developments to enable long-duration exposure of gaseous samples in tight closed cells enabling for the first time to derive quantitative results from gaseous phase samples exposed in space.

Cottin, H.; Saiagh, K.; Guan, Y. Y.; Cloix, M.; Khalaf, D.; Macari, F.; Jérome, M.; Polienor, J.-M.; Bénilan, Y.; Coll, P.; Fray, N.; Gazeau, M.-C.; Raulin, F.; Stalport, F.; Carrasco, N.; Szopa, C.; Bertrand, M.; Chabin, A.; Westall, F.; Vergne, J.; Da Silva, L. A.; Maurel, M.-C.; Chaput, D.; Demets, R.

2015-01-01

315

Biomineralisation of manganese on titanium surfaces exposed to seawater.  

PubMed

A 2-year long study was carried out to isolate and characterise various bacterial species present in the biofilm formed on titanium surfaces exposed to seawater and to assess the manganese oxidizing potential of the marine isolates. The amount of manganese present in the biofilm was also measured using atomic absorption spectrometry (AAS). The results showed that titanium was susceptible to biofouling. More than 50% of the culturable marine bacterial isolates were capable of bringing about oxidation of Mn(II). All these manganese oxidizing bacteria were heterotrophic. Autotrophic manganese oxidizing bacteria such as Leptothrix was not isolated in the present study. The AAS results confirmed that the manganese content in the biofilms increased with increasing exposure time. Hence, the study indicates that the titanium surfaces when exposed to seawater were colonised by a large number of heterotrophic bacteria, which have the ability of bringing about biomineralisation of manganese. PMID:18568665

Gopal, Judy; Muraleedharan, P; Sarvamangala, H; George, R P; Dayal, R K; Tata, B V R; Khatak, H S; Natarajan, K A

2008-01-01

316

Mechanisms of gas precipitation in plasma-exposed tungsten  

SciTech Connect

Precipitation in subsurface bubbles is a key process that governs how hydrogen isotopes migrate through and become trapped within plasma-exposed tungsten. We describe a continuum-scale model of hydrogen diffusion in plasma-exposed materials that includes the effects of precipitation. The model can account for bubble expansion via dislocation loop punching, using an accurate equation of state to determine the internal pressure. This information is used to predict amount of hydrogen trapped by bubbles, as well as the conditions where the bubbles become saturated. In an effort to validate the underlying assumptions, we compare our results with published positron annihilation and thermal desorption spectroscopy data, as well as our own measurements using the tritium plasma experiment (TPE).

R. D. Kolasinski; D. F. Cowgill; D. C. Donovan; M. Shimada

2012-05-01

317

Field exposed water in a nanopore: liquid or vapour?  

E-print Network

We study the behavior of ambient temperature water under the combined effects of nanoscale confinement and applied electric field. Using molecular simulations we analyze the thermodynamic causes of field-induced expansion at some, and contraction at other conditions. Repulsion among parallel water dipoles and mild weakening of interactions between partially aligned water molecules prove sufficient to destabilize the aqueous liquid phase in isobaric systems in which all water molecules are permanently exposed to a uniform electric field. At the same time, simulations reveal comparatively weak field-induced perturbations of water structure upheld by flexible hydrogen bonding. In open systems with fixed chemical potential, these perturbations do not suffice to offset attraction of water into the field; additional water is typically driven from unperturbed bulk phase to the field-exposed region. In contrast to recent theoretical predictions in the literature, our analysis and simulations confirm that classical electrostriction characterizes usual electrowetting behavior in nanoscale channels and nanoporous materials.

Dusan Bratko; Christopher D. Daub; Alenka Luzar

2008-09-19

318

Temperature increase in the fetus exposed to UHF RFID readers.  

PubMed

Exposure to electromagnetic fields (EMFs) has prominently increased during the last decades due to the rapid development of new technologies. Among the various devices emitting EMFs, those based on Radio-frequency identification (RFID) technologies are used in all aspects of everyday life, and expose people unselectively. This scenario could pose a potential risk for some groups of the general population, such as pregnant women, who are expected to be possibly more sensitive to the thermal effects produced by EMF exposure. This is the first paper that addresses the estimation of temperature rise in two pregnant women models exposed to ultrahigh frequency RFID by computational techniques. Results show that the maximum temperature increase of the fetus and of the pregnancy-related tissues is relatively high (even about 0.7 °C), not too far from the known threshold of biological effects. However, this increase is confined to a small volume in the tissues. PMID:24956619

Fiocchi, Serena; Parazzini, Marta; Liorni, Ilaria; Samaras, Theodoros; Ravazzani, Paolo

2014-07-01

319

Laser-induced fluorescence of space-exposed polyurethane  

NASA Technical Reports Server (NTRS)

The object of this work was to utilize laser-induced fluorescence technique to characterize several samples of space-exposed polyurethane. These samples were flown on the Long Duration Exposure Facility (LDEF), which was in a shuttle-like orbit for nearly 6 years. Because of our present work to develop laser-induced-fluorescence inspection techniques for polymers, space-exposed samples and controls were lent to us for evaluation. These samples had been attached to the outer surface of LDEF; therefore, they were subjected to thermal cycling, solar ultraviolet radiation, vacuum, and atomic oxygen. It is well documented that atomic oxygen and ultraviolet exposure have detrimental effects on many polymers. This was a unique opportunity to make measurements on material that had been naturally degraded by an unusual environment. During our past work, data have come from artificially degraded samples and generally have demonstrated a correlation between laser-induced fluorescence and tensile strength or elasticity.

Hill, Ralph H., Jr.

1993-01-01

320

Temperature tolerance of nitrite-exposed channel catfish  

SciTech Connect

Upper temperature tolerances of channel catfish Ictalurus punctatus were determined with the critical thermal maximum (CTM) method after fish were exposed to various sublethal concentrations of nitrite for 24 hours at 20/sup 0/C. The CTM was inversely related to nitrite concentration; group means ranged from 38.0/sup 0/C for controls to 35.9/sup 0/C for fish exposed to 1.4 mg NO/sub 2//L. As expected from previous studies, percent methemoglobin was correlated with nitrite concentration, and thus was inversely correlated with CTM. These results indicate that nitrite-temperature interactions have the potential of adversely affecting the productivity of high-density channel catfish aquaculture systems, particularly those located in the southern US during summer. 40 references, 1 table.

Watenpaugh, D.E.; Beitinger, T.L.; Huey, D.W.

1985-03-01

321

Recovering badly exposed objects from digital photos using internet images  

NASA Astrophysics Data System (ADS)

In this paper we consider the problem of clipped-pixel recovery over an entire badly exposed image region, using two correctly exposed images of the scene that may be captured under different conditions. The first reference image is used to recover texture; feature points are extracted along the boundaries of both the source and reference regions, while a warping function deforms the reference region to fit inside the source. The second reference is used to recover color by replacing the mean and variance of the texture reference image with those of the color reference. A user study conducted with both modified and original images demonstrates the benefits of our method. The results show that a majority of the enhanced images look natural and are preferred to the originals.

Savoy, Florian M.; Vonikakis, Vassilios; Winkler, Stefan; Süsstrunk, Sabine

2014-03-01

322

Skin friction measurement with partially exposed polymer dispersed liquid crystals  

NASA Technical Reports Server (NTRS)

Partially exposed polymer dispersed liquid crystal thin film (10-25 microns) deposited on a flat glass substrate has been used for the first time to measure skin friction. Utilizing the shear-stress-induced director reorientation in the partially exposed liquid-crystal droplets, optical transmission under crossed polarization has been measured as a function of the air flow differential pressure. Direct measurement of the skin friction with a skin friction drag balance, under the same aerodynamic conditions, lets us correlate the skin friction with optical transmission. This provides a unique technique for the direct measurement of skin friction from the transmitted light intensity. The results are in excellent agreement with the model suggested in this paper.

Parmar, D. S.; Holmes, H. K.

1993-01-01

323

Diseases specific to radiation-exposed veterans. Final rule.  

PubMed

The Department of Veterans Affairs (VA) is amending its adjudication regulations concerning presumptive service connection for certain diseases for veterans who participated in radiation-risk activities during active service or while members of reserve components during active duty for training or inactive duty training. This amendment adds cancers of the bone, brain, colon, lung, and ovary to the list of diseases which may be presumptively service connected and amends the definition of the term "radiation-risk activity." The intended effect of this amendment is to ensure that veterans who may have been exposed to radiation during military service do not have a higher burden of proof than civilians exposed to ionizing radiation who may be entitled to compensation for these cancers under comparable Federal statutes. PMID:11820253

2002-01-25

324

Potential contribution of exposed resin to ecosystem emissions of monoterpenes  

NASA Astrophysics Data System (ADS)

Conifers, especially pines, produce and store under pressure monoterpene-laden resin in canals located throughout the plant. When the plants are damaged and resin canals punctured, the resin is exuded and the monoterpenes are released into the atmosphere, a process that has been shown to influence ecosystem-level monoterpene emissions. Less attention has been paid to the small amounts of resin that are exuded from branches, expanding needles, developing pollen cones, and terminal buds in the absence of any damage. The goal of this study was to provide the first estimate of the potential of this naturally-exposed resin to influence emissions of monoterpenes from ponderosa pine (Pinus ponderosa) ecosystems. When resin is first exuded as small spherical beads from undamaged tissues it emits monoterpenes to the atmosphere at a rate that is four orders of magnitude greater than needle tissue with an equivalent exposed surface area and the emissions from exuded beads decline exponentially as the resin dries. We made measurements of resin beads on the branches of ponderosa pine trees in the middle of the growing season and found, on average, 0.15 cm2 of exposed resin bead surface area and 1250 cm2 of total needle surface area per branch tip. If the resin emerged over the course of 10 days, resin emissions would make up 10% of the ecosystem emissions each day. Since we only accounted for exposed resin at a single point in time, this is probably an underestimate of how much total resin is exuded from undamaged pine tissues over the course of a growing season. Our observations, however, reveal the importance of this previously unrecognized source of monoterpenes emitted from pine forests and its potential to influence regional atmospheric chemistry dynamics.

Eller, Allyson S. D.; Harley, Peter; Monson, Russell K.

2013-10-01

325

Lung Cancer in Railroad Workers Exposed to Diesel Exhaust  

Microsoft Academic Search

Diesel exhaust has been suspected to be a lung carcinogen. The assessment of this lung cancer risk has been limited by lack of studies of exposed workers followed for many years. In this study, we assessed lung cancer mortality in 54,973 U.S. railroad workers between 1959 and 1996 (38 years). By 1959, the U.S. railroad industry had largely converted from

Eric Garshick; Francine Laden; Jaime E. Hart; Bernard Rosner; Thomas J. Smith; Douglas W. Dockery; Frank E. Speizer

2004-01-01

326

Constitutive Model for Aluminum Alloys Exposed to Fire Conditions  

Microsoft Academic Search

An existing constitutive model for creep, developed by Dorn and Harmathy, is modified in order to be used for fire-exposed\\u000a aluminum alloys. Two alloys, 5083-O\\/H111 and 6060-T66, are selected for the development of this constitutive model because\\u000a of their different behavior at elevated temperature and their frequent application in structures for which fire design is\\u000a relevant. The material parameters in

J. Maljaars; F. Soetens; L. Katgerman

2008-01-01

327

Biochemical responses in gills of rainbow trout exposed to propiconazole  

Microsoft Academic Search

The aim of this study is to investigate the toxic effect of PCZ, a triazole fungicide commonly present in surface and ground\\u000a water, on the ROS defense system and Na+-K+-ATPase in gills of rainbow trout exposed to sublethal concentrations (0.2, 50 and 500 ?g L?1) for 7, 20 and 30 days. After prolonged exposure of PCZ at higher test concentrations

Zhi-Hua Li; Vladimir Zlabek; Roman Grabic; Ping Li; Tomas Randak

2011-01-01

328

Vaporization of Bicomponent Droplets Exposed to Asymmetric Radiant Heating  

Microsoft Academic Search

In this work, the fuel vapor distribution around vaporizing bicomponent droplets, exposed to asymmetric radiant heating, is investigated as an extension of prior work done by the authors involving single-component droplets. Acetone\\/octane and acetone\\/hexane mixtures (50\\/50 by volume) are used to explore bicomponent droplet phenomena within the context of asymmetric radiant heating. Planar laser-induced fluorescence images yield acetone vapor molar

K. Ammigan; R. S. Miller; H. L. Clack

2011-01-01

329

DAMAGE TO COMMERCIAL AND INDUSTRIAL BUILDINGS EXPOSED TO NUCLEAR EFFECTS  

Microsoft Academic Search

One equipment control building designed to be blast resistant and two ;\\u000a each of three standardized types of metal warehouse or utility buildings were ;\\u000a exposed to the effects of a nuclear device detonation. One of the utility ;\\u000a buildings was frameless, with deeply corrugated wall and roof sections; a second ;\\u000a was very largely frameless, utilizing interlocking channel sections;

2009-01-01

330

Radiation-exposed populations: who, why, and how to study.  

PubMed

Everyone is exposed to natural and manmade ionizing radiation that can originate from sources in the environment and in medical and occupational settings. There is notable variation, however, among individuals and across populations in the types of sources of radiation and in the frequency, level, and duration of exposure. Adverse health effects associated with radiation exposure have been known for decades, and ionizing radiation exposure has been linked with a broad range of different types of cancer and benign neoplasms as well as birth defects, reproductive effects, and diseases of the circulatory, hematologic, and neurologic systems. Our present understanding of radiation-related health risks derives primarily from multidisciplinary health risk (epidemiologic) studies that provide the key information on radiation-associated health outcomes, quantify radiation-related disease risks, and enhance understanding of mechanisms of radiation-related disease pathogenesis. Such information is central to quantifying risks in relation to benefits; addressing public concerns, including societal and clinical needs in relation to radiation exposure; and providing the database needed for establishing recommendations for radiation protection. Because of the importance of determining risks compared to benefits for all situations where exposure to ionizing radiation might result, it is useful for planning new health risks studies to categorize exposed populations according to the sources and types of radiation. This paper describes a wide range of populations exposed to radiation and the motivation and key methodological criteria that drive the rationale and priority of studying such populations. Also, discussed are alternative methods for evaluating radiation-related health risks in these populations, with a major focus on epidemiologic approaches. This paper concludes with a short summary of major highlights from radiation epidemiologic research and important unanswered questions.Introduction of Exposed Populations (Video 1:29, http://links.lww.com/HP/A22). PMID:24378492

Simon, Steven L; Linet, Martha S

2014-02-01

331

Maize pollen is an important allergen in occupationally exposed workers  

PubMed Central

Background The work- or environmental-related type I sensitization to maize pollen is hardly investigated. We sought to determine the prevalence of sensitization to maize pollen among exposed workers and to identify the eliciting allergens. Methods In July 2010, 8 out of 11 subjects were examined who were repeatedly exposed to maize pollen by pollinating maize during their work in a biological research department. All 8 filled in a questionnaire and underwent skin prick testing (SPT) and immune-specific analyses. Results 5 out of the 8 exposed subjects had repeatedly suffered for at least several weeks from rhinitis, 4 from conjunctivitis, 4 from urticaria, and 2 from shortness of breath upon occupational exposure to maize pollen. All symptomatic workers had specific IgE antibodies against maize pollen (CAP class ? 1). Interestingly, 4 of the 5 maize pollen-allergic subjects, but none of the 3 asymptomatic exposed workers had IgE antibodies specific for grass pollen. All but one of the maize pollen-allergic subjects had suffered from allergic grass pollen-related symptoms for 6 to 11 years before job-related exposure to maize pollen. Lung function testing was normal in all cases. In immunoblot analyses, the allergenic components could be identified as Zea m 1 and Zea m 13. The reactivity is mostly caused by cross-reactivity to the homologous allergens in temperate grass pollen. Two sera responded to Zea m 3, but interestingly not to the corresponding timothy allergen indicating maize-specific IgE reactivity. Conclusion The present data suggest that subjects pollinating maize are at high risk of developing an allergy to maize pollen as a so far underestimated source of occupational allergens. For the screening of patients with suspected maize pollen sensitization, the determination of IgE antibodies specific for maize pollen is suitable. PMID:22165847

2011-01-01

332

Acoustic cry characteristics of infants exposed to methadone during pregnancy  

Microsoft Academic Search

Objective: Infant cry characteristics reflect the neurological and medical status of the infant. This study compared the acoustic cry characteristics of infants born to mothers maintained on methadone during pregnancy with those of infants not exposed to methadone during pregnancy. Methods: At 42 weeks of post-menstrual age, 89 crying episodes ranging in duration from 1.15 to 1.97 sec were collected

Zoe L Quick; Michael P Robb; Lianne J Woodward

2009-01-01

333

Improving antenatal risk assessment in women exposed to high risks.  

PubMed

Antenatal substance use and related psychosocial risk factors are known to increase the likelihood of child protection involvement; less is known about the predictive nature of maternal reflective functioning (RF) in this population. This preliminary study assessed psychosocial and psychological risk factors for a group of substance dependent women exposed to high risks in pregnancy, and their impact on child protection involvement. Pregnant women on opiate substitution treatment (n = 11) and a comparison group (n = 15) were recruited during their third trimester to complete measures of RF (Pregnancy Interview), childhood trauma, mental health and psychosocial assessments. At postnatal follow-up, RF was reassessed (Parent Development Interview - Revised Short Version) and mother-infant dyads were videotaped to assess emotional availability (EA). Child protection services were contacted to determine if any concerns had been raised for infant safety. Significant between-group differences were observed for demographics, psychosocial factors, trauma and mental health symptoms. Unexpectedly, no significant differences were found for RF or EA between groups. Eight women in the 'exposed to high risks' group became involved with child protection services. Reflective functioning was not significantly associated with psychosocial risk factors, and therefore did not mediate the outcome of child protection involvement. Women 'exposed to high risks' were equally able to generate a model of their own and their infants' mental states and should not be seen within a deficit perspective. Further research is required to better understand the range of risk factors that predict child protection involvement in high risk groups. PMID:23982989

Perry, Natasha; Newman, Louise K; Hunter, Mick; Dunlop, Adrian

2015-01-01

334

A method to compare exposed populations in seroepidemiology.  

PubMed

In seroepidemiology when a single sample is taken from exposed and non-exposed subjects, the results of serological tests are usually reduced to a dichotomy: normal (low or no antibodies) or elevated (high or antibodies found). The choice of the cutoff point between these values has been based on various vaguely defined methods and the results depend, at least partly, on the method chosen. An alternative method is introduced here which is not based on the absolute value of a serological test but on the rank order of the values of the test. In this ordered series the risk ratio (RR) and the upper and lower confidence limits (CL) are plotted for each exposed subject as the cutoff value is moved from the highest value to the lowest one. The method is applicable in quantitative immunoassays. If a priori defined RR and confidence limit or limits are reached at any point of the plot, the data support the original hypothesis. The advantage of this alternative method is that no single cutoff value is needed. PMID:1483826

Seuri, M; Granfors, K

1992-12-01

335

Symptoms and signs in workers exposed predominantly to xylenes.  

PubMed

Surveys were conducted in factories in China where workers were engaged in the production of rubber boots or plastic-coated wire or in printing work, and were exposed to xylene vapors. Based on the data on exposure as monitored by personal diffusive sampling, 175 xylene-exposed workers (107 men and 68 women) were selected as those (1) who underwent all examinations and (2) for whom the sum of the three xylene isomers accounted for 70% or more of the total exposure (on a ppm basis). The intensity of exposure was such that the sum of the three isomer concentrations was 14 ppm as a geometric mean and 21 ppm as an arithmetic mean. As controls, 241 nonexposed workers (116 men and 125 women) were recruited either from the same factories or from factories in the same regions. There was an increased prevalence of subjective symptoms in the exposed workers which were apparently related to the effects on the central nervous system and to the local effects on the eyes, the nose, and the throat, although dose-dependency of the symptoms was evident in only a limited number of cases, possibly because the intensity of exposure was rather low. It was further observed that the findings of hematology and serum biochemistry in respect of liver and kidney functions were generally negative, showing that xylenes are not toxic to the hematopoietic organs, the liver, or the kidney. PMID:8314620

Uchida, Y; Nakatsuka, H; Ukai, H; Watanabe, T; Liu, Y T; Huang, M Y; Wang, Y L; Zhu, F Z; Yin, H; Ikeda, M

1993-01-01

336

Reproduction success of American kestrels exposed to dietary polychlorinated biphenyls.  

PubMed

While reproduction of wild birds is adversely affected by multiple environmental contaminants, we determined that polychlorinated biphenyls (PCBs) alone alter reproduction. Captive American kestrels (Falco sparverius), fed PCB-spiked (Aroclor 1248:1254:1260) food (7 mg/kg body weight/d) prior to and during the first breeding season only (100 d) laid eggs with environmentally relevant levels of total PCBs (34.0 microg/g whole egg wet wt vs 0 microg/g for controls). Reproduction changed during, not after, PCB exposure in this two-year study. The PCB-exposed pairs laid smaller clutches later in the season and laid more totally infertile clutches. Hatching success was reduced in PCB-exposed pairs, and 50% of PCB nestlings died within 3 d of hatching. Nearly 60% of PCB-exposed pairs with hatchlings failed to produce fledglings. Higher levels of total PCB residues and congeners were associated with later clutch initiation and fewer fertile eggs, hatchlings, and fledglings. We suggest that nonpersistent PCB congeners have a greater influence on reproduction than do persistent congeners. PMID:11345453

Fernie, K J; Smits, J E; Bortolotti, G R; Bird, D M

2001-04-01

337

Survival Dynamics of Aphanomyces cochlioides Oospores Exposed to Heat Stress.  

PubMed

ABSTRACT To determine how exposure to heat effects their survival, oospores of Aphanomyces cochlioides isolate C22 were exposed in water to 35, 40, 45, or 50 degrees C for prescribed times and then examined for viability. The Weibull model was modified to represent the effects of temperature on survival of oospores. The final fitted model gave lethal doses for 50% of the oospores of 251, 49.8, 9.8, and 1.9 h at 35, 40, 45, and 50 degrees C, respectively. To determine if alternating high and low temperatures resulted in (i) recovery from heat damage during low temperature periods, (ii) increased susceptibility to heat damage, or (iii) if effects of heat damage were cumulative, oospores were examined after each of four 24-h cycles at 45 degrees C for 4 h and 21 degrees C for 20 h. Survival of oospores exposed to alternating high and low temperatures fit the cumulative effects model. Significant variability in heat tolerance among five isolates was observed (P< 0.001) but model parameters successfully accommodated this variability (R(2) = 0.96, P < 0.001). This research shows that under wet conditions, there are predictable patterns to mortality for A. cochlioides oospores exposed to continuous or fluctuating high temperatures. PMID:18943289

Dyer, A T; Windels, C E; Cook, R D; Leonard, K J

2007-04-01

338

Mechanical properties of MDCK II cells exposed to gold nanorods  

PubMed Central

Summary Background: The impact of gold nanoparticles on cell viability has been extensively studied in the past. Size, shape and surface functionalization including opsonization of gold particles ranging from a few nanometers to hundreds of nanometers are among the most crucial parameters that have been focussed on. Cytoxicity of nanomaterial has been assessed by common cytotoxicity assays targeting enzymatic activity such as LDH, MTT and ECIS. So far, however, less attention has been paid to the mechanical parameters of cells exposed to gold particles, which is an important reporter on the cellular response to external stimuli. Results: Mechanical properties of confluent MDCK II cells exposed to gold nanorods as a function of surface functionalization and concentration have been explored by atomic force microscopy and quartz crystal microbalance measurements in combination with fluorescence and dark-field microscopy. Conclusion: We found that cells exposed to CTAB coated gold nanorods display a concentration-dependent stiffening that cannot be explained by the presence of CTAB alone. The stiffening results presumably from endocytosis of particles removing excess membrane area from the cell’s surface. Another aspect could be the collapse of the plasma membrane on the actin cortex. Particles coated with PEG do not show a significant change in elastic properties. This observation is consistent with QCM measurements that show a considerable drop in frequency upon administration of CTAB coated rods suggesting an increase in acoustic load corresponding to a larger stiffness (storage modulus).

Pietuch, Anna; Brückner, Bastian Rouven; Schneider, David; Tarantola, Marco; Rosman, Christina; Sönnichsen, Carsten

2015-01-01

339

Asthma, rhinitis, and dermatitis in workers exposed to reactive dyes.  

PubMed Central

A survey was conducted at 15 textile plants with dyehouses in western Sweden. Employees with a history of work related rhinitis, asthma, or skin symptoms were offered a clinical and immunological investigation including skin prick tests, skin patch tests, and radioallergosorbent tests (RASTs) to detect specific allergy to reactive dyes. Among the 1142 employees, 162 were exposed to reactive dyes and 10 of these (6%) reported work related respiratory or nasal symptoms. An allergy to reactive dyes could be confirmed in five (3%, 95% confidence interval 1-7%). All but one had been exposed to reactive dyes for one year or less before the onset of symptoms. Positive RASTs could be detected in four of the five patients. All of the RAST positive patients were positive to remazol black B, but six out of eight additional remazol dyes also elicited positive results. RAST and RAST inhibition showed a cross reactivity between some of the dyes. Seven persons with work related dermatitis and three with urticaria or Quincke oedema were found. In one patient contact dermatitis to a monoazo dye was shown, but no positive patch test reactions to reactive dyes. IgE-mediated allergy to reactive dyes seems to be an important cause of respiratory and nasal symptoms among dyehouse employees exposed to dust from reactive dyes. PMID:8431393

Nilsson, R; Nordlinder, R; Wass, U; Meding, B; Belin, L

1993-01-01

340

Cross-sectional neurotoxicology study of lead-exposed cohort  

SciTech Connect

Although the toxic effects of lead have been known for centuries, lead intoxication is still widespread in the United States. Without baseline tests of neuropsychological, neurobehavioral and neurophysiological testing it may be difficult to detect subtle changes in neurological function after lead exposure. This may be further confounded by partial chelation treatment and exposure to neurotoxic mixtures or inability to quantitate alcohol consumption. We undertook a cross-sectional study to address these problems in 24 exposed and 29 control subjects in a plant that manufactured electrical components using fritted leaded glass to coat capacitors and transistors. Potentially exposed workers had blood lead levels ranging between 3 micrograms/dL to 135 micrograms/dL. Industrial hygiene monitoring revealed the plant's air lead levels ranged from 61 micrograms/m3 to 1,700 micrograms/m3 in excess of OSHA permissible exposure limits of 40 micrograms/m3/10 hr day. Using a specially designed battery of neurophysiological, neurobehavioral and neuropsychological screening tests, we demonstrated a significant difference from controls in measures of psychomotor speed, motor strength and verbal memory. Although limited by the cross-sectional design, these findings support the hypothesis that the battery of neurophysiological, neuropsychological and neurobehavioral tests can detect a significant inter-group differences between lead-exposed and control subjects.

Pasternak, G.; Becker, C.E.; Lash, A.; Bowler, R.; Estrin, W.J.; Law, D. (San Francisco General Hospital, CA (USA))

1989-01-01

341

Analysis Of The Returned Samples From A Space Exposure Experiment: The ORGANIC Experiment on EXPOSE-R on the ISS  

NASA Astrophysics Data System (ADS)

The ORGANIC experiment on the multi-user facility EXPOSE-R on the International Space Station investigated the chemical evolution, survival, destruction, and chemical modification of PAHs and fullerenes in space. Aromatic networks are among the most abundant organic material in space. PAHs and fullerenes have been identified in meteorites and are thought to be among the carriers for numerous astronomical absorption and emission features.Thin films of selected PAHs and fullerenes have been subjected to the low Earth orbit environment as part of the ORGANIC experiment.EXPOSE-R with its experiment inserts was mounted on the outside of the ISS for 682 days starting in 2009. The samples were returned to Earth and inspected in spring 2011. The period outside the ISS provided continuous exposure to the cosmic-, solar-, and trapped-particle radiation background and >2500 h of unshadowed solar illumination. All trays carry both solar-irradiation-exposed and dark samples shielded from the UV photons, enabling discrimination between the effects of exposure to solar photons and cosmic rays. The samples were analyzed before exposure to the space environment with UV-VIS and IR spectroscopy. Ground truth monitoring of additional sample carriers was performed through UV-VIS spectroscopy at regular intervals at NASA ARC (Bryson et al. 2011, Adv. Space Res. 48, 1980). The UV-VIS and IR spectroscopic measurements were collected for the returned flight samples.We report on the scientific experiment, the details of the ground control analysis, and returned flight sample results. We discuss how extended space exposure experiments allow to enhance our knowledge on the evolution of organic compounds in space.

Bryson, Kathryn; Peeters, Zan; Salama, Farid; Foing, Bernard; Ehrenfreund, Pascale; Elsaesser, Andreas; Ricco, Antonio; Jessberger, Elmar K; Schmidt, Werner; Robert, François

2014-06-01

342

Cultural Heritage exposed to landslide and flood risk in Italy  

NASA Astrophysics Data System (ADS)

Italy is the country that owns most of the world cultural heritage as it's clear from the list of sites of inestimable value to humanity, prepared by UNESCO under the Convention concerning the protection of the world cultural and natural heritage ratified in 1972. The Italian territory is also particularly prone to natural hazards such as landslides, floods, earthquakes, volcanic eruptions, subsidence and coastal erosion which undermine the protection and preservation of cultural heritage. Aim of the present work is to provide an estimate of architectural, monumental and archaeological heritage exposed to landslide and flood risk at national scale. The input data are: the Italian Cultural Heritage database (Carta del Rischio del patrimonio culturale) realized by ISCR (Central Institute for the Conservation and Restoration); the Italian Landslide Inventory (Progetto IFFI) developed by ISPRA (Italian National Institute for Environmental Protection and Research) and the Regions and Self-Governing Provinces of Italy and the flood hazard zones defined by the Italian River Basin Authorities. Italian landslide inventory contains more than 486,000 landslides affecting an area of about 20,800 km2, equal to 6.9% of Italian territory. In order to estimate the number and type of cultural heritage at risk some GIS processing have been carried out, overlapping information from the above mentioned databases. The analysis provided the following results: Cultural Heritage exposed to landslide risk were estimated to 5.511 (6.6%) while the ones exposed to flood risk results 9.859 (11.7%). Two case studies concerning landslide phenomena affecting important Italian municipalities and the flood risk of historical centre of Rome, have been also analyzed. These results could be used to identify priorities and plan field surveys, detailed studies and monitoring systems, allowing job scheduling of cultural heritage maintenance. This need becomes more and more a necessity taking into account the importance of the Italian cultural heritage and the lack of funds available for its protection and conservation.

Spizzichino, Daniele; Cacace, Carlo; Iadanza, Carla; Trigila, Alessandro

2013-04-01

343

Petroleum films exposed to sunlight produce hydroxyl radical.  

PubMed

Sunlight exposed oil films on seawater or pure water produced substantial amounts of hydroxyl radical as a result of irradiation. Oil was collected from the surface of the Gulf of Mexico following the Deepwater Horizon spill and exposed to simulated sunlight in thin films over water. Photochemical production of hydroxyl radical was measured with benzoic acid as a selective chemical probe in the aqueous layer. Total hydroxyl radical formation was studied using high benzoic acid concentrations and varying exposure time. The total amount of hydroxyl radical produced in 24 h irradiations of thin oil films over Gulf of Mexico water and pure water were 3.7×10(-7) and 4.2×10(-7) moles respectively. Steady state concentrations of hydroxyl radical were measured using a competition kinetics approach. Hydroxyl radical concentrations of 1.2×10(-16) to 2.4×10(-16) M were observed for seawater and pure water under oil films. Titanium dioxide (TiO2) nanomaterials were added to the system in an effort to determine if the photocatalyst would enhance oil photodegradation. The addition of TiO2 nanoparticles dramatically changed the observed formation rate of hydroxyl radical in the systems with NP water at pH 3, showing increased formation rate in many cases. With photocatalyst, the steady state concentration of radical decreased, predominantly due to an increase in the hydroxyl radical scavenging rate with oxide present. This study illustrates that oil is a strong and important source of hydroxyl radical when exposed to sunlight. The fate of oil and other dissolved species following oil spills will be heavily dependent on the formation and fate of hydroxyl radical. PMID:24405967

Ray, Phoebe Z; Tarr, Matthew A

2014-05-01

344

Juvenile hypothyroidism among two populations exposed to radioiodine.  

PubMed Central

We found an epidemic of juvenile hypothyroidism among a population of self-defined "downwinders" living near the Hanford nuclear facility located in southeast Washington State. The episode followed massive releases of 131I. Self-reported data on 60 cases of juvenile hypothyroidism (<20 years of age) among a group of 801 Hanford downwinders are presented, as well as data concerning the thyroid status of approximately 160,000 children exposed to radioiodine before 10 years of age as a result of the 26 April 1986 Chernobyl explosion in the former Soviet Union. These children were residents of five regions near Chernobyl. They were examined by standardized screening protocols over a period of 5 years from 1991 to 1996. They are a well-defined group of 10 samples. Fifty-six cases of hypothyroidism were found among boys and 92 among girls. Body burdens of 137Cs have been correlated with hypothyroidism prevalence rates. On the other hand, the group of juvenile (<20 years of age) Hanford downwinders is not a representative sample. Most of the 77 cases of juvenile hypothyroidism in the Hanford group were diagnosed from 1945 to 1970. However, the ratio of reported cases to the county population under 20 years of age is roughly correlated with officially estimated mean levels of cumulative thyroid 131I uptake in these counties, providing evidence that juvenile hypothyroidism was associated with radioiodine exposures. Because even subtle hypothyroidism may be of clinical significance in childhood and can be treated, it may be useful to screen for the condition in populations exposed to radioiodine fallout. Although radiation exposure is associated with hypothyroidism, its excess among fallout-exposed children has not been previously quantified. Images Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 PMID:10090710

Goldsmith, J R; Grossman, C M; Morton, W E; Nussbaum, R H; Kordysh, E A; Quastel, M R; Sobel, R B; Nussbaum, F D

1999-01-01

345

Prevalence of metabolic syndrome in Chinese nickel-exposed workers.  

PubMed

The prevalence of metabolic syndrome (MS) was investigated in Chinese nickel-exposed workers. A total of 35 104 subjects were enrolled in this study. The age-adjusted prevalence of MS, BMI?25, diabetes, hypertension, and abnormal lipid was 13.9%, 29.5%, 12.8%, 27.5%, and 47.1%, respectively. The prevalence of BMI?25, hyperglycemia, and hypertension increased with the age of males and females, and was higher in males than in females (37.1% vs 21.5%, 15.9% vs 12.1%, 35.0% vs 24.3%, 54.3% vs 40.4%). PMID:24961859

Yang, Ai Min; Bai, Ya Na; Pu, Hong Quan; Zheng, Tong Zhang; Cheng, Ning; Li, Juan Sheng; Li, Hai Yan; Zhang, Ya Wei; Ding, Jiao; Su, Hui; Ren, Xiao Wei; Hu, Xiao Bin

2014-06-01

346

Susuk - Black Magic Exposed “White” by Dental Radiographs  

PubMed Central

Susuk or charm needles are a facial cum body art widely practiced among women of Malaysia, Brunei, Singapore, Thailand and Indonesia. These are small, needle-shaped metallic talismans inserted subcutaneously in different parts of the body. The concealed art of susuk was “exposed” by routine radiographic examination in the oral and maxillofacial region. This paper reports two such cases of unusual incidental radiographic finding in dental radiographs which were taken on a routine basis as part of the diagnostic work up. This article will also primarily enlighten the importance of radiographs in detecting such charm needles as the wearer keeps the body art a “hidden secret” thereby avoiding misdiagnosis. PMID:25177646

Mohammed, Faraz

2014-01-01

347

Erosion of graphite surface exposed to hot supersonic hydrogen gas  

NASA Technical Reports Server (NTRS)

A theoretical model based on laminar boundary layer flow equations is developed to predict the erosion rate of a graphite (AGCarb-101) surface exposed to a hot supersonic stream of hydrogen gas. The supersonic flow in the nozzle outside the boundary layer formed over the surface of the specimen is determined by assuming one-dimensional isentropic conditions. An overall surface reaction rate expression based on the experimental studies by Clarke and Fox is used to describe the interaction of hydrogen with graphite. A satisfactory agreement is found between the results of the computation, and the available experimental data. Some shortcomings of the model, and further possible improvements are discussed.

Sharma, O. P.

1972-01-01

348

Effective UV radiation dose in polyethylene exposed to weather  

NASA Astrophysics Data System (ADS)

In this work we quantified the effective UV radiation dose in orange and colorless polyethylene samples exposed to weather in the city of Aguascalientes, Ags. Mexico. The spectral distribution of solar radiation was calculated using SMART 2.9.5.; the samples absorption properties were measured using UV-Vis spectroscopy and the quantum yield was calculated using samples reflectance properties. The determining factor in the effective UV dose is the spectral distribution of solar radiation, although the chemical structure of materials is also important.

González-Mota, R.; Soto-Bernal, J. J.; Rosales-Candelas, I.; Calero Marín, S. P.; Vega-Durán, J. T.; Moreno-Virgen, R.

2009-09-01

349

Spontaneous abortions in female populations occupationally exposed to ionizing radiation  

Microsoft Academic Search

Objective  Exposure to radioisotopes of metals and halogen elements occurring in medical practice may cause spontaneous abortions. The\\u000a potential role of occupational exposure to X-rays and internal radioisotopes on pregnancy outcome in childbearing age women\\u000a employed in hospital departments were analyzed in order to estimate miscarriage risk.\\u000a \\u000a \\u000a \\u000a Methods  Over a period of 16 years, the occurrence of miscarriages in 61 women exposed to

Aleksandra Fucic; Domenico Franco Merlo; Marcello Ceppi; Joe N. Lucas

2008-01-01

350

Histopathological study of ovaries of Rhipicephalus sanguineus (Acari: Ixodidae) exposed to different thymol concentrations.  

PubMed

Thymol is a monoterpene with proven acaricide action for several tick species. In addition to killing these ectoparasites, thymol can also reduce oviposition and egg hatch rate. However, the effects of thymol on the morphophysiology of tick ovaries are still unknown. Thus, the aim of this study was to evaluate the morphophysiological changes caused by this active principle in ovaries of Rhipicephalus sanguineus after a 6-day feeding period, through the application of morphohistochemical techniques. After the feeding period, a total of 50 females were divided into five groups and immersed in the following solutions: (I) distilled water (control), (II) 30% ethanol (control), (III) 1.25 mg/mL thymol, (IV) 2.5 mg/mL thymol, and (V) 5.0 mg/mL thymol. The experimental groups were kept in a climatic chamber (27?±?1 °C; RH 80?±?10%) for 5 days. After this period, morphological (hematoxylin/eosin) and histochemical (von Kossa) techniques were applied after remotion of the ovaries. The morphological results revealed large vacuoles in germ cells at different developmental stages and invaginations that represent deformations in the chorionic membrane. From the results obtained in this study, it was concluded that thymol interfered with the development of oocytes, which showed degeneration signs. The treatment containing 5.0 mg/mL thymol affected more accentuately the morphological development. Moreover, thymol also altered the calcium content of yolk granules, which generally showed an intense staining for this element. PMID:25300417

da Silva Matos, Renata; Daemon, Erik; Camargo-Mathias, Maria Izabel; Furquim, Karim Christina Scopinho; Sampieri, Bruno Rodrigues; Remédio, Rafael Neodini; Araújo, Laryssa Xavier; Novato, Tatiane Pinheiro Lopes

2014-12-01

351

Microstructural examination of service exposed coal mill liner material  

SciTech Connect

This study mainly focuses the microstructural characterisation of the service exposed coal liner. These liners are generally referred to as bull ring segments in the bowl mill of coal pulveriser systems. The failed bull ring segment was collected from a coal-fired power plant of Kolaghat thermal plant, West Bengal, India. The crack that has been observed in the middle of the liner was observed under SEM and detailed microstructural studies are made for the liner material. The hardness measurements are made and XRD is carried out to identify the phases present in the sample. The results suggest that the material confirms to high chromium cast iron and microstructural studies reveal that the cracks are mainly due to the heavy service exposed conditions where lumps of coal and silica sand falling on these liners causing severe impact and abrasion conditions. High abrasive studies on the liner material are carried out and it showed that increasing the abrasive size as well as load is responsible for higher wear loss. The results suggest that prolonged exposure to abrasion conditions results in the progressive removal of the matrix material and due to various phase transformations from austenite to martensite introduces surface volume changes and causes the generation of cracks and further lead to failure of the component.

Venkateswarlu, K.; Chowdhury, S.G.; Pathak, L.C.; Ray, A.K. [National Metallurgical Laboratory, Jamshedpur (India)

2007-10-15

352

Experiences of being exposed to intimate partner violence during pregnancy  

PubMed Central

In this study a phenomenological approach was used in order to enter deeply into the experience of living with violence during pregnancy. The aim of the study was to gain a deeper understanding of women's experiences of being exposed to intimate partner violence (IPV) during pregnancy. The data were collected through in-depth interviews with five Norwegian women; two during pregnancy and three after the birth. The women were between the age of 20 and 38 years. All women had received support from a professional research and treatment centre. The essential structure shows that IPV during pregnancy is characterized by difficult existential choices related to ambivalence. Existential choices mean questioning one's existence, the meaning of life as well as one's responsibility for oneself and others. Five constituents further explain the essential structure: Living in unpredictability, the violence is living in the body, losing oneself, feeling lonely and being pregnant leads to change. Future life with the child is experienced as a possibility for existential change. It is important for health professionals to recognize and support pregnant women who are exposed to violence as well as treating their bodies with care and respect. PMID:22468147

Lidén, Eva; Lundgren, Ingela

2012-01-01

353

Gender-related behavior in women exposed prenatally to diethylstilbestrol.  

PubMed Central

Accumulating evidence in experimental animals over the past three decades suggests that mammalian brain development and differentiation of the central nervous system are influenced by perinatal exposure to sex hormones. Hence, changes in human behavioral patterns may be associated with prenatal exposure to estrogenic substances such as diethylstilbestrol (DES). This paper reviews relevant studies from a series of laboratories and finds that no clear-cut differences can be demonstrated to date between unexposed and DES-exposed women in gender-related behavior, although the physical and psychological impact of the problems associated with exposure to DES are well documented. If both prenatal and postnatal influences such as social, economic, and environmental factors are taken into consideration, individual variation is more apparent than differences in gender-related behavior between unexposed and DES-exposed women. In summary, gender-related behavior is determined by a complex array of interacting factors, and prenatal influences are only one of many developmental events. More studies are needed using larger populations with carefully controlled selection criteria to suggest a direct role of prenatal DES exposure on subsequent gender-related behavior. Images p208-a PMID:8404755

Newbold, R R

1993-01-01

354

Cancer in Experimental Animals Exposed to Arsenic and Arsenic Compounds  

PubMed Central

Inorganic arsenic is a ubiquitous environmental contaminant that has long been considered a human carcinogen. Recent studies raise further concern about the metalloid as a major, naturally occurring carcinogen in the environment. However, during this same period it has proven difficult to provide experimental evidence of the carcinogenicity of inorganic arsenic in laboratory animals and, until recently, there was considered to be a lack of clear evidence for carcinogenicity of any arsenical in animals. More recent work with arsenical methylation metabolites and early life exposures to inorganic arsenic has now provided evidence of carcinogenicity in rodents. Given that tens of millions of people worldwide are exposed to potentially unhealthy levels of environmental arsenic, in vivo rodent models of arsenic carcinogenesis are a clear necessity for resolving critical issues, like mechanisms of action, target tissue specificity, and sensitive subpopulations, and in developing strategies to reduce cancers in exposed human populations. This work reviews the available rodent studies considered relevant to carcinogenic assessment of arsenicals, taking advantage of the most recent review by the International Agency for Research on Cancer (IARC) that has not yet appeared as a full monograph but has been summarized (IARC 2009). Many valid studies show that arsenic can interact with other carcinogens/agents to enhance oncogenesis, and help elucidate mechanisms, and these too are summarized in this review. Finally, this body of rodent work is discussed in light of its impact on mechanisms and in the context of the persistent argument that arsenic is not carcinogenic in animals. PMID:20812815

Tokar, Erik J.; Benbrahim-Tallaa, Lamia; Ward, Jerold M.; Lunn, Ruth; Sams, Reeder L.; Waalkes, Michael P.

2011-01-01

355

Catecholamine synthesis and excretion in rats exposed intermittently to cold  

PubMed Central

Previous findings have shown a turnover of nuclear DNA, a condition related to the functional activity of these cells, in the adrenal medullae of rats intermittently exposed to cold. Striking differences have been observed between various strains of rats, particularly Italico and Wistar rats. In order to evaluate the function of the adrenal medullary cells, the content of catecholamines in the organ and their urinary excretion have been evaluated, with the fluorimetric method, in rats of Italico and Wistar strains kept at room temperature and exposed intermittently to cold. The results show that (i) at room temperature the levels of excretion are lower in Italico than in Wistar rats in spite of the equal amine contents of the adrenal medullae, (ii) the first exposure to cold causes a large increase in the urinary excretion and a decrease of adrenaline and noradrenaline content of the adrenal glands in both strains, (iii) after 3 days the catecholamine content in the organ was higher than normal in Wistar rats, whereas in the Italico strain it continued to decrease, and (iv) a new steady state at higher levels is reached after 20 days of exposure, when not only the catecholamine content but also the urinary excretion is equal in both strains. These differences between the two strains of rats during intermittent cold exposure are discussed in relation to the behaviour of DNA. PMID:5098080

Bibbiani, Cecilia; Viola-Magni, Maria Pia

1971-01-01

356

NMR relaxometry measurements of Fricke gel dosimeters exposed to neutrons  

NASA Astrophysics Data System (ADS)

Fricke infused gel matrices offer several features making them suitable for dosimetric applications; among these there are tissue equivalence, low cost and ease of preparation. Their nuclear magnetic resonance (NMR) relaxation properties can be used as a radiation detector for the dosimetry of beams used in cancer therapy. In recent years neutron capture therapy has been resumed for the treatment of various types of cancer and it requires three-dimensional mapping of the neutron fields. In this work, we investigated this particular application through NMR relaxometry and MR imaging of Fricke gels exposed to neutrons. We analyzed both the R1 and R2 relaxation rates, which relate to the longitudinal T1 and transversal T2 relaxation times. In particular, we found that the relaxation rate R2 does not depend on the neutron fluence, whereas the relaxation rate R1 increases linearly with the fluence. The magnetic resonance imaging acquisitions showed that T1-weighted images allow the characterization of samples exposed to different neutron fluences.

Marrale, Maurizio; Brai, Maria; Longo, Anna; Gallo, Salvatore; Tomarchio, Elio; Tranchina, Luigi; Gagliardo, Cesare; D'Errico, Francesco

2014-11-01

357

Biochemical changes in heat exposed buffalo heifers supplemented with yeast.  

PubMed

Serum electrolytes, minerals, blood biochemical and plasma enzymes were studied in heat exposed buffalo heifers supplemented with yeast powder in feed to alleviate the adverse effects of heat stress. Eighteen healthy Murrah buffalo heifers (270-280) kg were divided into three groups. Animals of group I were kept in shed and served as control, while group II and group III were exposed in a psychrometric chamber at 40°C for 4 hrs daily for 16 days continuously. The animals in group III were also supplemented with yeast powder at 10 g per animal per day. The serum sodium, potassium and chloride levels decreased significantly (P < 0.05) in group II and their levels tended to be maintained in group III. Serum calcium, magnesium, phosphorus, glucose and total cholesterol concentration decreased (P < 0.05) significantly whereas total protein increased in group II due to heat stress. The levels of these minerals tended to be normal in group III. The plasma concentration of SGOT and SGPT increased significantly (P < 0.05), whereas the concentration of plasma alkaline phosphatase and acid phosphatase decreased due to thermal exposure. The levels of these enzymes tended to be normal in group III. The results indicated significant deviations in blood biochemical due to thermal stress and their levels tended to be normal in yeast supplemented group of buffalo heifers. PMID:22415403

Singh, Shiv Pratap; Hooda, Om Kanwar; Kundu, Shivlal Singh; Singh, Sohanvir

2012-10-01

358

Error-Related Negativities During Spelling Judgments Expose Orthographic Knowledge  

PubMed Central

In two experiments, we demonstrate that error-related negativities (ERNs) recorded during spelling decisions can expose individual differences in lexical knowledge. The first experiment found that the ERN was elicited during spelling decisions and that its magnitude was correlated with independent measures of subjects’ spelling knowledge. In the second experiment, we manipulated the phonology of misspelled stimuli and observed that ERN magnitudes were larger when misspelled words altered the phonology of their correctly spelled counterparts than when they preserved it. Thus, when an error is made in a decision about spelling, the brain processes indexed by the ERN reflect both phonological and orthographic input to the decision process. In both experiments, ERN effect sizes were correlated with assessments of lexical knowledge and reading, including offline spelling ability and spelling-mediated vocabulary knowledge. These results affirm the interdependent nature of orthographic, semantic, and phonological knowledge components while showing that spelling knowledge uniquely influences the ERN during spelling decisions. Finally, the study demonstrates the value of ERNs in exposing individual differences in lexical knowledge. PMID:24389506

Harris, Lindsay N.; Perfetti, Charles A.; Rickles, Benjamin

2014-01-01

359

Constitutive Model for Aluminum Alloys Exposed to Fire Conditions  

NASA Astrophysics Data System (ADS)

An existing constitutive model for creep, developed by Dorn and Harmathy, is modified in order to be used for fire-exposed aluminum alloys. Two alloys, 5083-O/H111 and 6060-T66, are selected for the development of this constitutive model because of their different behavior at elevated temperature and their frequent application in structures for which fire design is relevant. The material parameters in the model are calibrated with the experimental results of creep tests, carried out with constant load and temperature in time. The model is validated with so-called transient state tests, with a constant load in time (stresses ranging from 20 to 150 N/mm2) and with an increasing temperature (with heating rates ranging from 1.6 °C/min to 11 °C/min and critical temperatures ranging from 170 °C to 380 °C). These tests are considered as representative for fire-exposed, insulated aluminum members. The existing constitutive model of Dorn and Harmathy provides good agreement with the transient state tests carried out for the 5xxx series alloy, but appeared to be not suited for the 6xxx series alloy. This is attributed to the early development of tertiary creep in case of 6xxx series alloys. The existing model was modified to incorporate this first stage of tertiary creep, to arrive at a good agreement between the tests and the modified model for 6xxx series alloys.

Maljaars, J.; Soetens, F.; Katgerman, L.

2008-04-01

360

Behavioral modification of estuarine fish exposed to sulfur dioxide  

SciTech Connect

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30/sup 0/C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30/sup 0/C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30/sup 0/C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20/sup 0/C. Both species avoided approximately the same concentration of sulfite at 25/sup 0/C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30/sup 0/C. 24 references, 2 figures, 3 tables.

Hall, L.W. Jr.; Burton, D.T.; Graves, W.C.; Margrey, S.L.

1984-01-01

361

Behavioral modification of estuarine fish exposed to sulfur dioxide.  

PubMed

This study was designed to determine the avoidance responses of juvenile striped bass (Morone saxatilis) and Atlantic menhaden (Brevoortia tyrannus) exposed to sulfur dioxide (sulfite) at acclimation temperatures of 15, 20, 25, and 30 degrees C. Predictive models were developed and compared for each species at each acclimation temperature. Striped bass avoided 2.2, 2.3, 3.0, and 3.5 mg sulfite/l at 15, 20, 25, and 30 degrees C, respectively. Atlantic menhaden avoided 3.2, 3.6, 2.9, and 3.0 mg sulfite/l at acclimation temperatures of 15, 20, 25, and 30 degrees C, respectively. Acclimation temperature was an important factor influencing the avoidance response of each species exposed to sulfur dioxide. Striped bass avoided lower concentrations of sulfite than Atlantic menhaden at 15 and 20 degrees C. Both species avoided approximately the same concentration of sulfite at 25 degrees C. Atlantic menhaden avoided lower concentrations of sulfur dioxide than striped bass at 30 degrees C. PMID:6492212

Hall, L W; Burton, D T; Graves, W C; Margrey, S L

1984-01-01

362

Neural Tube Defects In Mice Exposed To Tap Water  

PubMed Central

In May of 2006 we suddenly began to observe neural tube defects (NTDs) in embryos of untreated control mice. We hypothesized the mice were being exposed unknowingly to a teratogenic agent and investigated the cause. Our results suggested that NTDs were not resulting from bedding material, feed, strain or source of the mice. Additionally, mice were negative for routine and comprehensive screens of pathogens. To further test whether the NTDs resulted from infectious or genetic cause localized to our facility, we obtained three strains of timed pregnant mice from commercial suppliers located in 4 different states. All strains and sources of mice arrived in our laboratory with NTDs, implying that commercially available mice were possibly exposed to a teratogen prior to purchase. Our investigation eventually concluded that exposure to tap water was causing the NTDs. The incidence of NTDs was greatest in purchased mice provided tap water and lowest in purchased mice provided distilled deionized water (DDI). Providing mice DDI water for two generations (F2-DDI) eliminated the NTDs. When F2-DDI mice were provided tap water from three different urban areas prior to breeding, their offspring again developed NTDs. Increased length of exposure to tap water significantly increased the incidence of NTDs. These results indicate that a contaminant in municipal tap water is likely causing NTDs in mice. The unknown teratogen appears to have a wide geographic distribution but has not yet been identified. Water analysis is currently underway to identify candidate contaminants that might be responsible for the malformations. PMID:20549630

Mallela, Murali K; Werre, Stephen R; Hrubec, Terry C

2010-01-01

363

Methicillin Resistant Staphylococcus aureus Carriage, Antibiotic Resistance and Molecular Pathogenicity among Healthy Individuals Exposed and Not Exposed to Hospital Environment  

PubMed Central

Background: Healthcare workers as well as healthy community-dwelling individuals may be colonised by methicillin-resistant Staphylococcus aureus (MRSA). Healthcare workers who carry MRSA may transmit it to patients, causing various nosocomial infections. Literature shows that the differences between MRSA isolated from healthcare settings and from community settings, with regard to multi-drug resistance (traditionally exhibited by the former) and possession of pvl genes (traditionally exhibited by the latter), is diminishing due to a large community reservoir and increasing influx of community harboured strains into the hospital. However, there is no literature on the current scenario in India. Aims and Objectives: This study examines the influence of exposure to hospital environment on MRSA carriage, antimicrobial resistance patterns of MRSA, and the presence of genes encoding five extracellular pathogenicity determinants (pvl, sea, seb, tsst-1 and hly a). Materials and Methods: Nasal, throat and palmar swabs were collected from 119 nursing students of the age group 18-23 years (exposed group) and 100 age matched pharmacy students (non-exposed group). S. aureus was identified and antibiogram obtained as per Clinical and Laboratory Standards Institute (CLSI) guidelines. MRSA was detected by cefoxitin disc diffusion test and by growth on oxacillin screen agar as per CLSI guidelines. Conventional PCR was performed for mecA, pvl, sea, seb, tsst-1 and hly a. Results: The differences in carrier rates, antibiotic resistance patterns and expression of extracellular pathogenicity determinants between MRSA isolates from the two study groups were not significant, and pvl was found in all the MRSA isolates. Conclusion: The nursing students carried MRSA strains similar to those carried by the non-exposed group. Our results suggest that healthcare workers could act as a link and transmit MRSA acquired from the community to patients. PMID:25177563

Krishnamurthy, Veena; Renushri, Bhadravati Virupaksha; Nagaraj, Elkal Rajappa

2014-01-01

364

76 FR 67761 - Hearing of the Attorney General's National Task Force on Children Exposed to Violence  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Task Force on Children Exposed to Violence AGENCY: Office of Juvenile Justice and...National Task Force on Children Exposed to Violence (hereafter refered to as the Task Force...children's exposure to [[Page 67762

2011-11-02

365

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2012 CFR

... Casing and sealing of exposed underground openings: General requirements...PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.13 Casing and sealing of exposed underground openings: General...

2012-07-01

366

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2011 CFR

... Casing and sealing of exposed underground openings: General requirements...PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.13 Casing and sealing of exposed underground openings: General...

2011-07-01

367

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2014 CFR

... Casing and sealing of exposed underground openings: General requirements...PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.13 Casing and sealing of exposed underground openings: General...

2014-07-01

368

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2010 CFR

... Casing and sealing of exposed underground openings: General requirements...PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.13 Casing and sealing of exposed underground openings: General...

2010-07-01

369

30 CFR 817.13 - Casing and sealing of exposed underground openings: General requirements.  

Code of Federal Regulations, 2013 CFR

... Casing and sealing of exposed underground openings: General requirements...PERMANENT PROGRAM PERFORMANCE STANDARDS-UNDERGROUND MINING ACTIVITIES § 817.13 Casing and sealing of exposed underground openings: General...

2013-07-01

370

Crustal extension from exposed sheet intrusions: review and method proposal  

NASA Astrophysics Data System (ADS)

Sheet intrusions are probably the most widespread magmatic features on Earth. They create a space for themselves by dilating the host rock. The exposed sheet intrusions allow an estimate of a minimum value of the extension to which the crustal layers and the volcanic edifices are subject. The correct evaluation of the contribution of sheet intrusions to the crustal extension is of great importance in various geologic settings. The current methods used to evaluate the extension due to exposed sheet intrusions are reviewed in this paper. The effect of the dip of sheet intrusions on the evaluation of horizontal crustal extension is analysed. If the dip effect is neglected and the intrusions are (sub)vertical, the error due to the dip effect in the extension evaluation is small; if the intrusions are shallow dipping, the error may be great and varies as a function of the dyke dip. For dykes with dip range 45-65°, the error due to neglecting the dip effect is ˜30 to ˜15%. Increasing discrepancies of more than 25% are produced on the computed dilation when the intrusions progressively dip less than 50°. A simple method, based on structural field measurements of exposed sheet intrusions and on trigonometric considerations, is presented as an improvement of pre-existing methods to estimate the horizontal component of the crustal extension. Using this method, field data of 1154 dykes from different geodynamic contexts are analysed. The horizontal component of extension is computed using dyke data from the Tertiary massifs of Lanzarote and Tenerife, and from the active stratovolcanoes of Monte Somma-Vesuvius and Etna. Since the analysed dykes are steeply dipping, the cumulative difference between the extension computed neglecting and taking into account the dip effect remains less than 10% for all the data sets. The percentage difference is nearly constant and cumulatively higher for Monte Somma, where the mean dip of the intrusions is smaller. In Lanzarote, 237 dykes emplaced between ˜15.5 and ˜3.7 Ma give a peak extension of 276 m in direction N135°, and a time-averaged minimum extension rate of 1.9×10 -2 to 2.3×10 -2 mm a -1. In Tenerife, an extension of 562 m is computed in the direction N65° from 563 dykes emplaced from ˜7.4 to ˜3.3 Ma. The time-averaged minimum rate of extension for the Tertiary massifs of Tenerife ranges from 0.14 to 0.25 mm a -1. The peak extension computed for Monte Somma is 81.7 m in the direction N90°, based on 96 exposed sheets. Very likely, most of Monte Somma sheets intruded within ˜12 ka, giving a time-averaged minimum extension rate of ˜7 mm a -1. From 184 exposed dykes of Etna, a minimum extension rate of 6.2 mm a -1 is computed (peak extension is 212 m in direction N35°). The poor resolution of age constraints may affect deeply the reliability of the extension rates. However, from the examples presented it appears that the extension rates of pre-erosional successions from intraplate volcanic islands can be smaller than those of active stratovolcanoes. This may suggest a more active dynamics in the stratovolcanoes.

Marinoni, Laura B.

2001-06-01

371

77 FR 12881 - Hearing of the Attorney General's National Task Force on Children Exposed to Violence  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Task Force on Children Exposed to Violence AGENCY: Office of Justice Programs...National Task Force on Children Exposed to Violence (the ``task force''). The task...advice in the areas of children exposed to violence for the purpose of addressing the...

2012-03-02

372

77 FR 22000 - Hearing of the Attorney General's National Task Force on Children Exposed to Violence  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Task Force on Children Exposed to Violence AGENCY: Office of Justice Programs...National Task Force on Children Exposed to Violence (the ``task force''). The task...advice in the areas of children exposed to violence for the purpose of addressing the...

2012-04-12

373

77 FR 39264 - Meeting of the Attorney General's National Task Force on Children Exposed to Violence  

Federal Register 2010, 2011, 2012, 2013, 2014

...National Task Force on Children Exposed to Violence AGENCY: Office of Justice Programs...National Task Force on Children Exposed to Violence (the ``task force''). The task...advice in the areas of children exposed to violence for the purpose of addressing the...

2012-07-02

374

Corrosion of exposed rebars, associated mechanical degradation and correlation with accelerated corrosion tests  

Microsoft Academic Search

In a large number of steel reinforced concrete buildings in Greece, spalling of the cement has left the steel reinforcement (rebars) exposed to the atmosphere. This has led to corrosion of the exposed rebars, especially in coastal areas, with questions regarding their remaining load-carrying capacity. This work addresses the problem of corrosion and strength degradation of such exposed rebars. A

M. P. Papadopoulos; C. A. Apostolopoulos; A. D. Zervaki; G. N. Haidemenopoulos

2011-01-01

375

Survey of studies of occupational populations exposed to low-level radiation  

Microsoft Academic Search

Studies of occupational populations exposed to large doses of radiation, principally from the ingestion of radium by dial painters and inhalation of radon and its daughters by miners, have provided important information on the health effects of those radioisotopes. Studies of medical radiologists, military personnel exposed to nuclear tests, and factory workers exposed to thorium are in progress. Employees of

1980-01-01

376

Enhanced Natural Carbon Sequestration in Tectonically Exposed Mantle Peridotites  

NASA Astrophysics Data System (ADS)

Carbon sequestration via mineral carbonation of calcium and magnesium silicates has been proposed but efficient carbonation is limited by the cost and energy requirement associated with mineral pretreatment (grinding, heating). Weathering of tectonically exposed mantle peridotite (rich in olivine and minor pyroxene) forms solid carbonate minerals (magnesite, hydrated magnesite, and calcite) during interaction between ground water and either olivine and pyroxene, or their main hydration product, serpentine. Carbonates are deposited in veins and as interstitial minerals within weathered peridotites, and at the surface where alkaline, Ca-rich, CO2-poor spring waters formed during serpentinization combine with atmospheric CO2 to form large travertine deposits. Literature data and our new analyses of alkaline spring waters emerging from peridotite section of the Samail Ophiolite in the Sultanate of Oman, suggest that 10 to 100 times more CO2 is deposited in subsurface carbonate veins, compared to the volume of travertine formed on the surface. New radiocarbon ages show that both carbonate veins and travertine deposits in the large, tectonically exposed peridotite section of the Samail Ophiolite, formed on average in the past ~20,000 years. Using these data, we estimate that the approximate present day natural carbon sequestration rate is ~1E9 kg of CO2 per year. This process is not particularly efficient, but the available mass of olivine, pyroxene and serpentine is large. Present day carbonation in Oman is restricted to the upper few 10's of meters, whereas the peridotite massif is several km thick in places. Thus, drilling and hydrofracturing, followed by forced circulation of meteoric or seawater, would likely enhance carbonation rates significantly. Carbonation rates may also be enhanced by exploiting the chemical potential energy inherent in exposing CO2- and H2O-poor mantle peridotite to the ocean and atmosphere. We present a simple 1D model that quantifies past suggestions that exothermic hydration of olivine and pyroxene to form serpentine can heat surrounding rocks. Heating, in turn, enhances hydration rates until temperature approaches the thermal stability limit of serpentine. Heating can be tuned to maintain near-constant temperature close to the optimal olivine carbonation rate, so that carbonation rates potentially increase 100 or 1000-fold compared to present day

Matter, J. M.; Kelemen, P.

2007-12-01

377

Morbidity and mortality in talc-exposed workers  

SciTech Connect

Cancer incidence and cause-specific mortality were studied in a male cohort of 94 talc miners and 295 talc millers, exposed to non-asbestiform talc with low quartz content. No excess risk was found compared with national age-specific incidence. Six cases of lung cancer occurred versus 6.49 expected (miners: observed 2, expected 1.27; millers: observed 4, expected 5.22). There were 3 deaths due to non-malignant respiratory disease against 10.9 expected (miners: observed 1, expected 2.5; millers: observed 2, expected 8.4). Mesothelioma, tuberculosis, or pneumoconiosis were not recorded as causes of death. Pneumoconiosis was noted as a contributory cause in three cases (silicosis two, talcosis one). Further follow-up will reduce any potential impact of healthy worker selection.

Wergeland, E.; Andersen, A.; Baerheim, A. (Oslo Univ. (Norway))

1990-01-01

378

Support for Students Exposed to Trauma: A Pilot Study  

PubMed Central

With high rates of trauma exposure among students, the need for intervention programs is clear. Delivery of such programs in the school setting eliminates key barriers to access, but there are few programs that demonstrate efficacy in this setting. Programs to date have been designed for delivery by clinicians, who are a scarce resource in many schools. This study describes preliminary feasibility and acceptability data from a pilot study of a new program, Support for Students Exposed to Trauma, adapted from the Cognitive Behavioral Intervention for Trauma in Schools (CBITS) program. Because of its “pilot” nature, all results from the study should be viewed as preliminary. Results show that the program can be implemented successfully by teachers and school counselors, with good satisfaction among students and parents. Pilot data show small reductions in symptoms among the students in the SSET program, suggesting that this program shows promise that warrants a full evaluation of effectiveness. PMID:20811511

Jaycox, Lisa H.; Langley, Audra K.; Stein, Bradley D.; Wong, Marleen; Sharma, Priya; Scott, Molly; Schonlau, Matthias

2010-01-01

379

Nanoindentation Study of Na-Geopolymers Exposed to High Temperatures  

NASA Astrophysics Data System (ADS)

This paper reports the usefulness of nanoindentation as a characterization and monitoring tool for studying thermal behaviour of Geopolymer materials. The influence of the manufacturing process of Na-Geopolymers in their micro-mechanical properties and thermal behaviour has been studied. Two types of metakaolin-based geopolymer panels with almost identical composition were prepared by injection and pouring methods. Micro-mechanical properties of the two samples exposed to high temperatures up to 1000 ºC were studied by nanoindentation technique, supplemented by X-ray diffraction (XRD), Nuclear magnetic resonance (NMR), Thermogravimetric analysis (TGA) and Microscopy. Remarkable differences in micro-mechanical properties and thermal behaviour between the two samples were found. Statistical nanoindentation has been successfully used to provide information about the micro-mechanical properties of different phases in the material and their volume distributions.

Beleña, I.; Zhu, W.

380

Ultrasonographic abdominal screening of atomic bomb-exposed subjects.  

PubMed

Abdominal ultrasonographic screening for cancer was performed in 6,001 Hiroshima and Nagasaki A-bomb exposed and comparison subjects, all members of the Adult Health Study of the Radiation Effects Research Foundation, formerly the Atomic Bomb Casualty Commission. This study yielded 20 cancers, including 7 hepatocellular, 3 gastric, 3 renal and 2 urinary bladder cancers; one cancer each of the ovary, pancreas, colon and ureter; and one cancer metastatic to the liver, whose primary was unknown. Seventeen of these 20 subjects manifested no symptoms or signs of their disease. A variety of additional tumors, unproven and probably benign, including uterine myomata, and other abnormalities were also detected. Abdominal ultrasonographic screening greatly assisted in the detection of cancers, most of which neither the patients nor their physicians were aware. In this screened fixed population sample the cancer detection rate was 0.33%, exceeding any such rates previously reported in the medical literature. PMID:8172742

Russell, W J; Higashi, Y; Fukuya, T; Hosoda, Y; Murakami, J; Kawashima, A; Murayama, S; Ohuchida, T; Mihara, F; Takagi, M

1994-03-01

381

Reproductive adaptation in Drosophila exposed to oxygen-enriched atmospheres  

NASA Technical Reports Server (NTRS)

Ten successive generations of a Drosophila melanogaster population were exposed to an atmospheric mix of 50% oxygen/50% nitrogen at standard pressure. This atmospheric mix has been shown to be toxic to this species and causes significantly shortened life span. By the fifth generation, survivorship and life span for the first 25-30 days were identical to control populations and total life span was shorter by only a few days. Egg-laying rates were stable in the experimental populations but below those of the controls. Hatching success was identical between experimental and control populations. Even though the egg-laying rates were lower in 50% oxygen, it was concluded that the population had adapted and could maintain a stable population in these conditions. The near-normal life spans, normal hatching rates, and overall population stability, exhibited following five generations of adaptation, were considered sufficient to allow continued reproduction in spite of a reduced egg-laying rate.

Kloek, G.; Winkle, L.

1979-01-01

382

Susceptible-infected-recovered and susceptible-exposed-infected models  

NASA Astrophysics Data System (ADS)

Two stochastic epidemic lattice models, the susceptible-infected-recovered and the susceptible-exposed-infected models, are studied on a Cayley tree of coordination number k. The spreading of the disease in the former is found to occur when the infection probability b is larger than bc = k/2(k - 1). In the latter, which is equivalent to a dynamic site percolation model, the spreading occurs when the infection probability p is greater than pc = 1/(k - 1). We set up and solve the time evolution equations for both models and determine the final and time-dependent properties, including the epidemic curve. We show that the two models are closely related by revealing that their relevant properties are exactly mapped into each other when p = b/[k - (k - 1)b]. These include the cluster size distribution and the density of individuals of each type, quantities that have been determined in closed forms.

Tomé, Tânia; de Oliveira, Mário J.

2011-03-01

383

Nickel-exposed workers in China: a cohort study.  

PubMed

There are more than 50 000 workers in Jinchuan Group Co, Ltd (JNMC). Since all staff in JNMC are eligible for a medical examination every two years, only 23 484 nickel-exposed subjects who participated in medical examination were included in this study. Their data, collected from June 22, 2011 to September 28, 2012, in a comprehensive epidemiological survey and during medical examinations, permitted an extensive evaluation of the relation between metal exposure, gene, epigenetics and risk of human diseases. Their lifestyle investigation showed that the overall prevalence of current smokers, alcohol drinkers, and tea drinkers was 39.1%, 19.7%, and 55.2%, respectively. The prevalence of hypertension, allergic rhinitis and cholecystitis , the top 3 prevalent diseases, was 11.7%, 11.0%, and 8.9%, respectively. PMID:24709102

Bai, Ya Na; Yang, Ai Min; Yagn, Ai Min; Pu, Hong Quan; He, Jie; Cheng, Ning; Zheng, Tong Zhang; Dai, Min; Zhang, Ya Wei; Bassing, Bryan A; Wang, Qiu Ying

2014-03-01

384

Oxidative status in rat kidney exposed to petroleum hydrocarbons  

PubMed Central

Objective: The study investigates the possible role of oxidative stress on renal tissues in association with petroleum hydrocarbon-induced nephrotoxicity. Materials and Methods: Rats of comparable weights were randomly distributed into 10 groups: Control and groups exposed to kerosene, petrol, and diesel via inhalation, contamination by food, and contamination by water. The exposure lasted for eight weeks. Results: Exposure to petroleum hydrocarbon led to significant rise in serum urea and creatinine, and renal tissue malondialdehyde. It also caused significant reduction in urinary urea and creatinine, and reduced glutathione, superoxide dismutase, and catalase activities of renal tissue homogenate. However, serum and urine concentrations of albumin and total protein were comparable in all groups. Conclusion: Results from this study shows that exposure to petroleum hydrocarbon led to renal dysfunction via oxidative stress, increasing lipid peroxidation and reducing the antioxidant defense mechanism. PMID:23633852

Azeez, Oyebisi M.; Akhigbe, Roland E.; Anigbogu, Chikodi N.

2013-01-01

385

A cytogenetic study of men occupationally exposed to uranium.  

PubMed Central

Blood lymphocyte cultures from two groups of workers occupationally exposed to uranium were examined for asymmetrical chromosome aberrations and sister chromatid exchanges (SCEs). Significant increases in both cytogenetic endpoints were seen. For dicentrics this appeared to be particularly associated with exposure to soluble uranium. The external radiation exposure experienced by these men was insufficient to explain the increase in dicentrics, and irradiation of lymphocytes by internally deposited uranium would have been minimal. As the SCEs were also raised, the genotoxic effect is likely to be due to the chemical nature of the compound. The increase in frequency of dicentrics associated with smoking was greatest in the group with exposure to soluble uranium suggesting some interaction between the two clastogens. No such interactive effect was seen for SCE frequencies, in which increases attributable to smoking were similar in the worker and control groups. PMID:1998615

Martin, F; Earl, R; Tawn, E J

1991-01-01

386

Wear of connector contacts exposed to relative motion  

NASA Astrophysics Data System (ADS)

Connectors play a significant role in the performance, cost, and reliability of electronic equipment. In connection with the development of the system interconnection design, a factor which is often overlooked is related to the importance of connector selection and mounting to minimize relative motion between contacts during vibration encountered in handling, transportation, and service. This motion can lead to the loss of protective coatings (gold and nickel) due to frictional wear. If this happens, fretting corrosion of the base metals may occur. The produced damage can adversely affect performance due to increased joint resistance, eventually causing intermittent contacts. The present investigation is concerned with the study of different style contacts (tuning fork, box, and circular) to determine their endurance and wear characteristics when exposed to relative motion created by vibration. All contacts investigated were fabricated from brass, beryllium copper, or phosphor bronze, and had .00127 mm minimum gold plating over .00127 mm minimum nickel plating.

Wilk, R. A.

387

Lung content analysis of cases occupationally exposed to chrysotile asbestos.  

PubMed Central

The lung contents of six workers who had been occupationally exposed to chrysotile asbestos were examined. Five were lung cancer cases from Quebec, Canada. The sixth, an American worker who had developed pleural mesothelioma, was particularly interesting, with the lung content strikingly distinct from the Canadian cases; chrysotile, the predominant fiber in his lung, was present at a concentration 300 times that of the average total fiber content in the Canadian cases. The fiber length distribution of the chrysotile recovered from the U.S. mesothelioma case was indistinguishable from that of chrysotile specimens known to produce mesotheliomas in rats. It was also found that the characteristics of the calcium-magnesium-iron silicate fibers present in all six cases were not readily comparable to tremolite asbestos specimens known to induce mesotheliomas in animals. Images Figure 1. A Figure 1. B Figure 1. C Figure 1. D Figure 2. A Figure 2. B Figure 2. C Figure 2. D PMID:7882942

Nolan, R P; Langer, A M; Addison, J

1994-01-01

388

Characterization of oxidized Al-1100 exposed to hygrothermic environments  

NASA Astrophysics Data System (ADS)

The oxides formed on Al-1100 by chromate conversion, chronic acid and sulfuric acid anodizing were characterized, prior to (as previously published) and after exposure to hygrothermic environments, by spectroscopic methods. The suitability of adhesive bonding and durability accomplished with silicone rubber were evaluated by shear bond strength and by the locus of failure using single lap joints and SEM/EDAX, respectively. Results from Auger/ESCA and IR have shown that in the exposed oxide layers the oxygen concentration increased due to water absorption, leading to transformation from oxide to hydroxide. In the case of chromic acid anodizing, which gave the optimal bonding performance, the reverse occurred regarding oxygen concentration while IR results showed water absorption.

Dodiuk, H.; Yaniv, A. E.; Fin, N.

1987-09-01

389

Ion irradiated graphite exposed to fusion-relevant deuterium plasma  

NASA Astrophysics Data System (ADS)

Graphite samples were irradiated with 5 MeV carbon ions to simulate the damage caused by collision cascades from neutron irradiation in a fusion environment. The ion irradiated graphite samples were then exposed to a deuterium plasma in the linear plasma device, MAGPIE, for a total ion fluence of ?1 × 1024 ions m-2. Raman and near edge X-ray absorption fine structure (NEXAFS) spectroscopy were used to characterize modifications to the graphitic structure. Ion irradiation was observed to decrease the graphitic content and induce disorder in the graphite. Subsequent plasma exposure decreased the graphitic content further. Structural and surface chemistry changes were observed to be greatest for the sample irradiated with the greatest fluence of MeV ions. D retention was measured using elastic recoil detection analysis and showed that ion irradiation increased the amount of retained deuterium in graphite by a factor of four.

Deslandes, Alec; Guenette, Mathew C.; Corr, Cormac S.; Karatchevtseva, Inna; Thomsen, Lars; Ionescu, Mihail; Lumpkin, Gregory R.; Riley, Daniel P.

2014-12-01

390

Biomarkers of lung inflammation in recreational joggers exposed to ozone.  

PubMed

Humans exhibit an acute inflammatory response in the lungs after controlled laboratory exposure to ozone. The present study was designed to test whether biomarkers of inflammation are detectable in humans exposed to ozone and associated copollutants under natural conditions outdoors. Bronchoscopy with bronchoalveolar lavage (BAL) was carried out on 19 normal volunteer joggers from Governors Island, NY, who exercised in the afternoon during the 1992 summer (S1) season. Fifteen subjects were retested during the following, low ozone, winter season (W). The BAL protocol involved an initial instillation of 20 ml saline followed by four sequential 50-ml saline washes carried out in both the right middle lobe and the lingula. The eight 50-ml samples were pooled as the 'alveolar' sample. Analyses performed on the alveolar lavage samples included cell differentials, release of IL-8, TNF-alpha, and reactive oxygen species (ROS) by pooled cells, and levels of IL-8, protein, LDH, fibronectin, alpha1-antitrypsin (alpha1-AT), complement fragment 3a (C3a), and prostaglandin E2 (PGE2) in lavage fluids. Release of ROS by stimulated BAL cells was lower in S1 than in W (p = 0.03). In contrast, LDH levels in BAL fluids were 2-fold higher in S1 than in W (p = 0.02), as were IL-8 (p = 0.12) and PGE2 (p = 0.06). These results suggest a possible ongoing inflammatory response in the lungs of recreational joggers exposed to ozone and associated copollutants during the summer months. PMID:8912760

Kinney, P L; Nilsen, D M; Lippmann, M; Brescia, M; Gordon, T; McGovern, T; El-Fawal, H; Devlin, R B; Rom, W N

1996-11-01

391

Chromosome aberrations in human blood lymphocytes exposed to energetic protons  

NASA Astrophysics Data System (ADS)

During space flight, astronauts are exposed to space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and are therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/µm. and doses ranged from 0.2 to 3 Gy. Over this energy range the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction products such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are energy dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

Hada, Megumi; George, Ms Kerry; Cucinotta, Francis A.

392

Y:X sperm ratio in boron-exposed men.  

PubMed

Several epidemiologic investigations have shown shifts in sex ratios at birth toward females in populations with relatively high boron exposure. To investigate the paternal origin of these shifts, we assayed sperm Y:X ratio in men exposed to a range of environmental and workplace boron. Participants included 63 workers in boron industry: 39 men living in an area of high environmental boron but not employed in boron industry, and 44 controls living in an area of low environmental boron. Total daily boron exposure was calculated as the sum of boron in 24-hour duplicate food and fluid intakes plus personal air sampling for workplace inhalable dust. Internal dose was measured in blood, urine, and semen. Sperm were analyzed by fluorescence in situ hybridization for Y- versus X-bearing cells. Potential confounders were identified using a questionnaire. Total exposure was correlated with internal dose (Pearson correlation for total exposure and boron in blood = 0.63, P < .0001; semen = 0.80, P < .001; and urine = 0.79, P < .0001). Linear regression of logged boron in biologic fluids on Y:X ratio was significant for blood P = .02, semen P = .0003, and urine P = .005. Additionally, when subjects were categorized by exposure group, decreased Y:X sperm ratio was found for boron workers compared with men in a high boron environment and controls (P < .0001). Exogenous environmental or workplace boron exposures were associated with decreases in Y- versus X-bearing sperm. This may explain earlier findings from us and others showing changes in offspring sex ratios at birth for men exposed to boron. PMID:17881766

Robbins, Wendie A; Wei, Fusheng; Elashoff, David A; Wu, Guoping; Xun, Lin; Jia, Juan

2008-01-01

393

Chromosome Aberration in Human Blood Lymphocytes Exposed to Energetic Protons  

NASA Technical Reports Server (NTRS)

During space flight, astronauts are exposed to a space radiation consisting of high-energy protons, high charge and energy (HZE) nuclei, as well as secondary particles that are generated when the primary particles penetrate the spacecraft shielding. Secondary particles have a higher LET value than primary protons and therefore expected to have a higher relative biological effectiveness (RBE). To investigate this theory, we exposed human peripheral blood lymphocytes to protons with energies of 250 MeV, 800MeV, 2 GeV, or 2.5 GeV. LET values for these protons ranged from 0.4 to 0.2 keV/micrometer. and doses ranged from 0.2 to 3 Gy. Over this energy the probability of nuclear reaction leading to secondary radiation, and the multiplicity of reaction produces such as neutrons and mesons increases substantially. The effect of aluminum and polyethylene shielding was also assessed using the 2 GeV and 2.5GeV proton beams. After exposure lymphocytes were stimulated to divide and chromosomes were collected from cells in the first G2 and metaphase cell cycle after exposure using a chemical induced premature chromosome condensation (PCC) technique. Dose response data for chromosome damage was analyzed using the fluorescence in situ hybridization (FISH) chromosome painting technique. Selected samples were also analyzed with multicolor FISH (mFISH) and multicolor banding FISH (mBAND) techniques. Data indicates that the dose response for simple-type exchanges is similar for proton and gamma exposure, whereas protons induce higher yields of complex exchanges that are LET dependent. RBE values will be presented for each proton energy, and the effects of shielding and possible cytogenetic signatures of proton exposure will be discussed.

Hada, M.; George, Kerry A.; Cucinotta, F. A.

2008-01-01

394

Hearing loss in workers exposed to toluene and noise.  

PubMed

In this study we investigated the risk of hearing loss among workers exposed to both toluene and noise. We recruited 58 workers at an adhesive materials manufacturing plant who were exposured to both toluene and noise [78.6-87.1 A-weighted decibels; dB(A)], 58 workers exposed to noise only [83.5-90.1 dB(A)], and 58 administrative clerks [67.9-72.6 dB(A)] at the same company. We interviewed participants to obtain sociodemographic and employment information and performed physical examinations, including pure-tone audiometry tests between 0.5 and 6 kHz. A contracted laboratory certified by the Council of Labor in Taiwan conducted on-site toluene and noise exposure measurements. The prevalence of hearing loss of >or=25 dB in the toluene plus noise group (86.2%) was much greater than that in the noise-only group (44.8%) and the administrative clerks (5.0%) (p<0.001). The prevalence rates were 67.2, 32.8, and 8.3% (p<0.001), respectively, when 0.5 kHz was excluded from the estimation. Multivariate logistic regression analysis showed that the toluene plus noise group had an estimated risk for hearing loss>or=25 dB, 10.9 times higher than that of the noise-only group. The risk ratio dropped to 5.8 when 0.5 kHz was excluded from the risk estimation. Hearing impairment was greater for the pure-tone frequency of 1 kHz than for that of 2 kHz. However, the mean hearing threshold was the poorest for 6 kHz, and the least effect was observed for 2 kHz. Our results suggest that toluene exacerbates hearing loss in a noisy environment, with the main impact on the lower frequencies. PMID:16882540

Chang, Shu-Ju; Chen, Chiou-Jong; Lien, Chih-Hui; Sung, Fung-Chang

2006-08-01

395

Dry heat exposures of surface exposed and embedded Bacillus spores  

NASA Astrophysics Data System (ADS)

Dry heat microbial reduction (DHMR) is the primary technique used to reduce the microbial load of spacecraft and component parts. Often, manufacturing procedures require heating flight hardware to high temperatures for purposes other than planetary protection DHMR. The existing specifications, however, do not allow for additional planetary protection bioburden reduction credit if the hardware is exposed without controlled relative humidity. The intent of this study was to provide adequate data on the DHMR technique to support modification of four aspects of current requirements; expansion of acceptable time and temperature combinations used for spacecraft dry heat microbial reduction processes above 125° C, determining the effect that humidity has on spore lethality as a function of temperature, understanding the lethality for spores with exceptionally high thermal resistance and to investigate the extended exposure requirement for materials that might contain embedded microorganisms. Spores from two bacterial species were tested, B. atrophaeus ATCC 9372 and B. sp. ATCC 29669, under three conditions encompassing 5 temperature points. Embedded experiments utilized a silicone rubber polymer that is commonly used on robotic spacecraft, and surface exposed experiments were performed under both ambient and vacuum-controlled humidity conditions. The results obtained support the use of DHMR protocols that extend the maximum temperature range from 125° C to 170° C, with either controlled or ambient humidity. If implemented, this will give projects bioburden reduction credit for shorter treatments at extended temperatures, and allow spacecraft to be processed in more readily available and less expensive facilities that do not have humidity control, with significant cost and schedule benefits. The study also demonstrated that the required heating time for materials presumed to have embedded bioburden is conservative.

Schubert, Wayne

396

Damage assessment in CFRP laminates exposed to impact fatigue loading  

NASA Astrophysics Data System (ADS)

Demand for advanced engineering composites in the aerospace industry is increasing continuously. Lately, carbon fibre reinforced polymers (CFRPs) became one of the most important structural materials in the industry due to a combination of characteristics such as: excellent stiffness, high strength-to-weight ratio, and ease of manufacture according to application. In service, aerospace composite components and structures are exposed to various transient loads, some of which can propagate in them as cyclic impacts. A typical example is an effect of the wind gusts during flight. This type of loading is known as impact fatigue (IF); it is a repetition of low-energy impacts. Such loads can cause various types of damage in composites: fibre breaking, transverse matrix cracking, de-bonding between fibres and matrix and delamination resulting in reduction of residual stiffness and loss of functionality. Furthermore, this damage is often sub-surface, which reinforces the need for more regular inspection. The effects of IF are of major importance due its detrimental effect on the structural integrity of components that can be generated after relatively few impacts at low force levels compared to those in a standard fatigue regime. This study utilises an innovative testing system with the capability of subjecting specimens to a series of repetitive impacts. The primary subject of this paper is to assess the damaging effect of IF on the behaviour of drilled CFRP specimens, exposed to such loading. A detailed damage analysis is implemented utilising an X-ray micro computed tomography system. The main findings suggested that at early stages of life damage is governed by o degree splits along the length of the specimens resulting in a 20% reduction of stiffness. The final failure damage scenario indicated that transverse crasks in the 90 degree plies are the main reason for complete delamination which can be translated to a 50% stiffness reduction.

Tsigkourakos, George; Silberschmidt, Vadim V.; Ashcroft, I. A.

2011-07-01

397

Risk of Spontaneous Abortion among Women Exposed to Polybrominated Biphenyls  

PubMed Central

Accidental contamination of livestock in Michigan in 1973 with polybrominated biphenyls (PBBs) led to the establishment of a registry of exposed individuals in 1976. At the time of enrollment, serum was collected and analyzed for PBBs and polychlorinated biphenyls, PCBs. In 1997, women aged 18 years or older and active in the registry were invited to participate in a telephone interview about their health. Using generalized estimating equations to account for correlated outcomes within the same woman, we assessed the risk of spontaneous abortion among 529 women with 1344 potentially exposed pregnancies. PBB and PCB exposure were not associated with risk of spontaneous abortion after adjusting for maternal age at conception, age at menarche, and prior infertility. Compared to pregnancies with PBB exposure below the limit of detection, those with levels above 2.9 ppb had a non-significant reduced odds of spontaneous abortion (adjusted OR=0.73; 95% CI= 0.47-1.13). Compared to pregnancies with PCB exposure below the limit of detection, those with levels above 6.5 ppb had little difference in risk (adjusted OR=0.91; 95% CI= 0.59-1.41). Maternal age at conception above 34 years was significantly associated with elevated risk of spontaneous abortion (OR=2.46; 95% CI= 1.10-5.49). The effect of prior infertility was of borderline significance (OR=1.52; 95% CI= 0.98-2.38). Older age at menarche was associated with decreased risk of spontaneous abortion (adjusted OR=0.58; 95% CI: 0.38-0.89, comparing menarche at 12-13 with menarche <12). Our results do not support an association between exposure to PBBs or PCBs and risk of spontaneous abortion. PMID:17239850

Small, Chanley M.; Cheslack-Postava, Keely; Terrell, Metrecia; Blanck, Heidi Michels; Tolbert, Paige; Rubin, Carol; Henderson, Alden; Marcus, Michele

2008-01-01

398

Fish exposed to BP oil spill 'swim slower' Study finds the speed of mahi-mahi exposed to BP's Gulf of  

E-print Network

Fish exposed to BP oil spill 'swim slower' Study finds the speed of mahi-mahi exposed to BP's Gulf of Mexico oil spill has fallen 37pc The 87-day-long spill dumped an estimated 4.9m barrels of oil in the gulf shortly after the spill, which oil company BP disputed. "The study does not provide any evidence

Grosell, Martin

399

Mutagenesis in bacterial spores exposed to space and simulated martian conditions: data from the EXPOSE-E spaceflight experiment PROTECT.  

PubMed

As part of the PROTECT experiment of the EXPOSE-E mission on board the International Space Station (ISS), the mutagenic efficiency of space was studied in spores of Bacillus subtilis 168. After 1.5 years' exposure to selected parameters of outer space or simulated martian conditions, the rates of induced mutations to rifampicin resistance (Rif(R)) and sporulation deficiency (Spo(-)) were quantified. In all flight samples, both mutations, Rif(R) and Spo(-), were induced and their rates increased by several orders of magnitude. Extraterrestrial solar UV radiation (>110?nm) as well as simulated martian UV radiation (>200?nm) led to the most pronounced increase (up to nearly 4 orders of magnitude); however, mutations were also induced in flight samples shielded from insolation, which were exposed to the same conditions except solar irradiation. Nucleotide sequencing located the Rif(R) mutations in the rpoB gene encoding the ?-subunit of RNA polymerase. Mutations isolated from flight and parallel mission ground reference (MGR) samples were exclusively localized to Cluster I. The 21 Rif(R) mutations isolated from the flight experiment showed all a C to T transition and were all localized to one hotspot: H482Y. In mutants isolated from the MGR, the spectrum was wider with predicted amino acid changes at residues Q469K/L/R, H482D/P/R/Y, and S487L. The data show the unique mutagenic power of space and martian surface conditions as a consequence of DNA injuries induced by solar UV radiation and space vacuum or the low pressure of Mars. PMID:22680692

Moeller, Ralf; Reitz, Günther; Nicholson The Protect Team, Wayne L; Horneck, Gerda

2012-05-01

400

Loi constitutive chimioplastique pour le beton expose aux hautes temperatures  

NASA Astrophysics Data System (ADS)

Concrete is the most widely used construction material in the world. Even though it has been used for several centuries, its behavior to high temperature remains to be understood. In the light of recent extreme events, including accidents, and arson, special attention has been focused on the performance of concrete in the fire safety assessment of buildings and tunnels. Fire represents one of the most severe conditions encountered during the life-time of a structure. Concrete exposed to high temperature can significantly jeopardize the structural integrity and load bearing capacity of the structure. Spalling of concrete remains one of the main issues to be addressed in the case of fire in buildings and tunnels. Successful modeling of this phenomenon depends not only on the accurate prediction of the temperature distribution through structural concrete but also on its mechanical response to the heating and boundaries restrains conditions and the migration of moisture and associated pore pressures. Therefore, it is necessary to develop a reliable formulation of concrete with all required information to understand its behavior during and after exposure to elevated temperature. It is also necessary to properly assess the effects of thermal degradation in order to develop predictive tools and validate design codes. Many structural problems can be adequately worthy by an elastoplastic model. The ultimate goal of this study is the development of a new constitutive model under a chemoplastic framework. To do this, an experimental program is carried out. The purpose of this program is twofold. First, it is essential to calibrate the proposed constitutive law that will be developed, and, second, for defining an inverse a problem. Usually, uniaxial and triaxial tests, conducted with confining pressure varied between 1.3 and 24 MPa and a temperature up to 700°C, allow us to identify the constitutive law parameters. This law reproduces the reduced field strength due to degradation of exothermic origin. This experimental program puts emphasis on the fragile nature of the preheated concrete and demonstrates the non-applicability of two failure criteria often used in engineering calculation. An alternative is proposed and well-tested. Indeed, exposing the concrete to high temperature results in irreversible loss of stiffness as well as a loss of decohesion strength. These losses are, typically, expressed through semi-empirical relationships of the mechanical properties with temperature. Unfortunately, these relationships are inadequate because the direct impact of this degradation, on the macroscopic scale, can result in a dependency relationship between the elastic properties and the hydrates mass. Therefore, unlike traditional methods using conventional elasto-plastic models and adjusting certain parameters with local temperature, the proposed constitutive law that incorporates a function of dehydration similar to the softening index in chemo-plastics gives good results. An Etse and Willam similar criterion is used and modified for the occasion. Hardening and softening mechanisms are then needed to expand and contract the loading surface for defining the strength of the concrete on a wide range of dehydration processes. The direction and magnitude of a permanent deformation, core of the inelastic domain, are defined through the development of non-associated chemoplastic potential and new curve of ductility. The influence of hydrostatic pressure (dilatancy) and dehydration on the concrete behavior are taken into account in our model. The model is implemented in the Matlab(c) code. Strains and stresses generated in the concrete are now accurately predicted. To illustrate the capabilities of the developed model to predict the complex behavior of concrete exposed to high temperature, simulations are performed through numerical loading paths scenarios. The model is able to accurately reproduce all the experimental data.

Hammoud, Rabah

401

Transcriptional profiling of Saccharomyces cerevisiae exposed to propolis  

PubMed Central

Background Propolis is a natural product of plant resins collected by honeybees (Apis mellifera) from various plant sources. Our previous studies indicated that propolis sensitivity is dependent on the mitochondrial function and that vacuolar acidification and autophagy are important for yeast cell death caused by propolis. Here, we extended our understanding of propolis-mediated cell death in the yeast Saccharomyces cerevisiae by applying systems biology tools to analyze the transcriptional profiling of cells exposed to propolis. Methods We have used transcriptional profiling of S. cerevisiae exposed to propolis. We validated our findings by using real-time PCR of selected genes. Systems biology tools (physical protein-protein interaction [PPPI] network) were applied to analyse the propolis-induced transcriptional bevavior, aiming to identify which pathways are modulated by propolis in S. cerevisiae and potentially influencing cell death. Results We were able to observe 1,339 genes modulated in at least one time point when compared to the reference time (propolis untreated samples) (t-test, p-value 0.01). Enrichment analysis performed by Gene Ontology (GO) Term finder tool showed enrichment for several biological categories among the genes up-regulated in the microarray hybridization such as transport and transmembrane transport and response to stress. Real-time RT-PCR analysis of selected genes showed by our microarray hybridization approach was capable of providing information about S. cerevisiae gene expression modulation with a considerably high level of confidence. Finally, a physical protein-protein (PPPI) network design and global topological analysis stressed the importance of these pathways in response of S. cerevisiae to propolis and were correlated with the transcriptional data obtained thorough the microarray analysis. Conclusions In summary, our data indicate that propolis is largely affecting several pathways in the eukaryotic cell. However, the most prominent pathways are related to oxidative stress, mitochondrial electron transport chain, vacuolar acidification, regulation of macroautophagy associated with protein target to vacuole, cellular response to starvation, and negative regulation of transcription from RNA polymerase II promoter. Our work emphasizes again the importance of S. cerevisiae as a model system to understand at molecular level the mechanism whereby propolis causes cell death in this organism at the concentration herein tested. Our study is the first one that investigates systematically by using functional genomics how propolis influences and modulates the mRNA abundance of an organism and may stimulate further work on the propolis-mediated cell death mechanisms in fungi. PMID:23092287

2012-01-01

402

Serological characterization of surface-exposed proteins of Coxiella burnetii.  

PubMed

The obligate intracellular Gram-negative bacterium Coxiella burnetii causes Q fever, a worldwide zoonosis. Here we labelled Cox. burnetii with biotin and used biotin-streptavidin affinity chromatography to isolate surface-exposed proteins (SEPs). Using two-dimensional electrophoresis combined with mass spectrometry, we identified 37 proteins through bioinformatics analysis. Thirty SEPs expressed in Escherichia coli (recombinant SEPs, rSEPs) were used to generate microarrays, which were probed with sera from mice experimentally infected with Cox. burnetii or sera from Q fever patients. Thirteen rSEPs were recognized as seroreactive, and the majority reacted with at least 50?% of the sera from mice infected with Cox. burnetii but not with sera from mice infected with Rickettsia rickettsii, R. heilongjiangensis, or R. typhi. Further, 13 proteins that reacted with sera from patients with Q fever did not react with sera from patients with brucellosis or mycoplasma pneumonia. Our results suggest that these seroreactive SEPs have potential as serodiagnostic antigens or as subunit vaccine antigens against Q fever. PMID:25298245

Jiao, Jun; Xiong, Xiaolu; Qi, Yong; Gong, Wenping; Duan, Changsong; Yang, Xiaomei; Wen, Bohai

2014-12-01

403

WASTE CHARACTERIZATION OF POLYMERIC COMPONENTS EXPOSED TO TRITIUM GAS  

SciTech Connect

A recent independent review led to uncertainty about the technical basis for characterizing the residual amount of tritium in polymer components used in the Savannah River Site Tritium Facilities that are sent for waste disposal. A review of a paper published in the open literature firmly establishes the basis of the currently used characterization, 10 Ci/cc. Information provided in that paper about exposure experiments performed at the DOE Mound Laboratory allows the calculation of the currently used characterization. These experiments involved exposure of high density polyethylene (HD-PE) to initially 1 atm tritium gas. In addition, a review of recent research at the Savannah River Site not only further substantiates this characterization, but also establishes its use for ultra-high molecular weight polyethylene (UHMW-PE), polytetrafluoroethylene (PTFE, a trade name is Teflon{reg_sign}), and Vespel{reg_sign} polyimide. 10 Ci/cc tritium is a representative characterization for any type of polymer components exposed at ambient temperature and at approximately 1 atm. tritium gas.

Clark, E

2008-02-15

404

Immunological studies on mice exposed subacutely to methyl isocyanate  

SciTech Connect

The immunotoxicity of methyl isocyanate (MIC) was evaluated in female B6C3F1 mice exposed via inhalation to 0, 1, or 3 ppm for 6 hr per day on 4 consecutive days. The antibody response to sheep erythrocytes and natural killer cell activity were found to be unaffected by MIC exposure. Although lymphoproliferative responses to mitogens were moderately suppressed by MIC, the differences were not statistically significant. The response of splenic lymphocytes to allogeneic leukocytes in a mixed leukocyte response (MLR) was suppressed in a dose-related fashion and was significantly different from the control response at the 3 ppm level. This effect was thought to be secondary and a result of general toxicity rather than a direct effect of MIC on the immune system. Furthermore, resistance to the infectious agents Listeria monocytogenes, mouse malaria parasite, and influenza virus, or to transplantable tumor cells was not compromised by MIC exposure. Thus, the immune system does not appear to be a primary target for MIC toxicity.

Tucker, A.N.; Bucher, J.R.; Germolec, D.R.; Silver, M.T.; Vore, S.J.; Luster, M.I.

1987-06-01

405

Restoration of the NNE margin of the exposed Scandinavian Caledonides  

NASA Astrophysics Data System (ADS)

The NNE margin of the exposed part of the Scandes comprises a thin sliver of rocks likely deformed in the pre-Caledonian Timanian orogenic event, lying to the north of the strike-slip Trollfjorden-Komagelva Fault. The pre-Caledonian restored position of this sliver, probably representing a much larger block now at depth below post-Caledonian sediments in the Barents Sea, is thus important for our understanding of the Scandes and their relationship to the Timanides during plate accretion. Neoproterozoic to ?earliest Cambrian rocks to the north of the fault are ~15 km thick whilst directly to the south, the Neoproterozoic to basal Ordovician rocks are only ~5 km thick, or much less. Correlations of these successions are problematic due to the differing facies, with only one relatively fixed tie point. Other correlations across the fault have been proposed, but these have proved difficult to substantiate. Currently, the amount of lateral displacement on the Trollfjorden-Komagelva Fault remains uncertain. Earlier models based on palaeomagnetic and metamorphic data both suggested that in the order of a few hundred kilometres of dextral movement occurred. Geochemical data do allow detailed correlations to be made across the fault and these, when combined with branch-line and balanced section restorations based on detailed structural data both enable a better constrained displacement estimate to be made and also clarify the Neoproterozoic to basal Ordovician pre-Caledonian basin geometry.

Rice, A. H. N.

2012-04-01

406

Subaerially exposed Holocene coral reef, Enriquillo Valley, Dominican Republic  

NASA Technical Reports Server (NTRS)

An extremely well-preserved Holocene fringing coral reef occurs at an average elevation of 5 m below sea level around the margins of the central Enriquillo Valley, Dominican Republic. The reef records the latest marine incursion from the east into an 85-km-long, 12-km-wide tectonic depression and appears to represent a unique preservation. Excellent cross sections of the reef exposed in erosional gullies reveal a composition and zonation typical of modern Caribbean reefs that are found in offshore low-energy environments. Radiocarbon age determinations (2) indicate that reef growth coincided with sea-level rise following the last ice age (5,930 + or - 100 to 4,760 + or - 90 yr B.P.). Deltaic deposition and possible vertical movements on active fault scarps dammed the eastern mouth of the valley and created Lago Enriquillo, the level of which was then rapidly lowered by evaporation in an arid climate to produce a saline lake approximately 40 m below sea level. Stratigraphic studies of rocks along the valley edge and data from drill holes in the basin center indicate that there were earlier post-Miocene marine incursions similar to that described here.

Mann, P.; Taylor, F. W.; Burke, K.; Kulstad, R.

1984-01-01

407

Mortality among welders, including a group exposed to nickel oxides.  

PubMed

Mortality and causes of death were examined among 1,059 white male welders employed between 1943 and 1973 at three plants in Oak Ridge, Tennessee. Based on deaths reported as of 1974, the standardized mortality ratio (SMR) for all causes was 87 (173 deaths observed vs. 199.0 expected on the basis of death rates for US white males). There were no deaths resulting from sinonasal cancer, and the SMR for lung cancer was 150 (95% confidence limits = 87 and 240). A subgroup of these welders (N = 536) was exposed to nickel oxides at the Oak Ridge Gaseous Diffusion (K-25) Plant; recent air concentrations of nickel (from personal air samplers) were greater than proposed standards. Standardized mortality ratios for lung cancer and diseases of the respiratory system were not higher among K-25 Plant welders than among other welders (N = 523). Welders employed for greater than or equal to 50 wk at the K-25 Plant had an SMR for lung cancer of 188 (95% confidence limits = 61 and 438) based on small numbers of deaths (5 observed vs. 2.66 expected). Further follow-up of these groups is needed. PMID:7294887

Polednak, A P

1981-01-01

408

Placental morphology of rats prenatally exposed to methyl parathion.  

PubMed

Although prenatal exposure to pesticides has been associated with numerous adverse reproductive effects, data on the effects of such toxics in the placenta is limited. Thus, the present study was carried out to determine the morphology of the rat placenta exposed to the organophosphate pesticide methyl parathion (MP) in ad libitum fed and restricted diet animals. The pregnant females were randomly divided into control groups and experimental groups, the latter of which received MP at the doses of 0.0, 1.0, 1.5 and 2.0 mg/kg. Most cells in the maternal-fetal interface showed significant alterations in the presence of MP. Trophoblast giant cells exhibited either prominent characteristics of degeneration or normal morphology with many phagosome vacuoles, apparently containing cell debris. Vascular congestion was also more frequent in the labyrinth of the treated animals. Areas of fibrosis and hemorrhage were found in the decidua, as well as decidual cells presenting pyknotic nuclei and acidophilic cytoplasm. In the placentas of females treated with both restricted diet and MP, such changes were much more severe. Together, these alterations suggest a direct, toxic effect of MP on the placental cells. The phagocytic activity exhibited by trophoblast cells, may be playing a role in the removal of death cells from the maternal-placental interface and/or in a compensatory mechanism to maintain the uptake of maternal nutrients, following decreased metabolic exchange functions of the labyrinth due to the toxic effect of the MP. PMID:15384254

Levario-Carrillo, Margarita; Olave, María Elena; Corral, Dora Chávez; Alderete, Jaime Gutiérrez; Gagioti, Sonia María; Bevilacqua, Estela

2004-07-01

409

The efficiency of photovoltaic cells exposed to pulsed laser light  

NASA Technical Reports Server (NTRS)

Future space missions may use laser power beaming systems with a free electron laser (FEL) to transmit light to a photovoltaic array receiver. To investigate the efficiency of solar cells with pulsed laser light, several types of GaAs, Si, CuInSe2, and GaSb cells were tested with the simulated pulse format of the induction and radio frequency (RF) FEL. The induction pulse format was simulated with an 800-watt average power copper vapor laser and the RF format with a frequency-doubled mode-locked Nd:YAG laser. Averaged current vs bias voltage measurements for each cell were taken at various optical power levels and the efficiency measured at the maximum power point. Experimental results show that the conversion efficiency for the cells tested is highly dependent on cell minority carrier lifetime, the width and frequency of the pulses, load impedance, and the average incident power. Three main effects were found to decrease the efficiency of solar cells exposed to simulated FEL illumination: cell series resistance, LC 'ringing', and output inductance. Improvements in efficiency were achieved by modifying the frequency response of the cell to match the spectral energy content of the laser pulse with external passive components.

Lowe, R. A.; Landis, G. A.; Jenkins, P.

1993-01-01

410

Cancer mortality in workers exposed to chlorophenoxy herbicides and chlorophenols.  

PubMed

Epidemiological studies have revealed an increased risk of cancer, notably soft-tissue sarcomas and non-Hodgkin's lymphomas, in people occupationally exposed to chlorophenoxy herbicides, including those contaminated by 2, 3, 7, 8-tetrachlorodibenzo-p-dioxin (TCDD). We report here a historical cohort study of mortality in an international register of 18,910 production workers or sprayers from ten countries. Exposure was reconstructed through questionnaires, factory or spraying records, and job histories. Cause-specific national death rates were used as reference. No excess was observed in all-cause mortality, for all neoplasms, for the most common epithelial cancers, or for lymphomas. A statistically non-significant two-fold excess risk, based on 4 observed deaths, was noted for soft-tissue sarcoma with a standardised mortality ratio (SMR) of 196 and 95% confidence interval (Cl) 53-502; this was concentrated as a six-fold statistically significant excess, occurring 10-19 years from first exposure in the cohort as a whole (SMR = 606 [165-1552]) and, for the same time period, as a nine-fold excess among sprayers (SMR = 882 [182-2579]). Risks appeared to be increased for cancers of the testicle, thyroid, other endocrine glands, and nose and nasal cavity, based on small numbers of deaths. The excess of soft-tissue sarcomas among sprayers is compatible with a causal role of chlorophenoxy herbicides but the excess does not seem to be specifically associated with those herbicides probably contaminated by TCDD. PMID:1681353

Saracci, R; Kogevinas, M; Bertazzi, P A; Bueno de Mesquita, B H; Coggon, D; Green, L M; Kauppinen, T; L'Abbé, K A; Littorin, M; Lynge, E

1991-10-26

411

Phospholipid peroxidation in tumor promoter-exposed mouse skin.  

PubMed

We have investigated lipid peroxidation in the skin of CD1 mice following single or repeated topical applications of the tumor promoter, 12-O-tetradecanoylphorbol-13-acetate (TPA). A substantial accumulation of hydroxyphospholipids, to levels 3-5 times control values, followed exposure to two or more TPA treatments (24-72 h intervals), whereas single applications were ineffective. Sodium borohydride reduction increased the yield of product by approximately 50%, suggesting the additional presence of phospholipid hydroperoxides in the oxidized lipids. Straight phase HPLC analysis of the constituent hydroxy fatty acids, followed by gas chromatography/mass spectrometry, revealed that oxidized derivatives of linoleic acid, including 9- and 13-hydroxyoctadecadienoic acids (9- and 13-HODE), were the primary products. Stereochemical analysis showed ratios of S to R stereoisomers of 1.3 for 13-HODE and 1.27 for 9-HODE, which implied that TPA-induced peroxidation was primarily due to free radical oxidation, although a partial contribution of enzyme (lipoxygenase) activity is possible. The TPA-induced peroxidation was greater in the epidermis than in the dermis. Pre-exposure of mouse skin to the anti-inflammatory agent fluocinolone acetonide, antioxidants and enzyme (phospholipase A2 and lipoxygenase) inhibitors lowered the peroxidation response to subsequent exposure to TPA. Phospholipid peroxidation products may be useful markers of oxygen radical production in TPA-exposed mouse skin with possible relevance to tumor promotion. PMID:8001259

Beckman, J K; Bagheri, F; Ji, C; Blair, I A; Marnett, L J

1994-12-01

412

Coating concrete secondary containment structures exposed to agrichemicals  

SciTech Connect

Concrete has traditionally been the material of choice for building secondary containment structures because it is relatively inexpensive and has structural properties which make it ideal for supporting the loads of vehicles and large tanks. However, concrete`s chemical properties make it susceptible to corrosion by some common fertilizers. Though fairly impervious to water movement, concrete is easily penetrated by vapors and solvents. It is also prone to cracking. For these reasons, the Environmental Protection Agency (EPA) believes that concrete alone may not provide an effective barrier to pesticide movement and has proposed that concrete in pesticide secondary containment structures be sealed or coated to reduce its permeability. Some state secondary containment regulations require that concrete exposed to fertilizers and pesticides be sealed or protected with a coating. Lacking guidelines, some retailers have used penetrating sealants to satisfy the law, even though these products provide little protection from chemical attack nor do they prevent pesticide egress. Other retailers who have applied thick film coatings which were properly selected have had disastrous results because the application was poorly done. Consequently, much skepticism exists regarding the performance and benefit of protective coatings.

Broder, M.F.; Nguyen, D.T.

1995-06-01

413

Cancer mortality among petroleum-solvent-exposed Oklahoma dry cleaners  

SciTech Connect

This study assesses the solvent specific influence on the proportionate mortality occurring among white males with exposures to petroleum solvents, averaging 10.5 years, and were without known exposure to synthetic solvents. No excess in overall cancer mortality, or in any major noncancer cause of death was found. The proportionate mortality ration (PMR) for All malignant neoplasms was 1.04 and was independent of latency and years of exposure. No excess in overall cancer deaths was found to occur in cohort members dying before age 65. A significant excess in respiratory system cancer was detected, with all excesses occurring among those who died at age 65 and older. No relationship was noted to years of latency or years of exposure. A PMR of 1.96 for pancreatic cancer was noted with three of nine deaths occurring among men younger than age 65. Consistent elevations if PMRs were seen for all categories of duration of exposure greater than 5-9 years. No pancreatic cancer deaths occurred with less than 20 years of latency. Excesses found for kidney cancer among the entire cohort were lost when only petroleum solvent exposed white males were analyzed. The power to detect an excess or deficit in overall or site-specific cancer deaths was adequate at relative risk of four or less for most cancer sites of interest.

Petrone, R.L.

1987-01-01

414

Testicular phosphoproteome in perfluorododecanoic acid-exposed rats.  

PubMed

Perfluorododecanoic acid (PFDoA) is a common environmental pollutant, which has been detected in human sera and has adverse effects on testicular function in animal models. Exploring phosphorylation events in testes helps elucidate the specific phosphorylation signals involved in testicular toxicity of PFDoA. Combining efficient prefractionation of tryptic peptide mixtures using self-packed reversed phase C18 columns with TiO2 and IMAC phosphopeptide enrichment techniques followed by 2D-LC-MS/MS, we identified 4077 unique phosphopeptides from 1777 proteins with a false discovery rate below 1.0% in the testes of rats exposed to PFDoA for 110 days. In addition, 937 novel phosphorylation sites were discovered in testicular proteins. Hundreds of phosphorylated proteins identified might be involved in spermatogenesis and sperm function. With increasing PFDoA dosage, the number of casein kinase 2 kinase-modified peptides significantly increased. Pathway analysis suggested that the mitogen-activated protein kinase pathway and cell division cycle protein 2 (CDC2) may have contributed to sperm activity and testicular function. By in vitro experiments, CDC2 phosphorylation activity was found to be likely involved in PFDoA-induced toxicity in Leydig cells. This study provides the first examination of the whole proteins' phosphorylation profile in rat testis and suggests that the MAPK pathway and CDC2 protein phosphorylation are critical for PFDoA testicular toxicity. PMID:23800682

Shi, Zhimin; Hou, Junjie; Guo, Xuejiang; Zhang, Hongxia; Yang, Fuquan; Dai, Jiayin

2013-08-14

415

Exposing Middle School Students to Remote Sensing in Alaska  

NASA Astrophysics Data System (ADS)

The need for attracting young minds to scientific research at an early stage is already recognized. Efforts are underway by major organizations to inspire the next generation of scientists. To be effective, there is a need to exploit the potential of the World Wide Web and bring it to a status that printed media have already reached. We find series of theme oriented books for children but websites with such stories are few and scattered. NASA's efforts in generating remote sensing based web stories such as the 'Adventures of Amelia the Pigeon' and 'Echo the Bat' are very good examples and starting points for generating more theme based material for children. 'Alaska: A Bird's Eye View' is a web-based story, specifically designed for grade 5-8 students. The story that is told by a Canada Goose exposes children to the truths of the remote State of Alaska and to the potential of satellite remote sensing. Examples on use remote sensing for monitoring volcanoes and sea ice edge dynamics are related to children in simple and effective ways. The topic of global climate change and its effect on marine animals has also been introduced to children.

Prakash, A.

2003-12-01

416

Model building of thermoelectric generator exposed to dynamic transient sources  

NASA Astrophysics Data System (ADS)

This paper presents the modeling of thermal and power generation behavior of a thermoelectric generator (TEG) exposed to transient sources. Most of the previous research concerned the analysis for steady-state behavior which only involves constant temperature value. However, in practice, the temperature of the TEG input fluctuates with time. Therefore this research will look into a focal point on transient heat sources that is being supplied to the hot junction with natural convection cooling process at the cold junction for single and multiple configuration of TEG. The model obtained the data from existing experiments with predicted various conditions of temperature, heat gradient, internal resistance and current attribute of TEG. Transient analysis on single TEG has shown that the value of Seebeck coefficient, thermal conductivity and figure-of-merit vary with the value of cold side temperature. When the ratio between the load and the internal resistance increases, the voltage increases. By considering the multiple TEGs, the matched voltage shows different values when the number of cascaded TEGs is varied. The simulation results have proven that the variation in the number of cascaded TEGs can be used to determine the output power characteristics of a TEG.

Yusop, A. Md; Mohamed, R.; Ayob, A.

2013-12-01

417

Synthesis of protein in intestinal cells exposed to cholera toxin  

SciTech Connect

The mechanism by which cyclic adenosine monophosphate (AMP), formed by intestinal epithelial cells in response to cholera toxin, ultimately results in alterations in water and electrolyte transport is poorly understood. Several studies have indicated that inhibitors of transcription or translation block much of the transport of ions and water in the intestine and edema formation in tissue elicited by cholera toxin. Data presented in this study confirmed the inhibitory effects of cycloheximide on cholera toxin-induced fluid accumulation in the rabbit intestinal loop model. Neither cycloheximide nor actinomycin D altered the amount of cyclic AMP that accumulated in intestinal cells and Chinese hamster ovary cells exposed to cholera toxin. An increase in (/sup 3/H) leucine incorporation was readily demonstrable in intestinal epithelial cells from rabbits challenged with Vibrio cholerae. Similarly, intestinal epithelial cells incubated with cholera toxin for 4 hr synthesized substantially more protein than controls as determined by relative incorporation of (/sup 35/S) methionine. Most of the new protein synthesized in response to cholera toxin was membrane associated and of high molecular weight. The possible significance of the toxin-induced protein relative to cholera pathogenesis was discussed.

Peterson, J.W.; Berg, W.D. Jr.; Coppenhaver, D.H.

1987-11-01

418

Security Conference in Europe Exposes Rifts between US, Allies  

NSDL National Science Digital Library

A high-level security conference in Munich this weekend exposed rifts between the US and its European allies on the issues of a US missile defense system and the deployment of a "rapid reaction" European Union force. The US missile defense system took center stage over the weekend as Secretary of Defense Donald Rumsfeld announced the Bush administration's plan to go ahead with development and deployment, unilaterally if necessary. Deliberately dropping "national" or "US" from his references to the system, Rumsfeld offered to develop it with European allies and extend its protection to their countries as well. Nonetheless, the European response was guarded and cautiously negative. German Chancellor Gerhard Schroeder warned the US against "overly hasty and early determinations" about deploying missile defenses. The reaction of Russia was more pointed, referring to the possible development of a new arms race that could extend even into outer space (the Bush administration is considering a laser defense system) and the system's violation of the 1972 Anti-Ballistic Missile Treaty. Rumsfeld dismissed European fears as unfounded and suggested that the relationship with Russia needed to be renegotiated on the ground of current threats, rather than outdated cold war assumptions. In the meantime, talks at the conference also revealed some US concern over current European Union plans to develop a "rapid reaction" force that could operate independently of NATO. Turkey's opposition to such a force, combined with the US's concerns, may help to ultimately kill the project.

Charbonneau, David D.

2001-01-01

419

Transcriptomic and proteomic profiling of maize embryos exposed to camptothecin  

PubMed Central

Background Camptothecin is a plant alkaloid that specifically binds topoisomerase I, inhibiting its activity and inducing double stranded breaks in DNA, activating the cell responses to DNA damage and, in response to severe treatments, triggering cell death. Results Comparative transcriptomic and proteomic analyses of maize embryos that had been exposed to camptothecin were conducted. Under the conditions used in this study, camptothecin did not induce extensive degradation in the genomic DNA but induced the transcription of genes involved in DNA repair and repressed genes involved in cell division. Camptothecin also affected the accumulation of several proteins involved in the stress response and induced the activity of certain calcium-dependent nucleases. We also detected changes in the expression and accumulation of different genes and proteins involved in post-translational regulatory processes. Conclusions This study identified several genes and proteins that participate in DNA damage responses in plants. Some of them may be involved in general responses to stress, but others are candidate genes for specific involvement in DNA repair. Our results open a number of new avenues for researching and improving plant resistance to DNA injury. PMID:21595924

2011-01-01

420

Model for a dune field with exposed water table  

E-print Network

Aeolian transport in coastal areas can be significantly affected by the presence of an exposed water table. In some dune fields, such as in Len\\c{c}\\'ois Maranhenses, northeastern Brazil, the water table oscillates in response to seasonal changes of rainfall and rates of evapotranspiration, rising above the ground during the wet season and sinking below in the dry period. A quantitative understanding of dune mobility in an environment with varying groundwater level is essential for coastal management as well as for the study of long-term evolution of many dune fields. Here we apply a model for aeolian dunes to study the genesis of coastal dune fields in presence of an oscillating water table. We find that the morphology of the field depends on the time cycle, $T_{\\mathrm{w}}$, of the water table and the maximum height, $H_{\\mathrm{w}}$, of its oscillation. Our calculations show that long chains of barchanoids alternating with interdune ponds such as found at Len\\c{c}\\'ois Maranhenses arise when $T_{\\mathrm{w}...

Luna, Marco Cesar M de M; Herrmann, Hans J

2011-01-01

421

Model for a dune field with exposed water table  

E-print Network

Aeolian transport in coastal areas can be significantly affected by the presence of an exposed water table. In some dune fields, such as in Len\\c{c}\\'ois Maranhenses, northeastern Brazil, the water table oscillates in response to seasonal changes of rainfall and rates of evapotranspiration, rising above the ground during the wet season and sinking below in the dry period. A quantitative understanding of dune mobility in an environment with varying groundwater level is essential for coastal management as well as for the study of long-term evolution of many dune fields. Here we apply a model for aeolian dunes to study the genesis of coastal dune fields in presence of an oscillating water table. We find that the morphology of the field depends on the time cycle, $T_{\\mathrm{w}}$, of the water table and the maximum height, $H_{\\mathrm{w}}$, of its oscillation. Our calculations show that long chains of barchanoids alternating with interdune ponds such as found at Len\\c{c}\\'ois Maranhenses arise when $T_{\\mathrm{w}}$ is of the order of the dune turnover time, whereas $H_{\\mathrm{w}}$ dictates the growth rate of dune height with distance downwind. We reproduce quantitatively the morphology and size of dunes at Len\\c{c}\\'ois Maranhenses, as well as the total relative area between dunes.

Marco Cesar M. de M. Luna; Eric J. R. Parteli; Hans J. Herrmann

2011-09-01

422

Identifying redundancy and exposing provenance in crowdsourced data analysis.  

PubMed

We present a system that lets analysts use paid crowd workers to explore data sets and helps analysts interactively examine and build upon workers' insights. We take advantage of the fact that, for many types of data, independent crowd workers can readily perform basic analysis tasks like examining views and generating explanations for trends and patterns. However, workers operating in parallel can often generate redundant explanations. Moreover, because workers have different competencies and domain knowledge, some responses are likely to be more plausible than others. To efficiently utilize the crowd's work, analysts must be able to quickly identify and consolidate redundant responses and determine which explanations are the most plausible. In this paper, we demonstrate several crowd-assisted techniques to help analysts make better use of crowdsourced explanations: (1) We explore crowd-assisted strategies that utilize multiple workers to detect redundant explanations. We introduce color clustering with representative selection--a strategy in which multiple workers cluster explanations and we automatically select the most-representative result--and show that it generates clusterings that are as good as those produced by experts. (2) We capture explanation provenance by introducing highlighting tasks and capturing workers' browsing behavior via an embedded web browser, and refine that provenance information via source-review tasks. We expose this information in an explanation-management interface that allows analysts to interactively filter and sort responses, select the most plausible explanations, and decide which to explore further. PMID:24051786

Willett, Wesley; Ginosar, Shiry; Steinitz, Avital; Hartmann, Björn; Agrawala, Maneesh

2013-12-01

423

Discrimination of poorly exposed lithologies in AVIRIS data  

NASA Technical Reports Server (NTRS)

One of the advantages afforded by imaging spectrometers such as AVIRIS is the capability to detect target materials at a sub-pixel scale. This paper presents several examples of the identification of poorly exposed geologic materials - materials which are either subpixel in scale or which, while having some surface expression over several pixels, are partially covered by vegetation or other materials. Sabol et al. (1992) noted that a primary factor in the ability to distinguish sub-pixel targets is the spectral contrast between the target and its surroundings. In most cases, this contrast is best expressed as an absorption feature or features present in the target but absent in the surroundings. Under such circumstances, techniques such as band depth mapping (Clark et al., 1992) are feasible. However, the only difference between a target material and its surroundings is often expressed solely in the continuum. We define the 'continuum' as the reflectance or radiance spanning spectral space between spectral features. Differences in continuum slope and shape can only be determined by reduction techniques which considers the entire spectral range; i.e., techniques such as spectral mixture analysis (Adams et al., 1989) and recently developed techniques which utilize an orthogonal subspace projection operator (Harsanyi, 1993). Two of the three examples considered herein deal with cases where the target material differs from its surroundings only by such a subtle continuum change.

Farrand, William H.; Harsanyi, Joseph C.

1993-01-01

424

Telomeres are elongated in rats exposed to moderate altitude  

PubMed Central

Background Leukocyte telomere length has been shown to be associated with life span. Hypoxia-associated changes of telomere length have been detected in cell cultures, but no in vivo studies have reported the changes of telomere length under different hypoxic conditions. This study aimed to evaluate the effects of altitude on telomere length in rat leukocytes. Methods One hundred and ten male Wistar rats were randomized into 3 groups and maintained at sea-level (altitude of 10 m) (SL group, n?=?10), moderate altitude (2,260 m) (MA group, n?=?50), or simulated high altitude (5,000 m (SHA group, n?=?50). The last two groups were further divided into 5 subgroups and exposed to hypoxia for 1, 3, 7, 15, or 30 days (n?=?10). The leukocyte telomere length, hemoglobin concentration, red blood cell count, hematocrit, and plasma levels of telomerase reverse transcriptase (TERT), hypoxia-inducible factor 1? (HIF-1?), malondialdehyde (MDA) and superoxide dismutase (SOD) were measured. Results Leukocyte telomere length was significantly longer in the MA group than in the SL or SHA groups, and the TERT expression changed in a similar manner as the leukocyte telomere length. However, HIF-1? level was significantly higher in both MA and SHA groups than the SL group. SOD level was decreased and MDA level was elevated in SHA group. Conclusions The telomere length of blood leukocytes is elongated at a moderate altitude, but not at a high altitude. A mild hypoxic state may increase telomere length. PMID:24996852

2014-01-01

425

Reproductive effects in birds exposed to pesticides and industrial chemicals  

SciTech Connect

Environmental contamination by agricultural chemicals and industrial waste disposal results in adverse effects on reproduction of exposed birds. The diversity of pollutants results in physiological effects at several levels, including direct effects on breeding adults as well as developmental effects on embryos. The effects on embryos include mortality or reduced hatchability, failure of chicks to thrive (wasting syndrome), and teratological effects producing skeletal abnormalities and impaired differentiation of the reproductive and nervous systems through mechanisms of hormonal mimicking of estrogens. The range of chemical effects on adult birds covers acute mortality, sublethal stress, reduced fertility, suppression of egg formation, eggshell thinning, and impaired incubation and chick rearing behaviors. The types of pollutants shown to cause reproductive effects include organochlorine pesticides and industrial pollutants, organophosphate pesticides, petroleum hydrocarbons, heavy metals, and in a fewer number of reports, herbicides, and fungicides. o,p`-DDT, polychlorinated biphenyls (PCBs), and mixtures of organochlorines have been identified as environmental estrogens affecting populations of gulls breeding in polluted {open_quotes}hot spots{close_quotes} in southern California, the Great Lakes, and Puget Sound. Estrogenic organochlorines represent an important class of toxicants to birds because differentiation of the avian reproductive system is estrogen dependent. 85 refs.

Fry, D.M. [Univ. of California, Davis, CA (United States)

1995-10-01

426

Cytogenetic monitoring of nuclear workers occupationally exposed to ionising radiation.  

PubMed

Chromosome aberration (CA) analysis using Giemsa techniques was performed in blood lymphocytes of 84 nuclear workers with cumulative doses of 1-632 mSv during employment periods of 1-25 y. The control group comprised 82 healthy male donors. An estimated CA frequency in the total radiation-exposed group was significantly higher when compared with the controls (2.27 vs. 1.76 CA/100 cells, p < 0.05). CA analyses revealed no significant differences between workers with external gamma radiation exposure and the controls (1.60 vs. 1.76 CA/100 cells, p > 0.05). However, significant increase in the total CA frequency was determined in workers with additional internal exposure (2.54 CA/100 cells, p < 0.05) and those with registered neutron doses (2.95 CA/100 cells, p < 0.01). No correlation was found between CA frequency and occupational exposure dose. Borderline significant correlation was found between duration of employment and total CA (r = 0.218, p = 0.046, Fig. 2) and chromosome-type aberration (r = 0.265, p = 0.015) frequency. PMID:24748484

Gricien?, B; Slapšyt?, G; Mierauskien?, J

2014-06-01

427

X ray anomalies occurring in workers exposed to vibration caused by light tools.  

PubMed Central

A high frequency of radiological anomalies (vacuoles, cysts, enostoses) was found in workers exposed to vibration caused by light tools (screw drivers, nutrunners) compared with a non-exposed group. The lesions were mostly localised in the spongy carpal bones (os capitatum, os lunatum, os scaphoideum). There was no significant difference between the sexes, nor between the "active" or "passive" hand, both hands being simultaneously exposed. These findings support the need to implement preventive measures. Images PMID:6691930

Van den Bossche, J; Lahaye, D

1984-01-01

428

Mental Health Outcomes of Cocaine-Exposed Children at 6 Years of Age  

Microsoft Academic Search

Objective To assess 6-year-old cocaine- and noncocaine-exposed children's mental health outcomes controlling for potential confounders. Methods The sample consisted of 322 children (169 cocaine exposed (CE) and 153 noncocaine exposed (NCE)) enrolled in a longitudinal study since birth. At age 6, children were assessed for mental health symptoms using the Dominic Interactive (DI), a child self-report measure, and the Child

Teresa J. Linares; Lynn T. Singer; H. Lester Kirchner; Elizabeth J. Short; Meeyoung O. Min; Patrick Hussey; Sonia Minnes

2006-01-01

429

Semen Abnormalities, Sperm DNA Damage and Global Hypermethylation in Health Workers Occupationally Exposed to Ionizing Radiation  

PubMed Central

Background Cytogenetic studies have demonstrated that low levels of chronic radiation exposure can potentially increase the frequency of chromosomal aberrations and aneuploidy in somatic cells. Epidemiological studies have shown that health workers occupationally exposed to ionizing radiation bear an increased risk of hematological malignancies. Objectives To find the influence of occupational radiation exposure on semen characteristics, including genetic and epigenetic integrity of spermatozoa in a chronically exposed population. Methods This cross sectional study included 134 male volunteers of which 83 were occupationally exposed to ionizing radiation and 51 were non-exposed control subjects. Semen characteristics, sperm DNA fragmentation, aneuploidy and incidence of global hypermethylation in the spermatozoa were determined and compared between the non-exposed and the exposed group. Results Direct comparison of the semen characteristics between the non-exposed and the exposed population revealed significant differences in motility characteristics, viability, and morphological abnormalities (P<0.05–0.0001). Although, the level of sperm DNA fragmentation was significantly higher in the exposed group as compared to the non-exposed group (P<0.05–0.0001), the incidence of sperm aneuploidy was not statistically different between the two groups. However, a significant number of hypermethylated spermatozoa were observed in the exposed group in comparison to non-exposed group (P<0.05). Conclusions We provide the first evidence on the detrimental effects of occupational radiation exposure on functional, genetic and epigenetic integrity of sperm in health workers. However, further studies are required to confirm the potential detrimental effects of ionizing radiation in these subjects. PMID:23922858

Kumar, Dayanidhi; Salian, Sujith Raj; Kalthur, Guruprasad; Uppangala, Shubhashree; Kumari, Sandhya; Challapalli, Srinivas; Chandraguthi, Srinidhi Gururajarao; Krishnamurthy, Hanumanthappa; Jain, Navya; Kumar, Pratap; Adiga, Satish Kumar

2013-01-01

430

Exposing SAMOS Data and Vocabularies within the Semantic Web  

NASA Astrophysics Data System (ADS)

As part of the Ocean Data Interoperability Platform (ODIP), we at the Center for Ocean-Atmospheric Prediction Studies (COAPS) will present the development process for the exposure of quality-controlled data and core vocabularies managed by the Shipboard Automated Meteorological Oceanographic System (SAMOS) initiative using Semantic Web technologies. Participants in the SAMOS initiative collect continuous navigational (position, course, heading, speed), meteorological (winds, pressure, temperature, humidity, radiation), and near-surface oceanographic (sea temperature, salinity) parameters while at sea. One-minute interval observations are packaged and transmitted back to COAPS via daily emails, where they undergo standardized formatting and quality control. The authors will present methods used to expose these daily datasets. The Semantic Web, a vision of the World Wide Web Consortium, focuses on extending the principles of the web from connecting documents to connecting data. The creation of a web of Linked Data that can be used across different applications in a machine-readable way is the ultimate goal. The Resource Description Framework (RDF) is the standard language and format used in the Semantic Web. RDF pages may be queried using the SPARQL Protocol and RDF Query Language (SPARQL). The authors will showcase the development of RDF resources that map SAMOS vocabularies to internationally served vocabularies such as those found in the Natural Environment Research Council (NERC) Vocabulary Server. Each individual SAMOS vocabulary term (data parameter and quality control flag) will be described in an RDF resource page. These RDF resources will define each SAMOS vocabulary term and provide a link to the mapped vocabulary term (or multiple terms) served externally. Along with enhanced retrieval by parameter, time, and location, we will be able to add additional parameters with the confidence that they follow an international standard. The production of RDF resources that link daily SAMOS data to descriptors such as parameters, time and location information, quality assurance reports, and cruise tracks will also be described. The data is housed on a Thematic Real-time Environmental Distributed Data Services (THREDDS) data server, so these RDF resources will enable enhanced retrieval by any of the linked descriptors. We will showcase our collaboration with the Rolling Deck to Repository (R2R) program to develop SPARQL endpoints that distribute SAMOS content. R2R packages and transmits data on a per cruise basis, so an immediate result of the SAMOS exposure will be the narrowing of the gap between expedition type data (e.g. R2R cruises) and SAMOS observatory type data. The authors will present the development of RDF resources that will collectively expose shipboard data, vocabularies, and quality assurance reports in an overall structure which will serve as the basis for a COAPS SPARQL endpoint, enabling easier programmatic access to SAMOS data.

Dockery, Nkemdirim; Elya, Jocelyn; Smith, Shawn

2014-05-01

431

Modeling temperature and stress in rocks exposed to the sun  

NASA Astrophysics Data System (ADS)

The potential contribution of solar-driven thermal cycling to the progressive breakdown of surface rocks on the Earth and other planets is recognized but under studied. To shed light on this contribution we have launched a collaborative study integrating modern instrumental and numerical approaches to define surface temperatures, stresses, strains, and microfracture activity in exposed boulders, and to shed light on the thermo-mechanical response of boulders to diurnal solar exposure. The instrumental portion of our study is conducted by M. Eppes and coworkers who have monitored the surface and environmental conditions of two ~30 cm dia. granite boulders (one in North Carolina, one in New Mexico) in the field for one and tow years, respectively. Each boulder is instrumented with 8 thermocouples, 8 strain gauges, a surface moisture sensor and 6 acoustic emission (AE) sensors to monitor microfracture activity continuously and to locate it within 2.5 cm. Herein, we focus on the numerical modeling. Using a commercially available finite element program, MSC.Marc®2008r1, we have developed an adaptable, realistic thermo-mechanical model to investigate quantitatively the temporal and spatial distributions of both temperature and stress throughout a boulder. The model accounts for the effects of latitude and season (length of day and the sun's path relative to the object), atmospheric damping (reduction of solar radiation when traveling through the Earth's atmosphere), radiative interaction between the boulder and its surrounding soil, secondary heat exchange of the rock with air, and transient heat conduction in both rock and soil. Using representative thermal and elastic rock properties, as well as realistic representations of the size, shape and orientation of a boulder instrumented in the field in North Carolina, the model is validated by comparison with direct measurements of temperature and strain on the surface of one boulder exposed to the sun. Using the validated thermo-mechanical model, we systematically analyzed a series of idealized boulders of increasing size to assess the effect of size on the observed maximum tensile stress. All boulders were modeled as perfect spheres to eliminate shape effects on this study. Boulder diameters of 0.1, 0.2, 0.4, 0.80, 1.6, and 2 m were modeled. The magnitude, timing and location of maximal tensile stresses vary significantly with size. Seasonal effects between winter and summer were of little significance to the observed peak stress magnitude. AE data from the field, on the other hand, show a complex region-specific temporal variation in micro fracturing activity: in North Carolina, more AEs were recorded in winter than in summer and especially during other seasons, whereas in New Mexico, about an order of magnitude more AEs were recorded during the summer than in other seasons. Our approach of combining modeling efforts with field measurements holds considerable promise for advancing research on mechanical weathering with diverse potential applications including the deterioration of man-made structures, monuments and sculptures, and breakdown of surface rocks and bedrock on our planet and others.

Hallet, B.; Mackenzie, P.; Shi, J.; Eppes, M. C.

2012-12-01

432

Shorebird use of an exposed sandy beach in southern California  

NASA Astrophysics Data System (ADS)

Frequent morning surveys of birds were conducted on 1 km of beach in southern California to investigate shorebird use of an exposed sandy beach. The overall mean abundance (98.6 individuals km -1), estimated biomass (9.6 kg km -1), and species richness (5.5 species km -1) of shorebirds observed were very high for a sandy beach in the temperate zone. Eight species, sanderling ( Calidris alba), semipalmated plover ( Charadrius semipalmatus), marbled godwit ( Limosa fedoa), black-bellied plover ( Pluvialis squatarola), western sandpiper ( Calidris mauri), willet ( Catoptrophorus semipalmatus), surfbird ( Aphriza virgata), and whimbrel ( Numenius phaeopus), occurred in overall mean abundances >1 bird km -1 and accounted for 97% of the abundance and biomass of shorebirds. Sanderlings were the most abundant shorebird every year (64% of individuals and 35% of the biomass). Different species of abundant shorebirds exhibited distinct patterns of use of beach habitat, including fall, spring, and winter peaks in abundance. Temporal variation in shorebird use on seasonal and interannual scales was associated with migration patterns, and also with habitat availability and condition. Seasonal variation in monthly mean abundance and estimated biomass of shorebirds varied over more than an order of magnitude and followed a similar pattern in each year, reaching maxima in the fall or winter (161-280 individuals km -1 and 15.4-23.9 kg km -1) and minima in May or June (3-11 individuals km -1 and 0.8-2.2 kg km -1). A minor peak in shorebird abundance and biomass coinciding with spring migration was observed in April of most years. The number of species of shorebirds observed in individual surveys ranged from 0 to 11 species km -1 and was positively and significantly correlated with abundance. Monthly mean species richness and the total species observed monthly followed similar seasonal patterns, ranging from annual maxima of 7.4-9.1 and 12-17 species km -1 between August and October to minima of 0.8-2.1 and 2-8 species km -1, respectively, during June. In contrast, species turnover was lowest (1.1-1.7) in October and November, and generally highest (2-4) during early summer (June). The amount of sandy intertidal habitat available to shorebirds on the transect was estimated using sand elevations and predicted tide heights. In the fall and winter, the abundance of shorebirds was significantly and positively correlated with tide height, possibly reflecting feeding opportunities and high tide refuge effects during the highest tides. In the spring when sand levels were low, the abundance of shorebirds was negatively correlated with tide height. Prey availability, beach condition and the local availability, and condition of alternative foraging habitats may influence those relationships. Interannual variations in shorebird use and beach condition were observed in the course of the study. During an El Nino Southern Oscillation (ENSO) event (1997-1998), the extent of sandy habitat was greatly reduced and intertidal habitat was mostly converted to rocky substrate. The overall abundance of shorebirds and the mean abundance of some common species (e.g. sanderling) were depressed, and an uncommon species (surfbird, A. virgata) was unusually abundant during the ENSO event. In summary, the results suggest that sandy beaches are important habitat for many species of shorebirds, particularly in areas where alternative coastal foraging habitats, such as coastal wetlands, have become scarce. Understanding the dynamics of and threats to exposed sandy beaches may be increasingly important for shorebird conservation in many coastal regions.

Hubbard, David M.; Dugan, Jenifer E.

2003-10-01

433

Transcriptomic profiling in Silurana tropicalis testes exposed to finasteride.  

PubMed

Investigations of endocrine disrupting chemicals found in aquatic ecosystems with estrogenic and androgenic modes of action have increased over the past two decades due to a surge of evidence of adverse effects in wildlife. Chemicals that disrupt androgen signalling and steroidogenesis can result in an imbalanced conversion of testosterone (T) into 17?-estradiol (E2) and other androgens such as 5?-dihydrotestosterone (5?-DHT). Therefore, a better understanding of how chemicals perturb these pathways is warranted. In this study, the brain, liver, and testes of Silurana tropicalis were exposed ex vivo to the human drug finasteride, a potent steroid 5?-reductase inhibitor and a model compound to study the inhibition of the conversion of T into 5?-DHT. These experiments were conducted (1) to determine organ specific changes in sex steroid production after treatment, and (2) to elucidate the transcriptomic response to finasteride in testicular tissue. Enzyme-linked immunosorbent assays were used to measure hormone levels in media following finasteride incubation for 6 h. Finasteride significantly increased T levels in the media of liver and testis tissue, but did not induce any changes in E2 and 5?-DHT production. Gene expression analysis was performed in frog testes and data revealed that finasteride treatment significantly altered 1,434 gene probes. Gene networks associated with male reproduction such as meiosis, hormone biosynthesis, sperm entry, gonadotropin releasing hormone were affected by finasteride exposure as well as other pathways such as oxysterol synthesis, apoptosis, and epigenetic regulation. For example, this study suggests that the mode of action by which finasteride induces cellular damage in testicular tissue as reported by others, is via oxidative stress in testes. This data also suggests that 5-reductase inhibition disrupts the expression of genes related to reproduction. It is proposed that androgen-disrupting chemicals may mediate their action via 5-reductases and that the effects of environmental pollutants are not limited to the androgen receptor signalling. PMID:24530632

Bissegger, Sonja; Martyniuk, Christopher J; Langlois, Valérie S

2014-07-01

434

Ethnic minority health in Vietnam: a review exposing horizontal inequity  

PubMed Central

Background Equity in health is a pressing concern and reaching disadvantaged populations is necessary to close the inequity gap. To date, the discourse has predominately focussed on reaching the poor. At the same time and in addition to wealth, other structural determinants that influence health outcomes exist, one of which is ethnicity. Inequities based on group belongings are recognised as ‘horizontal’, as opposed to the more commonly used notion of ‘vertical’ inequity based on individual characteristics. Objective The aim of the present review is to highlight ethnicity as a source of horizontal inequity in health and to expose mechanisms that cause and maintain this inequity in Vietnam. Design Through a systematic search of available academic and grey literature, 49 publications were selected for review. Information was extracted on: a) quantitative measures of health inequities based on ethnicity and b) qualitative descriptions explaining potential reasons for ethnicity-based health inequities. Results Five main areas were identified: health-care-seeking and utilization, maternal and child health, nutrition, infectious diseases, and oral health and hygiene. Evidence suggests the presence of severe health inequity in health along ethnic lines in all these areas. Research evidence also offers explanations derived from both external and internal group dynamics to this inequity. It is reported that government policies and programs appear to be lacking in culturally adaptation and sensitivity, and examples of bad attitudes and discrimination from health staff toward minority persons were identified. In addition, traditions and patriarchal structures within ethnic minority groups were seen to contribute to the maintenance of harmful health behaviors within these groups. Conclusion Better understandings of the scope and pathways of horizontal inequities are required to address ethnic inequities in health. Awareness of ethnicity as a determinant of health, not only as a covariate of poverty or living area, needs to be improved, and research needs to be designed with this in mind. PMID:23462107

Målqvist, Mats; Hoa, Dinh Thi Phuong; Liem, Nguyen Thanh; Thorson, Anna; Thomsen, Sarah

2013-01-01

435

Fluctuations of an Exposed ?-Helix Involved in Lipoxygenase Substrate Recognition  

PubMed Central

The second helix in lipoxygenases adapts to permit substrate access to the active site, but details of this process are varied and poorly understood. We therefore examined the dynamics of helix 2 in solutions of spin-labeled soybean lipoxygenase-1 and spin relaxation at 60 K of the spin-labels by catalytic iron. Helix 2 in soybean lipoxygenase structures is surface-exposed and contains one turn of ?-helix, centrally located. A site-directed spin-label scan of 18 of the 21 helix 2 residues, and electron paramagnetic resonance, showed that the ?-helical segment became unusually mobile, on a nanosecond time scale, under conditions favoring substrate binding (pH 9 and lipid addition), while segments before and after had relatively unchanged dynamics. Backbone dynamics of residues in the ?-helical segment appeared to be correlated, at pH 9. Samples also were frozen to examine the polarity and proticity of the local environments, the effect of the local environment on intrinsic relaxation, and dipolar relaxation by two symmetries of catalytic iron. The average hyperfine tensor component, Azz, of four ?-helix residues decreased by 1.75 G, with an increase in pH from 7 to 9, while it remained unaffected for nearby buried residues. Power saturation data suggested the change in polarity specific to the ?-helix altered the intrinsic relaxation rates. Different symmetries of iron contributed to distance-dependent magnetic relaxation. We interpret these data to mean that a ?-helix in the second helix of plant lipoxygenases is highly dynamic and is the site where lipid chains penetrate to inner helices that outline the substrate pocket. PMID:25036469

2014-01-01

436

Polyamines and polyamine biosynthesis in cells exposed to hyperthermia  

SciTech Connect

The issue of how polyamines act to sensitize cultured cells to the lethal effects of hyperthermia was investigated using Chinese hamster cells which were induced to express thermotolerance. Intracellular levels of these naturally occurring polycations were manipulated in certain situations by treating whole cells with methylglyoxal bis-(guanylhydrazone), an inhibitor of the S-adenosyl-L-methionine decarboxylases. Exogenous spermine as low as 100 ..mu..M in the culture media dramatically sensitized cells expressing thermotolerance to the lethal effects of subsequent 42/sup 0/C exposures. When thermotolerance was differentially induced in cultures exposed to 42.4/sup 0/C by varying the rate of heating from 37 to 42.4/sup 0/C, the most resistant cells and the highest levels of intracellular spermidine and spermine. This finding was explainable in part by the observation that the putrescine-dependent S-adenosyl-L-methionine decarboxylase activity was minimally affected in cells expressng the greatest degree of thermotolerance. When this enzyme activity was inhibited by drug, lowered intracellular polyamine levels did not correspond with subsequent survival responses to heat. Interestingly, cultures treated with methylglyoxal bis-(guanylhydrazone) 24 hr previous to heat exposure showed a reduced capacity to express rate of heating-induced thermotolerance. Together, these results demonstrate that the polyamines, especially spermidine and spermine, enhance hyperthermia-induced cell killing by some mechanism involving the plasma membrane. Further, our data suggest that methylglyoxal bis-(guanylhydrazone) can act to affect thermal responses by a mechanism(s) other than modification of intracellular polyamine levels.

Gerner, E.W.; Stickney, D.G.; Herman, T.S.; Fuller, D.J.

1983-02-01

437

Chronic liver injury in phenoxy herbicide-exposed Vietnam veterans.  

PubMed

Reports of hepatotoxic injury in Vietnam veterans exposed to phenoxy herbicides (mainly, 2,4-D and 2,4,5-T) initiated a retrospective cohort study of veterans self-reporting exposure to Agent Orange (AO) while serving in Vietnam from 1962 to 1971. Historical, medical, and laboratory information was obtained in a subcohort of 100 randomly selected veterans from a pool of 350 registrants. An occupational work exposure ranking system was designed to estimate individual exposure to phenoxy herbicide and its contaminant, dioxin (TCDD). Job classifications were determined by military job codes. Military application of the herbicides used in Vietnam were derived from the National Research Council Report based on the Herbs tapes. Health examination included tests of body systems affected by TCDD and similar agents, e.g., hemopoietic system, cholesterol/lipid metabolism, hepatic function, and skin lesions. Skin rash was utilized as a marker disease, since no case of true chloracne was found among the cohort. The cohort was divided into those with (R) and without (NR) a reported rash during or after the Vietnam tour. The R group had higher frequency (31%) of abnormal liver studies of all types than the NR group (18%). Of the 14 Vietnam veterans with persistent serum transaminase elevations, 86% reported a rash. Abnormal liver functions correlated with herbicide exposure index in both groups, but was more prominent in the R group. Study of the exposure index components showed that the liver abnormalities were related to the months of exposure and not to job classification or exposure rank. Viral hepatitis and alcoholism among both groups accounted for the association between liver abnormalities and cumulative exposure to AO. These data provide strong supportive evidence that chronic liver abnormalities among Vietnam veterans applying to the AO Registry are mainly due to viral or alcoholic causality and not to herbicides and their TCDD contaminant. PMID:1425508

Tamburro, C H

1992-10-01

438

Estimated daily intake of phthalates in occupationally exposed groups.  

PubMed

Improved analytical methods for measuring urinary phthalate metabolites have resulted in biomarker-based estimates of phthalate daily intake for the general population, but not for occupationally exposed groups. In 2003-2005, we recruited 156 workers from eight industries where materials containing diethyl phthalate (DEP), dibutyl phthalate (DBP), and/or di(2-ethylhexyl) phthalate (DEHP) were used as part of the worker's regular job duties. Phthalate metabolite concentrations measured in the workers' end-shift urine samples were used in a simple pharmacokinetic model to estimate phthalate daily intake. DEHP intake estimates based on three DEHP metabolites combined were 0.6-850??g/kg/day, with the two highest geometric mean (GM) intakes in polyvinyl chloride (PVC) film manufacturing (17??g/kg/day) and PVC compounding (12??g/kg/day). All industries, except phthalate manufacturing, had some workers whose DEHP exposure exceeded the U.S. reference dose (RfD) of 20??g/kg/day. A few workers also exceeded the DEHP European tolerable daily intake (TDI) of 50??g/kg/day. DEP intake estimates were 0.5-170??g/kg/day, with the highest GM in phthalate manufacturing (27??g/kg/day). DBP intake estimates were 0.1-76??g/kg/day, with the highest GMs in rubber gasket and in phthalate manufacturing (17??g/kg/day, each). No DEP or DBP intake estimates exceeded their respective RfDs. The DBP TDI (10??g/kg/day) was exceeded in three rubber industries and in phthalate manufacturing. These intake estimates are subject to several uncertainties; however, an occupational contribution to phthalate daily intake is clearly indicated in some industries. PMID:20010977

Hines, Cynthia J; Hopf, Nancy B N; Deddens, James A; Silva, Manori J; Calafat, Antonia M

2011-01-01

439

Toxicokinetics of permethrin biomarkers of exposure in orally exposed volunteers.  

PubMed

Permethrin is a widely used pyrethroid insecticide for which the toxicokinetics of exposure biomarkers in humans is not fully documented. The time courses of key biomarkers of permethrin exposure were thus assessed in accessible biological matrices of orally exposed volunteers. Six volunteers ingested 0.1mg/kg body weight of permethrin (60:40 trans/cis). Blood samples were withdrawn at fixed periods over 72h following ingestion and complete timed-urine voids were collected over 84h post-dosing. Cis-and trans-3-(2,2-dichlorovinyl)-2,2-dimethyl-cyclopropane-1-carboxylic acids (cis-and trans-DCCA) and 3-phenoxybenzoic acid (3-PBA) were quantified in samples. In plasma, peak concentrations of cis-DCCA, trans-DCCA and 3-PBA were reached about ?7h post-dosing, and elimination appeared monophasic with a mean apparent elimination half-life (t½) of 6.2, 7.1 and 6.5h, respectively. In urine, elimination rate time courses of cis-DCCA, trans-DCCA and 3-PBA evolved in parallel with plasma, with respective mean apparent elimination t½ of 4.5, 5.4 and 5.7h. Over the 84h period post-treatment, 43-46% of administered molar dose were excreted in urine as trans-DCCA (molar % of trans-permethrin) and 3-PBA. Results show similarities in the different metabolite profiles and a rapid equilibrium between urine and plasma levels; data should help interpret the significance of biological measurements and optimal sampling strategies. PMID:25498136

Ratelle, Mylène; Côté, Jonathan; Bouchard, Michèle

2015-01-22

440

Hippocampal phosphoproteomics of F344 rats exposed to 1-bromopropane.  

PubMed

1-Bromopropane (1-BP) is neurotoxic in both experimental animals and human. To identify phosphorylated modification on the unrecognized post-translational modifications of proteins and investigate their role in 1-BP-induced neurotoxicity, changes in hippocampal phosphoprotein expression levels were analyzed quantitatively in male F344 rats exposed to 1-BP inhalation at 0, 400, or 1000ppm for 8h/day for 1 or 4weeks. Hippocampal protein extracts were analyzed qualitatively and quantitatively by Pro-Q Diamond gel staining and SYPRO Ruby staining coupled with two-dimensional differ