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Sample records for ai seropositive flocks

  1. Household-level risk factors for Newcastle disease seropositivity and incidence of Newcastle disease virus exposure in backyard chicken flocks in Eastern Shewa zone, Ethiopia.

    PubMed

    Chaka, Hassen; Goutard, Flavie; Roger, Francois; Bisschop, Shahn P R; Thompson, Peter N

    2013-05-01

    A cross-sectional study with repeated sampling was conducted to investigate potential risk factors for Newcastle disease (ND) seropositivity and for incidence of ND virus (NDV) exposure in household flocks of backyard chickens in Eastern Shewa zone, Ethiopia. Data were collected from 260 randomly selected households in 52 villages in Adami Tulu Jido Kombolcha and Ada'a woredas (districts) using a structured questionnaire, and serum samples from chickens were tested for NDV antibodies using a blocking enzyme-linked immunosorbent assay (ELISA). Sampling took place during September 2009 and the same households were again sampled in May 2010. Household-level seroprevalence and incidence of NDV exposure were estimated in various ways using serological results from the two samplings, flock dynamics, and farmers' reports of ND in their flocks. The risk factors were assessed using multivariable mixed-effects logistic regression models. Household-level seroprevalence at the two sampling times was 17.4% and 27.4%, respectively, and the estimated incidence of household-level NDV exposure during the intervening period ranged between 19.7% and 25.5%. At the first sampling, reduced frequency of cleaning of poultry waste was associated with increased odds of seropositivity (OR=4.78; 95% CI: 1.42, 16.11; P=0.01) while hatching at home vs. other sources (buying in replacement birds, receiving as gift or buying fertile eggs) was associated with lower odds of seropositivity, both at the first sampling (OR=0.30; 95% CI: 0.11, 0.82; P=0.02) and the second sampling (OR=0.23; 95% CI: 0.10, 0.52; P<0.001). The risk of NDV exposure was shown to be higher with larger flock size at the beginning of the observation period (OR=3.6; 95% CI: 1.25, 10.39; P=0.02). Using an open water source (pond or river) for poultry compared to closed sources (tap or borehole) was associated with increased risk of NDV exposure (OR=3.14; 95% CI: 1.12, 8.8; P=0.03). The use of a grain supplement (OR=0.14; 95% CI

  2. Internet AIS

    NASA Astrophysics Data System (ADS)

    Filjar, Renato; Desic, Sasa; Pokrajac, Danijela; Cubic, Ivica

    2005-05-01

    Automatic Identification System (AIS) has recently become the leading issue in maritime navigation and traffic management worldwide. The present AIS solution, based on a VHF data communications scheme, provides AIS functionalities for SOLAS (AIS Class A) vessels only in a limited environment defined by radio propagation properties. Here we present a novel approach in AIS development based on current mobile communication technologies. It utilises existing mobile communications equipment that the majority of targetted end-users own and are familiar with. A novel AIS concept aims to offer a transition of AIS data traffic to mobile Internet. An innovative AIS architecture supports AIS data processing, storing and transferring to authorised parties. This enhances not only the operational area, but also provides the global AIS with data transfer security and an improved aids-for-navigation service, with all legally traceable vessels (both AIS Class A and AIS Class B) included in the system. In order to provide the development framework for Internet AIS, a set of essential four use-cases, a communication protocol and the first Internet AIS prototype have been recently developed and are briefly introduced in this article.

  3. A method for sheep scab control by applying selective treatment based on flock serology.

    PubMed

    Jacober, Ph; Ochs, H; Torgerson, P R; Schnyder, M; Deplazes, P

    2006-03-31

    Sheep scab, caused by Psoroptes ovis, is a severe and debilitating disease that can be treated and controlled by the use of acaricidal dips or the use of broad-spectrum avermectins. In Switzerland, control measures are state regulated. In particular, sheep should be routinely treated with ectocide dips or avermectin injections before they are moved onto common alpine pasture in late spring. However, a substantial part of the sheep population remains untreated and represents a potential reservoir for the mite population. Untreated sheep that are not moved to alpine pasture may infest treated sheep when flocks are reassembled in autumn. In an attempt to identify infested sheep, all flocks in the Canton of Schwyz (Switzerland) were serologically tested in 2001 and in 2002 (587 and 565 flocks, respectively). In 2003, a representative number (182 of the 531 flocks) was again investigated. Seropositive flocks were treated with doramectin (0.3 mg kg(-1) body weight, intramuscularly) from 2001 to 2003. In spring 2002, no chemo-methaphylaxis was given to seronegative flocks before movement onto common alpine pastures. Of the 587 flocks surveyed in spring 2001, 34 were seropositive (5.8%). These consisted of 21 infested with P. ovis, 1 with P. cuniculi, 4 with Chorioptes spp. and 8 of seropositivity of unknown origin; there was a decrease of seropositive flocks in spring 2002 (4.4%) with 15, 0, 2 and 8, respectively. Of the 182 flocks surveyed in spring 2003, just 4 flocks (2.2%) were seropositive. All the seropositive reactions in these flocks were the result of Chorioptes spp. infestations. There was a corresponding decrease in the proportion of seropositive animals from 6.3% in spring 2001 to 2.1% in spring 2003. These results corroborate the concept that it may be possible to target chemo-metaphylaxis and hence decrease the use of endectocides as well as of ectocides to control sheep scab. This would be of great benefit in reducing the likelihood of development of

  4. Hydrodynamics of Turning Flocks.

    PubMed

    Yang, Xingbo; Marchetti, M Cristina

    2015-12-18

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well-polarized flocks. The continuum equations controlled by only two dimensionless parameters, orientational inertia and alignment strength, are derived by coarse-graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields anisotropic spin waves that mediate the propagation of turning information throughout the flock. The coupling between spin-current density to the local vorticity field through a nonlinear friction gives rise to a hydrodynamic mode with angular-dependent propagation speed at long wavelengths. This mode becomes unstable as a result of the growth of bend and splay deformations augmented by the spin wave, signaling the transition to complex spatiotemporal patterns of continuously turning and swirling flocks.

  5. Hydrodynamics of Turning Flocks

    NASA Astrophysics Data System (ADS)

    Yang, Xingbo; Marchetti, M. Cristina

    2015-12-01

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well-polarized flocks. The continuum equations controlled by only two dimensionless parameters, orientational inertia and alignment strength, are derived by coarse-graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields anisotropic spin waves that mediate the propagation of turning information throughout the flock. The coupling between spin-current density to the local vorticity field through a nonlinear friction gives rise to a hydrodynamic mode with angular-dependent propagation speed at long wavelengths. This mode becomes unstable as a result of the growth of bend and splay deformations augmented by the spin wave, signaling the transition to complex spatiotemporal patterns of continuously turning and swirling flocks.

  6. Hydrodynamics of Turning Flocks

    NASA Astrophysics Data System (ADS)

    Yang, Xingbo; Marchetti, M. Cristina

    2015-03-01

    We present a hydrodynamic model of flocking that generalizes the familiar Toner-Tu equations to incorporate turning inertia of well polarized flocks. The continuum equations are derived by coarse graining the inertial spin model recently proposed by Cavagna et al. The interplay between orientational inertia and bend elasticity of the flock yields spin waves that mediate the propagation of turning information throughout the flock. When the inertia is large, we find a novel instability that signals the transition to complex spatio-temporal patterns of continuously turning and swirling flocks. This work was supported by the NSF Awards DMR-1305184 and DGE-1068780 at Syracuse University and NSF Award PHY11-25915 and the Gordon and Betty Moore Foundation Grant No. 2919 at the KITP at the University of California, Santa Barbara.

  7. Serological and molecular evidence of Q fever among small ruminant flocks in Algeria.

    PubMed

    Khaled, H; Sidi-Boumedine, K; Merdja, S; Dufour, P; Dahmani, A; Thiéry, R; Rousset, E; Bouyoucef, A

    2016-08-01

    Q fever, a commonly reported zoonosis worldwide, is caused by infection with Coxiella burnetii, an obligate intracellular bacterium. The infection is often asymptomatic in ruminants, but it can lead to reproductive disorders with bacterial shedding into the environment. Between 2011 and 2013, a study was undertaken in small ruminant flocks in different regions of Algeria. A total of 35 flocks were visited and 227 sera and 267 genital swabs were collected from females after abortions or the lambing period to investigate Q fever infection. Indirect ELISA was used to detect specific antibodies against C. burnetii and real-time PCR for detecting bacterial DNA. Our survey indicated that 58% (95% CI=40-76%) of flocks had at least one positive animal (17 seropositive flocks) and individual seroprevalence was estimated at 14.1% (95% CI=11.8-16.4%) (32 seropositive animals). Bacterial excretion was observed in 21 flocks (60%), and 57 females showed evidence of C. burnetii shedding (21.3%). These results suggest that C. burnetii distribution is high at the flock level and that seropositive and infected (shedder) animals can be found all over the country. Further studies are needed in other regions and on different animal species to better understand the distribution and incidence of Q fever, as well as human exposure, and to develop an adequate prophylaxis program.

  8. Flocking in Flow

    NASA Astrophysics Data System (ADS)

    Ouellette, Nicholas; Khurana, Nidhi

    2013-03-01

    Models of active, self-propelled particles with simple interaction rules have long been shown to produce large-scale emergent behavior reminiscent of collective animal motion seen in nature. Such model flocks can be shown to be robust against random noise terms added to the equations. But real animals, such as birds, fish, or insects, live in fluid environments, where the background flow field is nonzero and is often turbulent. In this case, the fluctuations experienced by the individuals in the aggregation are not random, but rather are correlated in space and time. We explore the impact of such spatiotemporally correlated perturbations on flocking by numerically simulating the behavior of a simple flocking model in a turbulent-like flow field produced by a kinematic simulation. The introduction of flow strongly changes the flock formation dynamics. Additionally, we find that under some conditions the background flow tends to break stable flocks into smaller units. We study these clusters, and discuss their relation to the underlying flow field.

  9. Prevalence of avian respiratory viruses in broiler flocks in Egypt.

    PubMed

    Hassan, Kareem E; Shany, Salama A S; Ali, A; Dahshan, Al-Hussien M; El-Sawah, Azza A; El-Kady, Magdy F

    2016-06-01

    In this study, respiratory viral pathogens were screened using real-time RT-PCR in 86 broiler chicken flocks suffering from respiratory diseases problems in 4 Egyptian governorates between January 2012 and February 2014. The mortality rates in the investigated flocks ranged from 1 to 47%. Results showed that mixed infection represented 66.3% of the examined flocks. Mixed infectious bronchitis (IBV) and avian influenza (AI)-H9N2 viruses were the most common infection (41.7%). Lack of AI-H9N2 vaccination and high rates of mixed infections in which AI-H9N2 is involved indicate an early AI-H9N2 infection with a potential immunosuppressive effect that predisposes for other viral infections. High pathogenic AI-H5N1 and virulent Newcastle disease virus (vNDV) infections were also detected (26.7% and 8.1%, respectively). Interestingly, co-infection of AI-H9N2 with either AIV-H5N1 or vNDV rarely resulted in high mortality. Partial cell-mediated immunity against similar internal AI genes, as well as virus interference between AI and vNDV, could be an explanation for this. Highly prevalent IBV and AI-H9N2 were isolated and were molecularly characterized based on S1 gene hypervariable region 3 ( HVR3: ) and hemagglutinin gene (HA) sequences, respectively. IBV strains were related to the variant group of IBV with multiple mutations in HVR3. Though AI-H9N2 viruses showed low rate of evolution in comparison to recent strains, few amino acid substitutions indicative of antibody selection pressure were observed in the HA gene. In conclusion, mixed viral infections, especially with IBV and AI-H9N2 viruses, are the predominant etiology of respiratory disease problems in broiler chickens in Egypt. Further investigations of the role of AI, IBV, and ND viruses' co-infections and interference in terms of altering the severity of clinical signs and lesions and/or generating novel reassortants within each virus are needed.

  10. Flock-based microfluidics.

    PubMed

    Hitzbleck, Martina; Lovchik, Robert D; Delamarche, Emmanuel

    2013-05-21

    Flock-based microfluidics are created by depositing hydrophilic microfibers on an adhesive-coated substrate using an electric field. This enables the fabrication of self-powered microfluidics from one or more different kinds of fibers that form 2D and 3D flowpaths, which can wick 40 microliters of liquid per square centimeter. With this approach, large areas of functional wicking materials can be produced at extremely low cost.

  11. A cross-sectional study of the seroprevalence and flock-level factors associated with ovine and caprine brucellosis in southeastern Iran

    PubMed Central

    Sharifi, H; Tabatabaei, S; Rashidi, H; Kazeminia, S; Sabbagh, F; Khajooei, P; Karamouzian, M; Nekouei, O; Adeli Sardooei, M; Leontides, L

    2014-01-01

    This cross-sectional study was conducted to estimate seroprevalence and to identify flock-level factors associated with seropositivity to brucellosis in small ruminants in Kerman province, southeastern Iran. In October-November 2011, serum samples were randomly collected from 1767 sheep and 1233 goats, older than 18 months, from 300 flocks. The sera were initially screened for the presence of anti-Brucella antibodies using the Rose-Bengal test; those found to be positive were then examined by Wright and 2-mercaptoethanol Brucella agglutination tests. A questionnaire was used to collect data on flock-level factors likely associated with the within flock seroprevalence of brucellosis. The associations were statistically evaluated for significance in multivariable logistic models. Sixty three flocks (21.00%; 95% CI: 16.80-26.60) had at least one seropositive animal. The mean within-flock seroprevalence was 3.10% (95% CI: 2.60-3.90). The presence of newly purchased animals (OR=3.42; 95% CI: 1.35-8.65) was significantly associated with seropositivity. Our findings highlight the role of animal movement among flocks in the epidemiology of brucellosis in this region. Thus, a control program for brucellosis in the region is suggested to impose appropriate restrictions on animal trade and improve knowledge of livestock owners about quarantine principles for newly purchased animals. PMID:27175133

  12. Flock-level seroprevalence of, and risk factors for, Neospora caninum among sheep and goats in northern Jordan.

    PubMed

    Abo-Shehada, Mahmoud N; Abu-Halaweh, Marwan M

    2010-01-01

    During the period January 2002 to December 2003, serum samples were collected from 104 small ruminant flocks consisting of 18 sheep flocks, 27 goat flocks and 59 mixed flocks containing both sheep and goats in northern Jordan. Only female animals were sampled. At least 5 females aged over 2 years per flock per species were sampled and examined for anti-Neospora caninum antibodies using ELISA. To increase the chances of detecting positive flocks, sick or older ewes were sampled. Also, N. caninum DNA was investigated in 7 sheep brains using PCR technique and 1 was found positive. The flock-level true seroprevalence in small ruminants was 53% (95% CI: 43,63). The true flock-level seroprevalence was higher in sheep (92%) than goats (12%) (OR=55; 95% CI: 17,197). Similarly, the individual-level seroprevalence in sheep and goat was 63% and 2% respectively (OR=25; 95% CI: 16,39). Out of 32 production and health management variables, the presence of dogs with the flock (OR=3.6, 95% CI: 1.2,10) enhanced seropositivity. Cold temperate climate (OR=0.1, 95% CI: 0.03,0.4), veterinary supervision (OR=0.2, 95% CI: 0.06,0.6) and buying healthy animals to replace those culled (OR=0.3, 95% CI: 0.1,0.97) reduced the risk of seropositivity. Both sheep and goats in Jordan are exposed to N. caninum infection with higher seroprevalence in sheep than goats. The contribution of N. caninum to abortion in small ruminant flock needs to be evaluated. Educating the farmers with regard to the role of dogs in transmitting N. caninum infection is expected to enhance small ruminant health in Jordan.

  13. Salmonella enteritidis and other Salmonella in laying hens and eggs from flocks with Salmonella in their environment.

    PubMed Central

    Poppe, C; Johnson, R P; Forsberg, C M; Irwin, R J

    1992-01-01

    Seven Canadian layer flocks with Salmonella enteritidis in their environment were investigated to determine the numbers of hens infected with S. enteritidis, the localization of S. enteritidis in organs of infected hens and the numbers of S. enteritidis-infected eggs produced by two affected flocks. By a microagglutination test (MAT) using S. pullorum antigens, these flocks had more seropositive hens (mean 51.9 +/- 16.9%) than two Salmonella-free flocks (mean 13.0 +/- 4.2%). Culture of tissues of 580 hens (433 seropositive) from the seven flocks detected 26 (4.5%) S. enteritidis-infected hens from two flocks. In one flock, 2/150 hens were infected with S. enteritidis phage type (PT) 8, which was confined to the ceca, and no Salmonella spp. were isolated from 2520 eggs (one day's lay). In the second flock, where 24/150 hens were infected with S. enteritidis PT13, extraintestinal infection was found in nine hens and involved the ovaries and/or oviduct in two hens. Salmonella enteritidis PT13 was isolated from one sample of egg contents and from one sample of cracked shells from among 14,040 eggs (one day's lay) from this flock. The overall prevalence of S. enteritidis-contaminated eggs from the two flocks with infected hens was less than 0.06%. Other Salmonella spp. isolated were S. heidelberg from 58 hens (10%), and S. hadar, S. mbandaka and S. typhimurium from one hen (0.2%) each. The MAT with antigens of S. pullorum had a sensitivity of 81% and a specificity of 24% for detecting S. enteritidis-infected hens.(ABSTRACT TRUNCATED AT 250 WORDS) PMID:1423059

  14. Effects of housing on the incidence of visna/maedi virus infection in sheep flocks.

    PubMed

    Leginagoikoa, I; Minguijón, E; Juste, R A; Barandika, J; Amorena, B; de Andrés, D; Badiola, J J; Luján, L; Berriatua, E

    2010-06-01

    The incidence of seroconversion to visna/maedi virus (VMV) infection and its relationship with management and sheep building structure was investigated in 15 dairy sheep flocks in Spain during 3-7years. Incidence rates were 0.09 per sheep-year at risk in semi-intensive Latxa flocks and 0.44 per sheep-year at risk in intensive Assaf flocks and was greatest for the one year old Assaf replacement flock. Separate multivariable models developed for replacement and adult flocks indicated that in both cases seroconversion was strongly associated to direct contact exposure to infected sheep and to being born to a seropositive dam. The latter effect was independent of the mode of rearing preweaning and the risk of seroconversion was similar for sheep fed colostrum and milk from a seropositive or a seronegative dam. These results are further evidence of the efficiency of horizontal VMV transmission by close contact between sheep and also suggest a inheritable component of susceptibility and resistance to infection. In contrast, indirect aerogenous contact with seropositive sheep was not associated with seroconversion as evidenced in replacement sheep housed in separate pens in the same building as adult infected sheep for one year. Consequently, VMV may not be efficiently airborne over short distances and this is important for control of infection. Moreover, there was no relationship between seroconversion and shed open areas. The latter could be related to having examined few flocks in which high infection prevalence dominated the transmission process while ventilation, may depend on a variety of unrecorded factors whose relationship to infection needs to be further investigated.

  15. Detection of antibodies against Chlamydophila abortus in Costa Rican sheep flocks

    PubMed Central

    Villagra-Blanco, R.; Dolz, G.; Montero-Caballero, D.; Romero-Zúñiga, J.J.

    2015-01-01

    A total of 359 sheep samples from 15 flocks were analyzed for the presence of antibodies against Chlamydophila abortus using a commercial Enzyme linked Immunosorbent Assay (ELISA). Antibodies were detected in 19 (5.29%) sheep from 12 (80%) flocks. Seropositive animals were found in all analyzed regions (Central, Chorotega, Atlantic Huetar, North Huetar and Central Pacific) determining prevalence between 0.28% and 4.4%, and intra-flock positivity between 3.7% and 25.0%. The survey revealed two risk factors associated with seropositivity; introducing animals (males and females), embryos, or semen from other farms or from abroad without any sanitary certification, and flocks not having quarantine areas or separated boxes for diseased animals. No clinical signs of disease were observed in positive seroreactors. C. abortus seems to be present in Costa Rica in a very low prevalence in sheep flocks. Further studies, to isolate the bacteria are required. Finally, implementation of control measures to prevent the spread of C. abortus is recommended. PMID:26623377

  16. Detection of antibodies against Chlamydophila abortus in Costa Rican sheep flocks.

    PubMed

    Villagra-Blanco, R; Dolz, G; Montero-Caballero, D; Romero-Zúñiga, J J

    2015-01-01

    A total of 359 sheep samples from 15 flocks were analyzed for the presence of antibodies against Chlamydophila abortus using a commercial Enzyme linked Immunosorbent Assay (ELISA). Antibodies were detected in 19 (5.29%) sheep from 12 (80%) flocks. Seropositive animals were found in all analyzed regions (Central, Chorotega, Atlantic Huetar, North Huetar and Central Pacific) determining prevalence between 0.28% and 4.4%, and intra-flock positivity between 3.7% and 25.0%. The survey revealed two risk factors associated with seropositivity; introducing animals (males and females), embryos, or semen from other farms or from abroad without any sanitary certification, and flocks not having quarantine areas or separated boxes for diseased animals. No clinical signs of disease were observed in positive seroreactors. C. abortus seems to be present in Costa Rica in a very low prevalence in sheep flocks. Further studies, to isolate the bacteria are required. Finally, implementation of control measures to prevent the spread of C. abortus is recommended.

  17. Flocking ferromagnetic colloids

    PubMed Central

    Kaiser, Andreas; Snezhko, Alexey; Aranson, Igor S.

    2017-01-01

    Assemblages of microscopic colloidal particles exhibit fascinating collective motion when energized by electric or magnetic fields. The behaviors range from coherent vortical motion to phase separation and dynamic self-assembly. Although colloidal systems are relatively simple, understanding their collective response, especially under out-of-equilibrium conditions, remains elusive. We report on the emergence of flocking and global rotation in the system of rolling ferromagnetic microparticles energized by a vertical alternating magnetic field. By combing experiments and discrete particle simulations, we have identified primary physical mechanisms, leading to the emergence of large-scale collective motion: spontaneous symmetry breaking of the clockwise/counterclockwise particle rotation, collisional alignment of particle velocities, and random particle reorientations due to shape imperfections. We have also shown that hydrodynamic interactions between the particles do not have a qualitative effect on the collective dynamics. Our findings shed light on the onset of spatial and temporal coherence in a large class of active systems, both synthetic (colloids, swarms of robots, and biopolymers) and living (suspensions of bacteria, cell colonies, and bird flocks). PMID:28246633

  18. Coordinated Behaviour in Pigeon Flocks

    PubMed Central

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Vásárhelyi, Gábor; Nagy, Máté

    2015-01-01

    We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns. PMID:26485662

  19. Coordinated Behaviour in Pigeon Flocks.

    PubMed

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Vásárhelyi, Gábor; Nagy, Máté

    2015-01-01

    We analysed pigeon flock flights using GPS trajectory data to reveal the most important kinematic aspects of flocking behaviour. We quantitatively investigated the internal motion of the flock based on pairwise statistics and found the following general relationships in all datasets: i) the temporal order of decisions characterised by the delay between directional changes is strictly related to the spatial order characterised by the longitudinal relative position within the flock; ii) during circling motion, pigeons use a mixture of two idealised and fundamentally different turning strategies, namely, parallel-path and equal-radius type turning. While pigeons tend to maintain their relative position within the flock on average, as in the parallel-path approximation, those who turn later also get behind as in the equal-radius case. Equal-radius type turning also tends to be expressed more during smaller radius turns.

  20. Survey of Schmallenberg virus (SBV) infection in German goat flocks.

    PubMed

    Helmer, C; Eibach, R; Tegtmeyer, P C; Humann-Ziehank, E; Ganter, M

    2013-11-01

    Animal losses due to abortion and malformed offspring during the lambing period 2011/2012 amounted to 50% in ruminants in Europe. A new arthropod-borne virus, called Schmallenberg virus (SBV), was identified as the cause of these losses. Blood samples were obtained from 40 goat flocks and tested for antibodies against SBV by ELISA, with 95% being seropositive. The calculated intra-herd seroprevalence (median 36·7%, min-max 0-93·3%) was smaller than in cattle or sheep flocks. Only 25% of the farmers reported malformations in kids. Statistical analysis revealed a significantly lower risk of goats housed indoors all year-round to be infected by SBV than for goats kept outside day and night. The low intra-herd seroprevalence demonstrates that German goat flocks are still at risk of SBV infection. Therefore, they must be protected during the next lambing seasons by rescheduling the mating period, implementing indoor housing, and continuous treatment with repellents or vaccination.

  1. Seropositivity of cytomegalovirus in patients with recurrent pregnancy loss

    PubMed Central

    Sherkat, Roya; Meidani, Mohsen; Zarabian, Hossein; Rezaei, Abbas; Gholamrezaei, Ali

    2014-01-01

    Background: Some evidence has shown a relationship between human cytomegalovirus (CMV) infection and pregnancy loss. However, whether recurrent or latent CMV infection or altered immune response to CMV is related to recurrent pregnancy loss (RPL) is unclear. We evaluated CMV infection and avidity of antibodies to CMV in women with RPL. Materials and Methods: This case-control study was conducted on 43 women with RPL referred to a clinical immunology out-patient clinic in Isfahan (Iran), and 43 age-matched multiparous women without history of abortion as control subjects. Patients and controls were evaluated for anti-CMV IgG and IgM antibodies and IgG avidity index (AI) using the enzyme linked immunosorbent assay method. Student's t-test and Chi-square test were used to analyze the data. Results: One case (2.3%) of positive anti-CMV IgM was detected in each group. Anti-CMV IgG positivity was more frequent in patients than in controls (90.6% vs. 69.8%, P = 0.014), but there was no difference between the two groups in anti-CMV IgG AI (79.4 ± 11.4 vs. 80.1 ± 10.2, P = 0.781). IgG titer was significantly higher in seropositive cases with RPL than seropositive controls (5.18 ± 1.99 vs. 2.00 ± 0.81, P < 0.001). Conclusion: We found that previous exposure to CMV was significantly higher in patients with RPL than the control group. However, no association was found between IgG AI and RPL. Further investigations are needed to find whether latent CMV infection starts an indirect process of autoimmune etiology in RPL or women with RPL have recurrent or reactivation of CMV infection. PMID:25002889

  2. Avian hepatitis E virus infection and possible associated clinical disease in broiler breeder flocks in Hungary.

    PubMed

    Morrow, Chris J; Samu, Gyozo; Mátrai, Eszter; Klausz, Akos; Wood, Alasdair M; Richter, Susanne; Jaskulska, Barbara; Hess, Michael

    2008-10-01

    In broiler breeder flocks in one broiler integration in Hungary, a new syndrome appeared in January 2005 with initially four successive post-peak flocks experiencing significant decreases in egg production. Clinically birds became depressed and there was a small increase in the mortality rate. Postmortem examinations revealed enlarged livers in up to 19% of birds dying, and enlarged spleens in some. Also observed were birds with either clotted blood or serosanguineous fluid in the abdomen and subcapsular haemorrhages of the liver. Histopathology and polymerase chain reaction excluded tumours and the presence of common tumour-associated viruses. Chronic bacterial infections (especially causing hepatitis, peritonitis and airsacculitis) were common but many enlarged livers had no obvious bacterial involvement. After a 9-month period during which a majority of flocks became affected, no newly affected flocks occurred. Investigations showed that all tested affected flocks were seropositive in the big liver and spleen (BLS) Agar Gel Immunodiffusion test. Subsequent flocks without post-peak egg-production drops were shown to be seronegative in the BLS AGID test, as were all the parent flocks contributing to the affected flocks. Liver samples and cloacal swabs were positive by polymerase chain reaction (aHEV helicase target), and calicivirus-like particles were demonstrated in bile samples from affected birds. These observations are similar to hepatitis-splenomegaly syndrome as described in North America and BLS syndrome as described in Australia. Histopathological features were a non-specific chronic hepatitis similar to those described in BLS and hepatitis-splenomegaly syndrome. Immunohistochemistry using a BLS-specific monoclonal antibody confirmed the presence of avian hepatitis E virus antigen in livers and spleen.

  3. Transmission and control implications of seroconversion to Maedi-Visna virus in Basque dairy-sheep flocks.

    PubMed

    Berriatua, Eduardo; Alvarez, Vega; Extramiana, Belén; González, Lorenzo; Daltabuit, Mara; Juste, Ramón

    2003-09-12

    A retrospective analysis of seroconversion to Maedi-Visna virus (MVV) was carried out for 10 infected semi-intensively reared dairy-sheep flocks that were tested annually between 1994 and 1999. Four of the flocks raised replacement lambs artificially with bovine colostrum and milk replacement to avoid lactogenic MVV infection but did not prevent aerosol contact between replacements and other sheep in the flock. Flock culling percentages ranged between 14 and 25% and in eight flocks the number of sheep that seroconverted was similar to or lower than the number of sheep culled--suggesting that incidence could be reduced by culling seropositive sheep without increasing average culling percentages. Random-effects logistic regression indicated that seroconversion was associated positively with increasing contact with infected sheep and with lifetime MV-serological status of the dam (used as a proxy measure of genetic susceptibility), but not with mode of rearing pre-weaning (artificially or with a seropositive or seronegative dam). Our results indicate that when conditions allow efficient horizontal transmission, there is no evidence that lactogenic infection increases the risk of MV infection and that there is an important inheritable component of disease resistance or susceptibility.

  4. Hydrodynamics and phases of flocks

    SciTech Connect

    Toner, John; Tu Yuhai . E-mail: yuhai@us.ibm.com; Ramaswamy, Sriram

    2005-07-01

    We review the past decade's theoretical and experimental studies of flocking: the collective, coherent motion of large numbers of self-propelled 'particles' (usually, but not always, living organisms). Like equilibrium condensed matter systems, flocks exhibit distinct 'phases' which can be classified by their symmetries. Indeed, the phases that have been theoretically studied to date each have exactly the same symmetry as some equilibrium phase (e.g., ferromagnets, liquid crystals). This analogy with equilibrium phases of matter continues in that all flocks in the same phase, regardless of their constituents, have the same 'hydrodynamic'-that is, long-length scale and long-time behavior, just as, e.g., all equilibrium fluids are described by the Navier-Stokes equations. Flocks are nonetheless very different from equilibrium systems, due to the intrinsically nonequilibrium self-propulsion of the constituent 'organisms'. This difference between flocks and equilibrium systems is most dramatically manifested in the ability of the simplest phase of a flock, in which all the organisms are, on average moving in the same direction (we call this a 'ferromagnetic' flock; we also use the terms 'vector-ordered' and 'polar-ordered' for this situation) to exist even in two dimensions (i.e., creatures moving on a plane), in defiance of the well-known Mermin-Wagner theorem of equilibrium statistical mechanics, which states that a continuous symmetry (in this case, rotation invariance, or the ability of the flock to fly in any direction) can not be spontaneously broken in a two-dimensional system with only short-ranged interactions. The 'nematic' phase of flocks, in which all the creatures move preferentially, or are simply oriented preferentially, along the same axis, but with equal probability of moving in either direction, also differs dramatically from its equilibrium counterpart (in this case, nematic liquid crystals). Specifically, it shows enormous number fluctuations, which

  5. Artificial Intelligence Study (AIS).

    DTIC Science & Technology

    1987-02-01

    ARTIFICIAL INTELLIGNECE HARDWARE ....... 2-50 AI Architecture ................................... 2-49 AI Hardware ....................................... 2...Epstein (1986) has suggested that this version of PROLOG has been used for business and industrial applications in Eastern Europe. The Japanese have...have been in building expert systems in the business analysis area. Expert systems for policy and rate selection for insurance (i.e., risk analysis) and

  6. Outbreaks of highly pathogenic Eurasian H5N8 avian influenza in two commercial poultry flocks in California

    Technology Transfer Automated Retrieval System (TEKTRAN)

    In January 2015, a highly pathogenic Eurasian lineage H5N8 avian influenza (AI) virus was detected in a commercial meat turkey flock in Stanislaus County, California. Approximately 3 weeks later, a similar case was diagnosed in commercial chickens from a different company located in Kings County, C...

  7. Turkey knockdown in successive flocks.

    PubMed

    Evans, R D; Edson, R K; Watkins, K L; Robertson, J L; Meldrum, J B; Novilla, M N

    2000-01-01

    Turkey knockdown was diagnosed in three of five flocks of hen turkeys on a single farm within a 12-mo period. The age of birds in the flocks affected ranged from 6 wk 2 days to 7 wk 4 days. The attack rate ranged from 0.02% to 0.30% with a case fatality rate in affected birds ranging from 0 to 74%. The diagnosis was made on the basis of clinical signs and histopathologic lesions associated with knockdown. The feed in all flocks contained bacitracin methylene disalicylate and monensin (Coban). Affected birds were recumbent, demonstrated paresis, and were unable to vocalize. Postmortem examination revealed few significant lesions although pallor of the adductor muscles and petechiation in adductor and gastrocnemius muscles were noted. Birds that had been recumbent for extended periods were severely dehydrated. Consistent microscopic lesions included degeneration, necrosis, and regeneration of adductor, gastrocnemius, and abdominal muscles. No lesion in cardiac tissue was noted. Results of our investigation indicated that changes in water consumption, vitamin E status, and brooder to finisher movement correlated with the occurrence of knockdown. Turkey knockdown was defined in 1993 as any condition identified in a turkey flock that has affected the neuromuscular system to a degree that a turkey is unable to walk or stand. This definition was later modified to...neuromuscular or skeletal systems to a degree that a turkey is unable to walk or stand properly. Knockdown may be associated with numerous feed, management, or disease factors alone or in combination. Dosage of monensin, feed restriction/gorging, water restriction, heat stress, copper, mycotoxins, sodium chloride in feed, and sulfa drugs have all been suggested as contributing factors; however, laboratory studies to duplicate this have not been successful. This report presents observations from a single farm at which three of five hen flocks in a single year experienced knockdown. When a flock was reported as

  8. T'ai Chi

    MedlinePlus

    ... you start your first t'ai chi workout, dress comfortably so you can move and stretch easily. ... health problem. Is your schedule jam-packed with school, work, and social activities? Here are a few ...

  9. T'ai Chi

    MedlinePlus

    ... chi (pronounced: TY CHEE) is great for improving flexibility and strengthening your legs, abs, and arms. What ... general, though, practicing t'ai chi improves strength, flexibility, and respiratory function (breathing). So where can you ...

  10. AI aerospace components

    NASA Technical Reports Server (NTRS)

    Heindel, Troy A.; Murphy, Terri B.; Rasmussen, Arthur N.; Mcfarland, Robert Z.; Montgomery, Ronnie E.; Pohle, George E.; Heard, Astrid E.; Atkinson, David J.; Wedlake, William E.; Anderson, John M.

    1991-01-01

    An evaluation is made of the application of novel, AI-capabilities-related technologies to aerospace systems. Attention is given to expert-system shells for Space Shuttle Orbiter mission control, manpower and processing cost reductions at the NASA Kennedy Space Center's 'firing rooms' for liftoff monitoring, the automation of planetary exploration systems such as semiautonomous mobile robots, and AI for battlefield staff-related functions.

  11. Local equilibrium in bird flocks

    NASA Astrophysics Data System (ADS)

    Mora, Thierry; Walczak, Aleksandra M.; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    2016-12-01

    The correlated motion of flocks is an example of global order emerging from local interactions. An essential difference with respect to analogous ferromagnetic systems is that flocks are active: animals move relative to each other, dynamically rearranging their interaction network. This non-equilibrium characteristic has been studied theoretically, but its impact on actual animal groups remains to be fully explored experimentally. Here, we introduce a novel dynamical inference technique, based on the principle of maximum entropy, which accommodates network rearrangements and overcomes the problem of slow experimental sampling rates. We use this method to infer the strength and range of alignment forces from data of starling flocks. We find that local bird alignment occurs on a much faster timescale than neighbour rearrangement. Accordingly, equilibrium inference, which assumes a fixed interaction network, gives results consistent with dynamical inference. We conclude that bird orientations are in a state of local quasi-equilibrium over the interaction length scale, providing firm ground for the applicability of statistical physics in certain active systems.

  12. Neospora caninum infection as a cause of reproductive failure in a sheep flock.

    PubMed

    González-Warleta, Marta; Castro-Hermida, José Antonio; Regidor-Cerrillo, Javier; Benavides, Julio; Álvarez-García, Gema; Fuertes, Miguel; Ortega-Mora, Luis Miguel; Mezo, Mercedes

    2014-08-26

    Neospora caninum has been detected only sporadically in cases of ovine abortion, and it has therefore traditionally been considered as an unimportant parasite in small ruminants. This study was carried out with the aim of identifying the pathogen causing serious reproductive problems on a commercial sheep farm. Sera from all rams and ewes tested negative for antibodies against Border disease virus, Schmallenberg virus and Coxiella burnetii, and infections by these agents were therefore ruled out. Nevertheless, seropositivity to N. caninum and/or Toxoplasma gondii was detected, although the seroprevalence was higher in the case of N. caninum. The percentage of lambings and the number of lambs per dam were significantly lower in ewes that were seropositive to N. caninum while no effect on these parameters was detected in ewes that were seropositive to T. gondii. There was also no evidence of infection by T. gondii in the foetal/lamb tissues analyzed by PCR and/or immunohistopathological techniques. On the contrary, the DNA of N. caninum was detected in 13 out of 14 foetuses/lambs descendant from dams seropositive to this parasite. Characteristic lesions caused by N. caninum and/or its antigen were also detected. Genotyping of the N. caninum DNA revealed only two closely related microsatellite multilocus genotypes. The results clearly demonstrate that infection by N. caninum was the cause of the low reproductive performance of this sheep flock.

  13. Animation of flocks flying in line formations.

    PubMed

    Klotsman, Marina; Tal, Ayellet

    2012-01-01

    We provide a biologically motivated technique for modeling and animating bird flocks in flight, which produces plausible and realistic-looking flock animations. While most previous approaches have focused on animating cluster formations, this article introduces a technique for animating flocks that fly in certain patterns, so-called line formations. We distinguish between the behavior of such flocks during initiation and their behavior during steady flight. Our simulation of the initiation stage is rule-based and incorporates an artificial bird model. Our simulation of the steady-flight stage combines a data-driven approach and an energy-savings model.

  14. Short communication: investigation of Coxiella burnetii occurrence in dairy sheep flocks by bulk-tank milk analysis and antibody level determination.

    PubMed

    García-Pérez, A L; Astobiza, I; Barandika, J F; Atxaerandio, R; Hurtado, A; Juste, R A

    2009-04-01

    To estimate the prevalence of Coxiella burnetii in the dairy sheep population from the Basque Country (northern Spain), a study was carried out combining molecular and serological techniques. First, bulk-tank milk samples from 154 flocks belonging to the Latxa Breed Farmers Association were analyzed by PCR, with 22% of flocks testing positive for C. burnetii. Then, a selection of 34 flocks (7 PCR positive and 17 negative) was investigated for the presence of serum antibodies by ELISA test on 1,011 ewes (approximately 30 ewes per flock). A total of 8.9% of the animals were seropositive, 67.6% of the flocks had at least one seropositive animal, but only in 14.7% of them was seroprevalence greater than 25%. Older ewes showed a significantly greater prevalence (17.5%) compared with yearlings (7.5%) or replacement lambs (1.5%). A marginally significant association was found between seroprevalence and PCR detection of C. burnetii in bulk-tank milk. The widespread distribution of C. burnetii in the region advocates for the implementation of Q fever control strategies and highlights the potential risk of sheep as a reservoir and infection source for other domestic and wildlife species and the human population.

  15. A Leader-Follower Flocking System Based on Estimated Flocking Center

    NASA Astrophysics Data System (ADS)

    Wang, Zongyao; Gu, Dongbing

    This chapter introduces a robot flocking system in which only minority members are the group leaders who have global trajectory knowledge, while majority members are the group followers who do not have global trajectory information, but can communicate with neighbors. The followers even do not know who the leaders are in the group. In order to keep the flocking group connected, all the group members estimate the position of flocking center by using a consensus algorithm via local communication. Based on the estimated positions of flocking center, a leader-follower flocking algorithm is proposed. A group of real robots, "wifibots", are used to test the feasibility of the flocking algorithm. The simulation is conducted for a large group to demonstrate its scalability. The results show that this leader-follower flocking system can track desired trajectories led by the leaders.

  16. Flocking in Distributed Control and Optimization

    DTIC Science & Technology

    2015-06-01

    flocking discipline. Swarms, flocks and other group formations can be found in nature in many organisms ranging from simple bacteria to mammals. Such...Contact email if there is a problem with the report. agarcia@virginia.edu Primary Contact Phone Number Contact phone number if there is a problem with

  17. Viral infections in goose flocks in Poland.

    PubMed

    Kozdruń, W; Woźniakowski, G; Samorek-Salamonowicz, E; Czekaj, H

    2012-01-01

    The aim of this study was to determine the infectious agents isolated from infection - suspected geese sent for the diagnostic examination to National Veterinary Research Institute. The birds were sent from goose flocks localized in different parts of Poland. Totally, 1,013 birds from 122 flocks were examined. The presence of goose parvovirus (GPV), goose haemorrhagic polyomavirus (GHPV), and goose circovirus (GoCV) was detected by triplex PCR. The presence of GPV DNA was shown in 36 flocks. The disease was most frequently diagnosed in goslings aging 3.5 weeks (ten flocks), and 2.5 weeks (six flocks). The analysis of the nucleotide sequence of VP1 encoding region has shown close similarity of Polish GPV strains within the group which ranged from 92% to 100%. Moreover, the similarity level of these strains with GPV isolated in Europe was from 91.3% to 100%. The occurrence of GoCV DNA was shown in 25 goose flocks. The presence of GoCV DNA was found among geese aged from 2 to 6 weeks, but predominantly in those aging 3.5 (three flocks) and 5 weeks (five flocks). The sequence analysis of PCR products from the sequenced region of ORFC1 capsid protein of GoCV has shown that Polish isolates share from 85% to 91% similarity with the sequences of GoCV strains isolated in other countries. The presence of DNA of GHPV was found in 3-week-old geese. During the last 2 years the presence of GHPV was confirmed in three flocks of goslings at the age from 3 to 3.5 weeks. During the last 12 years the occurrence of co-infection with GPV and GoCV was detected in six flocks aging from 5 to 6 weeks.

  18. AI in manufacturing

    NASA Technical Reports Server (NTRS)

    Gross, John E.; Minato, Rick; Smith, David M.; Loftin, R. B.; Savely, Robert T.

    1991-01-01

    AI techniques are shown to have been useful in such aerospace industry tasks as vehicle configuration layouts, process planning, tool design, numerically-controlled programming of tools, production scheduling, and equipment testing and diagnosis. Accounts are given of illustrative experiences at the production facilities of three major aerospace defense contractors. Also discussed is NASA's autonomous Intelligent Computer-Aided Training System, for such ambitious manned programs as Space Station Freedom, which employs five different modules to constitute its job-independent training architecture.

  19. Collective Behaviour: Leadership and Learning in Flocks.

    PubMed

    Herbert-Read, James

    2015-12-07

    A new study has decoded which birds become leaders in homing pigeon flocks, finding an unexpected benefit of leadership: faster birds emerge as leaders, and these leaders learn more about their environment than their followers.

  20. Typhlocolitis associated with spirochaetes in duck flocks.

    PubMed

    Glávits, Róbert; Ivanics, Eva; Thuma, Akos; Kaszanyitzky, Eva; Samu, Péterné; Ursu, Krisztina; Dencso, László; Dán, Adám

    2011-02-01

    The aetiology of increased mortality observed in two breeder duck flocks (Flock A consisting of 3500 laying ducks and Flock B comprising 4300 laying ducks) during the first egg-laying season was studied. In Flocks A and B, 773 ducks and 715 ducks (18.4% and 16.6%) died within a 24-week and a 20-week period, respectively. Death was preceded by clinical signs including movement difficulties, lack of appetite and depression lasting for 1 to 2 days. Diarrhoea was not observed. On gross pathological examination, the ducks were found to have haemorrhagic to fibrinonecrotic typhlocolitis, renal degeneration accompanied by fibrosis and mineralization, hepatic and splenic amyloidosis, and swelling of some of the metatarsal and phalangeal joints. Histopathological and immunohistochemical examination consistently demonstrated spirochaetes in the mucous membrane of the affected large intestine. On the basis of their cultural and biochemical properties and polymerase chain reaction sequencing analysis, four out of seven spirochaete strains isolated from the ducks (Flock A) by culture on special media under anaerobic conditions were identified as Brachyspira hyodysenteriae, and five out of eight strains (Flock B) were identified as Brachyspira pilosicoli. This is the first report on the isolation of B. hyodysenteriae and B. pilosicoli from laying ducks affected by fibrinonecrotic typhlocolitis.

  1. Research on an infectious disease transmission by flocking birds.

    PubMed

    Tang, Mingsheng; Mao, Xinjun; Guessoum, Zahia

    2013-01-01

    The swarm intelligence is becoming a hot topic. The flocking of birds is a natural phenomenon, which is formed and organized without central or external controls for some benefits (e.g., reduction of energy consummation). However, the flocking also has some negative effects on the human, as the infectious disease H7N9 will easily be transmited from the denser flocking birds to the human. Zombie-city model has been proposed to help analyzing and modeling the flocking birds and the artificial society. This paper focuses on the H7N9 virus transmission in the flocking birds and from the flocking birds to the human. And some interesting results have been shown: (1) only some simple rules could result in an emergence such as the flocking; (2) the minimum distance between birds could affect H7N9 virus transmission in the flocking birds and even affect the virus transmissions from the flocking birds to the human.

  2. Farmers flock to coastal cities.

    PubMed

    Zhou, M; Mulley, S

    1994-01-01

    China's rural-urban migration flows, particularly into Shanghai, Guangdong province, Beijing, and coastal areas, present challenges for urban development. The impact on rural and urban areas and suggestions for minimizing undesirable consequences were discussed. Professor Zhang Qingwu, deputy director of the Population Research Institute of Xiamen University in Fujian province, believes that the large migrating populations and those without residence cards pose problems for heavily populated cities: they strain resources (housing, water and electricity supplies, transportation, telecommunication, environmental hygiene, food supplies, and educational facilities). Crime increases. Municipal departments must increase their administrative load in service sectors. The general idea is that rural-to-urban migration reflects social progress and adds to a productive work force. Flexible policies are recommended. In Guangdong province, where migrants arrived from Sichuan and Hunan provinces, counties from the latter two provinces have established offices for supervising their former residents. Employment adjustment can be anticipated when the major flock of migrants arrive after the Lantern Festival. Professor Gui Shixun of the Population Research Institute of East China Normal University and advisor to the State Family Planning Commission recommends that development strategies incorporate planning for imbalances between local population and migrant urban workers. In some areas, women represent the bulk of migrants, while in other areas men do. Cultural development should be stressed, with investments also improved in telecommunications, traffic and transportation, education, and hygiene. Professor Jiang Zhixue recommends shifting from labor-intensive enterprises to technology-intensive enterprises and a better trained work force. Other schemes, such as the purchase by migrants of residence cards in Xiamen, would entitle migrants to the same rights and obligations as

  3. Hierarchical group dynamics in pigeon flocks.

    PubMed

    Nagy, Máté; Akos, Zsuzsa; Biro, Dora; Vicsek, Tamás

    2010-04-08

    Animals that travel together in groups display a variety of fascinating motion patterns thought to be the result of delicate local interactions among group members. Although the most informative way of investigating and interpreting collective movement phenomena would be afforded by the collection of high-resolution spatiotemporal data from moving individuals, such data are scarce and are virtually non-existent for long-distance group motion within a natural setting because of the associated technological difficulties. Here we present results of experiments in which track logs of homing pigeons flying in flocks of up to 10 individuals have been obtained by high-resolution lightweight GPS devices and analysed using a variety of correlation functions inspired by approaches common in statistical physics. We find a well-defined hierarchy among flock members from data concerning leading roles in pairwise interactions, defined on the basis of characteristic delay times between birds' directional choices. The average spatial position of a pigeon within the flock strongly correlates with its place in the hierarchy, and birds respond more quickly to conspecifics perceived primarily through the left eye-both results revealing differential roles for birds that assume different positions with respect to flock-mates. From an evolutionary perspective, our results suggest that hierarchical organization of group flight may be more efficient than an egalitarian one, at least for those flock sizes that permit regular pairwise interactions among group members, during which leader-follower relationships are consistently manifested.

  4. Targeted survey of Newcastle disease virus in backyard poultry flocks located in wintering site for migratory birds from Southern Brazil.

    PubMed

    Marks, Fernanda S; Rodenbusch, Carla R; Okino, Cíntia H; Hein, Héber E; Costa, Eduardo F; Machado, Gustavo; Canal, Cláudio W; Brentano, Liana; Corbellini, Luís G

    2014-09-01

    Newcastle disease virus (NDV) causes a fast-spreading, highly contagious infectious disease in several bird species. Commercial poultry farms in Brazil were considered free of virulent NDV. Data on NDV infection levels in backyard poultry flocks and the epidemiology of the disease are limited. The aim of this study was to perform a NDV survey in backyard poultry from households flocks located around one of the main wintering sites for migratory wild birds in Brazil, and to identify potential risk factors associated with NDV. Backyard poultry may be sentinels and a source of infection for commercial poultry, since they may have as much contact with these birds as with migratory wild birds. Data were collected from 48 randomly selected households using an epidemiological questionnaire. Serum samples from poultry were tested for NDV antibodies using an ELISA, and tracheal and cloacal swabs were collected for NDV molecular detection. The risk factors were assessed using a multivariate Poisson regression with robust variance. The ELISA showed that 33.8% of the serum samples were positive for anti-NDV antibodies and in 42 households (87.5%) at least one NDV-positive bird was found. Tracheal and cloacal swabs were negative for NDV by real time RT-PCR, possible because within this region there might flow a low pathogenicity NDV strain, which can induce seroconversion with innaparent clinical findings. The prevalence ratio (PR) increased when farmers used their own replacement poultry to restock their flock (PR=1.64; 95% CI: 1.11-2.42). Furthermore, the increasing distance of the household flock from the "Laguna do Peixe" estuary was associated with decreasing NDV seropositivity (PR=0.94; 95% CI: 0.90-0.99). This is the first study in Brazil evaluating the presence of NDV and the associated risk factors in households with backyard poultry flocks. The great number of farms with seropositive birds indicates that the virus circulates in backyard flocks, and this breeding

  5. Phase Transitions in Models of Bird Flocking

    NASA Astrophysics Data System (ADS)

    Christodoulidi, H.; van der Weele, K.; Antonopoulos, Ch. G.; Bountis, T.

    2014-12-01

    The aim of the present paper is to elucidate the transition from collective to random behavior exhibited by various mathematical models of bird flocking. In particular, we compare Vicsek's model [Vicsek et al., Phys. Rev. Lett. 75, 1226-1229 (1995)] with one based on topological considerations. The latter model is found to exhibit a first order phase transition from flocking to decoherence, as the "noise parameter" of the problem is increased, whereas Vicsek's model gives a second order transition. Refining the topological model in such a way that birds are influenced mostly by the birds in front of them, less by the ones at their sides and not at all by those behind them (because they do not see them), we find a behavior that lies in between the two models. Finally, we propose a novel mechanism for preserving the flock's cohesion, without imposing artificial boundary conditions or attractive forces.

  6. Functional Diversification within a Predatory Species Flock

    PubMed Central

    Burress, Edward D.; Duarte, Alejandro; Serra, Wilson S.; Loueiro, Marcelo; Gangloff, Michael M.; Siefferman, Lynn

    2013-01-01

    Ecological speciation is well-known from adaptive radiations in cichlid fishes inhabiting lentic ecosystems throughout the African rift valley and Central America. Here, we investigate the ecological and morphological diversification of a recently discovered lotic predatory Neotropical cichlid species flock in subtropical South America. We document morphological and functional diversification using geometric morphometrics, stable C and N isotopes, stomach contents and character evolution. This species flock displays species-specific diets and skull and pharyngeal jaw morphology. Moreover, this lineage appears to have independently evolved away from piscivory multiple times and derived forms are highly specialized morphologically and functionally relative to ancestral states. Ecological speciation played a fundamental role in this radiation and our data reveal novel conditions of ecological speciation including a species flock that evolved: 1) in a piscivorous lineage, 2) under lotic conditions and 3) with pronounced morphological novelties, including hypertrophied lips that appear to have evolved rapidly. PMID:24278349

  7. Black knight of AI

    SciTech Connect

    Rose, F.

    1985-03-01

    For two decades now, Hubert Dreyfus, an existentialist philosopher at the University of California at Berkeley, has been in the forefront of the controversy over artificial intelligence. He maintains that computers will never be able to think because scientists will never come up with a suitably rigorous set of rules to describe how we think. To many computer scientists, this is like saying the Earth is flat. But so far, none of them have been able to prove him wrong. Even most AI researchers now admit that before they can make computers any smarter, they'll have to come up with an explanation of how intelligence works in people. This realization has coincided with the emergence of cognitive science, a new discipline linking philosophy, psychology, anthroplogy, linguistics, neuroscience, and computer science in an attempt to develop a theory of the way humans think. The guiding principle of most cognitive science research is the notion that the mind, like the computer, is a system for manipulating symbols - for processing information. The task of cognitive science is to discover how this processing occurs.

  8. Megabacteriosis in a flock of budgerigars.

    PubMed

    Christensen, N H; Hunter, J E; Alley, M R

    1997-10-01

    Megabacteriosis was diagnosed as the cause of depression and wasting in a flock of breeding budgerigars in the Manawatu. Large numbers of megabacteria were detected in direct smears from mucosal scrapings of the proventriculus of two birds and in the faeces of live birds. The diagnosis was confirmed by demonstrating a chronic proventriculitis histologically associated with megabacterial organisms. Treatment of seven individuals with amphotericin B resulted in clinically sustained weight gain over a 10-week period. Treatment of the whole flock resulted in the resumption of normal condition, behaviour and activity.

  9. 78 FR 25943 - Changes to Scrapie Flock Certification Program

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-05-03

    ... Animal and Plant Health Inspection Service Changes to Scrapie Flock Certification Program AGENCY: Animal... giving notice of changes to the Scrapie Flock Certification Program (SFCP), a voluntary program for sheep and goat flock owners who wish to reduce and/or eliminate the risk of introducing classical...

  10. 9 CFR 147.21 - Flock sanitation.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... brooder houses and other premises following infection of such premises by any contagious disease. (c) Poultry houses should be screened and proofed against free-flying birds. An active rodent eradication... status of both the flock and introduced birds should be evaluated. (h) In rearing broiler or...

  11. Vitamin A toxicosis in a lorikeet flock.

    PubMed

    Park, Fiona

    2006-09-01

    Vitamin A toxicosis has recently been recognized as a concern for granivorous birds such as cockatiels (Nymphicus hollandicus) and nectarivorous birds such as lorikeets. Such birds have little exposure to performed vitamin A in their wild diet, relying on carotene conversion to supply their vitamin A needs. Multiple clinical problems arose in a lorikeet flock when excessive vitamin A supplementation was used.

  12. Typical and atypical AIS. Pathogenesis.

    PubMed

    Dudin, M; Pinchuk, D

    2012-01-01

    AIS hypothesis has the right to recognition, if it explains the transition of "healthy" vertebra column into status of "scoliotic" one. AIS is the most investigated disease in the history of orthopedics, but up the present time there is no clear explanation of some its phenomena: vertebra column mono-form deformation along with its poly etiology character, interrelation of its origin and development and child's growth process etc. The key for authors' view at AIS was scoliosis with non-standard (concave side) rotation. On the bases of its' multifunctional instrumental investigation results (Rtg, EMG, EEG, optical topography, hormonal and neuropeptides trials, thermo-vision methods and other) in comparison with typical AIS was worked out the new hypothesis, part of it is suggested for discussion. In the work under observation is the sequence of appearance of typical and atypical scoliosis symptomatology beginning from the preclinical stage.

  13. Code AI Personal Web Pages

    NASA Technical Reports Server (NTRS)

    Garcia, Joseph A.; Smith, Charles A. (Technical Monitor)

    1998-01-01

    The document consists of a publicly available web site (george.arc.nasa.gov) for Joseph A. Garcia's personal web pages in the AI division. Only general information will be posted and no technical material. All the information is unclassified.

  14. Evaluating the risk of avian influenza introduction and spread among poultry exhibition flocks in Australia.

    PubMed

    Hernández-Jover, M; Schemann, K; East, I J; Toribio, J-A L M L

    2015-01-01

    Some practices undertaken by poultry exhibitors, such as allowing wild birds to contact domestic birds, the high frequency of bird movements and the lack of appropriate isolation for incoming birds, pose a risk for disease introduction and spread. The aim of the current study was to quantitatively assess the probability of introduction of low pathogenic avian influenza (LPAI) viruses from wild waterfowl into poultry exhibition flocks and the subsequent spread to other poultry flocks. Exposure and consequence assessments, using scenario trees and Monte Carlo stochastic simulation modelling, were conducted to identify potential pathways of introduction and spread and calculate the probabilities of these pathways occurring. Input parameters were estimated from two recently conducted cross-sectional studies among poultry exhibitors in Australia (Dusan et al., 2010; Hernández-Jover et al., 2013) and other scientific literature. According to reported practices of poultry exhibitors and the LPAI prevalence in wild birds in Australia, this assessment estimates a median (5-95%) probability of exposure of a bird kept by a poultry exhibitor of 0.004 (0.003-0.005). Due to the higher susceptibility of infection of turkeys and waterfowl, this probability is higher in flocks keeping these bird species than in those keeping chickens or pigeons only. Similarly, once exposure has occurred, establishment of infection and subsequent spread are more likely in those flocks keeping waterfowl and turkeys than in those keeping chicken and pigeons only. Spread through movement of birds is the most likely pathway of spread, followed by contaminated fomites, wild birds and airborne spread. The median probability of LPAI spread through movement of birds in flocks keeping waterfowl and turkeys was estimated to be 0.280 (0.123-0.541) and 0.230 (0.104-0.421), respectively. A lower probability was estimated for chicken (0.087; 0.027-0.202) and pigeon (0.0003; 3.0×10(-5)-0.0008) flocks. The

  15. AIS ASM Operational Integration Plan

    DTIC Science & Technology

    2013-08-01

    River , WA; and the future Vessel Traffic Service systems being developed under PAWSS. Interfacing the AIS Transmit architecture with agencies that...provides accurate real-time information such as water levels, currents, and other oceanographic and meteorological data. The USACE provide river lock...information and river level and current data on the Inland Waterways. AIS ASM Operational Integration Plan viii UNCLAS//Public | CG-926 R&DC

  16. Course and prognosis in seropositive and seronegative rheumatoid arthritis.

    PubMed

    Sahatçiu-Meka, Vjollca; Rexhepi, Sylejman; Kukeli, Anton; Manxhuka-Kërliu, Suzana; Pallaskas, Kelmend; Murtezani, Ardiana; Rexhepi, Mjellma; Rexhepi, Blerta

    2013-01-01

    Long since it have been suggested that a subpopulation of patients with rheumatoid arthritis (RA), diagnosed with negative rheumatoid factor (RF) tests, represents a clinical entity quite distinct from that of seropositive rheumatoid arthritis. The aim of the study was to establish a scientific comparative analysis between RA seronegative and seropositive, regarding course and prognoses of the disease. Two hundred fifty patients with rheumatoid arthritis according to the (American College of Rheumatology) criteria were retrospectively studied by analysis the course and prognoses of disease. All examinees were between 25-60 years of age (Xb=49.9, SD=10.3) with disease duration between 1-27 years (Xbox=6.41, SD=6.47). Course of the disease with "remissions and exacerbations", progressive continual course and bad prognoses, were more presented in seropositive group ofpatients. Partial remission was more common in seronegative patients but according to serostatus and gender has not shown statistically significant difference. Duration of the disease was a specific prognostic sign for both subsets [(r=0.32, p<0.01) seronegative, (r=0.22, p<0.05) seropositive], while age was only a specific prognostic sign for the seropositive subset [(r=0.01, p>0.05) seronegative, (r=0.18, p<0.05) seropositive]. Seropositive and seronegative RA distinguish in course and prognostic feature, but not enough to differentiate them in two different forms of the disease. Regarding the sero-status, differences within sex, with some exceptions, are not relevant.

  17. How backyard poultry flocks influence the effort required to curtail avian influenza epidemics in commercial poultry flocks.

    PubMed

    Smith, G; Dunipace, S

    2011-06-01

    This paper summarizes the evidence that the contribution of backyard poultry flocks to the on-going transmission dynamics of an avian influenza epidemic in commercial flocks is modest at best. Nevertheless, while disease control strategies need not involve the backyard flocks, an analysis of the contribution of each element of the next generation matrix to the basic reproduction number indicates that models which ignores the contribution of backyard flocks in estimating the effort required of strategies focused one host type (e.g. commercial flocks only) necessarily underestimate the level of effort to an extent that may matter to policy makers.

  18. Seroprevalence and risk factors associated with within-flock transmission of Leptospira interrogans in transhumant farming systems in Mexico.

    PubMed

    Arteaga-Troncoso, G; Jiménez-Estrada, J M; Montes De Oca-Jimenez, R; López-Hurtado, M; Luna-Alvarez, M; Hernandez-Andrade, L; Moreno-Alfaro, A; Galan-Herrera, J F; Guerra-Infante, F M

    2015-10-01

    A number of recent reports emphasize the risk of zoonotic diseases and the high degree of prevalence of asymptomatic animals infected with Leptospira interrogans. This report sought to assess the prevalence of antibodies to certain serovars of L. interrogans, and to describe the association between seropositivity and risk factors associated with within-flock transmission in a mountainous region of Mexico. Overall seroprevalence to L. interrogans was 54·5% (95% confidence interval 48·3-60·7); the most frequent serovar was Icterohaemorrhagiae. The accumulation of placentas and fetuses at a site close to lambing paddocks can play a significant role as a risk factor for within-flock transmission of L. interrogans in transhumant farming systems in the municipality of Xalatlaco. The high prevalence of L. interrogans antibodies supports the hypothesis that natural foci of this zoonosis are present in sheep flocks in this area. These findings emphasize the need for planning and implementation of control programmes for ovine leptospirosis in Mexico and elsewhere.

  19. Role of projection in the control of bird flocks

    PubMed Central

    Pearce, Daniel J. G.; Miller, Adam M.; Rowlands, George; Turner, Matthew S.

    2014-01-01

    Swarming is a conspicuous behavioral trait observed in bird flocks, fish shoals, insect swarms, and mammal herds. It is thought to improve collective awareness and offer protection from predators. Many current models involve the hypothesis that information coordinating motion is exchanged among neighbors. We argue that such local interactions alone are insufficient to explain the organization of large flocks of birds and that the mechanism for the exchange of long-range information necessary to control their density remains unknown. We show that large flocks self-organize to the maximum density at which a typical individual still can see out of the flock in many directions. Such flocks are marginally opaque—an external observer also still can see a substantial fraction of sky through the flock. Although this seems intuitive, we show it need not be the case; flocks might easily be highly diffuse or entirely opaque. The emergence of marginal opacity strongly constrains how individuals interact with one another within large swarms. It also provides a mechanism for global interactions: an individual can respond to the projection of the flock that it sees. This provides for faster information transfer and hence rapid flock dynamics, another advantage over local models. From a behavioral perspective, it optimizes the information available to each bird while maintaining the protection of a dense, coherent flock. PMID:25002501

  20. Is the species flock concept operational? The Antarctic shelf case.

    PubMed

    Lecointre, Guillaume; Améziane, Nadia; Boisselier, Marie-Catherine; Bonillo, Céline; Busson, Frédéric; Causse, Romain; Chenuil, Anne; Couloux, Arnaud; Coutanceau, Jean-Pierre; Cruaud, Corinne; d'Acoz, Cédric d'Udekem; De Ridder, Chantal; Denys, Gael; Dettaï, Agnès; Duhamel, Guy; Eléaume, Marc; Féral, Jean-Pierre; Gallut, Cyril; Havermans, Charlotte; Held, Christoph; Hemery, Lenaïg; Lautrédou, Anne-Claire; Martin, Patrick; Ozouf-Costaz, Catherine; Pierrat, Benjamin; Pruvost, Patrice; Puillandre, Nicolas; Samadi, Sarah; Saucède, Thomas; Schubart, Christoph; David, Bruno

    2013-01-01

    There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars), echinoids (sea urchins) and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness) over the two ecological ones (ecological diversity and habitat dominance). We propose a new protocol which includes an iterative fine-tuning of the monophyly and endemicity criteria in order to discover unsuspected flocks. As a result nine « full » species flocks (fulfilling the five criteria) are briefly described. Eight other flocks fit the three historical criteria but need to be further investigated from the ecological point of view (here called "core flocks"). The approach also shows that some candidate taxonomic components are no species flocks at all. The present study contradicts the paradigm that marine species flocks are rare. The hypothesis according to which the Antarctic shelf acts as a species flocks generator is supported, and the approach indicates paths for further ecological studies and may serve as a starting point to investigate the processes leading to flock-like patterning of biodiversity.

  1. Is the Species Flock Concept Operational? The Antarctic Shelf Case

    PubMed Central

    Lecointre, Guillaume; Améziane, Nadia; Boisselier, Marie-Catherine; Bonillo, Céline; Busson, Frédéric; Causse, Romain; Chenuil, Anne; Couloux, Arnaud; Coutanceau, Jean-Pierre; Cruaud, Corinne; d'Acoz, Cédric d'Udekem; De Ridder, Chantal; Denys, Gael; Dettaï, Agnès; Duhamel, Guy; Eléaume, Marc; Féral, Jean-Pierre; Gallut, Cyril; Havermans, Charlotte; Held, Christoph; Hemery, Lenaïg; Lautrédou, Anne-Claire; Martin, Patrick; Ozouf-Costaz, Catherine; Pierrat, Benjamin; Pruvost, Patrice; Puillandre, Nicolas; Samadi, Sarah; Saucède, Thomas; Schubart, Christoph; David, Bruno

    2013-01-01

    There has been a significant body of literature on species flock definition but not so much about practical means to appraise them. We here apply the five criteria of Eastman and McCune for detecting species flocks in four taxonomic components of the benthic fauna of the Antarctic shelf: teleost fishes, crinoids (feather stars), echinoids (sea urchins) and crustacean arthropods. Practical limitations led us to prioritize the three historical criteria (endemicity, monophyly, species richness) over the two ecological ones (ecological diversity and habitat dominance). We propose a new protocol which includes an iterative fine-tuning of the monophyly and endemicity criteria in order to discover unsuspected flocks. As a result nine « full » species flocks (fulfilling the five criteria) are briefly described. Eight other flocks fit the three historical criteria but need to be further investigated from the ecological point of view (here called « core flocks »). The approach also shows that some candidate taxonomic components are no species flocks at all. The present study contradicts the paradigm that marine species flocks are rare. The hypothesis according to which the Antarctic shelf acts as a species flocks generator is supported, and the approach indicates paths for further ecological studies and may serve as a starting point to investigate the processes leading to flock-like patterning of biodiversity. PMID:23936311

  2. Temporal and Contextual Consistency of Leadership in Homing Pigeon Flocks

    PubMed Central

    Santos, Carlos D.; Neupert, Stefanie; Lipp, Hans-Peter; Wikelski, Martin; Dechmann, Dina K. N.

    2014-01-01

    Organized flight of homing pigeons (Columba livia) was previously shown to rely on simple leadership rules between flock mates, yet the stability of this social structuring over time and across different contexts remains unclear. We quantified the repeatability of leadership-based flock structures within a flight and across multiple flights conducted with the same animals. We compared two contexts of flock composition: flocks of birds of the same age and flight experience; and, flocks of birds of different ages and flight experience. All flocks displayed consistent leadership-based structures over time, showing that individuals have stable roles in the navigational decisions of the flock. However, flocks of balanced age and flight experience exhibited reduced leadership stability, indicating that these factors promote flock structuring. Our study empirically demonstrates that leadership and followership are consistent behaviours in homing pigeon flocks, but such consistency is affected by the heterogeneity of individual flight experiences and/or age. Similar evidence from other species suggests leadership as an important mechanism for coordinated motion in small groups of animals with strong social bonds. PMID:25054203

  3. Neuropsychological abnormalities in AIDS and asymptomatic HIV seropositive patients.

    PubMed Central

    Villa, G; Monteleone, D; Marra, C; Bartoli, A; Antinori, A; Pallavicini, F; Tamburrini, E; Izzi, I

    1993-01-01

    Neuropsychological and immunological parameters were studied in 36 AIDS patients with early disease and without clinical, laboratory, and neuroradiological signs of CNS impairment, and also in 33 asymptomatic HIV seropositive subjects. Many AIDS patients performed abnormally on timed psychomotor tasks, tasks involving sequencing and "set-shifting", and memory tasks stressing attention, learning, active retrieval, and monitoring of information. Asymptomatic HIV seropositive subjects as a group did not perform significantly worse than controls. However, on the basis of a cut off number of pathological performances on neuropsychological tasks, 52.8% of AIDS and 30.3% of asymptomatic HIV seropositive subjects had cognitive impairment, compared with 3.9% of HIV seronegative controls. Low values of CD4+ cells and of CD4+/CD8+ ratio and high titres of P-24 antigen in the blood prevailed among subjects with cognitive impairment, especially in the asymptomatic HIV seropositive group. PMID:8350104

  4. Flocking algorithm for autonomous flying robots.

    PubMed

    Virágh, Csaba; Vásárhelyi, Gábor; Tarcai, Norbert; Szörényi, Tamás; Somorjai, Gergő; Nepusz, Tamás; Vicsek, Tamás

    2014-06-01

    Animal swarms displaying a variety of typical flocking patterns would not exist without the underlying safe, optimal and stable dynamics of the individuals. The emergence of these universal patterns can be efficiently reconstructed with agent-based models. If we want to reproduce these patterns with artificial systems, such as autonomous aerial robots, agent-based models can also be used in their control algorithms. However, finding the proper algorithms and thus understanding the essential characteristics of the emergent collective behaviour requires thorough and realistic modeling of the robot and also the environment. In this paper, we first present an abstract mathematical model of an autonomous flying robot. The model takes into account several realistic features, such as time delay and locality of communication, inaccuracy of the on-board sensors and inertial effects. We present two decentralized control algorithms. One is based on a simple self-propelled flocking model of animal collective motion, the other is a collective target tracking algorithm. Both algorithms contain a viscous friction-like term, which aligns the velocities of neighbouring agents parallel to each other. We show that this term can be essential for reducing the inherent instabilities of such a noisy and delayed realistic system. We discuss simulation results on the stability of the control algorithms, and perform real experiments to show the applicability of the algorithms on a group of autonomous quadcopters. In our case, bio-inspiration works in two ways. On the one hand, the whole idea of trying to build and control a swarm of robots comes from the observation that birds tend to flock to optimize their behaviour as a group. On the other hand, by using a realistic simulation framework and studying the group behaviour of autonomous robots we can learn about the major factors influencing the flight of bird flocks.

  5. Model flocks in a steady vortical flow

    NASA Astrophysics Data System (ADS)

    Baggaley, A. W.

    2015-05-01

    We modify the standard Vicsek model to clearly distinguish between intrinsic noise due to imperfect alignment between organisms and extrinsic noise due to fluid motion. We then consider the effect of a steady vortical flow, the Taylor-Green vortex, on the dynamics of the flock, for various flow speeds, with a fixed intrinsic particle speed. We pay particular attention to the morphology of the flow, and quantify its filamentarity. Strikingly, above a critical flow speed there is a pronounced increase in the filamentarity of the flock, when compared to the zero-flow case. This is due to the fact that particles appear confined to areas of low vorticity; a familiar phenomena, commonly seen in the clustering of inertial particles in vortical flows. Hence, the cooperative motion of the particles gives them an effective inertia, which is seen to have a profound effect on the morphology of the flock, in the presence of external fluid motion. Finally, we investigate the angle between the flow and the particles direction of movement and find it follows a power-law distribution.

  6. Increasing trend of HIV seropositivity in a sexually transmitted diseases centre and epidemiology of HIV seropositive individuals.

    PubMed

    Ray, K; Ramesh, V; Karmakar, S N; Misra, R S

    1996-01-01

    11,539 STD clinic attenders and 20,897 antenatal clinic (ANC) attenders at a New Delhi hospital were screened for HIV antibodies by ELISA over a 3-year period. Results were confirmed by Western Blot. A low HIV seropositivity rate (1 per 1000) with an increasing trend in 1993 (4 per 1000) was observed in the STD attenders as against 0.1 per 1000 in the normal control populations. Most of the STD attenders including all the HIV seropositives had heterosexual contact with female sex workers. Both the HIV seropositive ANC attenders acquired the infection through blood transfusion. Thirteen of 23 HIV positive STD attenders had genital lesions, 5 having ulcerative and 8 having nonulcerative STD. Their clinical presentation did not differ from the HIV negative cases but the therapeutic response in 4 was altered. None had signs of symptoms of ARC/AIDS. Two out of 6 spouses and a 2-year-old child of HIV seropositive patients were seropositive. Increasing HIV seropositivity observed in this study reflects the changing situation in the country and highlights the importance of improvement of surveillance, early diagnosis and combined approaches to the management and control of STDs and HIV.

  7. Nylon flocked swab severely reduces Hexagon Obti sensibility.

    PubMed

    Frippiat, Christophe; De Roy, Gilbert; Fontaine, Louis-Marie; Dognaux, Sophie; Noel, Fabrice; Heudt, Laeticia; Lepot, Laurent

    2015-02-01

    Hexagon Obti immunological blood test and flocked swab are widely used in forensic laboratories. Nevertheless, up to now, no compatibility tests have been published between sampling with the ethylene oxide treated flocked swab and the Hexagon Obti blood detection strip. In this study, we investigated this compatibility. Our work shows that sampling with ethylene oxide treated flocked swab reduces by a factor of at least 100 the detection threshold of blood using the Hexagon Obti immunological test.

  8. CASCADE: Introducing AI into CBT.

    ERIC Educational Resources Information Center

    Hendley, R. J.; Jurascheck, N.

    1992-01-01

    Discusses changes in training requirements of commerce and industry in the United Kingdom and describes a project, CASCADE, that was developed to investigate and implement the introduction of artificial intelligence (AI) techniques into computer-based training (CBT). An overview of pilot projects in higher education settings is provided. (eight…

  9. Entropic effects in a nonequilibrium system: Flocks of birds

    NASA Astrophysics Data System (ADS)

    Castellana, Michele; Bialek, William; Cavagna, Andrea; Giardina, Irene

    2016-05-01

    When European starlings come together to form a flock, the distribution of their individual velocities narrows around the mean velocity of the flock. We argue that, in a broad class of models for the joint distribution of positions and velocities, this narrowing generates an entropic effect that opposes the cohesion of the flock. The strength of this effect depends strongly on the nature of the interactions among birds: If birds are coupled to a fixed number of neighbors, the entropic forces are weak, while if they couple to all other birds within a fixed distance, the entropic effects are sufficient to tear a flock apart.

  10. Task-Based Flocking Algorithm for Mobile Robot Cooperation

    NASA Astrophysics Data System (ADS)

    He, Hongsheng; Ge, Shuzhi Sam; Tong, Guofeng

    In this paper, one task-based flocking algorithm that coordinates a swarm of robots is presented and evaluated based on the standard simulation platform. Task-based flocking algorithm(TFA) is an effective framework for mobile robots cooperation. Flocking behaviors are integrated into the cooperation of the multi-robot system to organize a robot team to achieve a common goal. The goal of the whole team is obtained through the collaboration of the individual robot’s task. The flocking model is presented, and the flocking energy function is defined based on that model to analyze the stability of the flocking and the task switching criterion. The simulation study is conducted in a five-versus-five soccer game, where the each robot dynamically selects its task in accordance with status and the whole robot team behaves as a flocking. Through simulation results and experiments, it is proved that the task-based flocking algorithm can effectively coordinate and control the robot flock to achieve the goal.

  11. Neospora caninum seropositivity and reproductive risk factors in dogs.

    PubMed

    Robbe, Domenico; Passarelli, Alessandra; Gloria, Alessia; Di Cesare, Angela; Capelli, Gioia; Iorio, Raffaella; Traversa, Donato

    2016-05-01

    Despite the importance of Neospora caninum in veterinary medicine, knowledge of distribution of neosporosis in dog populations in some countries is still poor. The aims of the present study were to determine the occurrence of anti-N. caninum antibodies in one-hundred dogs living in cattle farms or dog breedings in central Italy and to evaluate the risk factors associated with seropositivity. The incidence of reproductive system disorders (e.g. infertility after first pregnancy) was also evaluated. Serum from breeding and farm dogs was tested to an indirect immunofluorescent antibody test (IFAT) to assess the occurrence of seropositivity. Management and individual data were collected and analysed both by linear and logistic multiple-regression models to find reliable predictors of seroprevalence and anti-N. caninum antibody level. The seropositivity for N. caninum was 32%. Dogs reared for breeding and presence of cattle on the farm were associated with seropositivity for N. caninum. Dogs living in the cattle farms showed a higher seropositivity for N. caninum (46%) compared with those living in dogs breeding (18%) (P < 0.05). The high presence of seropositive dogs in cattle farms of the study region demonstrates the potential risk of horizontal transmission of N. caninum between dogs and cattle, regardless the occurrence of reproductive system disorders or with infectious bovine tissues contact. Although the Neospora seropositivity in dog breedings may appear relatively low if compared with that found in dogs living with livestock, this infection, apparently underestimated, should be considered as a potential serious problem in canine medicine.

  12. Gut parasites in HIV-seropositive Zambian adults with diarrhoea.

    PubMed

    Khumalo-Ngwenya, B; Luo, N P; Chintu, C; Sunkutu, R; Sakala-Kazembe, F; Baboo, K S; Mathewson, J; Zumla, A

    1994-06-01

    We undertook a nine month study to define the frequency of parasitic infections in adults with diarrhoea presenting at the medical filter clinic and the Dermatovenereology clinic of the University Teaching Hospital in Lusaka, Zambia. A total of 287 patients with diarrhoea were enrolled in the study; 130 from the adult medicine filter clinic recruitment consulting room and 157 patients from the Dermatovenereology clinic. Of 130 patients from the adult filter clinic, 85 (65%) were HIV-seropositive and 45 (35%) were seronegative for HIV. Out of 85 HIV-seropositive patients, 58 (68.2%) had acute diarrhoea and 27 (31.8%) had chronic diarrhoea. Of the 45 HIV-seronegative patients, 35 (77%) had acute diarrhoea and 10 (23%) had chronic diarrhoea. All of the 157 patients recruited from the Dermatovenereology clinic were HIV-seropositive. Of these, 97 (62%) had chronic diarrhoea; 7 (4%) had acute diarrhoea, and 53 (34%) patients had no diarrhoea. The common parasites detected were Ascaris lumbricoides, hookworm, Entamoeba coli, and Cryptosporidium spp. Isospora belli and Cryptosporidium spp were seen only in the HIV-seropositive group. In the Dermatovenereology clinic there was a statistically significant difference between parasite detection rate of Isospora belli and Cryptosporidium spp in HIV-seropositive patients with chronic diarrhoea compared to asymptomatic HIV-seropositive individuals P < 0.01 and p = 0.05, respectively). A significant difference in detection rates of Entamoeba coli was seen between the HIV-seropositive group in the Dermatovenereology clinic [17 (10.8%) out of 157] compared to 1 (1.5%) out of 85 in the adult medicine filter clinic.(ABSTRACT TRUNCATED AT 250 WORDS)

  13. Interepidemic Rift Valley Fever Virus Seropositivity, Northeastern Kenya

    PubMed Central

    Muchiri, Eric M.; Ndzovu, Malik; Mwanje, Mariam T.; Muiruri, Samuel; Peters, Clarence J.; King, Charles H.

    2008-01-01

    Most outbreaks of Rift Valley fever (RVF) occur in remote locations after floods. To determine environmental risk factors and long-term sequelae of human RVF, we examined rates of previous Rift Valley fever virus (RVFV) exposure by age and location during an interepidemic period in 2006. In a randomized household cluster survey in 2 areas of Ijara District, Kenya, we examined 248 residents of 2 sublocations, Gumarey (village) and Sogan-Godud (town). Overall, the RVFV seropositivity rate was 13% according to immunoglobulin G ELISA; evidence of interepidemic RVFV transmission was detected. Increased seropositivity was found among older persons, those who were male, those who lived in the rural village (Gumarey), and those who had disposed of animal abortus. Rural Gumarey reported more mosquito and animal exposure than Sogan-Godud. Seropositive persons were more likely to have visual impairment and retinal lesions; other physical findings did not differ. PMID:18680647

  14. AIS Investigation of Agricultural Monocultures

    NASA Technical Reports Server (NTRS)

    Wood, B. L.; Wrigley, R. C.

    1985-01-01

    Airborne Imaging Spectrometer (AIS) data were acquired over an agricultural area in eastern San Joaquin County, California in July, 1984. Cover type information was subsequently collected for all fields along this flight line. The lack of detailed ground data on individual fields, however, limited AIS data analysis to a qualitative comparison of the spectral reflectance curves for a total of nine cover types. Based on this analysis, it appears that cover types with a positive slope in the 1550 to 1700 nm region have a higher spectral response in the 1200 to 1300 nm region compared to those cover types with a negative slope in the 1550 to 1700 nm region. Within cover type, spectral variability was also found to be greater than that between cover types. Given the lack of additional field data, the reason for these differences is a matter of speculation.

  15. Lighting during grow-out and Salmonella in broiler flocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Lighting is used during broiler grow-out to modify bird behavior to reach the goals of production. The protocols for lighting intensity vary. In a field project, we evaluated if the lighting protocol impacts the burden of Salmonella in grow-out broiler flocks. Conventional grow-out flocks reared ...

  16. Formal verification of AI software

    NASA Technical Reports Server (NTRS)

    Rushby, John; Whitehurst, R. Alan

    1989-01-01

    The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms.

  17. Stability of model flocks in a vortical flow

    NASA Astrophysics Data System (ADS)

    Baggaley, A. W.

    2016-06-01

    We investigate the stability of self-propelled particle flocks in the Taylor-Green vortex, a steady vortical flow. We consider a model in which particles align themselves to a combination of the orientation and the acceleration of particles within a critical radius. We identify two distinct regimes: If alignment with orientation is dominant, the particles tend to be expelled from regions of high vorticity. In contrast, if anticipation is dominant, the particles accumulate in areas of large vorticity. In both regimes, the relative order of the flock is reduced. However, we show that there can be a critical balance of the two effects that stabilizes the flock in the presence of external fluid forcing. This strategy could provide a mechanism for animal flocks to remain globally ordered in the presence of fluid forcing, and it may also have applications in the design of flocking autonomous drones and artificial microswimmers.

  18. The prevalence of Campylobacter amongst a free-range broiler breeder flock was primarily affected by flock age.

    PubMed

    Colles, Frances M; McCarthy, Noel D; Layton, Ruth; Maiden, Martin C J

    2011-01-01

    Campylobacter successfully colonizes broiler chickens, but little is known about the longer term natural history of colonization, since most flocks are slaughtered at an immature age. In this study, the prevalence and genetic diversity of Campylobacter colonizing a single free-range broiler breeder flock was investigated over the course of a year. The age of the flock was the most important factor in determining both the prevalence and diversity of Campylobacter over time. There was no correlation with season, temperature, the amount of rain and sunshine, or the dynamics of colonization amongst geographically and temporally matched broiler flocks. The higher prevalence rates coincided with the age at which broiler chickens are typically slaughtered, but then in the absence of bio-security or other intervention methods, and despite changes in flock management, the prevalence fell to significantly lower levels for the remainder of the study. The genetic diversity of Campylobacter increased as the flock aged, implying that genotypes were accumulated within the flock and may persist for a long time. A better understanding of the ecology of Campylobacter within commercial chicken flocks will allow the design of more effective farm-based interventions.

  19. Mapping AIS coverage for trusted surveillance

    NASA Astrophysics Data System (ADS)

    Lapinski, Anna-Liesa S.; Isenor, Anthony W.

    2010-10-01

    Automatic Identification System (AIS) is an unattended vessel reporting system developed for collision avoidance. Shipboard AIS equipment automatically broadcasts vessel positional data at regular intervals. The real-time position and identity data from a vessel is received by other vessels in the area thereby assisting with local navigation. As well, AIS broadcasts are beneficial to those concerned with coastal and harbour security. Land-based AIS receiving stations can also collect the AIS broadcasts. However, reception at the land station is dependent upon the ship's position relative to the receiving station. For AIS to be used as a trusted surveillance system, the characteristics of the AIS coverage area in the vicinity of the station (or stations) should be understood. This paper presents some results of a method being investigated at DRDC Atlantic, Canada) to map the AIS coverage characteristics of a dynamic AIS reception network. The method is shown to clearly distinguish AIS reception edges from those edges caused by vessel traffic patterns. The method can also be used to identify temporal changes in the coverage area, an important characteristic for local maritime security surveillance activities. Future research using the coverage estimate technique is also proposed to support surveillance activities.

  20. Birth, death, and flight: a theory of Malthusian flocks.

    PubMed

    Toner, John

    2012-02-24

    I study "Malthusian flocks": moving aggregates of self-propelled entities (e.g., organisms, cytoskeletal actin, microtubules in mitotic spindles) that reproduce and die. Long-ranged order (i.e., the existence of a nonzero average velocity (v(r,t))≠0) is possible in these systems, even in spatial dimension d=2. Their spatiotemporal scaling structure can be determined exactly in d=2; furthermore, they lack both the longitudinal sound waves and the giant number fluctuations found in immortal flocks. Number fluctuations are very persistent, and propagate along the direction of flock motion, but at a different speed.

  1. USACE AIS Transmit Technical Support Summary Report

    DTIC Science & Technology

    2014-09-01

    USACE AIS Transmit Technical Support Summary Report Distribution Statement A: Approved for public release; distribution is unlimited...September 2014 Report No. CD-D-09-15 USACE AIS Transmit Technical Support Summary Report ii UNCLAS//Public | CG-926 RDC | I. Gonin et al. Public...States Coast Guard Research & Development Center 1 Chelsea Street New London, CT 06320 USACE AIS Transmit Technical Support Summary Report

  2. Prevalence and clustering of louse infestation in Queensland sheep flocks.

    PubMed

    Ward, M P; Armstrong, R T

    1999-04-12

    Information provided by wool growers in Queensland, Australia between 1995 and 1997 was used to assess the prevalence and spatial distribution of louse (Bovicola ovis) infestation in sheep flocks. The estimated prevalence of louse-infested flocks was 40% (95% confidence interval, 35-46%). Although the prevalence of infestation was higher in western regions (41-50%) compared to the south region of Queensland (31%), the difference was not statistically significant (P > 0.05). Significant (P = 0.02) clustering of infested flocks was detected in the south region where two foci were apparent. We conclude that Queensland sheep flocks have a moderate prevalence of louse infestation, and that clustering of infestation is not strong. The control of lice is an industry-wide issue that needs to be addressed by most wool growers in Queensland.

  3. Obstacle and predator avoidance in a model for flocking

    NASA Astrophysics Data System (ADS)

    Mecholsky, Nicholas A.; Ott, Edward; Antonsen, Thomas M.

    2010-06-01

    The modeling and investigation of the dynamics and configurations of animal groups is a subject of growing attention. In this paper, we present a deterministic continuum model of flocking and use it to investigate the linearized response of an infinite extent flock to an obstacle or an attacking predator. We show that the steady-state flock response is in the form of density disturbances that resemble Mach cones whose configuration is determined by the anisotropic propagation of waves through the flock. We analytically and numerically test relations that predict the Mach wedge angles, disturbance heights, and wake widths. We find that these expressions are insensitive to many of the parameters of the model.

  4. [Ultrastructural study of placentas from HIV seropositive women].

    PubMed

    Villegas Castrejon, H; Carrillo Farga, J; Paredes, Y; Barrón, A; Karchmer, S

    1994-05-01

    Eleven placentas from seropositive women for HIV, were analyzed. In three cases the material came from first trimester abortions and the other eight from term pregnancies. In five cases retroviruses were identified, similar to HIV in the placental tissue. It was demonstrated for the first time the internalization of a retrovirus and its presence in the syncytiotrophoblast. It is communicated for the first time the presence of one cell in the placental stroma different to Hofbauer's by its granules type.

  5. Molecular genotyping of HCV infection in seropositive blood donor

    NASA Astrophysics Data System (ADS)

    Zarin, Siti Noraziah Abu; Ibrahim, Nazlina

    2013-11-01

    This study is to investigate the prevalence of hepatitis C virus infection in seropositive blood donor. RNA was extracted from 32 positive samples in National Blood Centre and Melaka Hospital. The core and NS5B sequences were obtained from 23 samples. Genotype 3a is most prevalent in this study followed by genotype 1a. Evidence of mixed-genotypes (3a and 1b) infections was found in 5 subjects.

  6. Prevalence of Coxiella burnetii in clinically healthy German sheep flocks

    PubMed Central

    2012-01-01

    Background Current epidemiological data on the situation of Coxiella (C.) burnetii infections in sheep are missing, making risk assessment and the implementation of counteractive measures difficult. Using the German state of Thuringia as a model example, the estimated sero-, and antigen prevalence of C. burnetii (10% and 25%, respectively) was assessed at flock level in 39/252 randomly selected clinically healthy sheep flocks with more than 100 ewes and unknown abortion rate. Results The CHECKIT™ Q-fever Test Kit identified 11 (28%) antibody positive herds, whereas real-time PCR revealed the presence of C. burnetii DNA in 2 (5%) of the flocks. Multiple-locus variable number of tandem repeats analysis of 9 isolates obtained from one flock revealed identical profiles. All isolates contained the plasmid QpH1. Conclusions The results demonstrate that C. burnetii is present in clinically inconspicuous sheep flocks and sporadic flare-ups do occur as the notifications to the German animal disease reporting system show. Although C. burnetii infections are not a primary veterinary concern due to the lack of significant clinical impact on animal health (with the exception of goats), the eminent zoonotic risk for humans should not be underestimated. Therefore, strategies combining the interests of public and veterinary public health should include monitoring of flocks, the identification and culling of shedders as well as the administration of protective vaccines. PMID:22429653

  7. Assembly of avian mixed-species flocks in Amazonia.

    PubMed Central

    Graves, G R; Gotelli, N J

    1993-01-01

    Diamond's "assembly rules" model posits that competitive interactions among species govern the composition of avifaunas. Although originally applied to islands in archipelagoes, this controversial set of hypotheses is difficult to test because islands differ in habitat and resource availability, colonization history, and stochastic effects. Permanent mixed-species flocks of Amazonian birds are a model system for testing the assembly rules hypothesis because flocks occur in relatively homogeneous tracts of rain forest and because resident species are potentially interactive from minute to minute. To analyze cooccurrence patterns of species in flocks, we used null models that incorporate realistic autecological colonization parameters. Potentially competing pairs of congeneric species with similar ecologies cooccur in flocks less often than expected by chance, resulting in perfect checkerboard distributions. Interactions among more distantly related species, however, appear to have little effect on the assembly of mixed-species flocks. Checkerboard distributions enhance local species diversity within habitats by generating different combinations of species in different flocks. This process may have contributed to the immense species richness of the Amazonian avifauna. PMID:8433996

  8. Flying in a flock comes at a cost in pigeons.

    PubMed

    Usherwood, James R; Stavrou, Marinos; Lowe, John C; Roskilly, Kyle; Wilson, Alan M

    2011-06-22

    Flying birds often form flocks, with social, navigational and anti-predator implications. Further, flying in a flock can result in aerodynamic benefits, thus reducing power requirements, as demonstrated by a reduction in heart rate and wingbeat frequency in pelicans flying in a V-formation. But how general is an aerodynamic power reduction due to group-flight? V-formation flocks are limited to moderately steady flight in relatively large birds, and may represent a special case. What are the aerodynamic consequences of flying in the more usual 'cluster' flock? Here we use data from innovative back-mounted Global Positioning System (GPS) and 6-degrees-of-freedom inertial sensors to show that pigeons (1) maintain powered, banked turns like aircraft, imposing dorsal accelerations of up to 2g, effectively doubling body weight and quadrupling induced power requirements; (2) increase flap frequency with increases in all conventional aerodynamic power requirements; and (3) increase flap frequency when flying near, particularly behind, other birds. Therefore, unlike V-formation pelicans, pigeons do not gain an aerodynamic advantage from flying in a flock. Indeed, the increased flap frequency, whether due to direct aerodynamic interactions or requirements for increased stability or control, suggests a considerable energetic cost to flight in a tight cluster flock.

  9. Switching hierarchical leadership mechanism in homing flight of pigeon flocks

    NASA Astrophysics Data System (ADS)

    Chen, Duxin; Vicsek, Tamás; Liu, Xiaolu; Zhou, Tao; Zhang, Hai-Tao

    2016-06-01

    To explore the fascinating inter-individual interaction mechanism governing the abundant biological grouping behaviors, more and more efforts have been devoted to collective motion investigation in recent years. Therein, bird flocking is one of the most intensively studied behaviors. A previous study (Nagy M. et al., Nature, 464 (2010) 890.) claims the existence of a well-defined hierarchical structure in pigeon flocks, which implies that a multi-layer leadership network leads to the occurrence of highly coordinated pigeon flock movements. However, in this study, by using high-resolution GPS data of homing flight of pigeon flocks, we reveal an explicit switching hierarchical mechanism underlying the group motions of pigeons. That is, a pigeon flock has a long-term leader for smooth moving trajectories, whereas the leading tenure passes to a temporary one upon sudden turns or zigzags. Therefore, the present observation helps explore more deeply into the principle of a huge volume of bird flocking dynamics. Meanwhile, from the engineering point of view, it may shed some light onto industrial multi-robot coordination and unmanned air vehicle formation control.

  10. Prevalence and differentiation of diseases in Maryland backyard flocks.

    PubMed

    Madsen, Jennifer M; Zimmermann, Nickolas G; Timmons, Jennifer; Tablante, Nathaniel L

    2013-09-01

    Several epidemiologic surveillance studies have implicated backyard flocks as a reservoir for poultry diseases; however, much debate still exists over the risk these small flocks pose. To evaluate this concern, the prevalence of Newcastle disease (ND), infectious laryngotracheitis (ILT), Mycoplasma gallisepticum (MG), and Salmonella was determined in 39 Maryland backyard flocks. Serum, tracheal, and cloacal swabs were randomly collected from 262 birds throughout nine counties in Maryland. Through PCR and ELISA analysis, disease prevalence and seroprevalence were determined in flocks, respectively, for the following: ND (0%, 23%); ILT (26%, 77%); MG (3%, 13%); and Salmonella (0%, not done). Vaccine status could not be accurately confirmed. Premise positives were further differentiated and identified by partial nucleotide sequencing. Screening of the 10 ILT premise positives showed that most were live attenuated vaccines: eight matched a tissue culture origin vaccine, one matched a chicken embryo origin (CEO) vaccine, and one was CEO related. The single MG-positive flock, also positive for the CEO-related sequence, was identified as the infectious S6 strain. The prevalence rates for these economically important poultry diseases ranged from none to relatively low, with the vast majority of sampled flocks presenting no clinical signs.

  11. Emergence of Anisotropy in Flock Simulations and Its Computational Analysis

    NASA Astrophysics Data System (ADS)

    Makiguchi, Motohiro; Inoue, Jun-Ichi

    2010-03-01

    In real flocks, it was revealed that the angular density of nearest neighbors shows a strong anisotropic structure of individuals by very recent extensive field studies [Ballerini et al, Proceedings of the National Academy of Sciences USA 105, pp. 1232-1237 (2008)]. In this paper, we show that this structure of anisotropy also emerges in an artificial flock simulation, namely, Boid simulation by Reynolds [C.W. Reynolds, Flocks, Herds, and Schools: A Distributed Behavioral Model, Computer Graphics, 21, pp. 25-34 (1987)]. To quantify the anisotropy, we evaluate a useful statistics, that is to say, the so-called γ-value which is defined as an inner product between the vector in the direction of the lowest angular density of flocks and the vector in the direction of the flock is moving. Our results concerning the emergence of the anisotropy through the γ-value might enable us to judge whether an optimal flock simulation seems to be realistic or not.

  12. Helicobacter pylori seropositivity in subjects with acute myocardial infarction.

    PubMed Central

    Rathbone, B.; Martin, D.; Stephens, J.; Thompson, J. R.; Samani, N. J.

    1996-01-01

    OBJECTIVE: To determine whether Helicobacter pylori infection increases the risk of myocardial infarction. DESIGN: Case-control study. SETTING: University teaching hospital. METHODS: Serological evidence of H pylori infection was determined in 342 consecutive patients with acute myocardial infarction admitted into the coronary care unit and in 236 population-based controls recruited from visitors to patients on medical and surgical wards. RESULTS: 206/342 (60.2%) of cases were H pylori positive compared with 132/236 (55.9%) of controls (P = 0.30). Age and sex stratified odds ratio for myocardial infarction associated with H pylori seropositivity was 1.05 (95% CI 0.7 to 1.53, P = 0.87) and this remained non-significant (P = 0.46) when other risk factors for ischaemic heart disease were taken into account using logistic regression analysis. H pylori seropositivity was not associated with several coronary risk factors in either cases or controls. CONCLUSION: No increase was found in H pylori seropositivity in subjects with acute myocardial infarction. This suggests that previous H pylori infection is not a major risk factor for acute myocardial infarction. Images PMID:8983674

  13. The control of Corynebacterium pseudotuberculosis infection in sheep flocks: a mathematical model of the impact of vaccination, serological testing, clinical examination and lancing of abscesses.

    PubMed

    O'Reilly, K M; Medley, G F; Green, L E

    2010-06-01

    A mathematical model of Corynebacterium pseudotuberculosis infection in sheep flocks was used to evaluate strategies for control and elimination of caseous lymphadenitis (CLA). Control strategies tested were vaccination, serological testing and removal of seropositives, clinical examination and removal of sheep with abscesses, lancing abscesses, and appropriate combinations. Three different infection rates with and without replacement of culled ewes were used to evaluate the control options. Controls were either implemented immediately after infection was detected in a flock or once CLA was at endemic equilibrium, and with different frequencies of examination or testing. Elimination of infection was defined as 99% confidence that no sheep were infected with C. pseudotuberculosis. The control strategies were evaluated by estimating the reduction in infection or probability of elimination and the number of ewes culled from the flock. Lancing abscesses reduced the prevalence of infection when the initial prevalence was <0.60, but elimination was unlikely. A vaccine efficacy of 0.79 or more led to elimination of infection from the flock, provided that the endemic prevalence of infection was <0.60. A combination of vaccination and clinical examination reduced the prevalence of infection at a faster rate than using clinical examination or vaccination alone where five rounds of clinical examination were done. Serological testing led to elimination of infection after five tests, but was highly dependent upon the diagnostic test sensitivity and specificity and management options used: a test sensitivity of 0.90 always resulted in elimination. A test specificity greater than 0.90 prevented removal of many false positive ewes and consequently prevented a large reduction in lamb production. Elimination was most likely using a serological test with sensitivity and specificity >0.90, but vaccination combined with clinical examination reduced infection rapidly with little impact

  14. JGOMAS: New Approach to AI Teaching

    ERIC Educational Resources Information Center

    Barella, A.; Valero, S.; Carrascosa, C.

    2009-01-01

    This paper presents a new environment for teaching practical work in AI subjects. The main purpose of this environment is to make AI techniques more appealing to students and to facilitate the use of the toolkits which are currently widely used in research and development. This new environment has a toolkit for developing and executing agents,…

  15. The Relevance of AI Research to CAI.

    ERIC Educational Resources Information Center

    Kearsley, Greg P.

    This article provides a tutorial introduction to Artificial Intelligence (AI) research for those involved in Computer Assisted Instruction (CAI). The general theme is that much of the current work in AI, particularly in the areas of natural language understanding systems, rule induction, programming languages, and socratic systems, has important…

  16. Anti-HIV seropositivity was related to HBsAg seropositivity among injecting drug users in Taiwan.

    PubMed

    Hsieh, Meng-Hsuan; Hsieh, Ming-Yen; Huang, Chung-Feng; Yeh, Ming-Lun; Wang, Shu-Chi; Yang, Jeng-Fu; Chang, Ko; Lin, Wei-Ru; Lin, Chun-Yu; Chen, Tun-Chieh; Huang, Jee-Fu; Dai, Chia-Yen; Tsai, Jih-Jin; Chuang, Wan-Long; Yu, Ming-Lung

    2016-02-01

    In Taiwan, the number of new cases of human immunodeficiency virus (HIV) infection via drug injection has been increasing since 2003. Due to HIV and hepatitis B virus (HBV) having similar transmission routes, HBV and HIV infections among injecting drug users (IDUs) has become an important public health issue. The aim of this study was explore the prevalence of HBV infection among IDUs with and without HIV infection, and examine whether HIV infection is associated with HBV infection among IDUs in Southern Taiwan. We enrolled 566 IDUs, including 87 anti-HBV positive IDUs and 479 anti-HBV negative IDUs, and also analyzed the results of liver function tests, HBV DNA, anti-HIV, HIV RNA, and CD4 cell count. The results showed that the prevalence of HBV infection among IDUs was 15.4%. The prevalence of hepatitis B surface antigen (HBsAg) was higher among individuals born before 1985 (15.9% vs. 4.0%), but this was not significant. Anti-HIV seropositivity was related to HBsAg seropositivity [odds ratio (OR) = 2.47, 95% confidence interval = 1.26-4.82, p = 0.008). Anti-HCV and anti-HIV were risk factors for abnormal alanine aminotransferase (ALT; OR = 2.11, 95% confidence interval = 1.005-4.42, p = 0.048 and OR = 1.47, 95% confidence interval = 1.02-2.10, p = 0.04, respectively), and HBsAg was not a factor related to abnormal ALT. In conclusion, the prevalence of HBV infection was similar in the general population and in IDUs, and due to anti-HIV seropositivity being significantly related to HBsAg seropositivity, HBV infection among IDUs is still important. We suggest that for IDUs, HBsAg should be monitored closely.

  17. Artificial intelligence. Fears of an AI pioneer.

    PubMed

    Russell, Stuart; Bohannon, John

    2015-07-17

    From the enraged robots in the 1920 play R.U.R. to the homicidal computer H.A.L. in 2001: A Space Odyssey, science fiction writers have embraced the dark side of artificial intelligence (AI) ever since the concept entered our collective imagination. Sluggish progress in AI research, especially during the “AI winter” of the 1970s and 1980s, made such worries seem far-fetched. But recent breakthroughs in machine learning and vast improvements in computational power have brought a flood of research funding— and fresh concerns about where AI may lead us. One researcher now speaking up is Stuart Russell, a computer scientist at the University of California, Berkeley, who with Peter Norvig, director of research at Google, wrote the premier AI textbook, Artificial Intelligence: A Modern Approach, now in its third edition. Last year, Russell joined the Centre for the Study of Existential Risk at Cambridge University in the United Kingdom as an AI expert focusing on “risks that could lead to human extinction.” Among his chief concerns, which he aired at an April meeting in Geneva, Switzerland, run by the United Nations, is the danger of putting military drones and weaponry under the full control of AI systems. This interview has been edited for clarity and brevity.

  18. A continuum model for flocking: Obstacle avoidance, equilibrium, and stability

    NASA Astrophysics Data System (ADS)

    Mecholsky, Nicholas Alexander

    The modeling and investigation of the dynamics and configurations of animal groups is a subject of growing attention. In this dissertation, we present a partial-differential-equation based continuum model of flocking and use it to investigate several properties of group dynamics and equilibrium. We analyze the reaction of a flock to an obstacle or an attacking predator. We show that the flock response is in the form of density disturbances that resemble Mach cones whose configuration is determined by the anisotropic propagation of waves through the flock. We investigate the effect of a flock 'pressure' and pairwise repulsion on an equilibrium density distribution. We investigate both linear and nonlinear pressures, look at the convergence to a 'cold' (T → 0) equilibrium solution, and find regions of parameter space where different models produce the same equilibrium. Finally, we analyze the stability of an equilibrium density distribution to long-wavelength perturbations. Analytic results for the stability of a constant density solution as well as stability regimes for constant density solutions to the equilibrium equations are presented.

  19. Size differences in migrant sandpiper flocks: ghosts in ephemeral guilds

    USGS Publications Warehouse

    Eldridge, J.L.; Johnson, D.H.

    1988-01-01

    Scolopacid sandpipers were studied from 1980 until 1984 during spring migration in North Dakota. Common species foraging together in mixed-species flocks differed in bill length most often by 20 to 30 percent (ratios from 1.2:1 to 1.3:1). Observed flocks were compared to computer generated flocks drawn from three source pools of Arctic-nesting sandpipers. The source pools included 51 migrant species from a global pool, 33 migrant species from a Western Hemisphere pool, and 13 species that migrated through North Dakota. The observed flocks formed randomly from the available species that used the North Dakota migration corridor but the North Dakota species were not a random selection from the Western Hemisphere and global pools of Arctic-nesting scolopacid sandpipers. In short, the ephemeral, mixed-species foraging flocks that we observed in North Dakota were random mixes from a non-random pool. The size-ratio distributions were consistent with the interpretation that use of this migration corridor by sandpipers has been influenced by some form of size-related selection such as competition.

  20. [Anti HTLV-I antibody titers in seropositive infected individuals].

    PubMed

    Galeno, H; Ramírez, E; Mora, J; Ojeda, M; Cartier, L

    1994-09-01

    The aim of this study was to determine anti HTLV-I antibody titers in seropositive symptomatic and asymptomatic infected subjects. One hundred seven infected subjects (47 with spastic paraparesis and 60 asymptomatic) were studied. HTLV-I antibodies were determined using indirect immunofluorescence in cells infected with the retrovirus. The mean titer was 1/234 in asymptomatic subjects and 1/2138 in symptomatic patients (p < 0.001). These results suggest an association between HTLV-I antibody titers and clinical stage of infected subjects.

  1. Distortion and destruction of colloidal flocks in disordered environments

    NASA Astrophysics Data System (ADS)

    Morin, Alexandre; Desreumaux, Nicolas; Caussin, Jean-Baptiste; Bartolo, Denis

    2017-01-01

    How do flocks, herds and swarms move through disordered environments? The answer to this question is crucial not only to animal groups in the wild, but also to effectively all applications of collective robotics and active materials composed of synthetic motile units. In stark contrast, aside from rare exceptions, our physical understanding of flocking has so far been limited to homogeneous media. Here we explain how collective motion survives in geometrical disorder. To do so, we combine experiments and analytical theory to examine motile colloids cruising between randomly positioned microfabricated obstacles. We elucidate how disorder and bending elasticity compete to channel the flow of polar flocks along sparse river networks akin those found beyond plastic depinning in driven condensed matter. Further increasing the disorder, we demonstrate that collective motion is suppressed in the form of a first-order phase transition generic to all polar active materials.

  2. Prevalence of salmonellae in broiler, layer and breeder flocks in Thailand.

    PubMed

    Sasipreeyajan, J; Jerngklinchan, J; Koowatananukul, C; Saitanu, K

    1996-05-01

    Salmonellae were detected in thirteen broiler flocks, 15 layer flocks and 7 parent breeder flocks in Thailand from October 1991 to August 1992. Salmonellae were isolated from samples of feed, drinking water, cloacal swabs, faeces and litter from all broiler and breeder flocks, and 87% of the layer flocks. From broiler flocks, litter samples were more frequently contaminated than other samples, while feed left over in the layer house and drinking water in the parent breeder house were the most commonly contaminated. Of the total of 1,488 samples examined from all flocks, salmonellae were recovered from samples of litter (42%), water in drinking troughs (36%), feed left over in the feed trays (28%), water in the main tanks (17%), cloacal swabs (13%) and stock feed (8%). The most common serovars associated with the broiler, layer and parent breeder flocks were Salmonella blockley, S. weltevreden and S. amsterdam respectively.

  3. Interpreting the flock algorithm from a statistical perspective.

    PubMed

    Anderson, Eric C; Barry, Patrick D

    2015-09-01

    We show that the algorithm in the program flock (Duchesne & Turgeon 2009) can be interpreted as an estimation procedure based on a model essentially identical to the structure (Pritchard et al. 2000) model with no admixture and without correlated allele frequency priors. Rather than using MCMC, the flock algorithm searches for the maximum a posteriori estimate of this structure model via a simulated annealing algorithm with a rapid cooling schedule (namely, the exponent on the objective function →∞). We demonstrate the similarities between the two programs in a two-step approach. First, to enable rapid batch processing of many simulated data sets, we modified the source code of structure to use the flock algorithm, producing the program flockture. With simulated data, we confirmed that results obtained with flock and flockture are very similar (though flockture is some 200 times faster). Second, we simulated multiple large data sets under varying levels of population differentiation for both microsatellite and SNP genotypes. We analysed them with flockture and structure and assessed each program on its ability to cluster individuals to their correct subpopulation. We show that flockture yields results similar to structure albeit with greater variability from run to run. flockture did perform better than structure when genotypes were composed of SNPs and differentiation was moderate (FST= 0.022-0.032). When differentiation was low, structure outperformed flockture for both marker types. On large data sets like those we simulated, it appears that flock's reliance on inference rules regarding its 'plateau record' is not helpful. Interpreting flock's algorithm as a special case of the model in structure should aid in understanding the program's output and behaviour.

  4. Legionella pneumophila Seropositivity-Associated Factors in Latvian Blood Donors

    PubMed Central

    Valciņa, Olga; Pūle, Daina; Lucenko, Irina; Krastiņa, Dita; Šteingolde, Žanete; Krūmiņa, Angelika; Bērziņš, Aivars

    2015-01-01

    Continuous environmental exposure of humans to Legionella may induce immune responses and generation of antibodies. The aim of this study was to investigate the seroprevalence of Legionella pneumophila serogroups (SG) 1–6 in the general healthy population and identify the associated host-related and environmental risk factors. L. pneumophila SG 1–6 seroprevalence among a total of 2007 blood samples collected from healthy donors was 4.8%. Seroprevalence was higher in women (5.9%) than men (3.3%) and in areas with a larger number of inhabitants, ranging from 3.5% in rural regions to 6.8% in the capital, Riga. Blood samples from inhabitants of apartment buildings tested positive for L. pneumophila in more cases (5.8%) compared to those from inhabitants of single-family homes (2.7%). Residents of buildings with a municipal hot water supply system were more likely to be seropositive for L. pneumophila (OR = 3.16, 95% CI 1.26–7.91). Previous episodes of fever were additionally identified as a risk factor (OR = 2.42, 95% CI 1.43–4.1). In conclusion, centralized hot water supply, female gender and previous episodes of fever were determined as the main factors associated with L. pneumophila seropositivity in our study population. PMID:26703696

  5. High Toxoplasma gondii Seropositivity among Brain Tumor Patients in Korea

    PubMed Central

    Jung, Bong-Kwang; Song, Hyemi; Kim, Min-Jae; Cho, Jaeeun; Shin, Eun-Hee; Chai, Jong-Yil

    2016-01-01

    Toxoplasma gondii is an intracellular protozoan that can modulate the environment of the infected host. An unfavorable environment modulated by T. gondii in the brain includes tumor microenvironment. Literature has suggested that T. gondii infection is associated with development of brain tumors. However, in Korea, epidemiological data regarding this correlation have been scarce. In this study, in order to investigate the relationship between T. gondii infection and brain tumor development, we investigated the seroprevalence of T. gondii among 93 confirmed brain tumor patients (various histological types, including meningioma and astrocytoma) in Korea using ELISA. The results revealed that T. gondii seropositivity among brain tumor patients (18.3%) was significantly (P<0.05) higher compared with that of healthy controls (8.6%). The seropositivity of brain tumor patients showed a significant age-tendency, i.e., higher in younger age group, compared with age-matched healthy controls (P<0.05). In conclusion, this study supports the close relationship between T. gondii infection and incidence of brain tumors. PMID:27180580

  6. Recalcitrance of bacterial vaginosis among HSV-2 seropositive women

    PubMed Central

    Stoner, Kevin A.; Reighard, Seth D.; Miguel, Rodolfo D. Vicetti; Landsittel, Douglas; Cosentino, Lisa A.; Kant, Jeffrey A.; Cherpes, Thomas L.

    2011-01-01

    Aim The multifactorial etiology of bacterial vaginosis (BV) impedes development of effective treatment and prevention strategies. Herein, we evaluated the effects of herpes simplex virus type 2 (HSV-2), a suspected BV risk factor, on vaginal flora composition. Methods Relationships between HSV-2 infection and BV were prospectively explored among 12 HSV-2 seropositive women with asymptomatic BV that were asked to collect daily vaginal swab specimens for Gram stain analysis of vaginal flora and determination of HSV-2 shedding frequencies during the 1 month before and after metronidazole therapy. Results Unlike prior longitudinal studies that reported rapid fluctuations in vaginal flora composition and frequent episodes of spontaneously resolving BV, we found that 99.4% (310/312) of vaginal smears collected before initiation of metronidazole were consistent with a diagnosis of BV. Effectiveness of metronidazole therapy was also much lower than previously reported in studies not restricting enrollment to HSV-2 seropositive women; we observed a BV recurrence rate of 89% in the first month after completion of therapy while the median time to this recurrence occurred only 14 days after treatment. Conclusions Our study demonstrates BV recalcitrance among HSV-2 infected women and provides additional evidence for a linkage between this chronic viral infection and abnormal vaginal flora. Additional work will be needed to define mechanisms responsible for this relationship and to determine if vaginal flora health of HSV-2 infected women is improved by medications that suppress HSV-2 shedding. PMID:22136755

  7. Mapping Fishing Effort through AIS Data

    PubMed Central

    Natale, Fabrizio; Gibin, Maurizio; Alessandrini, Alfredo; Vespe, Michele; Paulrud, Anton

    2015-01-01

    Several research initiatives have been undertaken to map fishing effort at high spatial resolution using the Vessel Monitoring System (VMS). An alternative to the VMS is represented by the Automatic Identification System (AIS), which in the EU became compulsory in May 2014 for all fishing vessels of length above 15 meters. The aim of this paper is to assess the uptake of the AIS in the EU fishing fleet and the feasibility of producing a map of fishing effort with high spatial and temporal resolution at European scale. After analysing a large AIS dataset for the period January-August 2014 and covering most of the EU waters, we show that AIS was adopted by around 75% of EU fishing vessels above 15 meters of length. Using the Swedish fleet as a case study, we developed a method to identify fishing activity based on the analysis of individual vessels’ speed profiles and produce a high resolution map of fishing effort based on AIS data. The method was validated using detailed logbook data and proved to be sufficiently accurate and computationally efficient to identify fishing grounds and effort in the case of trawlers, which represent the largest portion of the EU fishing fleet above 15 meters of length. Issues still to be addressed before extending the exercise to the entire EU fleet are the assessment of coverage levels of the AIS data for all EU waters and the identification of fishing activity in the case of vessels other than trawlers. PMID:26098430

  8. 9 CFR 145.33 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... a flock qualifying by means of a blood test shall be tested within the past 12 months, except that the retesting of a participating flock which is retained for more than 12 months shall be conducted a... have existed in hatchery supply flocks within the State during the preceding 12 months. (c) U.S....

  9. 9 CFR 145.33 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... a flock qualifying by means of a blood test shall be tested within the past 12 months, except that the retesting of a participating flock which is retained for more than 12 months shall be conducted a... have existed in hatchery supply flocks within the State during the preceding 12 months. (c) U.S....

  10. Status of AIS Frequencies Nationally and Internationally: Improving Satellite Detection of AIS

    DTIC Science & Technology

    2008-09-04

    International Telecommunications Union? • ITU 2007 World Radio Conference – Authorized AIS 1 & AIS 2 as satellite uplink frequencies, on secondary basis...Collision Rate “AIS as is” How do results correlate with predictions? Satellite Detection Statistics with Correlation Processing – ITU -R Rep M.2084 (JSC...Status of AIS Frequencies  Nationally and  Internationally: Improving  satellite  detection of AIS CG‐622 | Joe Hersey Chief, Spectrum Mgt Div USCG

  11. Modeling the flocking propensity of passerine birds in two Neotropical habitats.

    PubMed

    Pomara, Lars Y; Cooper, Robert J; Petit, Lisa J

    2007-08-01

    We examined the importance of mixed-species flock abundance, individual bird home range size, foraging height, and foraging patch characteristics in predicting the propensity for five Neotropical passerine bird species (Slaty Antwren, Myrmotherula schisticolor; Golden-crowned Warbler, Basileuterus culicivorus; Slate-throated Redstart, Myioborus miniatus; Wilson's Warbler, Wilsonia pusilla; and Black-and-white Warbler, Mniotilta varia) to forage within flocks, rather than solitarily. We used study plots in primary mid-elevation forest and in shade coffee fields in western Panama. We expected that all species would spend as much time as possible flocking, but that the social and environmental factors listed above would limit compatibility between flock movements and individual bird movements, explaining variability in flocking propensity both within and among species. Flocking propensity was well predicted by home range size and flock abundance together, for four of the five species. While flock abundance was uniform across plots, home range sizes varied among species and plots, so that home range size appeared to be the principle factor limiting flocking propensity. Estimates of flock abundance were still required, however, for calculating flocking propensity values. Foraging height and patch characteristics slightly improved predictive ability for the remaining species, M. miniatus. In general, individual birds tended to join flocks whenever one was available inside their home range, regardless of a flock's specific location within the home range. Flocking propensities of individual species were lower in shade coffee fields than in forests, and probably vary across landscapes with variations in habitat. This variability affects the stability and species composition of flocks, and may affect survival rates of individual species.

  12. Speed Determines Leadership and Leadership Determines Learning during Pigeon Flocking.

    PubMed

    Pettit, Benjamin; Ákos, Zsuzsa; Vicsek, Tamás; Biro, Dora

    2015-12-07

    A key question in collective behavior is how individual differences structure animal groups, affect the flow of information, and give some group members greater weight in decisions. Depending on what factors contribute to leadership, despotic decisions could either improve decision accuracy or interfere with swarm intelligence. The mechanisms behind leadership are therefore important for understanding its functional significance. In this study, we compared pigeons' relative influence over flock direction to their solo flight characteristics. A pigeon's degree of leadership was predicted by its ground speeds from earlier solo flights, but not by the straightness of its previous solo route. By testing the birds individually after a series of flock flights, we found that leaders had learned straighter homing routes than followers, as we would expect if followers attended less to the landscape and more to conspecifics. We repeated the experiment from three homing sites using multiple independent flocks and found individual consistency in leadership and speed. Our results suggest that the leadership hierarchies observed in previous studies could arise from differences in the birds' typical speeds. Rather than reflecting social preferences that optimize group decisions, leadership may be an inevitable consequence of heterogeneous flight characteristics within self-organized flocks. We also found that leaders learn faster and become better navigators, even if leadership is not initially due to navigational ability. The roles that individuals fall into during collective motion might therefore have far-reaching effects on how they learn about the environment and use social information.

  13. How many dissenters does it take to disorder a flock?

    NASA Astrophysics Data System (ADS)

    Yllanes, David; Marchetti, M. Cristina

    Minimal models of active particles have had much success in the study of flocking behavior. Typically one considers a system of self-propelled particles with noisy aligning interactions. By varying the density of the system or the intensity of the noise one can switch between a disordered phase where the particles move randomly and independently and a flocking state where the velocities of the particles are aligned. In this work we consider what happens if a fraction p of the particles does not experience the aligning interaction. This is an interesting problem from a statistical mechanics point of view, with applications to collective behavior of living systems, where not all the members of a community (a flock of birds, a herd of sheep, etc.) behave in the same way. By carrying out extensive molecular dynamics simulations we show that even a very small fraction of such ''individualistic'' particles can have a dramatic effect on the whole system and, indeed, that the flocking can be destroyed for a very low value of p. We acknowledge support from NSF-DMR-305184 and the Syracuse Soft Matter Program.

  14. Two-level leader-follower organization in pigeon flocks

    NASA Astrophysics Data System (ADS)

    Chen, Zhiyong; Zhang, Hai-Tao; Chen, Xi; Chen, Duxin; Zhou, Tao

    2015-10-01

    The most attractive trait of collective animal behavior is the emergence of highly ordered structures (Cavagna A., Giardina I. and Ginelli F., Phys. Rev. Lett., 110 (2013) 168107). It has been conjectured that the interaction mechanism in pigeon flock dynamics follows a hierarchical leader-follower influential network (Nagy M., Ákos Z., Biro D. and Vicsek T., Nature, 464 (2010) 890). In this paper, a new observation is reported that shows that pigeon flocks actually adopt a much simpler two-level interactive network composed of one leader and some followers. By statistically analyzing the same experimental dataset, we show that for a certain period of time a sole leader determines the motion of the flock while the remaining birds are all followers directly copying the leader's direction with specific time delays. This simple two-level despotic organization is expected to save both motional energy and communication cost, while retaining agility and robustness of the whole group. From an evolutionary perspective, our results suggest that a two-level organization of group flight may be more efficient than a multilevel topology for small pigeon flocks.

  15. The art in getting flocks and herds to flerds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Flerds (small ruminants that consistently stay near cattle under free-ranging conditions) offer four distinct advantages over stocking simply flocks and herds to carry out mixed species stocking. One of the main advantages flerds offer is added protection from canine predation, reduced time in loca...

  16. Integrating UAS Flocking Operations with Formation Drag Reduction

    DTIC Science & Technology

    2014-03-01

    S., and Carl A. Shollenberger. "Formation Flight of Birds." Science, 1970: 1003-1005. Marks, Paul. "Aviation - The Shape of Wings to Come." New...34Autonomous Flight Control and Software Literatire Review." Presentation, 2005. Nathan, Andre , and Valmir C. Barbosa. "V-like Formations in Flocks of

  17. Human Trypanosoma cruzi infection and seropositivity in dogs, Mexico.

    PubMed

    Estrada-Franco, Jose G; Bhatia, Vandanajay; Diaz-Albiter, Hector; Ochoa-Garcia, Laucel; Barbabosa, Alberto; Vazquez-Chagoyan, Juan C; Martinez-Perez, Miguel A; Guzman-Bracho, Carmen; Garg, Nisha

    2006-04-01

    We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas.

  18. Human Trypanosoma cruzi Infection and Seropositivity in Dogs, Mexico

    PubMed Central

    Estrada-Franco, Jose G.; Bhatia, Vandanajay; Diaz-Albiter, Hector; Ochoa-Garcia, Laucel; Barbabosa, Alberto; Vazquez-Chagoyan, Juan C.; Martinez-Perez, Miguel A.; Guzman-Bracho, Carmen

    2006-01-01

    We used 5 diagnostic tests in a cross-sectional investigation of the prevalence of Trypanosoma cruzi in Tejupilco municipality, State of Mexico, Mexico. Our findings showed a substantial prevalence of immunoglobulin G (IgG) and IgM antibodies to T. cruzi in human (n = 293, IgG 2.05%, IgM 5.5%, both 7.1%) and dog (n = 114, IgG 15.8%, IgM 11.4%, both 21%) populations. We also found antibodies to T. cruzi (n = 80, IgG 10%, IgM 15%, both 17.5%) in dogs from Toluca, an area previously considered free of T. cruzi. Our data demonstrate the need for active epidemiologic surveillance programs in these regions. A direct correlation (r2 = 0.955) of seropositivity between humans and dogs suggests that seroanalysis in dogs may help identify the human prevalence of T. cruzi infection in these areas. PMID:16704811

  19. Organic Turkey Flocks: A Reservoir of Streptococcus gallolyticus subspecies gallolyticus

    PubMed Central

    Schulz, Jochen; Dumke, Jessika; Hinse, Dennis; Dreier, Jens; Habig, Christin; Kemper, Nicole

    2015-01-01

    Streptococcus gallolyticus subspecies gallolyticus (S. gallolyticus) can colonise the gastrointestinal tract of humans and animals and is known to cause similar infections in both humans and animals. Data about the spread or prevalence in farm animals are missing. In this study, Trypton Soya Agar was modified to a selective medium enabling the isolation and quantification of S. gallolyticus from faecal samples. The bacterium was observed in 82 out of 91 faecal samples obtained from 18 different organic turkey flocks. The prevalence of shedding birds was estimated by the number of positive fresh droppings and reached up to 100% on most farms. Furthermore, for the first time S. gallolyticus was quantified in faeces from poultry flocks. The median of colony forming units (CFU) per gramme faeces was 3.6 x 105CFU/g. Typing of one isolate from each positive faecal sample by multilocus sequence typing delivered 24 sequence types (STs). Most of the isolates belonged to the clonal complex CC58. The same STs of this complex were detected in up to six different flocks. Partly, these flocks were located in various regions and stocked with varying breeding lines. Regarding the biochemical profiles of the same STs from different farms, the results did not contradict a spread of specific STs in the organic turkey production. Moreover, checking the pubMLST database revealed that STs found in this study were also found in other animal species and in humans. The high detection rate and the number of S. gallolyticus in turkey faeces indicate that this bacterium probably belongs to the common microbiota of the gastrointestinal tract of turkeys from organic flocks. Furthermore, the findings of this study support the suggestion of a possible interspecies transmission. PMID:26657757

  20. The respiratory effects of occupational polypropylene flock exposure.

    PubMed

    Atis, S; Tutluoglu, B; Levent, E; Ozturk, C; Tunaci, A; Sahin, K; Saral, A; Oktay, I; Kanik, A; Nemery, B

    2005-01-01

    The present study evaluated the possible effects of exposure to polypropylene flock on respiratory health and serum cytokines in a cross-sectional study of workers from a plant in Turkey. A total of 50 polypropylene flocking workers were compared to a control group of 45 subjects. All subjects filled out a respiratory questionnaire and underwent a physical examination, a chest radiograph and pulmonary function testing, including single breath carbon monoxide diffusing capacity (DL,CO). Serum interleukin-8 (IL-8) and tumour necrosis factor-alpha (TNF-alpha) were measured. Additionally, high resolution computed tomography (HRCT) of the chest was performed in 10 exposed workers with low DL,CO. Work-related respiratory symptoms were reported in 26% of the exposed subjects and in 13.3% of the controls. Logistic regression analysis showed that the risk of respiratory symptoms increased 3.6 fold in polypropylene flocking workers when compared to controls. Parameters of the study group, including per cent predicted: forced vital capacity, forced expiratory volume in one second, forced mid-expiratory flow 25-75% and DL,CO, were significantly lower than in controls. Multivariate analyses showed that being a polypropylene flocking worker was a predictive factor for impairment of pulmonary function. Serum IL-8 and TNF-alpha levels were increased in the study group compared with the controls. HRCT revealed peribronchial thickening and diffuse ground glass attenuation in some subjects. The present study suggests the presence of subtle or the beginning of interstitial lung disease in these polypropylene flocking workers.

  1. Organic Turkey Flocks: A Reservoir of Streptococcus gallolyticus subspecies gallolyticus.

    PubMed

    Schulz, Jochen; Dumke, Jessika; Hinse, Dennis; Dreier, Jens; Habig, Christin; Kemper, Nicole

    2015-01-01

    Streptococcus gallolyticus subspecies gallolyticus (S. gallolyticus) can colonise the gastrointestinal tract of humans and animals and is known to cause similar infections in both humans and animals. Data about the spread or prevalence in farm animals are missing. In this study, Trypton Soya Agar was modified to a selective medium enabling the isolation and quantification of S. gallolyticus from faecal samples. The bacterium was observed in 82 out of 91 faecal samples obtained from 18 different organic turkey flocks. The prevalence of shedding birds was estimated by the number of positive fresh droppings and reached up to 100% on most farms. Furthermore, for the first time S. gallolyticus was quantified in faeces from poultry flocks. The median of colony forming units (CFU) per gramme faeces was 3.6 x 10(5) CFU/g. Typing of one isolate from each positive faecal sample by multilocus sequence typing delivered 24 sequence types (STs). Most of the isolates belonged to the clonal complex CC58. The same STs of this complex were detected in up to six different flocks. Partly, these flocks were located in various regions and stocked with varying breeding lines. Regarding the biochemical profiles of the same STs from different farms, the results did not contradict a spread of specific STs in the organic turkey production. Moreover, checking the pubMLST database revealed that STs found in this study were also found in other animal species and in humans. The high detection rate and the number of S. gallolyticus in turkey faeces indicate that this bacterium probably belongs to the common microbiota of the gastrointestinal tract of turkeys from organic flocks. Furthermore, the findings of this study support the suggestion of a possible interspecies transmission.

  2. Cyclic and Coherent States in Flocks with Topological Distance

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Biplab; Bhattacharya, Kunal; Manna, Subhrangshu

    A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first n neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. One of the two most prominent states is the `single sink state' where the entire flock travels along the same direction maintaining perfect cohesion and coherence. The other state is the `cyclic state' where every individual agent executes a uniform circular motion, and the correlation among the agents guarantees that the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. We have studied another limiting situation when refreshing rate of the interaction zone is the fastest. In this case the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic motion to a diffusive motion. Expectedly the crossover time is dependent on the strength of the noise eta and diverges as eta -> 0. An even more simpler version of this model has been studied by suppressing the translational degrees of freedom of the agents but retaining their angular motion. Here agents are the spins, placed at the sites of a square lattice with periodic boundary condition. Every spin interacts with its n = 2, 3 or 4 nearest neighbors. In the stationary state the entire spin pattern moves as a whole when interactions are anisotropic with n = 2 and 3; but it is completely frozen when the interaction is isotropic with n=4. These spin configu

  3. Cyclic and Coherent States in Flocks with Topological Distance

    NASA Astrophysics Data System (ADS)

    Bhattacherjee, Biplab; Bhattacharya, Kunal; Manna, Subhrangshu

    2014-01-01

    A simple model of the two dimensional collective motion of a group of mobile agents have been studied. Like birds, these agents travel in open free space where each of them interacts with the first n neighbors determined by the topological distance with a free boundary condition. Using the same prescription for interactions used in the Vicsek model with scalar noise it has been observed that the flock, in absence of the noise, arrives at a number of interesting stationary states. One of the two most prominent states is the `single sink state' where the entire flock travels along the same direction maintaining perfect cohesion and coherence. The other state is the `cyclic state' where every individual agent executes a uniform circular motion, and the correlation among the agents guarantees that the entire flock executes a pulsating dynamics i.e., expands and contracts periodically between a minimum and a maximum size of the flock. We have studied another limiting situation when refreshing rate of the interaction zone is the fastest. In this case the entire flock gets fragmented into smaller clusters of different sizes. On introduction of scalar noise a crossover is observed when the agents cross over from a ballistic motion to a diffusive motion. Expectedly the crossover time is dependent on the strength of the noise η and diverges as η → 0. An even more simpler version of this model has been studied by suppressing the translational degrees of freedom of the agents but retaining their angular motion. Here agents are the spins, placed at the sites of a square lattice with periodic boundary condition. Every spin interacts with its n = 2, 3 or 4 nearest neighbors. In the stationary state the entire spin pattern moves as a whole when interactions are anisotropic with n = 2 and 3; but it is completely frozen when the interaction is isotropic with n=4$. These spin configu

  4. Enhanced AIS receiver design for satellite reception

    NASA Astrophysics Data System (ADS)

    Clazzer, Federico; Lázaro, Francisco; Plass, Simon

    2016-12-01

    The possibility to detect Automatic Identification System (AIS) messages from low earth orbit (LEO) satellites paves the road for a plurality of new and unexplored services. Besides worldwide tracking of vessels, maritime traffic monitoring, analysis of vessel routes employing big data, and oceans monitoring are just few of the fields, where satellite-aided AIS is beneficial. Designed for ship-to-ship communication and collision avoidance, AIS satellite reception performs poorly in regions with a high density of vessels. This calls for the development of advanced satellite AIS receivers able to improve the decoding capabilities. In this context, our contribution focuses on the introduction of a new enhanced AIS receiver design and its performance evaluation. The enhanced receiver makes use of a coherent receiver for the low signal-to-noise ratio (SNR) region, while for medium to high SNRs, a differential Viterbi receiver is used. Additional novelty of our work is in the exploitation of previously decoded packets from one vessel that is still under the LEO reception range, to improve the vessel detection probability. The assessment of the performance against a common receiver is done making the use of a simple and tight model of the medium access (MAC) layer and the multi-packet reception (MPR) matrix for physical layer (PHY) representation. Performance results show the benefits of such enhanced receiver, especially when it is bundled with successive interference cancellation (SIC).

  5. Investigation of a Simple Model for Within-Flock Transmission of Scrapie

    PubMed Central

    Hagenaars, Thomas J.; Windig, Jack J.

    2015-01-01

    Genetic control programs for scrapie in sheep build on solid knowledge of how susceptibility to scrapie is modulated by the prion protein genotype at the level of an individual sheep. In order to satisfactorily analyze the effectivity of control programs at the population level, insight is needed at the flock level, i.e., how the grouping of sheep in flocks affects the population-level transmission risk. In particular, one would like to understand how this risk is affected by between-flock differences in genotype frequency distribution. A first step is to model the scrapie transmission risk within a flock as a function of the flock genotype profile. Here we do so by estimating parameters for a model of within-flock transmission using genotyping data on Dutch flocks affected by scrapie. We show that the data are consistent with a relatively simple transmission model assuming horizontal transmission and homogeneous mixing between animals. The model expresses the basic reproduction number for within-flock scrapie as a weighted average of genotype-specific susceptibilities, multiplied by a single overall transmission parameter. The value of the overall transmission parameter may vary between flocks to account for random between-flock variation in non-genetic determinants such as management practice. Here we provide an estimate of its mean value and variation for Dutch flocks. PMID:26426269

  6. Investigation of a Simple Model for Within-Flock Transmission of Scrapie.

    PubMed

    Hagenaars, Thomas J; Windig, Jack J

    2015-01-01

    Genetic control programs for scrapie in sheep build on solid knowledge of how susceptibility to scrapie is modulated by the prion protein genotype at the level of an individual sheep. In order to satisfactorily analyze the effectivity of control programs at the population level, insight is needed at the flock level, i.e., how the grouping of sheep in flocks affects the population-level transmission risk. In particular, one would like to understand how this risk is affected by between-flock differences in genotype frequency distribution. A first step is to model the scrapie transmission risk within a flock as a function of the flock genotype profile. Here we do so by estimating parameters for a model of within-flock transmission using genotyping data on Dutch flocks affected by scrapie. We show that the data are consistent with a relatively simple transmission model assuming horizontal transmission and homogeneous mixing between animals. The model expresses the basic reproduction number for within-flock scrapie as a weighted average of genotype-specific susceptibilities, multiplied by a single overall transmission parameter. The value of the overall transmission parameter may vary between flocks to account for random between-flock variation in non-genetic determinants such as management practice. Here we provide an estimate of its mean value and variation for Dutch flocks.

  7. The prevalence of Salmonella enteritidis and other Salmonella sp. among Canadian registered commercial chicken broiler flocks.

    PubMed Central

    Poppe, C.; Irwin, R. J.; Messier, S.; Finley, G. G.; Oggel, J.

    1991-01-01

    A nation-wide survey was conducted to estimate the prevalence of Salmonella enteritidis and other salmonellas among Canadian commercial broiler flocks. Environmental (litter and/or water) samples from 226 of 294 (76.9%) randomly selected flocks were contaminated with salmonellas. Litter samples were more often contaminated with salmonellas than water samples (47.4 v. 12.3%). Fifty different salmonella serovars were isolated. The most prevalent serovars were S. hadar, S. infantis, and S. schwarzengrund; they were isolated from samples of 98/294 (33.3%), 26/294 (8.8%), and 21/294 (7.1%) flocks, respectively. Feed samples of 39/290 (13.4%) flocks were contaminated with salmonellas. Salmonella enteritidis was isolated from the environmental samples of 9/294 (3.1%) flocks. Salmonella enteritidis phage type (PT) 8 was isolated from seven flocks, and PT 13a from two flocks. PMID:1879484

  8. [Factors associated with Brucella canis seropositivity in kennels of two regions of Antioquia, Colombia].

    PubMed

    Castrillón-Salazar, Laura; Giraldo-Echeverri, Carlos Andrés; Sánchez-Jiménez, Miryan Margot; Olivera-Angel, Martha

    2013-10-01

    The objectives of this study were to determine Brucella canis seroprevalence in dogs and in humans living near kennels and to explore risk factors associated with seropositivity. Twenty kennels were included in a serological survey with RSAT-2ME, and samples were collected from 428 dogs and 91 humans. An interview was applied to determine risk factors, and the data were analyzed using logistic regression. Seroprevalence was 15% in dogs and 9% in humans. Factors associated with current canine seropositivity were: history of canine seropositivity, non-culling of seropositive dogs, history of abortion, poor hygiene and personal protection during reproductive service, and unsafe procedures during care for abortions. Protective factors included: rural location of kennels, ease of cleaning kennels, pre-mating RSAT-2ME, and safe procedures during care for delivery. Factors associated with seropositive status in humans were: kennels located in Valle de Aburrá and urban location.

  9. High frequency of chlamydial co-infections in clinically healthy sheep flocks

    PubMed Central

    2011-01-01

    Background The epidemiological situation of ovine chlamydial infections in continental Europe, especially Germany is poorly characterised. Using the German state of Thuringia as a model example, the chlamydial sero- and antigen prevalence was estimated in thirty-two randomly selected sheep flocks with an average abortion rate lower than 1%. Seven vaccinated flocks were reviewed separately. Results A wide range of samples from 32 flocks were examined. Assumption of a seroprevalence of 10% (CI 95%) at flock level, revealed that 94% of the tested flocks were serologically positive with ongoing infection (i.e. animals with seroconversion) in nearly half (47%) of the flocks. On the basis of an estimated 25% antigen prevalence (CI 95%), PCR and DNA microarray testing, together with sequencing revealed the presence of chlamydiae in 78% of the flocks. The species most frequently found was Chlamydophila (C.) abortus (50%) followed by C. pecorum (47%) and C. psittaci genotype A (25%). Mixed infections occurred in 25% of the tested flocks. Samples obtained from the vaccinated flocks revealed the presence of C. abortus field samples in 4/7 flocks. C. pecorum was isolated from 2/7 flocks and the presence of seroconversion was determined in 3/7 flocks. Conclusions The results imply that chlamydial infections occur frequently in German sheep flocks, even in the absence of elevated abortion rates. The fact that C. pecorum and the potentially zoonotic C. psittaci were found alongside the classical abortifacient agent C. abortus, raise questions about the significance of this reservoir for animal and human health and underline the necessity for regular monitoring. Further studies are needed to identify the possible role of C. psittaci infections in sheep. PMID:21679409

  10. Spatio-temporal structure of hooded gull flocks.

    PubMed

    Yomosa, Makoto; Mizuguchi, Tsuyoshi; Hayakawa, Yoshinori

    2013-01-01

    We analyzed the spatio-temporal structure of hooded gull flocks with a portable stereo camera system. The 3-dimensional positions of individuals were reconstructed from pairs of videos. The motions of each individual were analyzed, and both gliding and flapping motions were quantified based on the velocity time series. We analyzed the distributions of the nearest neighbor's position in terms of coordinates based on each individual's motion. The obtained results were consistent with the aerodynamic interaction between individuals. We characterized the leader-follower relationship between individuals by a delay time to mimic the direction of a motion. A relation between the delay time and a relative position was analyzed quantitatively, which suggested the basic properties of the formation flight that maintains order in the flock.

  11. Flocking-based Document Clustering on the Graphics Processing Unit

    SciTech Connect

    Cui, Xiaohui; Potok, Thomas E; Patton, Robert M; ST Charles, Jesse Lee

    2008-01-01

    Abstract?Analyzing and grouping documents by content is a complex problem. One explored method of solving this problem borrows from nature, imitating the flocking behavior of birds. Each bird represents a single document and flies toward other documents that are similar to it. One limitation of this method of document clustering is its complexity O(n2). As the number of documents grows, it becomes increasingly difficult to receive results in a reasonable amount of time. However, flocking behavior, along with most naturally inspired algorithms such as ant colony optimization and particle swarm optimization, are highly parallel and have found increased performance on expensive cluster computers. In the last few years, the graphics processing unit (GPU) has received attention for its ability to solve highly-parallel and semi-parallel problems much faster than the traditional sequential processor. Some applications see a huge increase in performance on this new platform. The cost of these high-performance devices is also marginal when compared with the price of cluster machines. In this paper, we have conducted research to exploit this architecture and apply its strengths to the document flocking problem. Our results highlight the potential benefit the GPU brings to all naturally inspired algorithms. Using the CUDA platform from NIVIDA? we developed a document flocking implementation to be run on the NIVIDA?GEFORCE 8800. Additionally, we developed a similar but sequential implementation of the same algorithm to be run on a desktop CPU. We tested the performance of each on groups of news articles ranging in size from 200 to 3000 documents. The results of these tests were very significant. Performance gains ranged from three to nearly five times improvement of the GPU over the CPU implementation. This dramatic improvement in runtime makes the GPU a potentially revolutionary platform for document clustering algorithms.

  12. Kinetic theory of flocking: Derivation of hydrodynamic equations

    NASA Astrophysics Data System (ADS)

    Ihle, Thomas

    2011-03-01

    It is shown how to explicitly coarse-grain the microscopic dynamics of the rule-based Vicsek model for self-propelled agents. The hydrodynamic equations are derived by means of an Enskog-type kinetic theory. Expressions for all transport coefficients are given. The transition from a disordered to a flocking state, which at large particle speeds appears to be a fluctuation-induced first-order phase transition, is studied numerically and analytically.

  13. Cat scratch disease: analysis of 130 seropositive cases.

    PubMed

    Murakami, Kyoko; Tsukahara, Masato; Tsuneoka, Hidehiro; Iino, Hidechika; Ishida, Chizuru; Tsujino, Kumiko; Umeda, Akiko; Furuya, Tomoko; Kawauchi, Shigeto; Sasaki, Kohsuke

    2002-12-01

    To clarify the clinical manifestations of cat scratch disease (CSD), we evaluated a total of 130 seropositive patients with CSD. The patients' ages ranged from 1 to 68 years; 103 (79.2%) were under 18 years of age. CSD occurred predominantly in the fall and winter months. Regional lymphadenopathy was noted in 110 (84.6%) of the cases, and the most common sites were the neck (33%), axillary (27%), and inguinal (18%) regions. One hundred of the patients (77%) had general symptoms, such as fever, headache, and malaise. The clinical manifestations of CSD showed a wide spectrum from typical or classical CSD, with regional lymphadenopathy, to atypical or systemic CSD. Of the 130 cases, 103 (79.2%) were typical CSD and 27 (20.8%) were atypical CSD. Atypical cases of CSD were commonly reported as fever of unknown origin (37.0%), neuroretinitis (22.2%), encephalopathy (14.8%), hepatosplenic granuloma (11.1%), and Parinaud's oculoglandular syndrome (7.4%). Fever of unknown origin or prolonged fever lasting more than 14 days was evident in 27 (20.8%) of the 130 cases in this study. Eleven of the 27 cases lacked lymphadenopathy. Our findings suggest that CSD is not a rare disease in Japan. The indirect fluorescent antibody (IFA) test to detect Bartonella species may provide a prompt diagnosis of CSD and facilitate appropriate therapy.

  14. Sexually transmitted infections among HIV seropositive men and women

    PubMed Central

    Kalichman, S.; Rompa, D.; Cage, M.

    2000-01-01

    Objectives: To determine the prevalence of identified STIs and recognised symptoms of STIs and their association with health status, substance use, and sexual risk behaviour in a sample of HIV seropositive men and women. Methods: 223 men, 112 women, and five transsexual people living with HIV infection completed confidential surveys. Participants were recruited through community based services, community health clinics, and snowball (chain) recruitment techniques in Atlanta, GA, USA in December 1999. Results: We found that (263) 78% of participants had been sexually active in the previous 3 months. For the entire sample, 42 (12%) participants reported an STI in the past 3 months and 40 (11%) experienced symptoms of an STI without indicating a specific diagnosis in that time. Gonorrhoea, chlamydia, syphilis, and newly diagnosed herpes simplex virus (HSV) were identified at similar rates among men, whereas trichomonas, gonorrhoea, and newly diagnosed HSV occurred most often in women. STIs were associated with substance use in men and women, with "crack" cocaine users having the greatest likelihood of an STI relative to non-crack users. STIs were also associated with continued practice of sexual risk behaviours. Conclusions: This sample of people living with HIV-AIDS reported high rates of diagnoses and symptoms of STIs. There were significant associations between STIs, substance use, and continued high risk sexual practices in men and women. These findings support the need for studies that confirm prevalence of STIs using clinical laboratory tests. Key Words: HIV; sexual risk; HIV transmission PMID:11141850

  15. Spontaneous fluctuations in a zero-noise model of flocking

    NASA Astrophysics Data System (ADS)

    Chakraborty, Abhijit; Bhattacharya, Kunal

    2016-11-01

    Investigations into the complex structure and dynamics of collectively moving groups of living organisms have provided valuable insights. Understanding the emergent features, especially, the origin of fluctuations, appears to be challenging in the current scheme of models. It has been argued that flocks are poised at criticality. We present a two-dimensional self-propelled particle model where neighbourhoods and forces are defined through topology-based rules. The attractive forces are modeled in order to maintain cohesion in the flock in open-boundary conditions. We find that fluctuations occur spontaneously in the absence of any external noise. For certain values of the parameters the flock shows a high degree of order as well as scale-free decay of spatial correlations in velocity and speed. We characterize the dynamical behaviour of the system using the Lyapunov spectrum. Largest exponents being positive but small in magnitude suggest that the apparent high susceptibility may result from the system operating near the borderline of order and chaos.

  16. Multivariate epidemiological approach to salmonellosis in broiler breeder flocks.

    PubMed

    Henken, A M; Frankena, K; Goelema, J O; Graat, E A; Noordhuizen, J P

    1992-05-01

    A retrospective, case-control study into risk factors of salmonellosis was undertaken using data from 111 broiler breeder flocks assembled during a 5-yr period. The results of both univariate and multivariate analyses are presented. Many different Salmonella species were detected. Multivariate models were created based on the outcome of univariate analyses. The following variables appeared to be the most relevant: disinfection tubs, hygiene barriers, the interaction of disinfection tubs by hygiene barriers, and feed mills. The final model indicated that flocks housed at farms without a disinfection tub, with poor hygiene barriers, and receiving their feed from a small feed mill had a 46.1 times greater risk of being Salmonella-positive than flocks housed at farms with a disinfection tub, with good hygiene barriers, and receiving their feed from a large feed mill. It is concluded that the application of quantitative epidemiological methods can be valuable not only to identify potential risk factors but also to quantify their contributory effect on the disease outcome. Hence, it may be a useful tool for application in "integrated food chain quality control programs".

  17. Silent Flocks: Constraints on Signal Propagation Across Biological Groups

    NASA Astrophysics Data System (ADS)

    Cavagna, Andrea; Giardina, Irene; Grigera, Tomas S.; Jelic, Asja; Levine, Dov; Ramaswamy, Sriram; Viale, Massimiliano

    2015-05-01

    Experiments find coherent information transfer through biological groups on length and time scales distinctly below those on which asymptotically correct hydrodynamic theories apply. We present here a new continuum theory of collective motion coupling the velocity and density fields of Toner and Tu to the inertial spin field recently introduced to describe information propagation in natural flocks of birds. The long-wavelength limit of the new equations reproduces the Toner-Tu theory, while at shorter wavelengths (or, equivalently, smaller damping), spin fluctuations dominate over density fluctuations, and second-sound propagation of the kind observed in real flocks emerges. We study the dispersion relation of the new theory and find that when the speed of second sound is large, a gap in momentum space sharply separates first- from second-sound modes. This gap implies the existence of silent flocks, namely, of medium-sized systems across which information cannot propagate in a linear and underdamped way, either under the form of orientational fluctuations or under that of density fluctuations, making it hard for the group to achieve coordination.

  18. Predictive protocol of flocks with small-world connection pattern

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Tao; Chen, Michael Z. Q.; Zhou, Tao

    2009-01-01

    By introducing a predictive mechanism with small-world connections, we propose a new motion protocol for self-driven flocks. The small-world connections are implemented by randomly adding long-range interactions from the leader to a few distant agents, namely, pseudoleaders. The leader can directly affect the pseudoleaders, thereby influencing all the other agents through them efficiently. Moreover, these pseudoleaders are able to predict the leader’s motion several steps ahead and use this information in decision making towards coherent flocking with more stable formation. It is shown that drastic improvement can be achieved in terms of both the consensus performance and the communication cost. From the engineering point of view, the current protocol allows for a significant improvement in the cohesion and rigidity of the formation at a fairly low cost of adding a few long-range links embedded with predictive capabilities. Significantly, this work uncovers an important feature of flocks that predictive capability and long-range links can compensate for the insufficiency of each other. These conclusions are valid for both the attractive and repulsive swarm model and the Vicsek model.

  19. Questioning the activity of active matter: the case of bird flocks

    NASA Astrophysics Data System (ADS)

    Mora, Thierry; Walczak, Aleksandra; Del Castello, Lorenzo; Ginelli, Francesco; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano; Cavagna, Andrea; Giardina, Irene

    Animal flocking is a natural instance of active matter. What makes flocks active is the rearrangement of neighborhoods, which constantly remodels the network of interactions between individuals in the group, keeping the system out of equilibrium. Despite the predicted importance of this reshuffling, its true impact for natural flocks is not well understood. Here we analyse films of flocks of startlings with a novel statistical inference technique based on dynamical maximum entropy to measure the parameters of flock alignment - alignment strength, interaction range, and noise. We show that birds align their flight orientations must faster than they change neighbors. In the statistical mechanics sense, this means that flocks remain adiabatically in equilibrium, allowing for a rigorous analogy with equilibrium systems of interacting spins, and we show that an inference method based on equilibrium assumptions gives fully consistent results.

  20. Linear response to leadership, effective temperature, and decision making in flocks

    NASA Astrophysics Data System (ADS)

    Pearce, Daniel J. G.; Giomi, Luca

    2016-08-01

    Large collections of autonomously moving agents, such as animals or micro-organisms, are able to flock coherently in space even in the absence of a central control mechanism. While the direction of the flock resulting from this critical behavior is random, this can be controlled by a small subset of informed individuals acting as leaders of the group. In this article we use the Vicsek model to investigate how flocks respond to leadership and make decisions. Using a combination of numerical simulations and continuous modeling we demonstrate that flocks display a linear response to leadership that can be cast in the framework of the fluctuation-dissipation theorem, identifying an effective temperature reflecting how promptly the flock reacts to the initiative of the leaders. The linear response to leadership also holds in the presence of two groups of informed individuals with competing interests, indicating that the flock's behavioral decision is determined by both the number of leaders and their degree of influence.

  1. AI in space: Past, present, and possible futures

    NASA Technical Reports Server (NTRS)

    Rose, Donald D.; Post, Jonathan V.

    1992-01-01

    While artificial intelligence (AI) has become increasingly present in recent space applications, new missions being planned will require even more incorporation of AI techniques. In this paper, we survey some of the progress made to date in implementing such programs, some current directions and issues, and speculate about the future of AI in space scenarios. We also provide examples of how thinkers from the realm of science fiction have envisioned AI's role in various aspects of space exploration.

  2. Deploying Embodied AI into Virtual Worlds

    NASA Astrophysics Data System (ADS)

    Burden, David J. H.

    The last two years have seen the start of commercial activity within virtual worlds. Unlike computer games where Non-Player-Character avatars are common, in most virtual worlds they are the exception — and until recently in Second Life they were non-existent. However there is real commercial scope for Als in these worlds — in roles from virtual sales staff and tutors to personal assistants. Deploying an embodied AI into a virtual world offers a unique opportunity to evaluate embodied Als, and to develop them within an environment where human and computer are on almost equal terms. This paper presents an architecture being used for the deployment of chatbot driven avatars within the Second Life virtual world, looks at the challenges of deploying an AI within such a virtual world, the possible implications for the Turing Test, and identifies research directions for the future.

  3. Familial Analysis of Seropositivity to Trypanosoma cruzi and of Clinical Forms of Chagas Disease

    PubMed Central

    Silva-Grecco, Roseane L.; Balarin, Marly A. S.; Correia, Dalmo; Prata, Aluízio; Rodrigues, Virmondes

    2010-01-01

    A cross-sectional study was carried out in Água Comprida, MG, Brazil, a region previously endemic to Chagas disease whose vectorial transmission was interrupted around 20 year ago. A total of 998 individuals were examined for anti-Trypanosoma cruzi antibodies. Seropositivity was observed in 255 subjects (25.5%), and 743 subjects were negative. Forty-one families with 5–80 individuals with similar environmental conditions were selected for familial analysis. In 15 families, seropositivity to T. cruzi was observed in > 50% of individuals. The segregation analysis confirmed family aggregation for the seropositivity to the T. cruzi. Heart commitment was the major clinical form observed, and in six families, > 50% of the individuals display cardiopathy that may be attributed to T. cruzi infection. Our results support the hypothesis that there is a family aggregation for the seropositivity but without the effect of one major gene. PMID:20064994

  4. Vigilance and feeding behaviour in large feeding flocks of laughing gulls, Larus atricilla, on Delaware Bay

    NASA Astrophysics Data System (ADS)

    Burger, Joanna; Gochfeld, Michael

    1991-02-01

    Laughing gulls ( Larus atricilla) forage on horseshoe crab ( Limulus polyphemus) eggs during May in Delaware Bay each year. They feed in dense flocks, and foraging rates vary with vigilance, bird density, number of steps and location in the flock, whereas time devoted to vigilance is explained by number of steps, density, location and feeding rates. The time devoted to vigilance decreases with increasing density, increasing foraging rates and decreasing aggression. Birds foraging on the edge of flocks take fewer pecks and more steps, and devote more time to vigilance than those in the intermediate or central parts of a flock.

  5. Why Don't Accounting Students like AIS?

    ERIC Educational Resources Information Center

    Vatanasakdakul, Savanid; Aoun, Chadi

    2011-01-01

    Purpose: The demand for Accounting Information Systems (AIS) knowledge has increased exponentially over the past two decades, but studying AIS has not proved easy for many accounting students. The aim of the study is to understand the challenges accounting students face in studying AIS through investigation of the factors which may be contributing…

  6. The AI Interdisciplinary Context: Single or Multiple Research Bases?

    ERIC Educational Resources Information Center

    Khawam, Yves J.

    1992-01-01

    This study used citation analysis to determine whether the disciplines contributing to the journal literature of artificial intelligence (AI)--philosophy, psychology, linguistics, computer science, and engineering--share a common AI research base. The idea that AI consists of a completely interdisciplinary endeavor was refuted. (MES)

  7. 47 CFR 80.393 - Frequencies for AIS stations.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 47 Telecommunication 5 2012-10-01 2012-10-01 false Frequencies for AIS stations. 80.393 Section 80.393 Telecommunication FEDERAL COMMUNICATIONS COMMISSION (CONTINUED) SAFETY AND SPECIAL RADIO SERVICES STATIONS IN THE MARITIME SERVICES Frequencies Ais Stations § 80.393 Frequencies for AIS stations....

  8. Tactical AI in Real Time Strategy Games

    DTIC Science & Technology

    2015-03-26

    evolutionary algorithms (MOEAs) in this tactical decision making problem allows an AI agent to make fast , effective solutions that do not require modification...ranged attacks. The terran army operates most similarly to Warcraft. The player must still balance food (supply depots), and two other resources (minerals...types of methods analyze the current status of enemy units and makes a decision based on a single metric. These techniques are very fast , but are open to

  9. SDI satellite autonomy using AI and Ada

    NASA Technical Reports Server (NTRS)

    Fiala, Harvey E.

    1990-01-01

    The use of Artificial Intelligence (AI) and the programming language Ada to help a satellite recover from selected failures that could lead to mission failure are described. An unmanned satellite will have a separate AI subsystem running in parallel with the normal satellite subsystems. A satellite monitoring subsystem (SMS), under the control of a blackboard system, will continuously monitor selected satellite subsystems to become alert to any actual or potential problems. In the case of loss of communications with the earth or the home base, the satellite will go into a survival mode to reestablish communications with the earth. The use of an AI subsystem in this manner would have avoided the tragic loss of the two recent Soviet probes that were sent to investigate the planet Mars and its moons. The blackboard system works in conjunction with an SMS and a reconfiguration control subsystem (RCS). It can be shown to be an effective way for one central control subsystem to monitor and coordinate the activities and loads of many interacting subsystems that may or may not contain redundant and/or fault-tolerant elements. The blackboard system will be coded in Ada using tools such as the ABLE development system and the Ada Production system.

  10. Association between Toxoplasma gondii seropositivity and memory function in nondemented older adults.

    PubMed

    Wyman, Cynthia P; Gale, Shawn D; Hedges-Muncy, Ariana; Erickson, Lance D; Wilson, Eric; Hedges, Dawson W

    2017-02-03

    Toxoplasma gondii (T. gondii) seropositivity may be associated with decreased memory in older adults. To further investigate the association between T. gondii seropositivity and memory in nondemented older adults, we obtained serum samples from 114 nondemented older adults evaluated by the Alzheimer's Disease and Research Center at Washington University in St. Louis, Missouri, USA. We determined T. gondii seropositivity and anti-T. gondii IgG antibody titer and examined associations with memory function while controlling for socioeconomic status, education level, age, and apolipoprotein E4 status. There were few associations between T. gondii seropositivity or anti-T. gondii IgG antibodies and memory, although there was some support suggesting an interaction between anti-T. gondii and sex. In the seropositive-only sample, there was an inverse relationship between anti-T. gondii titer and performance on the selective reminding test. Overall, we found little evidence of an association between impaired memory function and T. gondii seropositivity and anti-T. gondii IgG antibodies in this sample of nondemented older adults.

  11. Validation of the nylon flocked swab for planetary protection applications

    NASA Astrophysics Data System (ADS)

    Moissl-Eichinger, Christine; Probst, Alexander

    The major issue of planetary protection is to prevent the contamination of extraterrestrial en-vironments by terrestrial biomolecules and life forms. In order not to affect or even to confound future life detection missions on celestial bodies, which are of interest for their chemical and bi-ological evolution, spacecraft are constructed in clean rooms and are subject to severe cleaning processes and microbiological controls before launch. Microbiological assays are used to mea-sure and control the bioburden on spacecraft itself and spacecraft hardware during assembly. The current NASA standard assays have originally been developed for the Viking programme in the 70s. Due to the stringent contamination control constrains of the upcoming ESA Ex-oMars mission, these protocols cannot be used, in particular the application of cotton swabs with wooden applicators is no longer possible. Therefore, cotton swabs will be replaced by the novel nylon flocked swabs. In the study presented here, the nylon flocked swabs were validated for the usage for measuring and controling of the bioburden on spacecraft related surfaces. The absolute recovery efficiency was determined, following the guidelines of USP1223 in preci-sion, accuracy, robustness, specificity, linearity and limit of detection. As a standard surface, stainless steel coupons were used, whereas B. atrophaeus (spores) served as standard microbial strain. Additionally, the nylon flocked swab was used for experiments on different rough and smooth surfaces with seven different Bacillus spores and two different protocols. Further details will be given concerning the new ESA standard swab procedure for the microbial examination of flight hardware and clean rooms to be used for the upcoming ExoMars mission.

  12. Collective motion with anticipation: Flocking, spinning, and swarming

    NASA Astrophysics Data System (ADS)

    Morin, Alexandre; Caussin, Jean-Baptiste; Eloy, Christophe; Bartolo, Denis

    2015-01-01

    We investigate the collective dynamics of self-propelled particles able to probe and anticipate the orientation of their neighbors. We show that a simple anticipation strategy hinders the emergence of homogeneous flocking patterns. Yet anticipation promotes two other forms of self-organization: collective spinning and swarming. In the spinning phase, all particles follow synchronous circular orbits, while in the swarming phase, the population condensates into a single compact swarm that cruises coherently without requiring any cohesive interactions. We quantitatively characterize and rationalize these phases of polar active matter and discuss potential applications to the design of swarming robots.

  13. From Particles to Fluid Dynamics for Flocking Phenomena

    NASA Astrophysics Data System (ADS)

    Toscani, G.

    2010-04-01

    We study the dynamics of groups of undistinguished agents, which, while interacting according to their relative positions, dissipate energy. These models are developed to mimic the collective motion of groups of living individuals such as bird flocks, fish schools or bacteria colonies. According to the Cucker and Smale model,7 binary interactions between agents are modelled by dissipative collisions in which the coefficient of restitution depends on their relative distance. Under the assumption of weak dissipation, it is shown that the consequent dynamics can be described at a fluid dynamic level by the Euler equation for compressible fluids, in which the equations for momentum and energy present a dissipative correction.

  14. Flocking of multi-agent systems with multiple groups

    NASA Astrophysics Data System (ADS)

    Jing, Gangshan; Zheng, Yuanshi; Wang, Long

    2014-12-01

    In this paper, we consider the flocking problem of multi-agent systems with multiple groups. First, some algorithms using local information are designed to divide the agents into any pre-assigned number of groups in fixed and switching heterogeneous networks, respectively. Based on algebraic graph theory and Barbalat's lemma, convergence criteria are established to ensure velocity alignment and cohesion of each subgroup as well as collision avoidance between any agents in the whole group. Second, an algorithm for homogeneous networks is studied. Simulation examples are finally presented to verify the effectiveness of our theoretical results.

  15. Apolipoprotein AI and Transthyretin as Components of Amyloid Fibrils in a Kindred with apoAI Leu178His Amyloidosis

    PubMed Central

    de Sousa, Mónica Mendes; Vital, Claude; Ostler, Dominique; Fernandes, Rui; Pouget-Abadie, Jean; Carles, Dominique; Saraiva, Maria João

    2000-01-01

    We found a new C-terminal amyloidogenic variant of apolipoprotein AI (apoAI), Leu178His in a French kindred, associated with cardiac and larynx amyloidosis and skin lesions with onset during the fourth decade. This single-point mutation in exon 4 of the apoAI gene was detected by DNA sequencing of polymerase chain reaction amplified material and restriction fragment length polymorphism analysis in two siblings. Blood, larynx, and skin biopsies were available from one sibling. Anti-apoAI immunoblotting of isoelectric focusing of plasma showed a +1 alteration in the charge of the protein. Extraction of fibrils from the skin biopsy revealed both full-length and N-terminal fragments of apoAI and transthyretin (TTR). ApoAI and TTR co-localized in amyloid deposits as demonstrated by immunohistochemistry. The present report, together with the first recently described C-terminal amyloidogenic variant of apoAI, Arg173Pro, shows that amyloidogenicity of apoAI is not a feature exclusive to N-terminal variants. The most striking characteristic of amyloid fibrils in Leu178His is that wild-type TTR is co-localized with apoAI in the fibrils. We have previously determined that a fraction of plasma TTR circulates in plasma bound to high-density lipoprotein and that this interaction occurs through binding to apoAI. Therefore we hypothesize that nonmutated TTR might influence deposition of apoAI as amyloid. PMID:10854214

  16. Apolipoprotein AI and transthyretin as components of amyloid fibrils in a kindred with apoAI Leu178His amyloidosis.

    PubMed

    de Sousa, M M; Vital, C; Ostler, D; Fernandes, R; Pouget-Abadie, J; Carles, D; Saraiva, M J

    2000-06-01

    We found a new C-terminal amyloidogenic variant of apolipoprotein AI (apoAI), Leu178His in a French kindred, associated with cardiac and larynx amyloidosis and skin lesions with onset during the fourth decade. This single-point mutation in exon 4 of the apoAI gene was detected by DNA sequencing of polymerase chain reaction amplified material and restriction fragment length polymorphism analysis in two siblings. Blood, larynx, and skin biopsies were available from one sibling. Anti-apoAI immunoblotting of isoelectric focusing of plasma showed a +1 alteration in the charge of the protein. Extraction of fibrils from the skin biopsy revealed both full-length and N-terminal fragments of apoAI and transthyretin (TTR). ApoAI and TTR co-localized in amyloid deposits as demonstrated by immunohistochemistry. The present report, together with the first recently described C-terminal amyloidogenic variant of apoAI, Arg173Pro, shows that amyloidogenicity of apoAI is not a feature exclusive to N-terminal variants. The most striking characteristic of amyloid fibrils in Leu178His is that wild-type TTR is co-localized with apoAI in the fibrils. We have previously determined that a fraction of plasma TTR circulates in plasma bound to high-density lipoprotein and that this interaction occurs through binding to apoAI. Therefore we hypothesize that nonmutated TTR might influence deposition of apoAI as amyloid.

  17. A national survey to estimate the prevalence of Salmonella species among Canadian registered commercial turkey flocks.

    PubMed Central

    Irwin, R J; Poppe, C; Messier, S; Finley, G G; Oggel, J

    1994-01-01

    In 1990-1991, a national survey was conducted to estimate the prevalence of Salmonella species among Canadian commercial turkey flocks. Two hundred and seventy flocks were randomly selected across Canada. The proportion sampled from each province was selected according to each province's share of the national turkey market. Samples, consisting of 12 pooled litter and four pooled dust samples, were used to determine the Salmonella status of the environment of each flock. Additionally, a one kilogram sample of feed was taken from each flock premise. Salmonella was recovered from environmental samples in 234/270 (86.7%) of flocks and from feed samples in 26/266 (9.8%) of flocks. Forty-eight different Salmonella serovars were isolated from flock environmental samples. The most prevalent serovars were S. anatum, S. hadar, S. agona, S. heidelberg and S. saintpaul which were isolated from 53/270 (19.6%), 49/270 (18.1%), 49/270 (18.1%), 42/270 (15.6%) and 34/270 (12.6%) flocks, respectively. PMID:7889457

  18. Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

    PubMed

    Henning, Joerg; Pfeiffer, Dirk U; Stevenson, Mark; Yulianto, Didik; Priyono, Walujo; Meers, Joanne

    2016-01-01

    Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI) virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised.

  19. Prevalence and risk factors of Campylobacter infection in broiler flocks from southern Spain.

    PubMed

    Torralbo, Alicia; Borge, Carmen; Allepuz, Alberto; García-Bocanegra, Ignacio; Sheppard, Samuel K; Perea, Anselmo; Carbonero, Alfonso

    2014-05-01

    An extensive epidemiological study was performed to determine the prevalence and risk factors of Campylobacter infection in broiler farms in Andalusia (southern Spain). A total of 2221 cloacal swabs and 747 environmental swabs from 291 broiler flocks were screened between April 2010 and May 2012. The prevalence of Campylobacter in individual animals was 38.1%, and the flock prevalence was 62.9%. Flocks were predominantly infected by C. jejuni and C. coli but were also infected by untyped Campylobacter spp., and mixed-species infection could be found. Risk factors for Campylobacter infection were assessed from direct interview of the farmers. The number of positive samples by flock was modelled assuming a binomial distribution. Analysis indicated five factors associated with increased intra-flock prevalence: presence of dogs or cats on the farm, older age of the broiler flock, the application of thinning of flocks, the presence of windows with canvas blinds, and the presence of rodents in the poultry house. Two factors were associated with decreased intra-flock prevalence: the treatment of drinking water and having an entrance room for access into the poultry house. This is the first study performed on broilers farms from Spain reporting the risk factors of Campylobacter infection and is the largest study on the prevalence of Campylobacter infection.

  20. Who Is Spreading Avian Influenza in the Moving Duck Flock Farming Network of Indonesia?

    PubMed Central

    Henning, Joerg; Pfeiffer, Dirk U.; Stevenson, Mark; Yulianto, Didik; Priyono, Walujo; Meers, Joanne

    2016-01-01

    Duck populations are considered to be a reservoir of Highly pathogenic avian influenza (HPAI) virus H5N1 in some agricultural production systems, as they are able to shed the virus for several days without clinical signs. Countries endemically affected with HPAI in Asia are characterised by production systems where ducks are fed on post-harvest spilled rice. During this scavenging process it is common for ducks to come into contact with other duck flocks or wild birds, thereby providing opportunities for virus spread. Effective risk management for HPAI has been significantly compromised by a limited understanding of management of moving duck flocks in these countries, despite of a small number of recent investigations. Here, for the first time, we described the management of moving duck flocks and the structure of the moving duck flock network in quantitative terms so that factors influencing the risk of HPAIV transmission can be identified. By following moving duck flock farmers over a period of 6 months in Java, Indonesia, we were able to describe the movement of flocks and to characterise the network of various types of actors associated with the production system. We used these data to estimate the basic reproductive number for HPAI virus spread. Our results suggest that focussing HPAI prevention measures on duck flocks alone will not be sufficient. Instead, the role of transporters of moving duck flocks, hatcheries and rice paddy owners, in the spread of the HPAI virus needs to be recognised. PMID:27019344

  1. Characteristics of two duck farming systems in the Mekong Delta of Viet Nam: stationary flocks and moving flocks, and their potential relevance to the spread of highly pathogenic avian influenza.

    PubMed

    Henning, Joerg; Henning, Kate A; Long, Ngo Thanh; Ha, Nguyen Truc; Vu, Le Tri; Meers, Joanne

    2013-03-01

    Ducks are considered to play a major role in the spread of highly pathogenic avian influenza (HPAI) H5N1 in Viet Nam, but detailed information on their management is limited. We distinguished two different systems (1) stationary duck flocks that are not commonly driven to rice fields beyond village boundaries and that are confined overnight on farms and (2) moving duck flocks that are intentionally driven to rice fields beyond village boundaries, that are not returning to home farms for extended periods and that are housed overnight in temporary enclosures in rice paddies. A total of 115 stationary and 22 moving flock farmers were interviewed in 2007 in the Mekong Delta of Viet Nam. Moving duck flocks are larger than stationary flocks, which is indicative of their more commercial production. Moving flock farmers apparently are more aware of HPAI risks than stationary flock farmers, as their flocks are more likely fully vaccinated and have less contact with chickens during scavenging. On the other hand, the spread of HPAI virus between birds might be promoted by moving duck flocks as they repeatedly use transport vehicles and numerous rice paddies for scavenging and are often visited by hatchery owners in the field for purchasing duck eggs. In addition, long distances travelled by moving duck flocks might also result in widespread dissemination of HPAI virus. Further studies are necessary to describe HPAI prevalence and travel patterns of moving duck flocks and to explore the moving duck flock network in detail.

  2. Impact of an HPV6/11/16/18 L1 virus-like particle vaccine on progression to cervical intraepithelial neoplasia in seropositive women with HPV16/18 infection.

    PubMed

    Haupt, Richard M; Wheeler, Cosette M; Brown, Darron R; Garland, Suzanne M; Ferris, Daron G; Paavonen, Jorma A; Lehtinen, Matti O; Steben, Marc; Joura, Elmar A; Giacoletti, Katherine E D; Radley, David R; James, Margaret K; Saah, Alfred J; Sings, Heather L

    2011-12-01

    The impact of a human papillomavirus (HPV) vaccine on development of cervical intraepithelial neoplasia grade 2-3 or adenocarcinoma in situ (CIN2-3/AIS) in women with ongoing HPV16 or 18 infections prevaccination is reported. Seventeen thousand six-hundred and twenty-two women aged 16-26 were enrolled in 1 of 2 randomized, placebo-controlled, efficacy trials (Protocols 013 and 015). Vaccine or placebo was given at day 1, month 2 and 6. Women were tested for HPV6/11/16/18 DNA and antibodies at day 1. We focus on the subset of women who were seropositive and DNA positive to HPV16 or HPV18 prevaccination. Incidence is expressed as the number of women with an endpoint per 100 person-years-at-risk. In total, 419 vaccine and 446 placebo recipients were both seropositive and DNA positive to HPV16 or HPV18 prevaccination and had at least one follow-up visit. In Protocol 013, the incidence of HPV16/18-related CIN2-3/AIS among these women was 10.9 in the vaccine arm and 7.0 in the placebo arm (vaccine efficacy = -54.9; 95% CI: -181.7, 13.0). In Protocol 015, the incidence of HPV16/18-related CIN2-3/AIS was 5.5 in the vaccine arm and 6.2 in the placebo arm (vaccine efficacy = 12.2%; 95% CI: -29.8, 40.9). These data suggest HPV vaccination neither reduces nor enhances progression to HPV16/18-related high grade cervical lesions, and cervical cytology screening and corresponding management should continue as per local recommendations. Ultimately, population-based surveillance of vaccinated individuals beyond these clinical trials will be required to further address questions regarding the impact of vaccination in women exposed to vaccine HPV types before vaccination.

  3. Diphacinone and zinc phosphide toxicity in a flock of Peafowl.

    PubMed

    Shivaprasad, H L; Galey, F

    2001-12-01

    Toxicity probably due to a combination of diphacinone and zinc phosphide was diagnosed in a flock of peafowl, in which 35 birds in a flock of 80 died over a span of 10 days without any apparent clinical signs. Chickens and guinea fowl, 30 each on the same premises, were not affected. Plastic tubes containing diphacinone and zinc phosphide were used on the premises to control ground squirrels. Most of the six dead peafowl, which ranged in age from 6 months to 4 years, had an accumulation of serosanguinous fluid in the abdominal cavity, semi-clotted blood over the liver lobes, increased pericardial fluid, and enlarged and pale kidneys. Pellets of diphacinone and zinc phosphide were found in the crop and gizzard contents from most of the birds. Microscopically, most of the birds had mild to moderate centrolobular degeneration of hepatocytes and multifocal degeneration of myofibres in the heart with infiltration by a few mononuclear cells. Acute nephrosis and mucosal oedema in the oesophagus and crop were also observed. Toxicological analysis of the crop and gizzard contents revealed the presence of diphacinone and phosphine gas, and analysis of the crop contents from two birds for heavy metals revealed zinc levels of up to 6600 parts/10 6 . It was suspected that only the peafowl and not the chickens and guinea fowl were affected because peafowl, with their longer necks, were able to reach into the plastic tubes and eat the pellets.

  4. Antimicrobial resistance in Campylobacter spp isolated from broiler flocks

    PubMed Central

    Kuana, Suzete Lora; dos Santos, Luciana Ruschel; Rodrigues, Laura Beatriz; Borsoi, Anderlise; Moraes, Hamilton Luis do Souza; Salle, Carlos Tadeu Pippi; do Nascimento, Vladimir Pinheiro

    2008-01-01

    The aim of this study was to assess the antimicrobial susceptibility of 62 Campylobacter spp. strains obtained from broiler flocks using the agar diffusion method. The Campylobacter spp strains were isolated from 22 flocks aged between 3 and 5 weeks of life, isolated from cloacae swabs, stools and cecal droppings in the farm and from the carcass rinsing in the slaughterhouse. Campylobacter spp strains were tested on Mueller-Hilton (MH) agar (27 samples) and MH plus TTC agar (35 samples). The antimicrobial susceptibility test revealed a 62.5% resistance to at least one drug, especially to enrofloxacin (71%), neomycin (50%), lincomycin (50%), tetracycline (43%), penicillin (42%), ceftiofur (33%) amoxicillin (27%), spiramycin (20%), ampicillin (18%) and norfloxacin (14%), whereas a lower percentage of strains was resistant to erythromycin (10%) and doxycycline (10%). All strains were sensitive to gentamicin and lincomycin-spectinomycin and 80% of them to colistin. These results indicate that it is necessary to reduce the use of antimicrobials in veterinary and human medicine. PMID:24031299

  5. Effects of Agent's Repulsion in 2d Flocking Models

    NASA Astrophysics Data System (ADS)

    Moussa, Najem; Tarras, Iliass; Mazroui, M'hammed; Boughaleb, Yahya

    In nature many animal groups, such as fish schools or bird flocks, clearly display structural order and appear to move as a single coherent entity. In order to understand the complex behavior of these systems, many models have been proposed and tested so far. This paper deals with an extension of the Vicsek model, by including a second zone of repulsion, where each agent attempts to maintain a minimum distance from the others. The consideration of this zone in our study seems to play an important role during the travel of agents in the two-dimensional (2D) flocking models. Our numerical investigations show that depending on the basic ingredients such as repulsion radius (R1), effect of density of agents (ρ) and noise (η), our nonequilibrium system can undergo a kinetic phase transition from no transport to finite net transport. For different values of ρ, kinetic phase diagrams in the plane (η ,R1) are found. Implications of these findings are discussed.

  6. Mic Flocks in the Cloud: Harnessing Mobile Ubiquitous Sensor Networks

    NASA Astrophysics Data System (ADS)

    Garces, M. A.; Christe, A.

    2015-12-01

    Smartphones provide a commercial, off-the-shelf solution to capture, store, analyze, and distribute infrasound using on-board or external microphones (mics) as well as on-board barometers. Free iOS infrasound apps can be readily downloaded from the Apple App Store, and Android versions are in progress. Infrasound propagates for great distances, has low sample rates, and provides a tractable pilot study scenario for open distributed sensor networks at regional and global scales using one of the most ubiquitous sensors on Earth - microphones. Data collection is no longer limited to selected vendors at exclusive prices: anybody on Earth can record and stream infrasound, and the diversity of recording systems and environments is rapidly expanding. Global deployment may be fast and easy (www.redvox.io), but comes with the cost of increasing data volume, velocity, variety, and complexity. Flocking - the collective motion of mobile agents - is a natural human response to threats or events of interest. Anticipating, modeling and harnessing flocking sensor topologies will be necessary for adaptive array and network processing. The increasing data quantity and complexity will exceed the processing capacity of human analysts and most research servers. We anticipate practical real-time applications will require the on-demand adaptive scalability and resources of the Cloud. Cloud architectures for such heterogeneous sensor networks will consider eventual integration into the Global Earth Observation System of Systems (GEOSS).

  7. Information transfer and behavioural inertia in starling flocks

    NASA Astrophysics Data System (ADS)

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Grigera, Tomas S.; Jelić, Asja; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Shen, Edward; Viale, Massimiliano

    2014-09-01

    Collective decision-making in biological systems requires all individuals in the group to go through a behavioural change of state. During this transition fast and robust transfer of information is essential to prevent cohesion loss. The mechanism by which natural groups achieve such robustness, however, is not clear. Here we present an experimental study of starling flocks performing collective turns. We find that information about direction changes propagates across the flock with a linear dispersion law and negligible attenuation, hence minimizing group decoherence. These results contrast starkly with present models of collective motion, which predict diffusive transport of information. Building on spontaneous symmetry breaking and conservation-law arguments, we formulate a theory that correctly reproduces linear and undamped propagation. Essential to this framework is the inclusion of the birds' behavioural inertia. The theory not only explains the data, but also predicts that information transfer must be faster the stronger the group's orientational order, a prediction accurately verified by the data. Our results suggest that swift decision-making may be the adaptive drive for the strong behavioural polarization observed in many living groups.

  8. A Distributed Flocking Approach for Information Stream Clustering Analysis

    SciTech Connect

    Cui, Xiaohui; Potok, Thomas E

    2006-01-01

    Intelligence analysts are currently overwhelmed with the amount of information streams generated everyday. There is a lack of comprehensive tool that can real-time analyze the information streams. Document clustering analysis plays an important role in improving the accuracy of information retrieval. However, most clustering technologies can only be applied for analyzing the static document collection because they normally require a large amount of computation resource and long time to get accurate result. It is very difficult to cluster a dynamic changed text information streams on an individual computer. Our early research has resulted in a dynamic reactive flock clustering algorithm which can continually refine the clustering result and quickly react to the change of document contents. This character makes the algorithm suitable for cluster analyzing dynamic changed document information, such as text information stream. Because of the decentralized character of this algorithm, a distributed approach is a very natural way to increase the clustering speed of the algorithm. In this paper, we present a distributed multi-agent flocking approach for the text information stream clustering and discuss the decentralized architectures and communication schemes for load balance and status information synchronization in this approach.

  9. Antimicrobial resistance in Campylobacter spp isolated from broiler flocks.

    PubMed

    Kuana, Suzete Lora; Dos Santos, Luciana Ruschel; Rodrigues, Laura Beatriz; Borsoi, Anderlise; Moraes, Hamilton Luis do Souza; Salle, Carlos Tadeu Pippi; do Nascimento, Vladimir Pinheiro

    2008-10-01

    The aim of this study was to assess the antimicrobial susceptibility of 62 Campylobacter spp. strains obtained from broiler flocks using the agar diffusion method. The Campylobacter spp strains were isolated from 22 flocks aged between 3 and 5 weeks of life, isolated from cloacae swabs, stools and cecal droppings in the farm and from the carcass rinsing in the slaughterhouse. Campylobacter spp strains were tested on Mueller-Hilton (MH) agar (27 samples) and MH plus TTC agar (35 samples). The antimicrobial susceptibility test revealed a 62.5% resistance to at least one drug, especially to enrofloxacin (71%), neomycin (50%), lincomycin (50%), tetracycline (43%), penicillin (42%), ceftiofur (33%) amoxicillin (27%), spiramycin (20%), ampicillin (18%) and norfloxacin (14%), whereas a lower percentage of strains was resistant to erythromycin (10%) and doxycycline (10%). All strains were sensitive to gentamicin and lincomycin-spectinomycin and 80% of them to colistin. These results indicate that it is necessary to reduce the use of antimicrobials in veterinary and human medicine.

  10. 9 CFR 147.10 - Laboratory procedure recommended for the bacteriological examination of egg-type breeding flocks...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... the bacteriological examination of egg-type breeding flocks with salmonella enteritidis positive... examination of egg-type breeding flocks with salmonella enteritidis positive environments. Birds selected for bacteriological examination from egg-type breeding flocks positive for Salmonella enteritidis after...

  11. AIS spectra of desert shrub canopies

    NASA Technical Reports Server (NTRS)

    Murray, R.; Isaacson, D. L.; Schrumpf, B. J.; Ripple, W. J.; Lewis, A. J.

    1986-01-01

    Airborne Imaging Spectrometer (AIS) data were collected 30 August 1985 from a desert shrub community in central Oregon. Spectra from artificial targets placed on the test site and from bare soil, big sagebrush (Artemesia tridentata wyomingensis), silver sagebrush (Artemesia cana bolander), and exposed volcanic rocks were studied. Spectral data from grating position 3 (tree mode) were selected from 25 ground positions for analysis by Principal Factor Analysis (PFA). In this grating position, as many as six factors were identified as significant in contributing to spectral structure. Channels 74 through 84 (tree mode) best characterized between-class differences. Other channels were identified as nondiscriminating and as associated with such errors as excessive atmospheric absorption and grating positin changes. The test site was relatively simple with the two species (A. tridentata and A. cana) representing nearly 95% of biomass and with only two mineral backgrounds, a montmorillonitic soil and volcanic rocks. If, as in this study, six factors of spectral structure can be extracted from a single grating position from data acquired over a simple vegetation community, then AIS data must be considered rich in information-gathering potential.

  12. AI techniques in geomagnetic storm forecasting

    NASA Astrophysics Data System (ADS)

    Lundstedt, Henrik

    This review deals with how geomagnetic storms can be predicted with the use of Artificial Intelligence (AI) techniques. Today many different Al techniques have been developed, such as symbolic systems (expert and fuzzy systems) and connectionism systems (neural networks). Even integrations of AI techniques exist, so called Intelligent Hybrid Systems (IHS). These systems are capable of learning the mathematical functions underlying the operation of non-linear dynamic systems and also to explain the knowledge they have learned. Very few such powerful systems exist at present. Two such examples are the Magnetospheric Specification Forecast Model of Rice University and the Lund Space Weather Model of Lund University. Various attempts to predict geomagnetic storms on long to short-term are reviewed in this article. Predictions of a month to days ahead most often use solar data as input. The first SOHO data are now available. Due to the high temporal and spatial resolution new solar physics have been revealed. These SOHO data might lead to a breakthrough in these predictions. Predictions hours ahead and shorter rely on real-time solar wind data. WIND gives us real-time data for only part of the day. However, with the launch of the ACE spacecraft in 1997, real-time data during 24 hours will be available. That might lead to the second breakthrough for predictions of geomagnetic storms.

  13. Correlation of Demographic and Clinical Characteristics with Rheumatoid Factor Seropositivity in Rheumatoid Arthritis Patients

    PubMed Central

    Othman, Maizatul Akmal; Ghazali, Wan Syamimee Wan; Yahya, Nurul Khaiza; Wong, Kah Keng

    2016-01-01

    Background The rheumatoid factor (RF) blood test is the most commonly adopted test for the diagnosis of rheumatoid arthritis (RA). RA patients who are seropositive for RF might face a greater likelihood of developing more aggressive symptoms. Methods Our goal was to study the demographic and clinical characteristics, as well as their correlation with RF seropositivity, among a series of 80 RA patients aged ≥ 18 years who attend Hospital Universiti Sains Malaysia (HUSM). Results Of the 80 RA patients included in this study, 66 (82.5%) were female and 14 (17.5%) were male. No significant associations between RF seropositivity and demographic and/or clinical characteristics or other laboratory investigations were observed, including gender, morning stiffness, individual joint involvement (from multiple sites of the body), and erythrocyte sedimentation rate (ESR) measurement. However, a significant association between RF seropositivity and patients aged ≥ 50 was found (P = 0.032). Conclusion RF seropositivity was found to be more common in much older RA patients. PMID:28090179

  14. Serum iron, Folate, Ferritin and CD4 Count in HIV Seropositive Women.

    PubMed

    Kharb, Simmi; Kumawat, Manjulata; Lallar, Meenakshi; Ghalaut, P S; Nanda, Smiti

    2017-03-01

    HIV infects cluster of differentiation 4 (CD4) T-lymphocytes, monocytes and macrophages resulting in decreased number and function of CD4 cells, changes that affect both cell mediated and humoral immunity. Hematological abnormalities are a common complication of human immune virus (HIV) infection and these abnormalities increase as the disease advances. Anemia is the most common haematological abnormality in HIV seropositive patients and its incidence is strongly associated with the progression of the disease. The aim of present study was to assess the haematological profile of HIV seropositive women and compare them with CD4 count. Two hundred seropositive females (age 18-25 years) attending antiretroviral therapy clinic were selected. Routine gynaecological and haematological investigations were carried out, study samples were drawn and serum iron, folate and ferritin were analysed by chemiluminiscence and CD4 count was determined by using flow-cytometry. Anemia was prevalent in seropositive women especially in those with low CD4 levels. Serum folate and ferritin levels were significantly lower in females with lower CD4 levels. Serum iron levels were higher at low CD4 levels. The mean CD4 count in HIV seropositive anaemic women were lower as compared to non anaemics suggesting that anaemia improves with higher CD4 cell counts. Plasma folate and ferritin levels are sensitive predictor of anaemia in early HIV infections and these patients should have a regular monitoring of their folate and ferritin levels especially with lower CD4 levels.

  15. Adenovirus-36 Seropositivity and Its Relation with Obesity and Metabolic Profile in Children

    PubMed Central

    Del Moral-Hernández, Oscar; Salgado-Bernabé, Aralia B.; Guzmán-Guzmán, Iris P.; Salgado-Goytia, Lorenzo; Muñoz-Valle, José F.

    2013-01-01

    The human adenovirus 36 (Ad-36) is causally and correlatively associated in animals and humans, respectively, with increased adiposity and altered metabolic profile. In previous studies, the relationship between Ad-36 seropositivity with obesity was established in adults and children. We evaluated the association of positive antibodies to Ad-36 with obesity and metabolic profile in Mexican children. Seventy-five children with normal-weight and 82 with obesity were studied in this research. All children had a clinic assessment which included weight, height, body circumferences, and skinfold thickness. Laboratory analyzes included triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, and glucose and insulin levels. An enzyme-linked immunosorbent assay (ELISA) was used to determine the antibodies to Ad-36 in the serum samples. The overall Ad-36 seroprevalence was 73.9%. Ad-36 seropositivity had a higher prevalence in obese children than in normal weight group (58.6 versus 41.4%, P = 0.007). Ad-36 seropositivity was associated with obesity (OR = 2.66, P = 0.01) and high-density lipoprotein <40 mg/dL (OR = 2.85, P = 0.03). The Ad-36 seropositive group had greater risk of 4 metabolic abnormalities compared with those children without none alteration. In summary, Ad-36 seropositivity was associated with obesity and low HDL-c levels in the sample of children studied. PMID:24324491

  16. Adenovirus-36 seropositivity and its relation with obesity and metabolic profile in children.

    PubMed

    Parra-Rojas, Isela; Del Moral-Hernández, Oscar; Salgado-Bernabé, Aralia B; Guzmán-Guzmán, Iris P; Salgado-Goytia, Lorenzo; Muñoz-Valle, José F

    2013-01-01

    The human adenovirus 36 (Ad-36) is causally and correlatively associated in animals and humans, respectively, with increased adiposity and altered metabolic profile. In previous studies, the relationship between Ad-36 seropositivity with obesity was established in adults and children. We evaluated the association of positive antibodies to Ad-36 with obesity and metabolic profile in Mexican children. Seventy-five children with normal-weight and 82 with obesity were studied in this research. All children had a clinic assessment which included weight, height, body circumferences, and skinfold thickness. Laboratory analyzes included triglycerides, total cholesterol, high-density lipoprotein, low-density lipoprotein, and glucose and insulin levels. An enzyme-linked immunosorbent assay (ELISA) was used to determine the antibodies to Ad-36 in the serum samples. The overall Ad-36 seroprevalence was 73.9%. Ad-36 seropositivity had a higher prevalence in obese children than in normal weight group (58.6 versus 41.4%, P = 0.007). Ad-36 seropositivity was associated with obesity (OR = 2.66, P = 0.01) and high-density lipoprotein <40 mg/dL (OR = 2.85, P = 0.03). The Ad-36 seropositive group had greater risk of 4 metabolic abnormalities compared with those children without none alteration. In summary, Ad-36 seropositivity was associated with obesity and low HDL-c levels in the sample of children studied.

  17. Serological and molecular investigation of Newcastle disease in household chicken flocks and associated markets in Eastern Shewa zone, Ethiopia.

    PubMed

    Chaka, Hassen; Goutard, Flavie; Gil, Patricia; Abolnik, Celia; Servan de Almeida, Renata; Bisschop, Shahn; Thompson, Peter N

    2013-03-01

    Cross-sectional survey for Newcastle disease (ND) were conducted in nonvaccinated household flocks of village chickens to assess serological and virological ND status in households and associated live bird markets. In total, 1,899 sera and 460 pools of cloacal and tracheal swabs were sampled and tested using a commercial enzyme-linked immunosorbent assay (ELISA) and real-time reverse transcriptase polymerase chain reaction (rRT-PCR), respectively. Additionally, paired cloacal and tracheal swabs from 1,269 individual chickens were collected from markets and tested using RT-PCR. The prevalence of households with at least one seropositive chicken was higher during the dry season (27.4 %) than during the wet season (17.4 %) (P = 0.003). Viral genome was detected in 14.2 % of households during the wet season using a fusion (F) gene assay and in 24.2 % of households during the dry season using a polymerase (L) gene assay that targets both class I and class II viruses. At the markets sampled, overall bird level prevalence was 4.9 % for period 1 (F gene assay), and 38.2 % and 27.6 % for periods 2 and 3, respectively (L gene assay). Partial sequencing of the F gene (239 bp) cleavage site indicated that the majority of the circulating strains exhibited motifs specific to virulent strains. Seroepidemiology coupled with molecular analysis can be a useful tool to assess the status of NDV infection. The village chicken population in Ethiopia is endemically infected with virulent NDV that pose a significant threat to emerging small- and medium-scale commercial poultry production.

  18. HBV & HIV seropositivity in multi-transfused haemophilics & thalassaemics in eastern India.

    PubMed

    De, M; Banerjee, D; Chandra, S; Bhattacharya, D K

    1990-01-01

    Seropositivity to HBV (HBsAg) in multi-transfused patients of haemophilia A, haemophilia B, B thalassaemia and EB thalassaemia from Eastern India, was found to be 9, 0, 22.1 and 13 per cent respectively. HIV seropositivity was detected in patients of haemophilia A (4.4%) and B thalassaemia (0.8%) who received plasma components and packed cells periodically. Seropositivity to both HBsAg and HIV was found in one patient of haemophilia A. Serum alanine amino transferase (ALT), raised in multi-transfused thalassaemics suggests concurrent hepatitis which might have enhanced the transmission of viruses due to disturbed immune status. The universal voluntary blood donation programme, screening of blood for HBV and HIV by sensitive tests, early immunisation and periodic monitoring of HBV and HIV status are prerequisites for the management of transfusion dependent thalassaemia and haemophilia.

  19. Opposite regulation of human versus mouse apolipoprotein A-I by fibrates in human apolipoprotein A-I transgenic mice.

    PubMed Central

    Berthou, L; Duverger, N; Emmanuel, F; Langouët, S; Auwerx, J; Guillouzo, A; Fruchart, J C; Rubin, E; Denèfle, P; Staels, B; Branellec, D

    1996-01-01

    The regulation of liver apolipoprotein (apo) A-I gene expression by fibrates was studied in human apo A-I transgenic mice containing a human genomic DNA fragment driving apo A-I expression in liver. Treatment with fenofibrate (0.5% wt/wt) for 7 d increased plasma human apo A-I levels up to 750% and HDL-cholesterol levels up to 200% with a shift to larger particles. The increase in human apo A-I plasma levels was time and dose dependent and was already evident after 3 d at the highest dose (0.5% wt/wt) of fenofibrate. In contrast, plasma mouse apo A-I concentration was decreased after fenofibrate in nontransgenic mice. The increase in plasma human apo A-I levels after fenofibrate treatment was associated with a 97% increase in hepatic human apo A-I mRNA, whereas mouse apo A-I mRNA levels decreased to 51%. In nontransgenic mice, a similar down-regulation of hepatic apo A-I mRNA levels was observed. Nuclear run-on experiments demonstrated that the increase in human apo A-I and the decrease in mouse apo A-I gene expression after fenofibrate occurred at the transcriptional level. Since part of the effects of fibrates are mediated through the nuclear receptor PPAR (peroxisome proliferator-activated receptor), the expression of the acyl CoA oxidase (ACO) gene was measured as a control of PPAR activation. Both in transgenic and nontransgenic mice, fenofibrate induced ACO mRNA levels up to sixfold. When transgenic mice were treated with gemfibrozil (0.5% wt/wt) plasma human apo A-I and HDL-cholesterol levels increased 32 and 73%, respectively, above control levels. The weaker effect of this compound on human apo A-I and HDL-cholesterol levels correlated with a less pronounced impact on ACO mRNA levels (a threefold increase) suggesting that the level of induction of human apo A-I gene is related to the PPAR activating potency of the fibrate used. Treatment of human primary hepatocytes with fenofibric acid (500 microM) provoked an 83 and 50% increase in apo A-I secretion and

  20. The implementation of AI technologies in computer wargames

    NASA Astrophysics Data System (ADS)

    Tiller, John A.

    2004-08-01

    Computer wargames involve the most in-depth analysis of general game theory. The enumerated turns of a game like chess are dwarfed by the exponentially larger possibilities of even a simple computer wargame. Implementing challenging AI is computer wargames is an important goal in both the commercial and military environments. In the commercial marketplace, customers demand a challenging AI opponent when they play a computer wargame and are frustrated by a lack of competence on the part of the AI. In the military environment, challenging AI opponents are important for several reasons. A challenging AI opponent will force the military professional to avoid routine or set-piece approaches to situations and cause them to think much deeper about military situations before taking action. A good AI opponent would also include national characteristics of the opponent being simulated, thus providing the military professional with even more of a challenge in planning and approach. Implementing current AI technologies in computer wargames is a technological challenge. The goal is to join the needs of AI in computer wargames with the solutions of current AI technologies. This talk will address several of those issues, possible solutions, and currently unsolved problems.

  1. Quantifying the tracking capability of space-based AIS systems

    NASA Astrophysics Data System (ADS)

    Skauen, Andreas Nordmo

    2016-01-01

    The Norwegian Defence Research Establishment (FFI) has operated three Automatic Identification System (AIS) receivers in space. Two are on dedicated nano-satellites, AISSat-1 and AISSat-2. The third, the NORAIS Receiver, was installed on the International Space Station. A general method for calculating the upper bound on the tracking capability of a space-based AIS system has been developed and the results from the algorithm applied to AISSat-1 and the NORAIS Receiver individually. In addition, a constellation of AISSat-1 and AISSat-2 is presented. The tracking capability is defined as the probability of re-detecting ships as they move around the globe and is explained to represent and upper bound on a space-based AIS system performance. AISSat-1 and AISSat-2 operates on the nominal AIS1 and AIS2 channels, while the NORAIS Receiver data used are from operations on the dedicated space AIS channels, AIS3 and AIS4. The improved tracking capability of operations on the space AIS channels is presented.

  2. Risk Factors for Enterovirus A71 Seropositivity in Rural Indigenous Populations in West Malaysia.

    PubMed

    NikNadia, Nmn; Sam, I-Ching; Khaidir, Nasibah; Ngui, Romano; Lim, Yvonne A L; Goh, Xiang Ting; Choy, Seow Huey; Chan, Yoke Fun

    2016-01-01

    Enterovirus A71 (EV-A71), which is transmitted by the fecal-oral route, causes hand, foot and mouth disease and, rarely, severe neurological complications. In Malaysia, the indigenous rural community (Orang Asli) has a high prevalence of parasitic diseases due to poor sanitation, water supply and hygiene practices. This cross-sectional study compared the seroepidemiology of EV-A71 among rural Orang Asli and urban Kuala Lumpur populations in West Malaysia, and determined the risk factors associated with EV-A71 seropositivity in rural Orang Asli. Seropositive rates were determined by neutralization assay. EV-A71 seropositivity was strongly associated with increasing age in both populations. Rural Orang Asli children ≤12 years had significantly higher EV-A71 seropositivity rates than urban Kuala Lumpur children (95.5% vs 57.6%, P < 0.001), and also higher rates in the age groups of 1-3, 4-6 and 7-12 years. Multivariate analysis confirmed that age ≤12 years (adjusted OR 8.1, 95% CI 3.2-20.7, P < 0.001) and using untreated water (adjusted OR 6.2, 95% CI 2.3-16.6, P < 0.001) were independently associated with EV-A71 seropositivity in the Orang Asli population. Supply of clean drinking water may reduce the risk of EV-A71 infection. With significantly higher EV-A71 seropositive rates, younger rural children should be a priority target for future vaccination programs in Malaysia.

  3. Risk Factors for Enterovirus A71 Seropositivity in Rural Indigenous Populations in West Malaysia

    PubMed Central

    NikNadia, NMN; Sam, I-Ching; Khaidir, Nasibah; Ngui, Romano; Lim, Yvonne A. L.; Goh, Xiang Ting; Choy, Seow Huey; Chan, Yoke Fun

    2016-01-01

    Enterovirus A71 (EV-A71), which is transmitted by the fecal-oral route, causes hand, foot and mouth disease and, rarely, severe neurological complications. In Malaysia, the indigenous rural community (Orang Asli) has a high prevalence of parasitic diseases due to poor sanitation, water supply and hygiene practices. This cross-sectional study compared the seroepidemiology of EV-A71 among rural Orang Asli and urban Kuala Lumpur populations in West Malaysia, and determined the risk factors associated with EV-A71 seropositivity in rural Orang Asli. Seropositive rates were determined by neutralization assay. EV-A71 seropositivity was strongly associated with increasing age in both populations. Rural Orang Asli children ≤12 years had significantly higher EV-A71 seropositivity rates than urban Kuala Lumpur children (95.5% vs 57.6%, P < 0.001), and also higher rates in the age groups of 1–3, 4–6 and 7–12 years. Multivariate analysis confirmed that age ≤12 years (adjusted OR 8.1, 95% CI 3.2–20.7, P < 0.001) and using untreated water (adjusted OR 6.2, 95% CI 2.3–16.6, P < 0.001) were independently associated with EV-A71 seropositivity in the Orang Asli population. Supply of clean drinking water may reduce the risk of EV-A71 infection. With significantly higher EV-A71 seropositive rates, younger rural children should be a priority target for future vaccination programs in Malaysia. PMID:26866912

  4. Sensitivity of two-stage sampling to detect sheep biting lice (Bovicola ovis) in infested flocks.

    PubMed

    James, P J; Garrett, J A; Moon, R D

    2002-01-03

    The sampling distribution of Bovicola ovis (Schrank) on sheep was examined in two flocks, one with a light and one with a heavy infestation of lice. The derived distributions were used to calculate the sensitivity of detecting lice on individual sheep and in flocks by fleece parting regimes that varied in number of parts per animal and number of sheep per flock, different scenarios of flock sizes, proportion infested and louse density were examined. Lice were aggregated among fleece partings in the heavily infested flock and described by a negative binomial distribution with k values between 0.3 and 1.92. The distribution was indistinguishable from Poisson in the lightly infested flock. The assumed distribution had little effect on sensitivity, except when only one fleece part per animal was examined. On individual sheep where louse density was 0.5 per 10 cm part or greater, there were only marginal gains from inspecting more than 10 parts per animal. Increasing the number of sheep inspected always increased sensitivity more than increasing number of parts per sheep by an equivalent amount. This advantage was greatest in situations where a low proportion of sheep in the flock were infested with a high density of lice, and less where a low proportion of sheep were infested with a low density of lice, or a high proportion of sheep were infested with a high density of lice.

  5. Structure and dynamics of mixed-species flocks in a Hawaiian rain forest

    USGS Publications Warehouse

    Hart, P.J.; Freed, L.A.

    2003-01-01

    Mixed-species flocks of native and introduced birds were studied for four years in an upper elevation Hawaiian rain forest. Those flocks were characterized by strong seasonality, large size, low species richness, high intraspecific abundance, a lack of migrants, and a general lack of territoriality or any sort of dominance hierarchy. There was high variability among years in patterns of occurrence at the species level, and high variability within years at the individual level. These flocks are loosely structured social groupings with apparently open membership. The fluid, unstable movement patterns, high degree of variability in size and composition, and lack of positive interspecific associations are not consistent with the "foraging enhancement" hypothesis for flocking. Two resident, endangered insectivores, the Akepa (Loxops coccineus) and Hawaii Creeper (Oreomystis mana) served as "nuclear" species. Flock composition was compared between two study sites that differed significantly in density of these two nuclear species. Flock size was similar at the two sites, primarily because the nuclear species were over-represented relative to their density. This observation suggests that birds are attempting to achieve a more optimal flock size at the lower density site.

  6. The dynamics of Salmonella occurrence in commercial laying hen flocks throughout a laying period.

    PubMed

    Schulz, J; Van Hoorebeke, S; Hald, B; Hartung, J; Van Immerseel, F; Radtke, I; Kabell, S; Dewulf, J

    2011-06-01

    Contaminated eggs and egg products have been recognized for many years as an important source of Salmonella infections in humans in the European Union and in the United States. Longitudinal studies can help to increase our knowledge about the dynamics of the occurrence of Salmonella in the course of a laying period. The total of 41 laying hen flocks-18 in Belgium, six in Denmark and 17 in Germany-were followed during an entire laying period. Samples taken from the empty cleaned and disinfected poultry houses were all negative for Salmonella. After hens arrived on the farms, five pooled faecal samples, one pooled dust sample and 40 cloacal swabs (Belgium and Germany) or 40 swabs from fresh droppings (Denmark) were taken four times from 18 flocks, three times from 21 flocks and two times from two flocks in the course of the laying period. Ten flocks (two Belgian and eight German flocks) tested up to three times positive for Salmonella. Forty-three out of 50 positive samples contained Salmonella Enteritidis phage type 4 (29 isolates) or phage type 8 (14 isolates). The probability of subsequent Salmonella-positive findings increased significantly in Salmonella-positive flocks (P<0.05, odds ratio = 6.4). However, the probability of finding Salmonella did not depend on the time of sampling in the laying period or the season.

  7. Coxiella burnetii seropositivity and associated risk factors in goats in Ontario, Canada.

    PubMed

    Meadows, S; Jones-Bitton, A; McEwen, S; Jansen, J; Menzies, P

    2015-10-01

    Coxiella burnetii is a zoonotic bacterium, and infection in goats with this bacterium can result in abortion, stillbirth or birth of non-viable kids. A cross-sectional study was conducted to identify the seroprevalence and risk factors for C. burnetii exposure in Ontario goats. Sera were collected between August 2010 and February 2012, and tested for C. burnetii specific antibodies using an enzyme-linked immunosorbent assay (IDEXX). Overall, 63.2% (48/76, 95% CI=51.9-73.4) of farms had one or more seropositive goats. A higher farm-level seroprevalence of 78.6% (33/42) was found on dairy goat farms, compared to 44.1% (15/34) on meat goat farms (p<0.01). At the overall individual-animal level, 32.5% (714/2195, 95% CI=30.6-34.5) of goats were seropositive. Similarly, a higher individual-level seroprevalence was identified for dairy goats (43.7%, 633/1447) compared to meat goats (10.8%, 81/748) (p<0.001). A mixed multivariable logistic model that controlled for farm-level clustering identified risk factors associated with seropositivity (p<0.05). Increases in the female herd size (logarithmic scale) were associated with increased odds of seropositivity, while increases in male herd size had a negative association with seropositivity. If other sheep or goat farms were located in a 5-km radius, goats had 5.6 times (95% CI=1.01-30.8) times the odds of seropositivity compared to those that were not. Relative to goats from farms where all kidding pen hygiene was practiced (adding bedding, removing birth materials and disinfection after kidding), goats from farms which only added bedding and removed birth materials had a higher odds of seropositivity (OR=19.3, 95% CI=1.1-330.4), as did goats from farms which practiced none of these measures (OR=161.0, 95% CI=2.4-10822.2). An interaction term revealed kidding outdoors when there were no swine on farm had a protective effect on seropositivity compared to kidding indoors, or kidding outdoors with swine on the farm. These

  8. Phenotypic Alteration of Neutrophils in the Blood of HIV Seropositive Patients

    PubMed Central

    Cloke, Tom; Munder, Markus; Bergin, Philip; Herath, Shanthi; Modolell, Manuel; Taylor, Graham; Müller, Ingrid; Kropf, Pascale

    2013-01-01

    We have recently identified a novel population of activated low-density granulocytes (LDGs) in peripheral blood mononuclear cells of HIV seropositive patients. LDGs have a similar morphology to normal density granulocytes (NDGs), but are phenotypically different. Here we measured the expression levels of different phenotypic markers of granulocytes in the blood of HIV seropositive patients at different stages of HIV infection to determine whether the phenotype of NDGs and LDGs are affected by disease severity. Our results reveal that the phenotype of NDGs, but not that of LDGs, varies according to the severity of the disease. PMID:24039734

  9. AI tools in computer based problem solving

    NASA Technical Reports Server (NTRS)

    Beane, Arthur J.

    1988-01-01

    The use of computers to solve value oriented, deterministic, algorithmic problems, has evolved a structured life cycle model of the software process. The symbolic processing techniques used, primarily in research, for solving nondeterministic problems, and those for which an algorithmic solution is unknown, have evolved a different model, much less structured. Traditionally, the two approaches have been used completely independently. With the advent of low cost, high performance 32 bit workstations executing identical software with large minicomputers and mainframes, it became possible to begin to merge both models into a single extended model of computer problem solving. The implementation of such an extended model on a VAX family of micro/mini/mainframe systems is described. Examples in both development and deployment of applications involving a blending of AI and traditional techniques are given.

  10. Human Frontal Lobes and AI Planning Systems

    NASA Technical Reports Server (NTRS)

    Levinson, Richard; Lum, Henry Jr. (Technical Monitor)

    1994-01-01

    Human frontal lobes are essential for maintaining a self-regulating balance between predictive and reactive behavior. This paper describes a system that integrates prediction and reaction based on neuropsychological theories of frontal lobe function. In addition to enhancing our understanding of deliberate action in humans' the model is being used to develop and evaluate the same properties in machines. First, the paper presents some background neuropsychology in order to set a general context. The role of frontal lobes is then presented by summarizing three theories which formed the basis for this work. The components of an artificial frontal lobe are then discussed from both neuropsychological and AI perspectives. The paper concludes by discussing issues and methods for evaluating systems that integrate planning and reaction.

  11. Application of AIS Technology to Forest Mapping

    NASA Technical Reports Server (NTRS)

    Yool, S. R.; Star, J. L.

    1985-01-01

    Concerns about environmental effects of large scale deforestation have prompted efforts to map forests over large areas using various remote sensing data and image processing techniques. Basic research on the spectral characteristics of forest vegetation are required to form a basis for development of new techniques, and for image interpretation. Examination of LANDSAT data and image processing algorithms over a portion of boreal forest have demonstrated the complexity of relations between the various expressions of forest canopies, environmental variability, and the relative capacities of different image processing algorithms to achieve high classification accuracies under these conditions. Airborne Imaging Spectrometer (AIS) data may in part provide the means to interpret the responses of standard data and techniques to the vegetation based on its relatively high spectral resolution.

  12. Competition in foraging flocks of migrating semipalmated sandpipers.

    PubMed

    Beauchamp, Guy

    2007-11-01

    I examined the effect of competitor density on foraging success in staging semipalmated sandpipers (Calidris pusilla) foraging on a burrowing amphipod (Corophium volutator) in each of two study years. Little is known about the effect of competitor density when predation attempts disturb prey, causing a temporary decrease in food availability. Controlling for Corophium density and other potentially confounding factors such as temperature, pecking rate and capture rate increased linearly with sandpiper density. Success rate, the ratio of captures to pecks, was not influenced by sandpiper density. The effect of sandpiper density was similar in each of the two study years and was documented early and late in the low tide period. The increase in foraging rate is argued to be a response to increased competition for rapidly depleting prey at the temporal scale of exploitation by a flock. Potential fitness costs associated with higher foraging costs may include decreased ability to distinguish between the profitability of different prey and reduced vigilance against predators.

  13. A Density-Independent Flocking Transition in Confluent Tissues

    NASA Astrophysics Data System (ADS)

    Czajkowski, Michael; Bi, Dapeng; Manning, M. Lisa; Marchetti, M. Cristina

    Some of us recently demonstrated a density-independent solid-liquid transition in confluent tissues controlled by cell motility and a cell shape parameter measuring the interplay of cortical tension and cell-cell adhesion. An important insight of this work is that the rigidity and dynamics of cell layers depends sensitively on cell shape. To explore the influence of cell shape on collective states, we have constructed continuum equations that couple a scalar field describing cell-shape anisotropy to cell polarization. The model displays a density independent transition to a polarized state of elongated cells driven by a cellular ``shape-index'' parameter. We map out the phase diagram using linear stability analysis and numerical solution of the nonlinear hydrodynamic equations. The proposed transition constitutes a density-independent flocking transition. We acknowledge support from The Simons Foundation and NSF-DGE-1068780.

  14. Adaptive Flocking of Robot Swarms: Algorithms and Properties

    NASA Astrophysics Data System (ADS)

    Lee, Geunho; Chong, Nak Young

    This paper presents a distributed approach for adaptive flocking of swarms of mobile robots that enables to navigate autonomously in complex environments populated with obstacles. Based on the observation of the swimming behavior of a school of fish, we propose an integrated algorithm that allows a swarm of robots to navigate in a coordinated manner, split into multiple swarms, or merge with other swarms according to the environment conditions. We prove the convergence of the proposed algorithm using Lyapunov stability theory. We also verify the effectiveness of the algorithm through extensive simulations, where a swarm of robots repeats the process of splitting and merging while passing around multiple stationary and moving obstacles. The simulation results show that the proposed algorithm is scalable, and robust to variations in the sensing capability of individual robots.

  15. AI And Early Vision - Part II

    NASA Astrophysics Data System (ADS)

    Julesz, Bela

    1989-08-01

    A quarter of a century ago I introduced two paradigms into psychology which in the intervening years have had a direct impact on the psychobiology of early vision and an indirect one on artificial intelligence (AI or machine vision). The first, the computer-generated random-dot stereogram (RDS) paradigm (Julesz, 1960) at its very inception posed a strategic question both for AI and neurophysiology. The finding that stereoscopic depth perception (stereopsis) is possible without the many enigmatic cues of monocular form recognition - as assumed previously - demonstrated that stereopsis with its basic problem of finding matches between corresponding random aggregates of dots in the left and right visual fields became ripe for modeling. Indeed, the binocular matching problem of stereopsis opened up an entire field of study, eventually leading to the computational models of David Marr (1982) and his coworkers. The fusion of RDS had an even greater impact on neurophysiologists - including Hubel and Wiesel (1962) - who realized that stereopsis must occur at an early stage, and can be studied easier than form perception. This insight recently culminated in the studies by Gian Poggio (1984) who found binocular-disparity - tuned neurons in the input stage to the visual cortex (layer IVB in V1) in the monkey that were selectively triggered by dynamic RDS. Thus the first paradigm led to a strategic insight: that with stereoscopic vision there is no camouflage, and as such was advantageous for our primate ancestors to evolve the cortical machinery of stereoscopic vision to capture camouflaged prey (insects) at a standstill. Amazingly, although stereopsis evolved relatively late in primates, it captured the very input stages of the visual cortex. (For a detailed review, see Julesz, 1986a)

  16. Scale-Free Correlations, Influential Neighbours and Speed Control in Flocks of Birds

    NASA Astrophysics Data System (ADS)

    Hemelrijk, Charlotte K.; Hildenbrandt, Hanno

    2015-02-01

    Coordination of birds in large flocks is amazing, especially, since individual birds only interact with a few neighbors (the so-called `influential neighbours'). Yet, empirical data show that fluctuations of velocity and speed of different birds are correlated beyond the influential neighbours and are correlated over a larger distance in a larger flock. This correlation between the correlation length of velocity or speed and flock size was found to be linear, called a scale-free correlation. It depends on the way individuals interact in the flock, for instance, on the number of influential neighbours and speed control. It is unknown however, how exactly the number of influential neighbours affects this scale-free correlation. Recent empirical data show that different degrees of control of speed affect the scale-free correlation for speed fluctuations. Theoretically, based on statistical mechanics, it is predicted that at very high speed control, the correlation is no longer scale-free but saturates at a certain correlation length and this hampers coordination in flocks. We study these issues in a model, called StarDisplay, because its behavioural rules are biologically inspired and many of its flocking patterns resemble empirical data. Our results show that the correlation length of fluctuations of velocity as well as speed correlate with flock size in a scale-free manner. A higher number of influential neighbours causes a diminishing increase of the slope of the scale-free correlation with velocity, resulting thus in flocks that coordinate more uniformly. Similar to recent empirical data higher speed control reduces the correlation length of speed fluctuations in our model. As predicted theoretically, at very high speed control the model generates a non-scale free correlation, and although there are still flocks, they are in the process of disintegrating.

  17. Risk of Salmonella transmission via cryopreserved semen in turkey flocks.

    PubMed

    Iaffaldano, N; Reale, A; Sorrentino, E; Coppola, R; Di Iorio, M; Rosato, M P

    2010-09-01

    To investigate the possibility to carry pathogen bacteria in turkey flocks via cryopreserved semen, research was carried out 1) to investigate the microbial contamination of fresh and frozen thawed turkey semen and 2) to evaluate the effect of the freezing-thawing process on the survival of 3 serovars of Salmonella spp. experimentally inoculated in turkey semen. Five pools of semen diluted 4-fold were cooled, added with 8% of dimethylacetamide as a cryoprotectant, and aliquots of 80 muL were directly plunged into liquid nitrogen to form frozen pellets. Mesophilic viable counts, total and fecal coliforms, Enterobacteriaceae, enterococci, Campylobacter spp., and Salmonella spp. were investigated on fresh and thawed samples. Further, 5 pools of diluted semen were each divided into 3 subsamples, inoculated with 7.8 +/- 0.2 log cfu.mL(-1) of Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup, respectively, and cryopreserved before to assess the postthaw viability of Salmonella spp. strains. Fresh semen was highly contaminated by all of the saprophytic bacteria investigated and the cryopreservation process reduced the amount of mesophilic viable count and total coliforms (P < 0.05) and fecal coliforms, Enterobacteriaceae, and enterococci (P < 0.01) by about 1 log cfu.mL(-1). Conversely, neither Campylobacter spp. nor Salmonella spp. were found as endogenous bacteria in semen. In the inoculated semen, both Salmonella Liverpool, Salmonella Montevideo, and Salmonella Braenderup colonies were recovered postthaw, showing a significant reduction of 2.03 +/- 0.28, 3.08 +/- 0.22, and 2.72 +/- 0.23 log cfu.mL(-1), respectively, compared with the fresh semen (P < 0.001). In conclusion, the cryopreservation process allowed us to obtain a low reduction of microbial count both in endogenous saprophytic bacteria and artificially inoculated Salmonella spp. strains; therefore, the possibility of Samonella spp. transmission to flocks through the use of infected

  18. Genetic IS901 RFLP diversity among Mycobacterium avium subsp. avium isolates from four pheasant flocks.

    PubMed

    Moravkova, Monika; Lamka, Jiri; Slany, Michal; Pavlik, Ivo

    2013-01-01

    IS901 RFLP analysis of 36 Mycobacterium avium subsp. avium (MAA) isolates from 15 pheasants (Phasianus colchicus) and two goshawks (Accipiter gentilis) from four pheasant farms was performed. Using this method, six different IS901 RFLP types (E, F, G, M, Q, and V) were identified. The distribution of IS901 RFLP profiles was tightly linked to individual flocks. Matching IS901 RFLP profiles observed in the present study indicate MAA transmission between pheasants and goshawks in the same locality. In two flocks, different pheasants within a flock as well as in various organs of five individual pheasants were found to have two distinct IS901 RFLP profiles.

  19. Worm control practice against gastro-intestinal parasites in Norwegian sheep and goat flocks

    PubMed Central

    2011-01-01

    Background Anthelmintic treatment is the most common way of controlling nematode infections in ruminants. However, several countries have reported anthelmintic resistance (AR), representing a limitation for sustainable small ruminant production. The knowledge regarding worm control management represents a baseline to develop a guideline for preventing AR. The aim of the present study was therefore to improve our knowledge about the worm control practices in small ruminant flocks in Norway. Methods A questionnaire survey regarding worm control practices was performed in small ruminant flocks in Norway. Flocks were selected from the three main areas of small ruminant farming, i.e. the coastal, inland and northern areas. A total of 825 questionnaires, comprising 587 sheep flocks (return rate of 51.3%) and 238 goat flocks (52.6%) were included. Results The results indicated that visual appraisal of individual weight was the most common means of estimating the anthelmintic dose used in sheep (78.6%) and goat (85.1%) flocks. The mean yearly drenching rate in lambs and ewes were 2.5 ± 1.7 and 1.9 ± 1.1, respectively, whereas it was 1.0 (once a year) in goats. However, these figures were higher in sheep in the coastal area with a rate of 3.4 and 2.2 in lambs and ewes, respectively. Benzimidazoles were the predominant anthelmintic class used in sheep flocks (64.9% in 2007), whereas benzimidazoles and macrocyclic lactones were both equally used in dairy goat flocks. In the period of 2005-2007, 46.3% of the sheep flocks never changed the anthelmintic class. The dose and move strategy was practiced in 33.2% of the sheep flocks. Conclusions The present study showed that inaccurate weight calculation gives a risk of under-dosing in over 90% of the sheep and goat flocks in Norway. Taken together with a high treatment frequency in lambs, a lack of anthelmintic class rotation and the common use of a dose-and-move strategy, a real danger for development of anthelmintic resistance

  20. Ada in AI or AI in Ada. On developing a rationale for integration

    NASA Technical Reports Server (NTRS)

    Collard, Philippe E.; Goforth, Andre

    1988-01-01

    The use of Ada as an Artificial Intelligence (AI) language is gaining interest in the NASA Community, i.e., by parties who have a need to deploy Knowledge Based-Systems (KBS) compatible with the use of Ada as the software standard for the Space Station. A fair number of KBS and pseudo-KBS implementations in Ada exist today. Currently, no widely used guidelines exist to compare and evaluate these with one another. The lack of guidelines illustrates a fundamental problem inherent in trying to compare and evaluate implementations of any sort in languages that are procedural or imperative in style, such as Ada, with those in languages that are functional in style, such as Lisp. Discussed are the strengths and weakness of using Ada as an AI language and a preliminary analysis provided of factors needed for the development of criteria for the integration of these two families of languages and the environments in which they are implemented. The intent for developing such criteria is to have a logical rationale that may be used to guide the development of Ada tools and methodology to support KBS requirements, and to identify those AI technology components that may most readily and effectively be deployed in Ada.

  1. Pedagogy and the PC: Trends in the AIS Curriculum

    ERIC Educational Resources Information Center

    Badua, Frank

    2008-01-01

    The author investigated the array of course topics in accounting information systems (AIS), as course syllabi embody. The author (a) used exploratory data analysis to determine the topics that AIS courses most frequently offered and (b) used descriptive statistics and econometric analysis to trace the diversity of course topics through time,…

  2. Integrating the Wall Street Journal into AIS Courses

    ERIC Educational Resources Information Center

    Kohlmeyer, James M., III

    2008-01-01

    While it is important for accounting information systems (AIS) students to understand computer technology, internal controls and business processes, such knowledge is of little use without reference to appropriate contexts. Integrating Wall Street Journal (WSJ) readings and discussions into AIS classes can enrich learning by stimulating…

  3. An Immune Agent for Web-Based AI Course

    ERIC Educational Resources Information Center

    Gong, Tao; Cai, Zixing

    2006-01-01

    To overcome weakness and faults of a web-based e-learning course such as Artificial Intelligence (AI), an immune agent was proposed, simulating a natural immune mechanism against a virus. The immune agent was built on the multi-dimension education agent model and immune algorithm. The web-based AI course was comprised of many files, such as HTML…

  4. Prevalence and risk factors for Coxiella burnetii seropositivity in small ruminant veterinarians and veterinary students in Ontario, Canada.

    PubMed

    Meadows, Shannon L; Jones-Bitton, Andria; McEwen, Scott A; Jansen, Jocelyn; Patel, Samir N; Filejski, Catherine; Menzies, Paula

    2017-04-01

    Coxiella burnetii is a zoonotic pathogen that causes Q fever in humans. Serological and questionnaire data on C. burnetii were obtained from 32 small ruminant veterinarians and veterinary students in Ontario, Canada, in February 2012. Overall, 59% of participants were seropositive; advanced stage of career and increased age were associated with seropositivity.

  5. Household risk factors for Trypanosoma cruzi seropositivity in two geographic regions of Ecuador.

    PubMed

    Black, Carla L; Ocaña, Sofia; Riner, Diana; Costales, Jaime A; Lascano, Mauricio S; Davila, Santiago; Arcos-Teran, Laura; Seed, J Richard; Grijalva, Mario J

    2007-02-01

    Few studies on the relationship between environmental factors and Trypanosoma cruzi transmission have been conducted in Ecuador. We conducted a cross-sectional study of household risk factors for T. cruzi seropositivity in 2 distinct geographical regions of Ecuador. Exposure information was collected via household surveys, and subjects were tested for serological evidence of T. cruzi infection. In total, 3,286 subjects from 997 households were included. In the coastal region, factors associated with seropositivity were living in a house with a palm roof (odds ratio [OR] = 2.63, 95% confidence interval, [1.61. 4.27]), wood walls (OR = 5.75 [2.04, 16.18]), or cane walls (OR = 2.81 11.31, 6.04]), and the presence of firewood in the peridomicile (OR = 2.48 [1.54, 4.01]). Accumulation of trash outside the home was associated with a reduced risk of seropositivity (OR = 0.25 [0.12, 0.51]). In the Andean region, living in a house with adobe walls was the only factor predictive of T. cruzi seropositivity. In conclusion, risk factors for T. cruzi transmission in Ecuador varied by geographic region, probably because of differing behavior of the triatomine vector species in each region. An understanding of the transmission dynamics of T. cruzi in a particular area is necessary for the development of effective Chagas disease control strategies in those areas.

  6. Obstructive nephropathy due to sulfa crystals in two HIV seropositive patients treated with sulfadiazine.

    PubMed

    Colebunders, R; Depraetere, K; De Droogh, E; Kamper, A; Corthout, B; Bottiau, E

    1999-08-01

    Two HIV seropositive patients receiving sulfadiazine for presumed cerebral toxoplasmosis who developed an obstructive nephropathy are described. Ultrasound examination showed respectively a bilateral hydro-ureteronephrosis in one patient and unilateral hydro-ureteronephrosis in the other. The obstructive nephropathy resolved in both patients with alkalic hydration and discontinuation of the sulfadiazine.

  7. Prevention for HIV-Seropositive Persons: Successive Approximation Toward a New Identity

    ERIC Educational Resources Information Center

    Lightfoot, Marguerita; Rotheram-Borus, Mary Jane; Milburn, Norweeta G.; Swendeman, Dallas

    2005-01-01

    This article presents a three-module intervention based on social action theory that focuses on health promotion and social identity formation for seropositive youth. The modules are designed to reduce transmission of HIV by reducing sexual and substance abuse acts, increasing healthy acts and adherence to care, and maintaining positive behavioral…

  8. Toxoplasma gondii seropositivity and cognitive functions in school-aged children.

    PubMed

    Mendy, A; Vieira, E R; Albatineh, A N; Gasana, J

    2015-08-01

    Toxoplasma gondii (T. gondii) infects one-third of the world population, but its association with cognitive functions in school-aged children is unclear. We examined the relationship between Toxoplasma seropositivity and neuropsychological tests scores (including math, reading, visuospatial reasoning and verbal memory) in 1755 school-aged children 12-16 years old who participated to the Third National Health and Nutrition Examination Survey, using multiple linear regressions adjusted for covariates. Toxoplasma seroprevalence was 7·7% and seropositivity to the parasite was associated with lower reading skills (regression coefficient [β] = -5·86, 95% confidence interval [CI]: -11·11, -0·61, P = 0·029) and memory capacities (β = -0·86, 95% CI: -1·58, -0·15, P = 0·017). The interaction between T. gondii seropositivity and vitamin E significantly correlated with memory scores. In subgroup analysis, Toxoplasma-associated memory impairment was worse in children with lower serum vitamin E concentrations (β = -1·61, 95% CI: -2·44, -0·77, P < 0·001) than in those with higher values (β = -0·12, 95% CI: -1·23, 0·99, P = 0·83). In conclusion, Toxoplasma seropositivity may be associated with reading and memory impairments in school-aged children. Serum vitamin E seems to modify the relationship between the parasitic infection and memory deficiency.

  9. Persistent seropositivity for yellow fever in a previously vaccinated autologous hematopoietic stem cell transplantation recipient.

    PubMed

    Hayakawa, Kayoko; Takasaki, Tomohiko; Tsunemine, Hiroko; Kanagawa, Shuzo; Kutsuna, Satoshi; Takeshita, Nozomi; Mawatari, Momoko; Fujiya, Yoshihiro; Yamamoto, Kei; Ohmagari, Norio; Kato, Yasuyuki

    2015-08-01

    The duration of a protective level of yellow fever antibodies after autologous hematopoietic stem cell transplantation in a previously vaccinated person is unclear. The case of a patient who had previously been vaccinated for yellow fever and who remained seropositive for 22 months after autologous peripheral blood stem cell transplantation for malignant lymphoma is described herein.

  10. Thoughts of Death and Suicidal Ideation in Nonpsychiatric Human Immunodeficiency Virus Seropositive Individuals

    ERIC Educational Resources Information Center

    Robertson, Kevin; Parsons, Thomas D.; van der Horst, Charles; Hall, Colin

    2006-01-01

    The present study examines the prevalence of death thoughts and suicidality in HIV infection. Subjects (n=246) were examined for psychiatric morbidity and suicidality. Compared to high risk HIV seronegatives, HIV seropositives (HIV+) had significantly increased frequency and severity of both suicidal ideation and death thoughts. Two-thirds of…

  11. Doctor AI: Predicting Clinical Events via Recurrent Neural Networks

    PubMed Central

    Choi, Edward; Bahadori, Mohammad Taha; Schuetz, Andy; Stewart, Walter F.; Sun, Jimeng

    2017-01-01

    Leveraging large historical data in electronic health record (EHR), we developed Doctor AI, a generic predictive model that covers observed medical conditions and medication uses. Doctor AI is a temporal model using recurrent neural networks (RNN) and was developed and applied to longitudinal time stamped EHR data from 260K patients over 8 years. Encounter records (e.g. diagnosis codes, medication codes or procedure codes) were input to RNN to predict (all) the diagnosis and medication categories for a subsequent visit. Doctor AI assesses the history of patients to make multilabel predictions (one label for each diagnosis or medication category). Based on separate blind test set evaluation, Doctor AI can perform differential diagnosis with up to 79% recall@30, significantly higher than several baselines. Moreover, we demonstrate great generalizability of Doctor AI by adapting the resulting models from one institution to another without losing substantial accuracy. PMID:28286600

  12. Seropositivity among Korean Young Adults Approximately 2 Years after a Single-Dose Vaccination against Hepatitis A Virus.

    PubMed

    Song, Yeong-Jun; Lim, Jiseun; Park, Woong-Sub; Sohn, Haesook; Lee, Moo-Sik; Shin, Dong-Hoon; Kim, Chun-Bae; Kim, Hwasung; Oh, Gyung-Jae; Ki, Moran

    2015-01-01

    We previously observed 80.7% seropositivity and a significant interaction between gender and hepatitis A virus (HAV) vaccine type (Havrix vs. Epaxal) on the seropositivity approximately 11 months after single-dose HAV vaccinations in Korean young adults. Our objective was to evaluate seropositivity approximately 2 years after a single-dose HAV vaccination and the influence of demographic characteristics on seropositivity, including the interaction between gender and vaccine type. Seronegative medical school students were randomly vaccinated with Havrix or Epaxal. Based on a total serum anti-HAV antibody titer cutoff of 20 IU/mL, 338 participants (76.0%) of the 445 vaccinees were seropositive 20-25 months after a single-dose HAV vaccination. The seropositive rates were similar after vaccination with Havrix (77.0%) and Epaxal (74.9%). Univariate analysis indicated that female (p = 0.052) and less obese (p < 0.001) participants had a higher seropositive rate, whereas other characteristics such as age, alcohol use, smoking history, vaccine type, and follow-up duration were not associated with seropositivity. Multivariate analysis indicated that women (p = 0.026) and participants with moderate alcohol use (p < 0.001) showed significantly higher seropositive rates than men and participants with no or low alcohol use, respectively. The seropositive rates after vaccination with Havrix and Epaxal were 70.9% and 67.5% in men and 87.7% and 91.3% in women, respectively (p for interaction = 0.304). Compared with the seropositive rate approximately 11 months after vaccination, the seropositive rate decreased substantially only in men in the Havrix group (11.0% points), and consequently, the interaction between gender and vaccine type disappeared while seropositivity remained high (87.7% and 91.3% in Havrix and Epaxal groups, respectively) among women approximately 2 years after vaccination. Further studies are needed to assess whether the seropositive rate would be maintained in

  13. Atypical velogenic Newcastle disease in a commercial layer flock in Japan.

    PubMed

    Umali, Dennis V; Ito, Hiroshi; Shirota, Kazutoshi; Ito, Toshihiro; Katoh, Hiromitsu

    2015-05-01

    In 2002, a commercial layer flock in Japan was initially diagnosed as being infected with infectious bronchitis (IB) based on clinical signs, virus isolation, and serological analysis but was later found to be atypically infected with velogenic Newcastle disease virus (NDV) following molecular diagnosis. The flock had slightly decreased egg production and an increased occurrence of soft-shelled eggs without significant mortality. IB-like viruses were isolated, which caused dwarfing and curling in 12-day-old chicken embryos. Ten years after this case, retrospective genetic analyses showed that apart from IB virus (IBV), the flock was also infected with NDV. Mean death time (MDT), intracerebral pathogenicity index (ICPI), and deduced amino acid sequence of the cleavage site of the fusion (F)-protein gene revealed that the NDV isolate was velogenic ((112)RRQKR(116)). These results indicate that poultry clinicians should look out for atypical velogenic ND, especially in vaccinated commercial chicken flocks, which may harbor hidden NDV infection.

  14. Reduction of campylobacter infections in broiler flocks by application of hygiene measures.

    PubMed Central

    van de Giessen, A. W.; Tilburg, J. J.; Ritmeester, W. S.; van der Plas, J.

    1998-01-01

    Transmission routes of Campylobacter spp. in broilers and possibilities for prevention of infections were studied on two Dutch broiler farms. The occurrence of Campylobacter spp. was studied in successive broiler flocks, in the environment of the farms and in some of the parent flocks involved. Isolates of Campylobacter spp. were typed by using randomly amplified polymorphic DNA (RAPD) analysis. The results indicate that broiler flocks become infected from environmental sources. The typing results suggest that on one farm transmission of Campylobacter spp. occurred from cattle to broilers via the farmer's footwear. After several campylobacter positive broiler cycles hygiene measures, including thorough cleaning and disinfection procedures, change of footwear at the entrance of each broiler house, control of vermin and other hygienic precautions, were introduced on both farms in order to prevent transmission of Campylobacter spp. from the farm environment to the broilers. The results indicate that the application of hygiene measures significantly reduced campylobacter infections of broiler flocks on both farms. PMID:9747756

  15. Predator avoidance as a function of flocking in the sexually dichromatic Hawaii akepa

    USGS Publications Warehouse

    Hart, P.J.; Freed, L.A.

    2005-01-01

    Hypotheses for joining a mixed-species bird flock consider each species as a single unit. In sexually dichromatic birds, differential conspicuousness between the sexes may result in differences in vigilance for predators. Aspects of the predator avoidance and foraging enhancement hypotheses for the selective value of joining a mixed-species flock were assessed for the strongly sexually dichromatic Hawaii akepa (Loxops coccineus coccineus). There was support for the primary predictions of the predator avoidance hypothesis: vigilance levels decreased with increasing group size, and with membership in a flock, but only for brightly colored adult males. There was little support for the hypothesis that the primary benefit of joining a mixed-species flock is to enhance foraging efficiency through "local enhancement".

  16. Risk factors for Campylobacter spp. infection in Senegalese broiler-chicken flocks.

    PubMed

    Cardinale, E; Tall, F; Guèye, E F; Cisse, M; Salvat, G

    2004-06-10

    Our objective was to identify the risk factors for Campylobacter infection in Senegalese broiler flocks. Seventy broiler farms were studied around Dakar from January 2000 to December 2001 around Dakar. A questionnaire was administered to the farmers, and samples of fresh droppings were taken to assess the flocks' Campylobacter status. About 63% of the flocks were infected by Campylobacter spp.; Campylobacter jejuni was the most-prevalent species (P < 0.05). An elevated risk of Campylobacter infection was associated with other animals (mainly laying hens, cattle and sheep) being bred in the farm, the farm staff not wearing their work clothing exclusively in the poultry houses, uncemented poultry-house floors and the use of cartons that transport chicks from the hatchery to the farm as feed plates (rather than specifically designed feed plates). Alternatively, thorough cleaning and disinfection of poultry-house surroundings and manure disposal outside the farm were associated with decreased flock risk.

  17. Seropositivity of Toxoplasmosis in Pregnant Women by ELISA at Minia University Hospital, Egypt.

    PubMed

    Kamal, Amany M; Ahmed, Azza K; Abdellatif, Manal Z M; Tawfik, Mohamed; Hassan, Ebtesam E

    2015-10-01

    Toxoplasmosis is considered as an important risk factor for bad obstetric history (BOH) and one of the major causes of congenitally acquired infections. The present study aimed to estimate the seropositivity of T. gondii infection and associated risk factors among the attendees of high risk pregnancy and low risk antenatal care clinic of Minia Maternity and Pediatric University Hospital, Minia, Egypt. The study was carried out from April 2013 to April 2014 through 2 phases, the first phase was case-control study, and the second phase was follow-up with intervention. A total of 120 high risk pregnant and 120 normal pregnant females were submitted to clinical examinations, serological screening for anti-Toxoplasma IgM and IgG antibodies by ELISA, and an interview questionnaire. Seropositive cases were subjected to spiramycin course treatment. The results showed that the seroprevalence of toxoplasmosis in high-risk pregnancy group was 50.8%, which was significantly different from that of normal pregnancy group (P<0.05). Analysis of seropositive women in relation to BOH showed that abortion was the commonest form of the pregnancy wastage (56.5%). The high prevalence of T. gondii seropositive cases was observed in the age group of 21-30 years. Post-delivery adverse outcome was observed in 80.3% of high-risk pregnancy group compared to 20% of normal pregnancy group. There was a statistically significant relationship between seropositivity and living in rural area, low socioeconomic level, and undercooked meat consumption (P<0.05). Serological screening for anti-Toxoplasma antibodies should be routine tests especially among high-risk pregnant women.

  18. Seropositivity of Toxoplasmosis in Pregnant Women by ELISA at Minia University Hospital, Egypt

    PubMed Central

    Kamal, Amany M.; Ahmed, Azza K.; Abdellatif, Manal Z. M.; Tawfik, Mohamed; Hassan, Ebtesam E.

    2015-01-01

    Toxoplasmosis is considered as an important risk factor for bad obstetric history (BOH) and one of the major causes of congenitally acquired infections. The present study aimed to estimate the seropositivity of T. gondii infection and associated risk factors among the attendees of high risk pregnancy and low risk antenatal care clinic of Minia Maternity and Pediatric University Hospital, Minia, Egypt. The study was carried out from April 2013 to April 2014 through 2 phases, the first phase was case-control study, and the second phase was follow-up with intervention. A total of 120 high risk pregnant and 120 normal pregnant females were submitted to clinical examinations, serological screening for anti-Toxoplasma IgM and IgG antibodies by ELISA, and an interview questionnaire. Seropositive cases were subjected to spiramycin course treatment. The results showed that the seroprevalence of toxoplasmosis in high-risk pregnancy group was 50.8%, which was significantly different from that of normal pregnancy group (P<0.05). Analysis of seropositive women in relation to BOH showed that abortion was the commonest form of the pregnancy wastage (56.5%). The high prevalence of T. gondii seropositive cases was observed in the age group of 21-30 years. Post-delivery adverse outcome was observed in 80.3% of high-risk pregnancy group compared to 20% of normal pregnancy group. There was a statistically significant relationship between seropositivity and living in rural area, low socioeconomic level, and undercooked meat consumption (P<0.05). Serological screening for anti-Toxoplasma antibodies should be routine tests especially among high-risk pregnant women. PMID:26537040

  19. Blood serotonin and joint pain in seropositive versus seronegative rheumatoid arthritis.

    PubMed Central

    Kopp, Sigvard; Alstergren, Per

    2002-01-01

    AIM: To investigate whether blood serotonin (5-hydroxytryptamine) (5-HT) modulates musculoskeletal pain differently in seropositive and seronegative rheumatoid arthritis (RA). METHODS: Patients with temporomandibular joint (TMJ) involvement of seropositive RA (33 patients) or seronegative RA (28 patients) and 26 healthy individuals were included. TMJ pain, general musculoskeletal pain, plasma and serum 5-HT, acute phase reactants and thrombocyte count were investigated. RESULTS: The patients with seropositive RA had higher serum (median = 1130 nmol/l) and plasma (55 nmol/l) levels of 5-HT than the healthy individuals (704 nmol/l, p = 0.044 and 23 nmol/l, p < 0.001, respectively), and higher plasma levels of 5-HT than the seronegative patients (14 nmol/l, p < 0.001). There was no significant correlation between serum and plasma levels of 5-HT in any group. In the seropositive RA patients, positive correlations were found between serum levels of 5-HT and the number of painful mandibular movements (r(s) = 0.36, n = 33, p = 0.042), as well as pain on maximum mouth opening (r(s) = 0.41, n = 24, p = 0.047) and tenderness to digital palpation (r(s) = 0.49, n = 33, p = 0.003). In the healthy individuals, there was a negative correlation between plasma level of 5-HT and the TMJ pressure pain threshold (r(s) = -0.47, n = 20, p = 0.037). CONCLUSION: Peripheral serotonergic pain mechanisms seem to be activated by blood 5-HT in patients with seropositive RA, in contrast to seronegative patients. PMID:12396472

  20. Immunological response and markers of cell damage in seropositive horses for Toxoplasma gondii.

    PubMed

    Do Carmo, Guilherme M; Da Silva, Aleksandro S; Klauck, Vanderlei; Pazinato, Rafael; Moura, Anderson B; Duarte, Thiago; Duarte, Marta M M F; Bochi, Guilherme V; Moresco, Rafael N; Stefani, Lenita M

    2015-02-01

    Toxoplasmosis is an important parasitic disease affecting several species of mammals, but little is known about this disease in horses. This study aimed to investigate the levels of several immunological variables and markers of cell damage in the serum of seropositive horses for Toxoplasma gondii. Sera samples of adult horses from the Santa Catarina State, Brazil used on a previous study were divided into groups according to their antibody levels for T. gondii determined by immunofluorescence assay, i.e. 20 samples from seronegative horses (Group A - control), 20 samples from horses with titers of 1:64 (Group B), 20 samples of horses with titers of 1:256 (Group C), and five samples from horses with titers of 1:1024 (Group D). Positive animals (Groups B, C, and D) had higher levels of immunoglobulins (IgM and IgG), pro-inflammatory cytokines (TNF-α, IFN-γ, IL-1, IL-4, and IL-6) and protein C-reactive protein, as well as lower levels of IL-10 (anti-inflammatory cytokine) when compared to seronegative horses (Group A). The nitric oxide levels were also elevated in seropositive horses. Therefore, we have found humoral and cellular immune responses in seropositive horses, and a correlation between high antibody levels and inflammatory mediators. Markers of cell injury by lipid peroxidation (TBARS) and protein oxidation (AOPP) were elevated in animals seropositives for T. gondii when compared to seronegatives. Therefore, seropositive horses to T. gondii can keep active immune responses against the parasite. As a consequence with chronicity of disease, they show cellular lesions that may lead to tissue damage with the appearance of clinical disease.

  1. Housing conditions and management practices associated with neonatal lamb mortality in sheep flocks in Norway.

    PubMed

    Holmøy, Ingrid H; Kielland, Camilla; Stubsjøen, Solveig Marie; Hektoen, Lisbeth; Waage, Steinar

    2012-12-01

    A study was conducted in order to obtain information about sheep farms in Norway and to identify housing and management characteristics that were risk factors for neonatal mortality of lambs 0-5 days of age. A questionnaire was submitted to sheep farmers, who provided demographic data and information on sheep housing conditions and feeding and management practices. Our description of farms is based on the questionnaire responses received from 2260 farmers. Data on lamb mortality during the preceding lambing season were available for those flocks that were enrolled in the Norwegian Sheep Recording System. Some flocks where the number of lambing ewes was less than 20 or greater than 400 were excluded. The total number of flocks included in the analysis of neonatal mortality was 1125. An increase in the mean number of live-born lambs per ewe per flock was associated with increasing neonatal mortality. Factors independently associated with increased neonatal survival were continuous monitoring of the ewes during the lambing season, active support to ensure sufficient colostrum intake of the lambs, feeding a combination of grass silage and hay compared with grass silage alone, and supplying roughage at least twice per day versus only once. Increased survival was also observed in flocks where the farmer had at least 15 years of experience in sheep farming. Flocks in which the Spæl breed predominated had lower odds for neonatal deaths compared to flocks in which the Norwegian White breed predominated. In conclusion, measures in sheep flocks targeted at feeding practices during the indoor feeding period and management practice during lambing season would be expected to reduce neonatal lamb mortality.

  2. Infectious bronchitis virus in different avian physiological systems-a field study in Brazilian poultry flocks.

    PubMed

    Balestrin, Eder; Fraga, Aline P; Ikuta, Nilo; Canal, Cláudio W; Fonseca, André S K; Lunge, Vagner R

    2014-08-01

    Avian infectious bronchitis is a highly contagious viral disease with economic effects on poultry agribusiness. The disease presents multi-systemic clinical signs (respiratory, renal, enteric, and reproductive) and is caused by one coronavirus (infectious bronchitis virus, IBV). Infectious bronchitis virus is classified into different serotypes and genotypes (vaccine strains and field variants). This study aimed to evaluate the occurrence of IBV in commercial poultry flocks from 3 important producing regions in Brazil and to determine the tropism of the main circulating genotypes to 3 different avian physiological systems (respiratory, digestive, urinary/reproductive). Clinical samples with suggestive signs of IBV infection were collected from 432 different poultry commercial flocks (198 from broilers and 234 from breeders). The total number of biological samples consisted of organ pools from the 3 above physiological systems obtained of farms from 3 important producing regions: midwest, northeast, and south. Infectious bronchitis virus was detected by reverse-transcription, real-time PCR of the 5' untranslated region. The results showed 179 IBV-positive flocks (41.4% of the flocks), with 107 (24.8%) from broilers and 72 (16.8%) from breeders. There were similar frequencies of IBV-positive flocks in farms from different regions of the country, most often in broilers (average 54%) compared with breeders (average 30.8%). reverse-transcription was more frequently detected in the digestive system of breeders (40%), and in the digestive (43.5%) and respiratory (37.7%) systems of broilers. Infectious bronchitis virus genotyping was performed by a reverse-transcription nested PCR and sequencing of the S1 gene from a selection of 79 IBV-positive flocks (45 from broilers and 34 from breeders). The majority of the flocks were infected with Brazilian variant genotype than with Massachusetts vaccine genotype. These results demonstrate the predominance of the Brazilian variant

  3. Failed landings after laying hen flight in a commercial aviary over two flock cycles.

    PubMed

    Campbell, D L M; Goodwin, S L; Makagon, M M; Swanson, J C; Siegford, J M

    2016-01-01

    Many egg producers are adopting alternative housing systems such as aviaries that provide hens a tiered cage and a litter-covered open floor area. This larger, more complex environment permits expression of behaviors not seen in space-limited cages, such as flight. Flight is an exercise important for strengthening bones; but domestic hens might display imperfect flight landings due to poor flight control. To assess the potential implications of open space, we evaluated the landing success of Lohmann white laying hens in a commercial aviary. Video recordings of hens were taken from 4 aviary sections at peak lay, mid lay and end lay across two flock cycles. Observations were made in each focal section of all flights throughout the day noting flight origin and landing location (outer perch or litter) and landing success or failure. In Flock 1, 9.1% of all flights failed and 21% failed in Flock 2. The number of flights decreased across the laying cycle for both flocks. Proportionally more failed landings were observed in the double row sections in Flock 2. Collisions with other hens were more common than slipping on the ground or colliding with aviary structures across sections and flocks. More hens slipped on the ground and collided with physical structures at peak lay for Flock 2 than at other time points. More collisions with other hens were seen at mid and end lay than at peak lay for Flock 2. Landings ending on perches failed more often than landings on litter. These results indicate potential for flight-related hen injuries in aviary systems resulting from failed landings, which may have implications for hen welfare and optimal system design and management.

  4. Chicken infectious anemia virus infection in Israeli commercial flocks: virus amplification, clinical signs, performance, and antibody status.

    PubMed

    Davidson, I; Kedem, M; Borochovitz, H; Kass, N; Ayali, G; Hamzani, E; Perelman, B; Smith, B; Perk, S

    2004-01-01

    The impact of chicken infectious anemia virus (CIAV) infection on commercial chicken flocks in Israel was examined by analyzing flocks with or without typical CIAV signs, signs of other diseases, or apparently healthy flocks. In 23 flocks (broilers and layers) of ages up to 8 wk, typical signs of CIAV infection (stunting, gangrenous dermatitis, and secondary bacterial infections) were recorded. When permitted by flock owners, in several cases among these 23 flocks the morbidity, mortality, and performance parameters were recorded; the presence of CIAV was detected by polymerase chain reaction (PCR); and the antibody status of parents and broilers was measured. In addition, total mortality, number of birds sold, total kilograms of meat sold, density (kg/m2), mean age at slaughter, daily growth rate in grams, total kilogram of food consumed, food conversion rate, and the European Index were calculated. We also surveyed flocks affected by other diseases, such as tumors, respiratory diseases, or coccidiosis, and flocks with no apparent clinical signs. The latter flocks were negative by CIAV-PCR, indicating that typical CIAV clinical signs are associated with one-step PCR-CIAV amplification. However, a small amount of CIAV might still be present in these flocks, acting to induce the subclinical effects of CIAV infection. These data indicate a link between the presence of virus sequences and typical CIAV signs and strengthen the concept that CIAV infection has a negative economic impact on the chicken industry.

  5. Whole-flock, metaphylactic tilmicosin failed to eliminate contagious ovine digital dermatitis and footrot in sheep: a cluster randomised trial

    PubMed Central

    Angell, J. W.; Grove-White, D. H.; Williams, H. J.; Duncan, J. S.

    2016-01-01

    The aim of this study was to evaluate the clinical success of whole-flock systemic tilmicosin and enhanced biosecurity in eliminating active contagious ovine digital dermatitis (CODD) from sheep flocks. Thirty flocks in the UK were randomly allocated to receive either treatment as usual (as per the farmer's normal routine) or whole-flock treatment with tilmicosin, together with isolation and extended treatment of clinically affected individuals and isolation and treatment of purchased sheep during the study period. All flocks were visited once at onset of the trial to examine all sheep. One year later, all sheep were re-examined to determine the presence/absence of clinical lesions. The primary outcome was the clinical elimination of CODD from flocks. Secondary outcomes were reduction in prevalence of CODD, clinical elimination of footrot and reduction in prevalence of footrot. The analysis included 11 control flocks and 13 intervention flocks, with initially 3460 and 4686 sheep, respectively. For CODD: at follow-up, in the intervention group, 6/13 (46 per cent) flocks had a prevalence of zero compared with 1/11 (9 per cent) in the control group (P=0.12). For footrot: at follow-up, no flocks had a prevalence of zero. Therefore, the intervention is not recommended for the elimination of CODD or footrot in the UK. PMID:27450091

  6. Feasibility of pedigree recording and genetic selection in village sheep flocks of smallholder farmers.

    PubMed

    Gizaw, Solomon; Goshme, Shenkute; Getachew, Tesfaye; Haile, Aynalem; Rischkowsky, Barbara; van Arendonk, Johan; Valle-Zárate, Anne; Dessie, Tadelle; Mwai, Ally Okeyo

    2014-06-01

    Pedigree recording and genetic selection in village flocks of smallholder farmers have been deemed infeasible by researchers and development workers. This is mainly due to the difficulty of sire identification under uncontrolled village breeding practices. A cooperative village sheep-breeding scheme was designed to achieve controlled breeding and implemented for Menz sheep of Ethiopia in 2009. In this paper, we evaluated the reliability of pedigree recording in village flocks by comparing genetic parameters estimated from data sets collected in the cooperative village and in a nucleus flock maintained under controlled breeding. Effectiveness of selection in the cooperative village was evaluated based on trends in breeding values over generations. Heritability estimates for 6-month weight recorded in the village and the nucleus flock were very similar. There was an increasing trend over generations in average estimated breeding values for 6-month weight in the village flocks. These results have a number of implications: the pedigree recorded in the village flocks was reliable; genetic parameters, which have so far been estimated based on nucleus data sets, can be estimated based on village recording; and appreciable genetic improvement could be achieved in village sheep selection programs under low-input smallholder farming systems.

  7. Foraging efficiency of a predator flock for randomly moving prey: A simulation study

    NASA Astrophysics Data System (ADS)

    Lee, Sang-Hee; Kwon, Ohsung

    2016-03-01

    Flocking behavior of animals is highly advantageous for taking food resources. The degree of the advantage is related to the ability of flock members to detect their prey and the mobility of prey individuals. In this study, to explore the relation, we constructed a model to simulate a predator flock and its randomly moving prey. The predator members have the prey detection ability, which was characterized as sensing distance, R, and a sensing angle, θ. The mobility of the prey individuals was characterized as the maximum traveling distance of an iteration time step, L. The relative flock foraging efficiency, ɛ, was defined as ɛ = 1 - (Td/Tup). Tup and Td represent the spent time for the flock to eat all prey individuals and to uptake the last remaining 10% prey, respectively. Simulation results showed that ɛ increased, maximized, and decreased with the increase of R, regardless of L. As the number of prey, N, increased, the tendency of the increasing and decreasing was diluted. The result was briefly discussed in relation to the flock foraging behavior and the development of the model toward applications for real ecosystems.

  8. Effect of Testosterone Administration and Spiking on Reproductive Success of Broiler Breeder Flocks.

    PubMed

    Ordas, B; Vahedi, S; Seidavi, A; Rahati, M; Laudadio, V; Tufarelli, V

    2015-10-01

    Age negatively affects reproductive success of broiler breeder flocks. One of the main hormones involved in the change of fertility with the age is testosterone (TT). The introduction of young males at later production stages of broiler flocks is known as spiking and is expected to reduce the fertility decline with age. The aim of this study was to determine the effect of injection of different levels of TT and the effect of spiking on reproductive fitness of broiler breeder flocks. Two experiments were conducted on Ross 308 breeder flocks for 10 weeks (41-50 weeks of age). The experiment 1 included a control and three treatments corresponding to three doses of TT (0.1, 0.2 and 0.3 cc), while the experiment 2 included a control and one treatment corresponding to spiking. The lower dose of TT (0.1 cc) and the spiking clearly slowed down the decline in hatchability. Therefore, either the external administration of TT to the males when the natural concentration of TT starts to decline or spiking the breeder flock with young roosters could contribute to improve reproductive success in later stages of the production cycle in broiler breeder flocks.

  9. To flock or fight: neurochemical signatures of divergent life histories in sparrows.

    PubMed

    Goodson, James L; Wilson, Leah C; Schrock, Sara E

    2012-06-26

    Many bird species exhibit dramatic seasonal switches between territoriality and flocking, but whereas neuroendocrine mechanisms of territorial aggression have been extensively studied, those of seasonal flocking are unknown. We collected brains in spring and winter from male field sparrows (Spizella pusilla), which seasonally flock, and male song sparrows (Melospiza melodia), which are territorial year-round in much of their range. Spring collections were preceded by field-based assessments of aggression. Tissue series were immunofluorescently multilabeled for vasotocin, mesotocin (MT), corticotropin-releasing hormone (CRH), vasoactive intestinal polypeptide, tyrosine hydroxylase, and aromatase, and labeling densities were measured in many socially relevant brain areas. Extensive seasonal differences are shared by both species. Many measures correlate significantly with both individual and species differences in aggression, likely reflecting evolved mechanisms that differentiate the less aggressive field sparrow from the more aggressive song sparrow. Winter-specific species differences include a substantial increase of MT and CRH immunoreactivity in the dorsal lateral septum (LS) and medial amygdala of field sparrows but not song sparrows. These species differences likely relate to flocking rather than the suppression of winter aggression in field sparrows, because similar winter differences were found for two other emberizids that are not territorial in winter--dark-eyed juncos (Junco hyemalis), which seasonally flock, and eastern towhees (Pipilo erythropthalmus), which do not flock. MT signaling in the dorsal LS is also associated with year-round species differences in grouping in estrildid finches, suggesting that common mechanisms are targeted during the evolution of different life histories.

  10. Air samplings in a Campylobacter jejuni positive laying hen flock.

    PubMed

    Ahmed, Marwa Fawzy El Metwaly; Schulz, Jochen; Hartung, Joerg

    2013-01-01

    The air in laying hen houses contains high concentrations of airborne bacteria. The numbers of these bacteria can be influenced by the efficiency of the chosen sampling method. In the presented study, AGI-30 Impingers and the Coriolis(®)µ air Sampler were compared in terms of their efficiency in sampling aerobic mesophilic bacteria in a laying hen house. Measurements were conducted in a laying hen flock with high prevalences of C. jejuni in order to investigate if culturable cells of this organism can also be detected by the applied methods. Airborne dust was also analyzed for the presence of C. jejuni specific DNA to assess the possible occurrence of non-culturable C. jejuni in the hen house air. The numbers of mesophilic airborne bacteria ranged from 8 × 10(4) - 2 × 10(6) CFU/m(-3) when sampled using AGI-30 Impingers, and from 2 × 10(5) - 4 × 10(6) CFU/m -3 when sampled using a Coriolis(®)µ air Sampler. The concentrations detected simultaneously by both devices correlated well (rPearson = 0.755), but the Coriolis(®)µ air Sampler showed a significantly higher sampling efficiency (p<0.001). Although, the within flock prevalence of C. jejuni was high during the experiments (between 70-93%), neither of the air sampling methods could detect culturable C. jejuni from the air. However, C. jejuni specific DNA was detected in 15 out of 18 airborne dust samples by mapA PCR. Based on the results, it can be concluded that airborne culturable C. jejuni were not detectable, even with an efficient air sampler, because of their low concentration. Therefore, the risk of airborne infection to poultry workers on inhaling airborne C. jejuni seems negligible. Also, the transmission of culturable C. jejuni to neighboring farms by the airborne route is unlikely. Otherwise, the detection of airborne C. jejuni specific DNA suggests that non-culturable cells could appear in the hen house air, and in future it should be verified whether sampling stress of the air sampling methods

  11. Parameters influencing AIS 1 neck injury outcome in frontal impacts.

    PubMed

    Jakobsson, Lotta; Norin, Hans; Svensson, Mats Y

    2004-06-01

    In order to gain more knowledge of the neck injury scenario in frontal impacts, a statistical study of parameters influencing incidences of AIS 1 neck injuries was performed. The data set consisted of 616 occupants in Volvo cars. Information regarding the crash, the safety systems, occupant characteristics (including prior neck problems), behavior and sitting posture at the time of impact, and neck symptoms (including duration) was collected and analyzed. Occupant characteristics (mainly gender, weight, and age), kinematics (head impacts) and behavior at the time of impact were identified as the most prominent parameter areas with regard to AIS 1 neck injury outcome. Specifically, women had a significantly higher AIS 1 neck injury rate as compared to men, occupants under the age of 50 had a significantly higher AIS 1 neck injury rate as compared to those above 50 and occupants weighing less than 65 kg have a significantly higher AIS 1 neck injury rate than heavier occupants. Drivers stating that they impacted their head against a frontal interior structure had a significantly higher AIS 1 neck injury rate than those without head impact. Also, occupants who stated they had tensed their neck muscles at the time of impact, had a significantly higher AIS 1 neck injury rate as compared to occupants who did not. Occupant activities, such as tightly gripping the steering wheel or straightening their arms showed a significantly increased AIS 1 neck injury rate, indicating that occupant behavior at time of impact could be influential with respect to AIS 1 neck injury outcome. Also, occupants reporting prior neck problems had a higher rate of persistent symptoms (>1 year) but no difference with respect to passing symptoms (<3 months) as compared to those without prior neck problems. Additionally, there was no distinct pattern for the duration of neck symptoms.

  12. The heritability of abortion in pedigree Charollais flocks.

    PubMed

    Darlay, Rebecca; Stear, Michael J; Mason, Sam; Smith, Judith; Shaw, Marie-Anne

    2014-10-01

    Foetal death, or abortion at term, in sheep is of major significance to the livestock industry, accounting for more than £24million lost per annum. We have investigated whether there is a genetic component to abortion within two flocks of pedigree Charollais sheep, one followed from 1989 to 2006, the other from 1992 to 2006. Abortion occurred at a rate of 5.74-8.78% per annum against a total mortality rate of 14-24%. By model covariate analysis we have shown that 15.5% aborting ewes went on to have one or more abortions and that this risk increased with parity (p=0.006). Heritability estimates were approximately 0.08 as calculated by SOLAR, pedigreemm and ASReml3, with sire and dam components of 0.046 and 0.048, respectively. Where the lamb was aborted, heritability estimates were highly variable according to the method employed, 0.046-0.378, with sex of the lamb being a significant covariate. This variability indicated one or more underlying, significant factors that were not measured in these analyses, potentially including infectious agents that may be involved. Nevertheless, the ASReml3 estimate (0.179) resolved to 0.074 variance attributable to the sire and 0.092 attributable to the dam, which, while not significant, was suggestive that genetic variants passed by the dam to the lamb may be of more weight than that from the sire in determining whether a lamb will abort.

  13. Critical thresholds in flocking hydrodynamics with non-local alignment.

    PubMed

    Tadmor, Eitan; Tan, Changhui

    2014-11-13

    We study the large-time behaviour of Eulerian systems augmented with non-local alignment. Such systems arise as hydrodynamic descriptions of agent-based models for self-organized dynamics, e.g. Cucker & Smale (2007 IEEE Trans. Autom. Control 52, 852-862. (doi:10.1109/TAC.2007.895842)) and Motsch & Tadmor (2011 J. Stat. Phys. 144, 923-947. (doi:10.1007/s10955-011-0285-9)) models. We prove that, in analogy with the agent-based models, the presence of non-local alignment enforces strong solutions to self-organize into a macroscopic flock. This then raises the question of existence of such strong solutions. We address this question in one- and two-dimensional set-ups, proving global regularity for subcritical initial data. Indeed, we show that there exist critical thresholds in the phase space of the initial configuration which dictate the global regularity versus a finite-time blow-up. In particular, we explore the regularity of non-local alignment in the presence of vacuum.

  14. Determination of mechanism of flock sediment formation in tea beverages.

    PubMed

    Niino, Hitoshi; Sakane, Iwao; Okanoya, Kazunori; Kuribayashi, Syuhei; Kinugasa, Hitoshi

    2005-05-18

    The mechanism of sediment formation during the storage of green tea beverage was investigated. Green tea extract was separated by Diaion HP-20 column chromatography, and a sediment-formation test was performed. Results showed that at least one compound of the substance causing flock sediment was contained in each of the HP-20 nonadsorbed and adsorbed fractions. From the following fractionations and structure analyses, the substance in the HP-20 adsorbed fraction was determined to be 1-O-galloyl-4,6-O-(S)-hexahydroxydiphenoyl-beta-D-glucose (strictinin), which is one of the ellagitannins. Strictinin was hydrolyzed to ellagic acid by heat-sterilization processes such as retort sterilization or the ultra-high temperature processing used during the manufacturing of tea beverages. Ellagic acid combined with proteins in the HP-20 nonadsorbed fraction to form an irreversible sediment of green tea beverage; ellagic acid and proteins were confirmed to be present in that sediment. The HP-20 adsorbed fraction contained little strictinin and formed hardly any sediment, suggesting that control of the strictinin content is significant in avoiding sediment formation during the manufacturing process of tea beverages.

  15. Exploring flocking via quantum many-body physics techniques

    NASA Astrophysics Data System (ADS)

    Souslov, Anton; Loewe, Benjamin; Goldbart, Paul M.

    2015-03-01

    Flocking refers to the spontaneous breaking of spatial isotropy and time-reversal symmetries in collections of bodies such as birds, fish, locusts, bacteria, and artificial active systems. The transport of matter along biopolymers using molecular motors also involves the breaking of these symmetries, which in some cases are known to be broken explicitly. We study these classical nonequilibrium symmetry-breaking phenomena by means of models of many strongly interacting particles that hop on a periodic lattice. We employ a mapping between the classical and quantum dynamics of many-body systems, combined with tools from many-body theory. In particular, we examine the formation and properties of nematic and polar order in low-dimensional, strongly-interacting active systems using techniques familiar from fermionic systems, such as self-consistent field theory and bosonization. Thus, we find that classical active systems can exhibit analogs of quantum phenomena such as spin-orbit coupling, magnetism, and superconductivity. The models we study connect the physics of asymmetric exclusion processes to the spontaneous emergence of transport and flow, and also provide a soluble cousin of Vicsek's model system of self-propelled particles.

  16. Birds and dolphins flock to turn basin in feeding frenzy.

    NASA Technical Reports Server (NTRS)

    2000-01-01

    Birds by the score, especially gray and white pelicans, cormorants, sea gulls, herons and ospreys, flock to the turn basin east of the Vehicle Assembly Building in a feeding frenzy as schools of fish fill the waters. In the background is Launch Pad A with Space Shuttle Endeavour waiting for launch on Friday, Feb. 11 for mission STS-99. The basin is part of the Indian River Lagoon, which is made up of Mosquito Lagoon to the north, Banana River and Creek to the south and the Indian River to the west. It is called a lagoon because it is a body of water separated from the ocean by barrier islands, with limited exchange with the ocean through inlets. The Indian River Lagoon has one of the most diverse bird populations anywhere in America. Also, nearly one- third of the nation's manatee population lives here or migrates through the lagoon seasonally. The lagoon varies in width from .5 mile to 5 miles and averages only 3 feet in depth.

  17. Seropositivity rates for agents of canine vector-borne diseases in Spain: a multicentre study

    PubMed Central

    2013-01-01

    Background Controlling canine vector-borne diseases (CVBD) is a major concern, since some of these diseases are serious zoonoses. This study was designed to determine seropositivity rates in Spain for agents causing the following five CVBD: leishmaniosis (Leishmania infantum: Li), heartworm (Dirofilaria immitis: Di), ehrlichiosis (Ehrlichia canis: Ec), anaplasmosis (Anaplasma phagocytophilum/Anaplasma platys: An) and Lyme disease (Borrelia burgdorferi: Bb). Methods Anti-An, -Bb, and -Ec antibodies and the Di antigen were determined using the 4DX SNAP® Test (IDEXX Laboratories) and anti-L. infantum (Li) antibodies using the Leishmania SNAP® Test (IDEXX Laboratories) in blood and/or serum samples. Results Among 1100 dogs examined, overall seropositivity rates were: Li (15.7%), Ec (5%), An (3.1%), Di (1.25%) and Bb (0.4%). While seropositivity towards Bb and Di was similar in all geographic regions, rates were significantly higher in the east of Spain (8.3%) for An, significantly higher in the north (20%) for Ec, and significantly higher in the Southeast (46.6%) and South (27.4%), and significantly lower in the north (0%) for Li. No statistical associations were observed between sex and the CVBD analyzed (p ≥ 0.05) while the following associations with other variables were detected: a higher seropositivity to Ec (40%) and Bb (6.7%) in dogs under one year of age compared with adults (p < 0.05); and a higher seropositivity to An and Li in dogs that lived outdoors versus indoors (p = 0.01; p < 0.001, respectively). Seropositivity rates of 2.1%, 0%, 1.7%, 0.5% and 4.2% were recorded respectively for An, Bb, Ec, Di and Li in dogs with no clinical signs (n = 556) versus 3.8%, 0.6%, 7.5%, 1.8% and 25.9% for those with signs (n = 507) suggestive of a CVBD. Conclusion The data obtained indicate a risk for dogs in Spain of acquiring any of the five CVBD examined. Veterinarians in the different regions should include these diseases in their

  18. Risk factors for Campylobacter colonization in Danish broiler flocks, 2010 to 2011.

    PubMed

    Sandberg, M; Sørensen, L L; Steenberg, B; Chowdhury, S; Ersbøll, A K; Alban, L

    2015-03-01

    The objectives of the two studies presented were to estimate the prevalence of Campylobacter-positive farms and flocks and to acquire updated knowledge about risk factors for the introduction of Campylobacter in Danish broiler flocks. In the first study, from September 2010 to September 2011, there were 25 Danish broiler farms visited, and a questionnaire was filled in by a veterinarian/consultant. In the second study, a similar questionnaire was distributed electronically to all Danish broiler farmers (n=164) that were on record with an email address in the Quality Assurance System in the Danish Broiler Production (KIK) database. House- and flock-specific data collected in the surveys were supplemented with information obtained from the KIK database. Data obtained from the two studies were analyzed separately by logistic regression analysis. In both models, the dependent variable was "Campylobacter flock status (positive/negative)," which was based on real-time PCR testing of fecal material from the floor of each broiler house that had been collected preslaughter using a pair of tube gauze "socks." This material was pooled into one sample. Of the 25 farms visited, 17 had delivered Campylobacter-positive flocks during the study period, and eight farms had no Campylobacter-positive flocks. Moreover, the flock prevalence of Campylobacter was 17% (n=418). Data obtained from the electronically distributed survey revealed that 63% (n=71) of the farms were Campylobacter-positive. Further, the flock prevalence of Campylobacter was 14% (n=1,286). The multivariable models from the two sets of data identified the following statistically significant risk factors: summer vs. winter; if the previous flock in the house was positive for Campylobacter vs. if the previous flock in the house was negative; and litter delivered into the house close to the time of arrival of new chickens vs. storing litter on the farm. Furthermore, the data showed that a vertically based ventilation

  19. Fish gotta swim, Birds gotta fly, I gotta do Feynmann Graphs 'til I die: A continuum Theory of Flocking

    NASA Astrophysics Data System (ADS)

    Toner, John; Tu, Yu-Hai

    2002-05-01

    We have developed a new continuum dynamical model for the collective motion of large "flocks" of biological organisms (e.g., flocks of birds, schools of fish, herds of wildebeest, hordes of bacteria, slime molds, etc.) . This model does for flocks what the Navier-Stokes equation does for fluids. The model predicts that, unlike simple fluids, flocks show huge fluctuation effects in spatial dimensions d < 4 that radically change their behavior. In d=2, it is only these effects that make it possible for the flock to move coherently at all. This explains why a million wildebeest can march together across the Serengeti plain, despite the fact that a million physicists gathered on the same plane could NOT all POINT in the same direction. Detailed quantitative predictions of this theory agree beautifully with computer simulations of flock motion.

  20. Decay of interspecific avian flock networks along a disturbance gradient in Amazonia

    PubMed Central

    Mokross, Karl; Ryder, Thomas B.; Côrtes, Marina Corrêa; Wolfe, Jared D.; Stouffer, Philip C

    2014-01-01

    Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks. PMID:24335983

  1. Decay of interspecific avian flock networks along a disturbance gradient in Amazonia.

    PubMed

    Mokross, Karl; Ryder, Thomas B; Côrtes, Marina Corrêa; Wolfe, Jared D; Stouffer, Philip C

    2014-02-07

    Our understanding of how anthropogenic habitat change shapes species interactions is in its infancy. This is in large part because analytical approaches such as network theory have only recently been applied to characterize complex community dynamics. Network models are a powerful tool for quantifying how ecological interactions are affected by habitat modification because they provide metrics that quantify community structure and function. Here, we examine how large-scale habitat alteration has affected ecological interactions among mixed-species flocking birds in Amazonian rainforest. These flocks provide a model system for investigating how habitat heterogeneity influences non-trophic interactions and the subsequent social structure of forest-dependent mixed-species bird flocks. We analyse 21 flock interaction networks throughout a mosaic of primary forest, fragments of varying sizes and secondary forest (SF) at the Biological Dynamics of Forest Fragments Project in central Amazonian Brazil. Habitat type had a strong effect on network structure at the levels of both species and flock. Frequency of associations among species, as summarized by weighted degree, declined with increasing levels of forest fragmentation and SF. At the flock level, clustering coefficients and overall attendance positively correlated with mean vegetation height, indicating a strong effect of habitat structure on flock cohesion and stability. Prior research has shown that trophic interactions are often resilient to large-scale changes in habitat structure because species are ecologically redundant. By contrast, our results suggest that behavioural interactions and the structure of non-trophic networks are highly sensitive to environmental change. Thus, a more nuanced, system-by-system approach may be needed when thinking about the resiliency of ecological networks.

  2. The potential for improving welfare standards and productivity in United Kingdom sheep flocks using veterinary flock health plans.

    PubMed

    Scott, P R; Sargison, N D; Wilson, D J

    2007-05-01

    Data from industry sources detailing variable costs in 2003 revealed that the average farmer keeping 1000 lowland ewes in the United Kingdom spent 3500 UK pounds annually on veterinary fees and medicines. Despite such expenditure, psoroptic mange and cutaneous myiasis are common in the UK, resistance to one or more anthelmintic group is not only common but increasing in frequency and distribution, and abortion outbreaks caused by Toxoplasma gondii and Chlamydophila abortus are frequently reported by veterinary laboratories. Welfare concerns also arise from farmers' intransigence towards tail docking and castration in lambs (mutilations), reported market forces necessitating long distance road transportation to slaughter plants, and an unwillingness to employ veterinary surgeons for obstetrical problems. The spread of sheep scab in the UK over the past decade illustrates the failure of flock owners to effect rudimentary biosecurity and disease control measures. A first step towards improving the health and welfare of sheep would be the immediate implementation of basic good husbandry practices, including ectoparasiticide treatment for sheep scab eradication, prophylaxis for cutaneous myiasis in selected lambs, and appropriate vaccination strategies for clostridial diseases and certain abortion agents. There would also be money from within current farm expenditure to provide veterinary attention for obstetrical problems affecting up to 2% of ewes per annum. Planned use of ecto- and endoparasiticides is urgently needed to maintain the efficacy of these unique drugs.

  3. Recent progresses on AI-2 bacterial quorum sensing inhibitors.

    PubMed

    Zhu, Peng; Li, Minyong

    2012-01-01

    Quorum sensing (QS) is a communication procedure that predominates gene expression in response to cell density and fluctuations in the neighboring environment as a result of discerning molecules termed autoinducers (AIs). It has been embroiled that QS can govern bacterial behaviors such as the secretion of virulence factors, biofilm formation, bioluminescence production, conjugation, sporulation and swarming motility. Autoinducer 2 (AI-2), a QS signaling molecule brought up to be involved in interspecies communication, exists in both gram-negative and -positive bacteria. Therefore, novel approaches to interrupt AI-2 quorum sensing are being recognized as next generation antimicrobials. In the present review article, we summarized recent progresses on AI-2 bacterial quorum sensing inhibitors and discussed their potential as the antibacterial agents.

  4. Quality measures and assurance for AI (Artificial Intelligence) software

    NASA Technical Reports Server (NTRS)

    Rushby, John

    1988-01-01

    This report is concerned with the application of software quality and evaluation measures to AI software and, more broadly, with the question of quality assurance for AI software. Considered are not only the metrics that attempt to measure some aspect of software quality, but also the methodologies and techniques (such as systematic testing) that attempt to improve some dimension of quality, without necessarily quantifying the extent of the improvement. The report is divided into three parts Part 1 reviews existing software quality measures, i.e., those that have been developed for, and applied to, conventional software. Part 2 considers the characteristics of AI software, the applicability and potential utility of measures and techniques identified in the first part, and reviews those few methods developed specifically for AI software. Part 3 presents an assessment and recommendations for the further exploration of this important area.

  5. Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?

    PubMed

    Mammides, Christos; Chen, Jin; Goodale, Uromi Manage; Kotagama, Sarath Wimalabandara; Sidhu, Swati; Goodale, Eben

    2015-07-22

    Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in 'buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes.

  6. Does mixed-species flocking influence how birds respond to a gradient of land-use intensity?

    PubMed Central

    Mammides, Christos; Chen, Jin; Goodale, Uromi Manage; Kotagama, Sarath Wimalabandara; Sidhu, Swati; Goodale, Eben

    2015-01-01

    Conservation biology is increasingly concerned with preserving interactions among species such as mutualisms in landscapes facing anthropogenic change. We investigated how one kind of mutualism, mixed-species bird flocks, influences the way in which birds respond to different habitat types of varying land-use intensity. We use data from a well-replicated, large-scale study in Sri Lanka and the Western Ghats of India, in which flocks were observed inside forest reserves, in ‘buffer zones' of degraded forest or timber plantations, and in areas of intensive agriculture. We find flocks affected the responses of birds in three ways: (i) species with high propensity to flock were more sensitive to land use; (ii) different flock types, dominated by different flock leaders, varied in their sensitivity to land use and because following species have distinct preferences for leaders, this can have a cascading effect on followers' habitat selection; and (iii) those forest-interior species that remain outside of forests were found more inside flocks than would be expected by chance, as they may use flocks more in suboptimal habitat. We conclude that designing policies to protect flocks and their leading species may be an effective way to conserve multiple bird species in mixed forest and agricultural landscapes. PMID:26156772

  7. The rate of anti-HIV seropositivity among donated cadavers: experience in a cadaver donation center.

    PubMed

    Wiwanitkit, Viroj; Agthong, Sithiporn

    2002-01-01

    Cadavers are crucial for the medical education provided by medical schools. However, currently, donation is the only way to obtain cadavers for education in Thailand. Moreover, some traditional beliefs result in insufficient numbers of cadavers. Apart from finding donors, the occupational health of the workers in the cadaver donation center and the users, the medical students, residents, and staffs should be addressed. Screening for anti-HIV in donated organs is the current trend in transplantation medicine. Therefore, screening for anti-HIV in donated cadavers is useful. Here, we report the rate of anti-HIV seropositivity in cadavers in a 1-year period in our setting, the largest Thai Red Cross Society hospital. Of the total 84 cadavers received, two cadavers (2.4%) were anti-HIV seropositive. With the increasing rate of anti-HIV, screening for anti-HIV serology in donated cadavers for medical teaching is of great benefit.

  8. Comparison of seronegative and seropositive rheumatoid arthritis with regard to some clinical characteristics.

    PubMed

    Sahatçiu-Meka, Vjollca; Izairi, Remzi; Rexhepi, Sylejman; Manxhuka-Kerliu, Suzana

    2009-01-01

    The aim of this study is to establish a scientific comparative analysis between seronegative and seropositive rheumatoid arthritis (RA), with regard to some clinical characteristics. The studied group consisted of RA seronegative patients with titters lower then 1:64 defined by Rose-Waaler test, while the control group consisted of RA seropositive patients with titters of 1:64 or higher. Examinees all belonged to the 2nd and 3rd functional classes according to ARA criteria, were between 25-60 years of age (Xb = 49.96), with disease duration between 1-27 years (Xbox = 6.41). In the disease onset most frequently affected joints were metacarpophalangeal (MCP) and proximal interphalangeal (PIP) joint of the hands, almost equally represented with regard to sero-status and sex. During the examination seropositive patients showed a higher presence of inflamation of peripheral joints of hand and foot, but only the presence of PIP of the hands was statistically significant (chi2 = 15.63, p < 0.01). Knees, talocrural joints and elbows were more frequently affected in seropositive patients, whereas humeroscapular, coxofemoral and sacroiliacal joints were more frequently affected in seronegative patients, but without significant statistical difference with regard to sero-status. The presence of affected PIP of the hands (chi2 = 9.96, p < 0.01) and knees (chi2 = 4.17, p < 0.05) with regard to sex was statistically significant in seropositive female patients, as well as the presence of atacked PIP of the hands (chi2 = 6.08, p < 0.05), and cervical vertebrae (chi2 = 6.00, p < 0.05) in seropositive male patients. There were some differences between groups with regard to sex in metatarsophalangealjoints (MTP), PIP of the foot, and other joints, but without any statistical significance. In both subsets statistically significant domination was found in affected second (chi2 = 20.85, p < 0.01) and third (chi2 = 15.70, p < 0.01) fingers of the PIP level of hands and third finger (chi2

  9. Alveolar bone necrosis and spontaneous tooth exfoliation in an HIV-seropositive subject with herpes zoster.

    PubMed

    Feller, L; Wood, N H; Raubenheimer, E J; Meyerov, R; Lemmer, J

    2008-03-01

    Herpes zoster in the distribution of the maxillary and mandibular divisions of the trigeminal nerve is characterized by painful vesicular eruptions of the skin and oral mucosa in the distribution of the affected nerves. Oral complications may occur, including post-herpetic neuralgia, devitalization of teeth, abnormal development of permanent teeth, root resorption and periapical lesions. In cases where necrosis of the alveolar bony process occur it may be preceded or accompanied by spontaneous exfoliation of teeth. This usually follows the resolution of the acute phase of HZ and is more prevalent in HIV-seropositive than in HIV-seronegative subjects. A case of HZ of the trigeminal nerve in an HIV-seropositive subject, with complications of necrosis of alveolar bony process, external root resorption and tooth exfoliation is presented and the literature of HIV-associated HZ is reviewed.

  10. The importance of serial immunoglobulin evaluations in HIV-seropositive haemophiliacs.

    PubMed

    Mares, M; Sartori, M T; Zerbinati, P; Girolami, A

    1993-01-01

    The aim of our investigation was to evaluate whether the alteration of immunoglobulins (Igs) may be a predictive marker of the evolution of HIV infection in seropositive haemophiliacs. For this purpose two groups of haemophiliac patients (16 seronegative and 21 seropositive) were compared to evaluate the variations of the Ig profile over a period of 5 years (1985-1989). The two populations were similar for the number of transfusions of blood products and for the severity of post-transfusional hepatic disorders. The IgM increase, in the first stages of HIV infection, appears to be more discriminant than polyclonal elevation of IgG, which is already present in seronegative polytransfused haemophiliac patients.

  11. NASA space station automation: AI-based technology review

    NASA Technical Reports Server (NTRS)

    Firschein, O.; Georgeff, M. P.; Park, W.; Neumann, P.; Kautz, W. H.; Levitt, K. N.; Rom, R. J.; Poggio, A. A.

    1985-01-01

    Research and Development projects in automation for the Space Station are discussed. Artificial Intelligence (AI) based automation technologies are planned to enhance crew safety through reduced need for EVA, increase crew productivity through the reduction of routine operations, increase space station autonomy, and augment space station capability through the use of teleoperation and robotics. AI technology will also be developed for the servicing of satellites at the Space Station, system monitoring and diagnosis, space manufacturing, and the assembly of large space structures.

  12. Lookback study of HTLV-1 and 2 seropositive donors and their recipients in Belo Horizonte, Brazil.

    PubMed

    Namen-Lopes, M S S; Martins, M L; Drummond, P C; Lobato, R R; Carneiro-Proietti, A B F

    2009-08-01

    The objective of this study was to perform lookback study in recipients of blood components from human T-lymphotropic virus (HTLV) seropositive donors. HTLV-1/2 may be transmitted by blood transfusion. Brazil is an endemic area for the virus and its screening in blood donors is mandatory since 1993. Hemominas Foundation (HF) is the public transfusion centre in Minas Gerais, Brazil. Data on HTLV-1/2 seropositive donors and recipients from 1993 to 2004 were obtained at HF and 24 contracting hospitals. From 1993 to 2004, HTLV-1/2 enzyme immunoassay (EIA) was performed in 918 678 donations of approximately 422 600 blood donor candidates. Of these, 456 donors (0.1%) were reactive and confirmed by Western blot (WB): 449 HTLV-1 and 7 HTLV-2. Sixty-six (14.5%) were repeat donors and had 194 blood cellular components produced from their previous donations. Of the distributed components, 119/146 (81.5%) had the recipient traced, with a total of 114 individuals. Of these, only 13 recipients were tested: six (46%) were HTLV-1 positive (four recipients of red cell units, two of platelets) and seven (54%) were negative (six of red cell units and one of platelets). Eleven did not respond and 62/114 (54.0%) were deceased. Another 28/114 (25.0%) could not be located. All six seropositive HTLV-1 recipients identified had no symptoms suggestive of HTLV-1-associated diseases. Acellular components, when used alone, were not associated with HTLV seropositivity. HTLV-1 transmission by cellular blood components occurred before screening for the virus was introduced. Haemovigilance was difficult to perform due to unavailability of computer systems before 1999 and to inadequate medical records at hospitals.

  13. A case-control study of risk factors for brucellosis seropositivity in Portuguese small ruminants herds.

    PubMed

    Coelho, A M; Coelho, A C; Roboredo, M; Rodrigues, J

    2007-12-14

    A case-control study involving 255 small ruminants herds randomly selected was carried out in Portugal between January and December 2004, to identify risk factors associated with brucellosis seropositivity. To achieve this objective, two groups of herds selected according their prevalence status were compared: "cases" (farms with seroprevalence higher than 5%, n=123) and "controls" (farms seronegatives, n=132). A carefully structured questionnaire was used to collect data from each herd. A statistical analysis to compare "case" versus "control" herds was performed with the variables obtained from the questionnaire and the seroprevalence results. The effects on seroprevalence of several variables such as: individual characteristics; farm management practices; farm characteristics; animal health; knowledge and characteristics of farmers were evaluated. Data were analysed using logistic regression. Univariable analysis was used to screen the variables used in the logistic regression model. Nine variables were associated with brucellosis seropositivity in univariable analysis p<0.10. These variables were retained for multivariable logistic regression model. Regression model identified five variables as risk factors for seropositivity. The odds of brucellosis were increased: herds with more than 116 animals (OR=2.99); in herds with no cleaned-watering places (OR=3.05); in herds with insufficient manure removal and insufficient cleaning of premises (OR=2.87); in introduction of animals from non-free brucellosis herds or from herds of unknown status (OR=12.11). In the other hand, farmers' age (the eldest) was related to decreased odds (OR=0.4). Potential risk factors identified in this study were consistent factors associated with brucellosis seropositivity and support current recommendations for the control of brucellosis. Considering the paucity of epidemiological reports on brucellosis in the Northeast of Portugal and the absence of any data concerning factors related

  14. Microstructural visual system changes in AQP4-antibody–seropositive NMOSD

    PubMed Central

    Oertel, Frederike C.; Kuchling, Joseph; Zimmermann, Hanna; Chien, Claudia; Schmidt, Felix; Knier, Benjamin; Bellmann-Strobl, Judith; Korn, Thomas; Scheel, Michael; Klistorner, Alexander; Ruprecht, Klemens; Paul, Friedemann

    2017-01-01

    Objective: To trace microstructural changes in patients with aquaporin-4 antibody (AQP4-ab)-seropositive neuromyelitis optica spectrum disorders (NMOSDs) by investigating the afferent visual system in patients without clinically overt visual symptoms or visual pathway lesions. Methods: Of 51 screened patients with NMOSD from a longitudinal observational cohort study, we compared 6 AQP4-ab–seropositive NMOSD patients with longitudinally extensive transverse myelitis (LETM) but no history of optic neuritis (ON) or other bout (NMOSD-LETM) to 19 AQP4-ab–seropositive NMOSD patients with previous ON (NMOSD-ON) and 26 healthy controls (HCs). Foveal thickness (FT), peripapillary retinal nerve fiber layer (pRNFL) thickness, and ganglion cell and inner plexiform layer (GCIPL) thickness were measured with optical coherence tomography (OCT). Microstructural changes in the optic radiation (OR) were investigated using diffusion tensor imaging (DTI). Visual function was determined by high-contrast visual acuity (VA). OCT results were confirmed in a second independent cohort. Results: FT was reduced in both patients with NMOSD-LETM (p = 3.52e−14) and NMOSD-ON (p = 1.24e−16) in comparison with HC. Probabilistic tractography showed fractional anisotropy reduction in the OR in patients with NMOSD-LETM (p = 0.046) and NMOSD-ON (p = 1.50e−5) compared with HC. Only patients with NMOSD-ON but not NMOSD-LETM showed neuroaxonal damage in the form of pRNFL and GCIPL thinning. VA was normal in patients with NMOSD-LETM and was not associated with OCT or DTI parameters. Conclusions: Patients with AQP4-ab–seropositive NMOSD without a history of ON have microstructural changes in the afferent visual system. The localization of retinal changes around the Müller-cell rich fovea supports a retinal astrocytopathy. PMID:28255575

  15. Crusted Scabies: Presenting as erythroderma in a human immunodeficiency virus-seropositive patient

    PubMed Central

    Kulkarni, Shruti; Shah, Hiral; Patel, Bharti; Bhuptani, Neela

    2016-01-01

    Crusted scabies is a rare manifestation of scabies characterized by uncontrolled proliferation of mites in the skin. It is common in patients with sensory neuropathy, mentally retarded persons and in patients who are immunosuppressed. Further, crusted scabies can rarely present as erythroderma (<0.5% cases) necessitating a high index of suspicion for its diagnosis. Because of its rare occurrence, we are reporting a case of crusted scabies presenting as erythroderma, in a human immunodeficiency virus seropositive patient. PMID:27190417

  16. AI-2 of Aggregatibacter actinomycetemcomitans inhibits Candida albicans biofilm formation.

    PubMed

    Bachtiar, Endang W; Bachtiar, Boy M; Jarosz, Lucja M; Amir, Lisa R; Sunarto, Hari; Ganin, Hadas; Meijler, Michael M; Krom, Bastiaan P

    2014-01-01

    Aggregatibacter actinomycetemcomitans, a Gram-negative bacterium, and Candida albicans, a polymorphic fungus, are both commensals of the oral cavity but both are opportunistic pathogens that can cause oral diseases. A. actinomycetemcomitans produces a quorum-sensing molecule called autoinducer-2 (AI-2), synthesized by LuxS, that plays an important role in expression of virulence factors, in intra- but also in interspecies communication. The aim of this study was to investigate the role of AI-2 based signaling in the interactions between C. albicans and A. actinomycetemcomitans. A. actinomycetemcomitans adhered to C. albicans and inhibited biofilm formation by means of a molecule that was secreted during growth. C. albicans biofilm formation increased significantly when co-cultured with A. actinomycetemcomitans luxS, lacking AI-2 production. Addition of wild-type-derived spent medium or synthetic AI-2 to spent medium of the luxS strain, restored inhibition of C. albicans biofilm formation to wild-type levels. Addition of synthetic AI-2 significantly inhibited hypha formation of C. albicans possibly explaining the inhibition of biofilm formation. AI-2 of A. actinomycetemcomitans is synthesized by LuxS, accumulates during growth and inhibits C. albicans hypha- and biofilm formation. Identifying the molecular mechanisms underlying the interaction between bacteria and fungi may provide important insight into the balance within complex oral microbial communities.

  17. Calibrating AIS images using the surface as a reference

    NASA Technical Reports Server (NTRS)

    Smith, M. O.; Roberts, D. A.; Shipman, H. M.; Adams, J. B.; Willis, S. C.; Gillespie, A. R.

    1987-01-01

    A method of evaluating the initial assumptions and uncertainties of the physical connection between Airborne Imaging Spectrometer (AIS) image data and laboratory/field spectrometer data was tested. The Tuscon AIS-2 image connects to lab reference spectra by an alignment to the image spectral endmembers through a system gain and offset for each band. Images were calibrated to reflectance so as to transform the image into a measure that is independent of the solar radiant flux. This transformation also makes the image spectra directly comparable to data from lab and field spectrometers. A method was tested for calibrating AIS images using the surface as a reference. The surface heterogeneity is defined by lab/field spectral measurements. It was found that the Tuscon AIS-2 image is consistent with each of the initial hypotheses: (1) that the AIS-2 instrument calibration is nearly linear; (2) the spectral variance is caused by sub-pixel mixtures of spectrally distinct materials and shade, and (3) that sub-pixel mixtures can be treated as linear mixtures of pure endmembers. It was also found that the image can be characterized by relatively few endmembers using the AIS-2 spectra.

  18. Fatal disseminated toxoplasmosis in a cardiac transplantation with seropositive match for Toxoplasma: should prophylaxis be extended?

    PubMed

    Castagnini, Marta; Bernazzali, Sonia; Ginanneschi, Chiara; Marchi, Bruna; Maccherini, Massimo; Tsioulpas, Charilaos; Tanganelli, Piero

    2007-11-01

    In cardiac transplant, toxoplasmosis in the immunocompromised recipient can result either from the transmission of the parasite from a seropositive donor (D+) to a seronegative recipient (R-) with the transplanted organ (more common) or from the reactivation of a pre-transplant latent infection (D-/R+ or D+/R+). In the immunocompromised patient, toxoplasmosis is a life-threatening disease. We report a case of disseminated toxoplasmosis following heart transplantation in a Toxoplasma seropositive recipient before transplantation (R+) (IgG 1:160, IgM negative) who received an organ from a Toxoplasma seropositive donor (D+) (IgG 1:640, IgM negative). No anti-Toxoplasma prophylactic treatment was administered. A number of complications arose in the postoperative period, as well as Enterobacter cloacae and Cytomegalovirus (CMV) (reactivation) infections, but neither serological nor histological toxoplasma recrudescence was evidenced. The patient died on post transplant day 41. Post-autopsy histological examinations revealed an unexpected diffuse toxoplasmosis (lungs, brain, heart).

  19. Risk factors for Toxoplasma gondii and Neospora caninum seropositivity in buffaloes in Paraiba State, Brazil.

    PubMed

    Brasil, Arthur Willian de Lima; Parentoni, Roberta Nunes; Feitosa, Thais Ferreira; Bezerra, Camila de Sousa; Vilela, Vinicius Longo Ribeiro; Pena, Hilda Fátima de Jesus; de Azevedo, Sergio Santos

    2015-01-01

    The aims of this survey were to determine the frequency of anti-Toxoplasma gondii and anti-Neospora caninum antibodies and to identify the risk factors associated with seropositivity among buffaloes in the state of Paraíba, Brazil. This survey included 136 buffaloes belonging to 14 herds. To detect anti-T. gondii and anti-N. caninum antibodies, the indirect fluorescent antibody test (IFAT) was used. Among the 136 samples analyzed, 17 (12.5%) were positive for anti-T. gondii antibodies with titers ranging from 64 to 1,024, and 26 (19.1%) for anti-N. caninum with titers from 200 to 1,600. Animals seropositive for both T. gondii and N. caninum were found in 10 of the 14 herds (71.4%). Semi-intensive management systems (odds ratio = 2.99) and presence of pigs (odds ratio = 4.33) were identified as risk factors for T. gondii and N. caninum, respectively. It can be suggested that T. gondii and N. caninum are widespread in buffaloes in Paraíba, and that additional surveys are needed in order to ascertain the importance of these agents for this species and for pigs, and the influence of the farming type on occurrences of seropositive animals.

  20. Seropositivity of Toxoplasma gondii and Toxocara spp. in Children with Cryptogenic Epilepsy, Benha, Egypt

    PubMed Central

    Eraky, Maysa Ahmad; Abdel-Hady, Soha; Abdallah, Karim Fetouh

    2016-01-01

    The present study aimed to investigate the possible association of Toxoplasma gondii and Toxocara spp. infections with cryptogenic epilepsy in children. The study was carried out between June 2014 and March 2015. Total 90 children (40 with cryptogenic epilepsy, 30 with non-cryptogenic epilepsy, and 20 healthy control children) were evaluated to determine the anti-Toxocara and anti-T. gondii IgG seropositivity using ELISA kits. Epileptic cases were selected from those attending the pediatrics outpatient clinic of Benha University Hospital, Pediatrics Neurology Unit, and from Benha Specialized Hospital of children. The results showed that the level of anti-T. gondii IgG seropositivity was significantly higher among children with cryptogenic epilepsy (20%) than among children with non-cryptogenic children (0%). In healthy controls (10%), there was no association between toxocariasis seropositivity and cryptogenic epilepsy (only 5.7%; 4 out of 70 cases) among cases and 10% (2 out of 20) among controls. Among toxocariasis IgG positive cases, 3 (7.5%) were cryptogenic, and only 1 (3.3%) was non-cryptogenic. These statistically significant results support the association between T. gondii infection and cryptogenic epilepsy while deny this association with toxocariasis. PMID:27417090

  1. Omega 3 Fatty Acids Supplementation and Oxidative Stress in HIV-Seropositive Patients. A Clinical Trial

    PubMed Central

    Amador-Licona, Norma; Díaz-Murillo, Teresa A.; Pereyra-Nobara, Texar A.; Guízar-Mendoza, Juan M.; Barbosa-Sabanero, Gloria; Orozco-Aviña, Gustavo; Moreno-Martínez, Sandra C.; Luna-Montalbán, Rafael; Vázquez-Valls, Eduardo

    2016-01-01

    HIV-seropositive patients show high incidence of coronary heart disease and oxidative stress has been described as relevant key in atherosclerosis development. The aim of this study was to assess the effect of omega 3 fatty acids on different markers of oxidative stress in HIV-seropositive patients. We performed a randomized parallel controlled clinical trial in The Instituto Mexicano del Seguro Social, a public health hospital. 70 HIV-seropositive patients aged 20 to 55 on clinical score A1, A2, B1 or B2 receiving highly active antiretroviral therapy (HAART) were studied. They were randomly assigned to receive omega 3 fatty acids 2.4 g (Zonelabs, Marblehead MA) or placebo for 6 months. At baseline and at the end of the study, anthropometric measurements, lipid profile, glucose and stress oxidative levels [nitric oxide catabolites, lipoperoxides (malondialdehyde plus 4-hydroxialkenals), and glutathione] were evaluated. Principal HAART therapy was EFV/TDF/FTC (55%) and AZT/3TC/EFV (15%) without difference between groups. Treatment with omega 3 fatty acids as compared with placebo decreased triglycerides (-0.32 vs. 0.54 mmol/L; p = 0.04), but oxidative stress markers were not different between groups. Trial Registration ClinicalTrials.gov NCT02041520 PMID:27015634

  2. Human cytomegalovirus latent gene expression in granulocyte-macrophage progenitors in culture and in seropositive individuals.

    PubMed Central

    Kondo, K; Xu, J; Mocarski, E S

    1996-01-01

    Following infection with cytomegalovirus, human granulocyte-macrophage progenitors carry the viral genome but fail to support productive replication. Viral transcripts arise from a region encompassing the major regulatory gene locus; however, their structure differs significantly from productive phase transcripts. One class, sense transcripts, is encoded in the same direction as productive phase transcripts but uses two novel start sites in the ie1/ie2 promoter/enhancer region. These transcripts have the potential to encode a novel 94 aa protein. The other class, antisense transcript, is unspliced and complimentary to ie1 exons 2-4, and has the potential to encode novel 154 and 152 aa proteins. Consistent with a role in latency, these transcripts are present in bone marrow aspirates from naturally infected, healthy seropositive donors but are not present in seronegative controls. Sense latent transcripts are present in a majority of seropositive individuals. Consistent with the expression of latent transcripts, antibody to the 94 aa and 152 aa proteins is detectable in the serum of seropositive individuals. Thus, latent infection by cytomegalovirus is accompanied by the presence of latency-associated transcripts and expression of immunogenic proteins. Overall, these results suggest that bone marrow-derived myeloid progenitors are an important natural site of viral latency. Images Fig. 1 Fig. 2 Fig. 3 PMID:8855322

  3. Association between malaria exposure and Kaposi's sarcoma-associated herpes virus seropositivity in Uganda

    PubMed Central

    Nalwoga, Angela; Cose, Stephen; Wakeham, Katie; Miley, Wendell; Ndibazza, Juliet; Drakeley, Christopher; Elliott, Alison; Whitby, Denise; Newton, Robert

    2015-01-01

    Objective Unlike other herpes viruses, Kaposi's sarcoma-associated herpes virus (KSHV) is not ubiquitous worldwide and is most prevalent in sub-Saharan Africa. The reasons for this are unclear. As part of a wider investigation of factors that facilitate transmission in Uganda, a high prevalence country, we examined the association between antimalaria antibodies and seropositivity against KSHV. Methods Antibodies against P. falciparum merozoite surface protein (PfMSP)-1, P. falciparum apical membrane antigen (PfAMA)-1 and KSHV antigens (ORF73 and K8.1) were measured in samples from 1164 mothers and 1227 children. Results Kaposi's sarcoma-associated herpes virus seroprevalence was 69% among mothers and 15% children. Among mothers, KSHV seroprevalence increased with malaria antibody titres: from 60% to 82% and from 54% to 77%, comparing those with the lowest and highest titres for PfMSP-1 and PfAMA-1, respectively (P < 0.0001). Among children, only antibodies to PfAMA-1 were significantly associated with KSHV seropositivity, (P < 0.0001). In both mothers and children, anti-ORF73 antibodies were more strongly associated with malaria antibodies than anti-K8.1 antibodies. Conclusion The association between malaria exposure and KSHV seropositivity suggests that malaria is a cofactor for KSHV infection or reactivation. PMID:25611008

  4. Seropositivity of Hepatitis B and C among Syrian Multi-transfused Patients with Hemoglobinopathy

    PubMed Central

    Yazaji, Widad; Habbal, Wafa; Monem, Fawza

    2016-01-01

    Background and objectives Blood transfusion is a lifesaving therapy for patients with hemoglobinopathies. However, the need of frequent transfusion carries the risk of transmitting hepatitis B and C infections which are intermediately prevalent in Syria. Despite screening blood donations with sensitive methods, the risk of transmission is still present when infectious blood is donated within the window period. This study aimed to investigate the incidence of HBV and HCV seropositivity, and its association with multiple transfusions among Syrian hemoglobinopathies patients. Materials and Methods HBsAg, anti-HBc, anti-HBs and anti-HCV were tested for 159 Syrian multi-transfused patients by Enzyme-Linked Immunosorbent Assay (ELISA). Results Thirty-nine of 159 (24.5%) multi-transfused patients were HBsAg/anti-HBc or anti-HCV positive, 26 (16%) of which never visited the dentist, and they either tested postsurgically negative for HBsAg and anti-HCV or never underwent a surgical procedure. On the contrary of anti-HCV seropositivity, HBsAg/anti-HBc seropositivity was significantly associated with the number of blood transfusions, number of blood units and age (P < 0.001). Conclusion About one-sixth of our patients most likely acquired HBV/HCV infection via blood transfusion. Administering HBV vaccine, ensuring the immune status, and monitoring hepatitis markers might considerably minimize the incidence of viral hepatitis among multi-transfused patients. PMID:27648209

  5. Recent radiation in a marine and freshwater dinoflagellate species flock

    PubMed Central

    Annenkova, Nataliia V; Hansen, Gert; Moestrup, Øjvind; Rengefors, Karin

    2015-01-01

    Processes of rapid radiation among unicellular eukaryotes are much less studied than among multicellular organisms. We have investigated a lineage of cold-water microeukaryotes (protists) that appear to have diverged recently. This lineage stands in stark contrast to known examples of phylogenetically closely related protists, in which genetic difference is typically larger than morphological differences. We found that the group not only consists of the marine-brackish dinoflagellate species Scrippsiella hangoei and the freshwater species Peridinium aciculiferum as discovered previously but also of a whole species flock. The additional species include Peridinium euryceps and Peridinium baicalense, which are restricted to a few lakes, in particular to the ancient Lake Baikal, Russia, and freshwater S. hangoei from Lake Baikal. These species are characterized by relatively large conspicuous morphological differences, which have given rise to the different species descriptions. However, our scanning electron microscopic studies indicate that they belong to a single genus according to traditional morphological characterization of dinoflagellates (thecal plate patterns). Moreover, we found that they have identical SSU (small subunit) rDNA fragments and distinct but very small differences in the DNA markers LSU (large subunit) rDNA, ITS2 (internal transcribed spacer 2) and COB (cytochrome b) gene, which are used to delineate dinoflagellates species. As some of the species co-occur, and all four have small but species–specific sequence differences, we suggest that these taxa are not a case of phenotypic plasticity but originated via recent adaptive radiation. We propose that this is the first clear example among free-living microeukaryotes of recent rapid diversification into several species followed by dispersion to environments with different ecological conditions. PMID:25603395

  6. Socialized sub-groups in a temporary stable Raven flock?

    PubMed Central

    Braun, Anna; Walsdorff, Thomas; Fraser, Orlaith N.; Bugnyar, Thomas

    2015-01-01

    A complex social life serves as one of the main driving forces behind the evolution of higher cognitive abilities in vertebrates. In birds, however, data are primarily derived from captive animals, which strongly contrast with free-flying birds in terms of the number of interaction partners as well as available space. In captivity, Common Raven Corvus corax, nonbreeder groups show strong social bonds and complex tactical manoeuvring, whereas wild non-breeders are thought to resemble anonymous aggregations. Over 2 years, we observed a free-flying population of Ravens that visits a game park in the northern Alps. We here focus on the daily fission–fusion dynamics, individual spacing, and the influence of spacing on the birds’ agonistic and affiliative behaviour. The composition of marked Ravens in the local population changed slowly but constantly, although often remaining stable for several weeks. Birds only flocked for feeding, mobbing and roosting, and spent the rest of the day in loose aggregations, characterised by temporary small subgroups of 2–5 individuals. Aggression was high during crowd foraging but low outside of a feeding context. Affiliative behaviours, such as sitting within reaching distance, allo-preening and social play, were observed particularly in the small subgroups. These findings suggest that Raven aggregations are not as unstructured as previously thought. Birds may spend time and/or interact affilliatively with multiple individuals during the day. This, along with temporary stability in group composition, provides the opportunity for social relationships to develop, and enables the existence of socialised subgroups within free-flying Raven aggregations. PMID:25892747

  7. The confusion effect when attacking simulated three-dimensional starling flocks

    PubMed Central

    Hildenbrandt, Hanno; Scott-Samuel, Nicholas E.; Cuthill, Innes C.; Hemelrijk, Charlotte K. 

    2017-01-01

    The confusion effect describes the phenomenon of decreasing predator attack success with increasing prey group size. However, there is a paucity of research into the influence of this effect in coherent groups, such as flocks of European starlings (Sturnus vulgaris). Here, for the first time, we use a computer game style experiment to investigate the confusion effect in three dimensions. To date, computerized studies on the confusion effect have used two-dimensional simulations with simplistic prey movement and dynamics. Our experiment is the first investigation of the effects of flock size and density on the ability of a (human) predator to track and capture a target starling in a realistically simulated three-dimensional flock of starlings. In line with the predictions of the confusion effect, modelled starlings appear to be safer from predation in larger and denser flocks. This finding lends credence to previous suggestions that starling flocks have anti-predator benefits and, more generally, it suggests that active increases in density in animal groups in response to predation may increase the effectiveness of the confusion effect. PMID:28280553

  8. Three dimensional reconstruction of starling flocks: an empirical investigation of collective animal behavior

    NASA Astrophysics Data System (ADS)

    Giardina, Irene

    2009-03-01

    Bird flocking is a striking example of animal collective behaviour: thousands of birds gather above the roosting site, forming sharp-bordered flocks, which wheel and turn with remarkable coherence and synchronization. Despite an increasing theoretical interest, empirical investigations of collective motion have been limited so far by the difficulties of getting data on large systems. By means of stereoscopic photography and using statistical mechanics, optimization theory and computer vision techniques, we have measured for the first time the three-dimensional positions and trajectories of individual birds in groups of up to three thousands elements. This allowed us to analyze global morphological properties of the flocks, as well as structural and dynamical properties. Most notably, we investigated the nature of the inter-individual interaction. We found that the interaction between birds does not depend on their mutual metric distance, as most current models and theories assume, but rather on the topological distance (number of intermediate neighbors). In fact, we discovered that each individual interacts on average with a fixed number of neighbors (six-seven), rather than with all neighbors within a fixed metric distance. We argue that a topological interaction of this kind is indispensable to maintain flock's cohesion against the large density changes caused by external perturbations, typically predation. More recently, we characterized the velocity field, and computed dynamical observables. We showed that flocks exhibit long range correlations, which are a signature of their remarkable collective behavior.

  9. Prevalence and risk factors for Campylobacter spp. in chicken broiler flocks in Reunion Island (Indian Ocean).

    PubMed

    Henry, Isabelle; Reichardt, Jef; Denis, Martine; Cardinale, Eric

    2011-06-01

    Our objectives were to determine Campylobacter prevalence in broiler chicken flocks in Reunion Island and to define specific practices associated with the presence of Campylobacter spp. Infection in Reunionese broiler flocks. Fifty broiler flocks were studied in Reunion Island from May 2007 to February 2009. A questionnaire was submitted to the farmers and samples of fresh droppings were collected to assess the flock's Campylobacter status. Fifty four percent of the flocks were infected by Campylobacter spp.: 30% (95% CI: 28.71-31.29) were infected with Campylobacter coli and 17% (95% CI: 15.95-18.05) with Campylobacter jejuni; only 7% (95% CI: 6.28-7.72) were infected by both species at the same time. Several poultry houses in the farm (OR=11.2; [1.05-92]) and cleaning without any detergent (OR=13.1; [2.1-78.3]) increased the risk of Campylobacter infection. A distance higher than 500 m between broiler farms (OR=0.27; [0.1-0.8]) and use of disinfectant during the rearing period decreased this risk of infection (OR=0.15; [0.1-0.75]).

  10. Comparison of prevalence factors in horses with and without seropositivity to Neospora hughesi and/or Sarcocystis neurona.

    PubMed

    Pusterla, Nicola; Tamez-Trevino, Eva; White, Alexandria; Vangeem, Joshua; Packham, Andrea; Conrad, Patricia A; Kass, Philip

    2014-05-01

    Equine protozoal myeloencephalitis is a commonly diagnosed neurological disease of horses in North America and is caused by infection with Sarcocystis neurona or Neospora hughesi. The aim of this study was to compare prevalence factors among horses seropositive or seronegative to N. hughesi and/or S. neurona. A total of 3123 submissions were included in the study, with horses originating from 49 States. Thirty-eight animals from 21 States tested seropositive for N. hughesi only, 840 horses from 40 States were seropositive for S. neurona only, 25 horses from 14 States were seropositive for both protozoa, and 2220 horses from 49 States tested seronegative for both parasites. Significant associations were found between geographical location (State), month of submission, breed and serological status.

  11. [Investigation of Legionella pneumophila seropositivity in the professional long distance drivers as a risky occupation].

    PubMed

    Polat, Yusuf; Ergin, Cağri; Kaleli, Ilknur; Pinar, Ahmet

    2007-04-01

    Contaminated water sources, reservoirs and systems such as evaporative condensers of air-conditioners are known to be the main transmission routes of Legionella spp. which are ubiquitous aquatic bacteria. By virtue of this point the aim of this study was to investigate the rate of Legionella pneumophila seropositivity in a profession considered as risky due to the direct and prolonged exposure to air-conditioning and air-circulating systems. For this purpose, in the period of February-August 2004 a total of 79 male subjects (63 were bus drivers and 16 were driver assistants) who were continously travelling to two different route (South part as hot climate and Middle/North parts as cold climate of Turkey) from Denizli province coach station (a province located in internal Aegian where accepted as crossroads), were included to the study. The mean age and mean working duration of bus drivers were 43.0 +/- 1.1 years and 20.0 +/- 1.1 years, respectively, while these values were 22.5 +/- 0.9 years and 4.0 +/- 0.6 years, respectively, for the drivers' assistants. The serum samples collected from the subjects were screened by a commercial indirect immunofluorescence method (Euroimmun, Germany) using L. pneumophila serogrup 1-14 antigens for the presence of specific antibodies. Additionally, air-conditioners' moisture exhaust samples of the busses in which seropositive subjects travelling with have been examined by culture and 5S rRNA gene targeted polymerase chain reaction (PCR) methods, for the presence of Legionella spp. The overall L. pneumophila seropositivity rate was detected as 15.2% (12/79). This rate was 19% (12/63) for bus drivers while all of the drivers' assistants were found seronegative. The seropositivity rate was found statistically higher in the personnel who were travelling to the hot climates (10/36, 27.8%) than those who travel to cold climates (2/43, 4.6%), (p < 0.05). The culture and PCR yielded negative results for Legionella spp. in the exhaust

  12. Characterization of the axon initial segment (AIS) of motor neurons and identification of a para-AIS and a juxtapara-AIS, organized by protein 4.1B

    PubMed Central

    2011-01-01

    Background The axon initial segment (AIS) plays a crucial role: it is the site where neurons initiate their electrical outputs. Its composition in terms of voltage-gated sodium (Nav) and voltage-gated potassium (Kv) channels, as well as its length and localization determine the neuron's spiking properties. Some neurons are able to modulate their AIS length or distance from the soma in order to adapt their excitability properties to their activity level. It is therefore crucial to characterize all these parameters and determine where the myelin sheath begins in order to assess a neuron's excitability properties and ability to display such plasticity mechanisms. If the myelin sheath starts immediately after the AIS, another question then arises as to how would the axon be organized at its first myelin attachment site; since AISs are different from nodes of Ranvier, would this particular axonal region resemble a hemi-node of Ranvier? Results We have characterized the AIS of mouse somatic motor neurons. In addition to constant determinants of excitability properties, we found heterogeneities, in terms of AIS localization and Nav composition. We also identified in all α motor neurons a hemi-node-type organization, with a contactin-associated protein (Caspr)+ paranode-type, as well as a Caspr2+ and Kv1+ juxtaparanode-type compartment, referred to as a para-AIS and a juxtapara (JXP)-AIS, adjacent to the AIS, where the myelin sheath begins. We found that Kv1 channels appear in the AIS, para-AIS and JXP-AIS concomitantly with myelination and are progressively excluded from the para-AIS. Their expression in the AIS and JXP-AIS is independent from transient axonal glycoprotein-1 (TAG-1)/Caspr2, in contrast to juxtaparanodes, and independent from PSD-93. Data from mice lacking the cytoskeletal linker protein 4.1B show that this protein is necessary to form the Caspr+ para-AIS barrier, ensuring the compartmentalization of Kv1 channels and the segregation of the AIS, para-AIS

  13. [Retrospective evaluation of Toxoplasma gondii seropositivity in fertile and infertile women].

    PubMed

    Aral Akarsu, Gülay; Elhan, Halil Atilla; Akarsu, Cem

    2011-01-01

    Toxoplasma gondii infection is associated with a wide spectrum of clinical pictures in man, changing from asymptomatic infection to severe central nervous system disease. It has been well documented that toxoplasmosis is of crucial importance especially for pregnant women and immunocompromised patients. In addition to the risks of gestation complications and congenital infections, it has been suggested that toxoplasmosis has some unfavorable effects on reproductive capacity in both men and women. The data obtained from limited studies performed in animal models as well as in infertile couples, have supported the relationship between toxoplasma and infertility. The hypothesis concerning infertility mechanisms due to T.gondii in females include development of endometritis and fetal rejection due to local release of T.gondii from latently located cysts in endometrial tissue on stimulation during plansenta formation; impaired folliculogenesis in ovaries and uterine atrophy and reproductive failure due to hypothalamic dysfunction as a result of chronic toxoplasmosis. The aim of this retrospective study was the comparative evaluation of toxoplasma seropositivity rates of fertile and infertile female spouses who were admitted to an in vitro fertilization (IVF) center in Ankara, between 2004-2009 period, from different geographical regions of Turkey. A total of 1314 women (mean age: 31.8 ± 5.6 years) were included to the study. In the study group, 376 (28.6%) were positive for T.gondii IgG, 5 (0.4%) were positive for IgG + IgM and 1 (%0.07) was positive only for IgM antibodies, while total toxoplasma seropositivity was 29.1% (382/1314). Of the 1117 evaluated couples, women with well-defined cause of infertility due to male factors have been grouped as fertile (n= 495) and the others were accepted as infertile (n= 622). Toxoplasma IgG seropositivity was found in 145 (29.3%) of fertile and in 179 (28.8%) of infertile women and the difference between the seropositivity rates

  14. Partner awareness of the serostatus of HIV-seropositive men who have sex with men: impact on unprotected sexual behavior.

    PubMed

    Hart, Trevor A; Wolitski, Richard J; Purcell, David W; Parsons, Jeffrey T; Gómez, Cynthia A

    2005-06-01

    Prior research has provided conflicting evidence about the association between partner awareness of an HIV-seropositive person's serostatus and HIV transmission behavior via unprotected intercourse. The current study examined partner awareness of participant HIV-seropositive status and sexual behavior in a multiethnic sample of HIV-seropositive men who have sex with men. Most HIV-seropositive men reported that their primary partners are aware, and most reported that at least some non-primary partners are aware the participant was HIV-seropositive before first having sex. Partner awareness of participant HIV-serostatus was related to unprotected sexual behavior during the past 3 months in a non-linear fashion, as men with partners who were inconsistently aware had higher rates of unprotected receptive anal intercourse than men with partners who were consistently aware or consistently unaware. Men with partners who were inconsistently aware also had higher rates of insertive oral intercourse than men with partners who were consistently aware. However, there were no differences in HIV transmission risk behavior between men with partners who were consistently aware and men with partners who were consistently unaware a participant was HIV-seropositive.

  15. Inverse modeling of biomass smoke emissions using the TOMS AI

    NASA Astrophysics Data System (ADS)

    Zhang, S. Y.; Penner, J. E.; Torres, O.

    2003-12-01

    Results of inverse modeling of biomass smoke emissions using the TOMS AI and a three-dimensional transport model are presented. The IMPACT model with DAO meteorology data in 1997 are utilized to obtain aerosol spatial and temporal distributions. Two absorbing aerosol types are considered, including biomass smoke and mineral dust. First, a radiative transfer model is applied to generate the modeled AI. Then a Bayesian inverse technique is applied to optimize the difference between the modeled AI and the EP TOMS AI in the same period by regulating monthly a priori biomass smoke emissions, while the dust emissions are fixed. The modeled AI with a posteriori emissions generally is in better agreement with the EP TOMS AI. The annual global a posteriori source increases by about 13% for the year 1997 (6.31 Tg/yr BC) in the base scenario, with a larger adjustment of monthly regional emissions. Five sensitivity scenarios are carried out, including sensitivity to the a priori uncertainties, the height of the smoke layer, the cloud screening criteria of the daily EP TOMS AI, the adjustment of emissions in a lumped region outside of the major biomass burning regions, and the covariances between observations. Results suggest that a posteriori annual global emissions in the sensitivity scenarios are within 15% of that of the base scenario. However, the difference of annual a posteriori emissions between the sensitivity scenarios and the base scenario can be as large as 50% on regional scale. We are also applying the inverse model technique to the year 2000 to compare with biomass emissions deduced from an analysis based on burned areas.

  16. Linear response to leadership, effective temperature and decision making in flocks

    NASA Astrophysics Data System (ADS)

    Pearce, Daniel; Giomi, Luca

    The Vicsek model is the prototypical system for studying collective behavior of interacting self propelled particles (SPPs). It has formed the basis for models explaining the collective behavior of many active systems including flocks of birds and swarms of insects. To the standard Vicsek model we introduce a small angular torque to a subset of the particles and observe how this effects the direction of polarisation of the entire swarm. This is analogous to a few informed birds trying to lead the rest of a large flock by initiating a turn. We find a linear response to this perturbation and fluctuations that are in agreement with fluctuation dissipation theorem. This allows the identification of an effective temperature for the Vicsek model that follows a power law with the noise amplitude. The linear response can also be extended to the process of decision-making, wherein flocks must decide between the behaviors of two competing subgroups of individuals.

  17. A Distributed Agent Implementation of Multiple Species Flocking Model for Document Partitioning Clustering

    SciTech Connect

    Cui, Xiaohui; Potok, Thomas E

    2006-01-01

    The Flocking model, first proposed by Craig Reynolds, is one of the first bio-inspired computational collective behavior models that has many popular applications, such as animation. Our early research has resulted in a flock clustering algorithm that can achieve better performance than the Kmeans or the Ant clustering algorithms for data clustering. This algorithm generates a clustering of a given set of data through the embedding of the highdimensional data items on a two-dimensional grid for efficient clustering result retrieval and visualization. In this paper, we propose a bio-inspired clustering model, the Multiple Species Flocking clustering model (MSF), and present a distributed multi-agent MSF approach for document clustering.

  18. A natural outbreak of clinical toxoplasmosis in a backyard flock of guinea fowl in Mississippi.

    PubMed

    Jones, Kelli H; Wilson, Floyd D; Fitzgerald, Scott D; Kiupel, Matti

    2012-12-01

    A case of a naturally occurring infection with Toxoplasma gondii in a backyard flock of guinea fowl in north Mississippi is reported. To our knowledge, this is the first worldwide report of a natural clinical infection in a flock of guinea fowl. This case was two of seven birds lost out of approximately 20 guinea fowl present in the flock. Birds reportedly exhibited lethargy prior to death. Necropsy examinations were performed on two of the dead birds. There were no gross lesions; however, intralesional protozoan cysts suggestive of T. gondii were observed microscopically. One of two guinea fowl demonstrated dramatic microscopic pathology consisting of variable multifocal necrosis, fibrin exudation, and inflammation of spleen, lung, and heart associated with protozoa cysts and tachyzoites compatible with toxoplasmosis. The bone marrow also exhibited multifocal necrosis and fibrin exudation, as well as marked erythroid and lesser granulocytic hyperplasia with intralesional protozoan cysts. The diagnosis of toxoplasmosis was confirmed with immunohistochemistry and PCR.

  19. 76 FR 44045 - Establishment of the SANE/SART AI/AN Initiative Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-07-22

    ... of Justice Programs Establishment of the SANE/SART AI/AN Initiative Committee AGENCY: Office for... (SART) American Indian/Alaskan Native (AI/AN) Initiative (``SANE/SART AI/AN Initiative Committee'' or... (FACA), as amended, 5 U.S.C., App. 2. The SANE/SART AI/AN Initiative Committee will provide the...

  20. A prospective study of management and litter variables associated with cellulitis in California broiler flocks.

    PubMed

    Schrader, J S; Singer, R S; Atwill, E R

    2004-09-01

    Cellulitis has emerged as an economically important disease of broiler chickens. The impact of environmental risk factors on the incidence of cellulitis has not been evaluated in the United States. Escherichia coli (E. coli), the causative agent, is introduced through skin scratches during the grow out. Our previous work suggested that the litter was an important reservoir for cellulitis-associated E. coli. We hypothesized that factors contributing to a positive environment for E. coli growth would increase the opportunity for exposure of a broiler to an infectious dose of E. coli, capable of initiating a cellulitis lesion. This prospective study of 304 flocks on five farms from two integrated broiler companies was conducted to determine the effect of environmental factors on the prevalence of cellulitis in California broiler flocks. Environmental variables included temperature, wind velocity, and relative humidity (RH) at the litter surface. Litter variables measured included E. coli and total gram-negative bacteria load (colony forming units/g dry matter), water activity, and pH. Management variables such as clean out, the number of flocks reared on the same litter (litter run, LR), and downtime (DT) between flocks were also evaluated. Cellulitis ranged from 0.197% to 6.04%. Significant associations were identified using linear regression between farm, LR, DT, ambient temperature during the brooding period, gram-negative bacteria load in the litter during the brooding period, RH mid-grow out, and E. coli load late in the grow out. The significant variation in the rate of cellulitis between farms combined with the strong association of LR and DT with cellulitis demonstrated that management choices were highly influential in this disease syndrome. Based on these data and our previous findings, managers would be advised to increase DT between flocks and perform a total clean out of the house when a flock processes with a high incidence of cellulitis.

  1. Pilot trials in Australia on eradication of footrot by flock specific vaccination.

    PubMed

    Dhungyel, O P; Lehmann, D R; Whittington, R J

    2008-12-10

    Footrot is a contagious disease of ruminants requiring strains of Dichelobacter nodosus that possess virulence factors including proteases and fimbriae. Sheep can be immunised against footrot using vaccine-containing fimbriae, either native or recombinant. The fimbriae are responsible for the serological K-agglutination reaction, which has been used to classify field isolates into nine major serogroups. The range of protection conferred by vaccination is largely restricted to the serogroup involved, but antigenic competition precludes effective vaccination with multivalent vaccines that contain all serogroups. However, vaccination with specific bivalent recombinant fimbrial vaccine led to eradication of virulent footrot from small ruminants in Nepal and the same result was obtained in Bhutan using a specific whole cell vaccine. In the study reported here two pilot trials have been conducted in Australian sheep flocks, one with a virulent form of footrot caused by a single serogroup F, and the other with an intermediate form also caused by a single serogroup C. In trial 1 pre-vaccination prevalence of clinical footrot in a group of randomly selected animals was 44%. This reduced to 2% at 3 months and 0.5% at 4 months, and there were no clinical cases at 5 months or at 16 months post-vaccination in the whole flock. Similarly in trial 2 pre-vaccination whole flock prevalence was 8.5%, while it was 2% at 3 months, 0.3% at 6 months and zero at 18 months post-vaccination. Use of flock specific monovalent whole cell vaccines over whole flocks for only one season and culling of the few non-responders has been a successful approach in eradication of the disease from both these flocks. This is the first study to report the successful use of specific vaccine for the intermediate form of footrot.

  2. Herd immunity to Newcastle disease virus in broiler flocks in Israel.

    PubMed

    Wiseman, Anat; Berman, Elyakum M

    2017-03-27

    Due to the ongoing need to protect poultry from virulent Newcastle disease virus, all commercial poultry flocks in Israel are vaccinated according to a defined programme using a combination of live and inactivated vaccines. The vaccination protocol for broilers during the years of the study comprised a live vaccine administered by spray on the day of hatching, inactivated vaccine by subcutaneous injection at 10-12 days of age, and another live vaccine given by aerosol at 17-21 days of age. A cross-sectional study was designed in order to examine the influence of herd immunity on the risk of Newcastle disease outbreak in broiler flocks. The study was based on the extensive field data kept in the Poultry Health Laboratories database. The results of serology tests employing haemagglutination inhibition for Newcastle disease virus were analysed and crossed with the list of flocks that had been diagnosed with ND in the years 2007-2014. At the peak of induced immunization (fifth week of growth), 87.5% of the tested flocks had achieved herd immunity (≥85% of birds in the flock with an HI titre ≥4). Based on a logistic regression model, the odds ratio for ND in flocks without herd immunity was 3.7 (95% CI 1.8-7.3, P-value < 0.001). The higher the percentage of birds with low HI titres the higher the risk of ND outbreak. Under field conditions, herd immunity is an important indicator for the risk of ND outbreak.

  3. Comparison of flocked and rayon swabs for collection of respiratory epithelial cells from uninfected volunteers and symptomatic patients.

    PubMed

    Daley, Peter; Castriciano, Santina; Chernesky, Max; Smieja, Marek

    2006-06-01

    Significantly more epithelial cells were collected by flocked swabs than by rayon swabs in parallel nasopharyngeal and nasal swabs taken from 16 volunteers. Nasopharyngeal sampling of 61 symptomatic patients also yielded more cells by flocked than rayon swabs, providing better clinical specimens for diagnosis.

  4. Molecular typing of avian pathogenic Escherichia coli colonies originating from outbreaks of E. coli peritonitis syndrome in chicken flocks.

    PubMed

    Landman, W J M; Buter, G J; Dijkman, R; van Eck, J H H

    2014-01-01

    Escherichia coli colonies isolated from the bone marrow of fresh dead hens of laying flocks with the E. coli peritonitis syndrome (EPS) were genotyped using pulsed-field gel electrophoresis (PFGE). Typing is important from an epidemiological point of view and also if the use of autogenous (auto)vaccines is considered. Birds with EPS originated from one house of each of three layer farms and one broiler breeder farm. Farms were considered as separate epidemiological units. In total, six flocks were examined including two successive flocks of one layer farm and the broiler breeder farm. E. coli colonies (one per bird) from nine to 16 hens of each flock were genotyped. The clonality of E. coli within birds was studied using five colonies of each of nine to 14 birds per flock. E. coli genotypes, which totalled 15, differed between farms and flocks except for two successive layer flocks that shared three genotypes. One to five genotypes were found per flock with one or two genotypes dominating each outbreak. Within hens, E. coli bacteria were always clonal. Colonies of the same PFGE type always had the same multilocus sequence type. However, four PFGE types shared sequence type 95. Neither PFGE types nor multilocus sequence types were unambiguously related to avian pathogenic E. coli from EPS. In cases where persistence of E. coli strains associated with EPS is found to occur frequently, routine genotyping to select strains for autovaccines should be considered.

  5. 9 CFR 147.6 - Procedure for determining the status of flocks reacting to tests for Mycoplasma gallisepticum...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ..., molecular examination procedure, or culture procedure is negative, the Official State Agency may qualify the flock for the classification for which it was tested. In the event of contaminated cultures, the..., molecular examination procedure, or culture procedure is positive, the flock will be considered infected....

  6. 9 CFR 147.6 - Procedure for determining the status of flocks reacting to tests for Mycoplasma gallisepticum...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ..., molecular examination procedure, or culture procedure is negative, the Official State Agency may qualify the flock for the classification for which it was tested. In the event of contaminated cultures, the..., molecular examination procedure, or culture procedure is positive, the flock will be considered infected....

  7. Application of AI techniques to blast furnace operations

    SciTech Connect

    Iida, Osamu; Ushijima, Yuichi; Sawada, Toshiro

    1995-10-01

    It was during the first stages of application of artificial intelligence (AI) to industrial fields, that the ironmaking division of Mizushima works at Kawasaki Steel recognized its potential. Since that time, the division has sought applications for these techniques to solve various problems. AI techniques applied to control the No. 3 blast furnace operations at the Mizushima works include: Blast furnace control by a diagnostic type of expert system that gives guidance to the actions required for blast furnace operation as well as control of furnace heat by automatically setting blast temperature; Hot stove combustion control by a combination of fuzzy inference and a physical model to insure good thermal efficiency of the stove; and blast furnace burden control using neural networks makes it possible to connect the pattern of gas flow distribution with the condition of the furnace. Experience of AI to control the blast furnace and other ironmaking operations has proved its capability for achieving automation and increased operating efficiency. The benefits are very high. For these reasons, the applications of AI techniques will be extended in the future and new techniques studied to further improve the power of AI.

  8. Discovering Knowledge from AIS Database for Application in VTS

    NASA Astrophysics Data System (ADS)

    Tsou, Ming-Cheng

    The widespread use of the Automatic Identification System (AIS) has had a significant impact on maritime technology. AIS enables the Vessel Traffic Service (VTS) not only to offer commonly known functions such as identification, tracking and monitoring of vessels, but also to provide rich real-time information that is useful for marine traffic investigation, statistical analysis and theoretical research. However, due to the rapid accumulation of AIS observation data, the VTS platform is often unable quickly and effectively to absorb and analyze it. Traditional observation and analysis methods are becoming less suitable for the modern AIS generation of VTS. In view of this, we applied the same data mining technique used for business intelligence discovery (in Customer Relation Management (CRM) business marketing) to the analysis of AIS observation data. This recasts the marine traffic problem as a business-marketing problem and integrates technologies such as Geographic Information Systems (GIS), database management systems, data warehousing and data mining to facilitate the discovery of hidden and valuable information in a huge amount of observation data. Consequently, this provides the marine traffic managers with a useful strategic planning resource.

  9. Backyard poultry flocks and salmonellosis: a recurring, yet preventable public health challenge.

    PubMed

    Behravesh, Casey Barton; Brinson, Denise; Hopkins, Brett A; Gomez, Thomas M

    2014-05-01

    Poultry are well recognized as possible carriers of Salmonella species. As part of the local foods movement, backyard poultry flocks have increased in popularity in recent years. Between 1996 and 2012, 45 outbreaks of human Salmonella infections linked to live poultry from mail-order hatcheries were documented. This review examines the history of live poultry-associated salmonellosis in humans in the United States, the current status of the issue, and what can be done to help prevent these illnesses. An integrated One Health approach involving the mail-order hatchery industry, feed stores, healthcare providers, veterinarians, and backyard flock owners is needed to help prevent live poultry-associated salmonellosis.

  10. A complete backbone spectral assignment of human apolipoprotein AI on a 38 kDa preβHDL (Lp1-AI) particle

    SciTech Connect

    Ren, Xuefeng; Yang, Yunhuang; Neville, T.; Hoyt, David W.; Sparks, Daniel L.; Wang, Jianjun

    2007-06-12

    Apolipoprotein A-I (apoAI, 243-residues) is the major protein component of the high-density lipoprotein (HDL) that has been a hot subject of interests because of its anti-atherogenic properties. This important property of apoAI is related to its roles in reverse cholesterol transport pathway. Upon lipid-binding, apoAI undergoes conformational changes from lipid-free to several different HDL-associated states (1). These different conformational states regulate HDL formation, maturation and transportation. Two initial conformational states of apoAI are lipid-free apoAI and apoAI/preβHDL that recruit phospholipids and cholesterol to form HDL particles. In particular, lipid-free apoAI specifically binds to phospholipids to form lipid-poor apoAI, including apoAI/preβ-HDL (~37 kDa). As a unique class of lipid poor HDL, both in vitro and in vivo evidence demonstrates that apoAI/preβ-HDLs are the most effective acceptors specifically for free cholesterol in human plasma and serves as the precursor of HDL particles (2). Here we report a complete backbone spectral assignment of human apoAI/preβHDL. Secondary structure prediction using backbone NMR parameters indicates that apoAI/preβHDL displays a two-domain structure: the N-terminal four helix-bundle domain (residues 1-186) and the C-terminal flexible domain (residues 187-243). A structure of apoAI/preβ-HDL is the first lipid-associated structure of apoAI and is critical for us to understand how apoAI recruits cholesterol to initialize HDL formation. BMRB deposit with accession number: 15093.

  11. Using egg production data to quantify within-flock transmission of low pathogenic avian influenza virus in commercial layer chickens.

    PubMed

    Gonzales, J L; Elbers, A R W; van der Goot, J A; Bontje, D; Koch, G; de Wit, J J; Stegeman, J A

    2012-12-01

    Even though low pathogenic avian influenza viruses (LPAIv) affect the poultry industry of several countries in the world, information about their transmission characteristics in poultry is sparse. Outbreak reports of LPAIv in layer chickens have described drops in egg production that appear to be correlated with the virus transmission dynamics. The objective of this study was to use egg production data from LPAIv infected layer flocks to quantify the within-flock transmission parameters of the virus. Egg production data from two commercial layer chicken flocks which were infected with an H7N3 LPAIv were used for this study. In addition, an isolate of the H7N3 LPAIv causing these outbreaks was used in a transmission experiment. The field and experimental estimates showed that this is a virus with high transmission characteristics. Furthermore, with the field method, the day of introduction of the virus into the flock was estimated. The method here presented uses compartmental models that assume homogeneous mixing. This method is, therefore, best suited to study transmission in commercial flocks with a litter (floor-reared) housing system. It would also perform better, when used to study transmission retrospectively, after the outbreak has finished and there is egg production data from recovered chickens. This method cannot be used when a flock was affected with a LPAIv with low transmission characteristics (R(0)<2), since the drop in egg production would be low and likely to be confounded with the expected decrease in production due to aging of the flock. Because only two flocks were used for this analysis, this study is a preliminary basis for a proof of principle that transmission parameters of LPAIv infections in layer chicken flocks could be quantified using the egg production data from affected flocks.

  12. Artificial intelligence (AI) based tactical guidance for fighter aircraft

    NASA Technical Reports Server (NTRS)

    Mcmanus, John W.; Goodrich, Kenneth H.

    1990-01-01

    A research program investigating the use of artificial intelligence (AI) techniques to aid in the development of a Tactical Decision Generator (TDG) for Within Visual Range air combat engagements is discussed. The application of AI programming and problem solving methods in the development and implementation of the Computerized Logic For Air-to-Air Warfare Simulations (CLAWS), a second generation TDG, is presented. The knowledge-based systems used by CLAWS to aid in the tactical decision-making process are outlined in detail, and the results of tests to evaluate the performance of CLAWS versus a baseline TDG developed in FORTRAN to run in real time in the Langley Differential Maneuvering Simulator, are presented. To date, these test results have shown significant performance gains with respect to the TDG baseline in one-versus-one air combat engagements, and the AI-based TDG software has proven to be much easier to modify and maintain than the baseline FORTRAN TDG programs.

  13. Toward detecting California shrubland canopy chemistry with AIS data

    NASA Technical Reports Server (NTRS)

    Price, Curtis V.; Westman, Walter E.

    1987-01-01

    Airborne Imaging Spectrometer (AIS)-2 data of coastal sage scrub vegetation were examined for fine spectral features that might be used to predict concentrations of certain canopy chemical constituents. A Fourier notch filter was applied to the AIS data and the TREE and ROCK mode spectra were ratioed to a flat field. Portions of the resulting spectra resemble spectra for plant cellulose and starch in that both show reduced reflectance at 2100 and 2270 nm. The latter are regions of absorption of energy by organic bonds found in starch and cellulose. Whether the relationship is sufficient to predict the concentration of these chemicals from AIS spectra will require testing of the predictive ability of these wavebands with large field sample sizes.

  14. Diversity and uncommon HPV types in HIV seropositive and seronegative women attending an STI clinic

    PubMed Central

    de Mattos, Adriana Tonani; de Freitas, Luciana Bueno; Lima, Bettina Moulin Coelho; Miranda, Angélica Espinosa; Spano, Liliana Cruz

    2011-01-01

    Given the causal relationship between specific types of HPV with cervical cancer and precursor lesions, it is important to identify the viral type involved. The aim of this study is to access the prevalence of HPV types in HIV seropositive and seronegative women. Accordingly, 77 HPV positive cervical samples were obtained from 284 women (seropositive (n=112) and seronegative (n=172) for HIV) who attended a Sexually Transmitted Infection clinic, in Vitoria, Southeastern Brazil. Viral DNA was amplified by PCR using MY09/MY11 degenerated primers and the genotyping was performed by Restriction Fragment Length Polymorphism. Seventy five out of the 77 HPV samples were genotyped: 6, 11, 13, 16, 18, 26, 31, 31b, 32, 33, 34, 35, 52, 53, 55, 56, 58, 59, 61, 62, 64, 66, 71, 81, 83, 84. The most prevalent type was HPV16 followed by HPV types 6, 11 and 53. Fifty five percent and 45% belonged to high and low risk types, respectively. High risk types corresponded to 59% and 54.5% of the HPV detected in HIV seronegative and seropositive women, respectively. The uncommon HPV 13 type in cervical samples was also observed in this study. The oncogenic types were more common in the HIV seronegative samples and the number of cases with multiple infections was similar for the two groups. HPV typing is not only important clinically for the establishment of monitoring and treatment of a patient, it also provides knowledge of the viral types circulating in a population, which is of interest in the development of prevention and treatment programs for this disease. PMID:24031694

  15. Risk Factors of Coxiella burnetii (Q Fever) Seropositivity in Veterinary Medicine Students

    PubMed Central

    de Rooij, Myrna M. T.; Schimmer, Barbara; Versteeg, Bart; Schneeberger, Peter; Berends, Boyd R.; Heederik, Dick; van der Hoek, Wim; Wouters, Inge M.

    2012-01-01

    Background Q fever is an occupational risk for veterinarians, however little is known about the risk for veterinary medicine students. This study aimed to assess the seroprevalence of Coxiella burnetii among veterinary medicine students and to identify associated risk factors. Methods A cross-sectional study with questionnaire and blood sample collection was performed among all veterinary medicine students studying in the Netherlands in 2006. Serum samples (n = 674), representative of all study years and study directions, were analyzed for C. burnetii IgG and IgM phase I and II antibodies with an immunofluorescence assay (IFA). Seropositivity was defined as IgG phase I and/or II titer of 1∶32 and above. Results Of the veterinary medicine students 126 (18.7%) had IgG antibodies against C. burnetii. Seropositivity associated risk factors identified were the study direction ‘farm animals’ (Odds Ratio (OR) 3.27 [95% CI 2.14–5.02]), advanced year of study (OR year 6: 2.31 [1.22–4.39] OR year 3–5 1.83 [1.07–3.10]) having had a zoonosis during the study (OR 1.74 [1.07–2.82]) and ever lived on a ruminant farm (OR 2.73 [1.59–4.67]). Stratified analysis revealed study direction ‘farm animals’ to be a study-related risk factor apart from ever living on a farm. In addition we identified a clear dose-response relation for the number of years lived on a farm with C. burnetii seropositivity. Conclusions C. burnetii seroprevalence is considerable among veterinary medicine students and study related risk factors were identified. This indicates Q fever as an occupational risk for veterinary medicine students. PMID:22363803

  16. Sera from patients with seropositive neuromyelitis optica spectral disorders caused the degeneration of rodent optic nerve.

    PubMed

    Matsumoto, Yoshiko; Kanamori, Akiyasu; Nakamura, Makoto; Takahashi, Toshiyuki; Nakashima, Ichiro; Negi, Akira

    2014-02-01

    Neuromyelitis optica (NMO) is an autoimmune inflammatory, neurodestructive disease primarily targeting the optic nerve and spinal cord. An autoantibody against water channel protein aquaporin-4 (AQP4), which is expressed at endofeet of astrocytes has been implicated in the pathogenesis of NMO. We evaluated the impact of sera of seropositive patients with NMO spectrum disorders (NMOSDs) on the rodent optic nerve and retina. Serum was obtained either from patients with seropositive NMOSD (AQP4+), seronegative patient with idiopathic optic neuritis (AQP4-), and healthy volunteers (control). Anti-AQP4 antibody in a serum was measured by a previously established cell-based assay. The patients' sera were applied on the optic nerve after de-sheathed. Immunohistochemistry showed that at 7 days after the treatment, the area of the optic nerve exposed to the AQP4+ sera lost expression of both AQP4 and glial fibrillary acidic protein. Also, Human-IgG immunoreactivity and marked invasion of inflammation cells were observed in the optic nerve treated with AQP4+ serum. Immnoreactivity of neurofilament was reduced at 14 days after the treatment, not 7 days. Real-time polymerase chain reaction revealed the reduced gene expression of neurofilament in retina from the eye that was exposed to the AQP4+ sera at 14 days. Retrograde fluorogold-labeling on the retinal flatmount disclosed the significantly reduced number of retinal ganglion cells when the AQP4+ sera were applied. The present model has demonstrated that the sera from patients with seropositive NMOSDs led to the regional astrocytic degeneration and inflammatory cell invasion in the optic nerve, resulting in the ultimate loss of RGCs and their axons at areas beyond the injury site.

  17. Association between contamination of public squares and seropositivity for Toxocara spp. in children.

    PubMed

    Manini, Marcos P; Marchioro, Ariella A; Colli, Cristiane M; Nishi, Letícia; Falavigna-Guilherme, Ana L

    2012-08-13

    A concomitant study was carried out, of the association of positive serology for Toxocara spp. in 90 children who played in public squares used for leisure, with the frequency with which each child used these areas, and the presence of eggs of Toxocara spp. in the sand or grass in these locations. The sand and grass of their peridomiciles and school playgrounds, as well as the feces of their dogs were also analyzed for Toxocara. Serum samples were tested for IgG antibodies to Toxocara canis excreted-secreted larval antigens by ELISA, and blood samples for eosinophilia. The water-sedimentation technique was used to evaluate the presence of parasite eggs in the sand and grass turfs, and in feces of the dogs that also frequented these locations. 16/90 (17.8%) of the children were seropositive for Toxocara spp. There was a positive association between seropositivity in children who played in the public squares six or seven times a week, with a parasite load above 1.1 eggs/g of sand, as well as with contamination of the peridomicile, even at less than 1.0 egg/g of sand. Eosinophilia, the habit of geophagy, age from one to four years, and the presence of parasitized pet dogs were also positively correlated with seropositivity in the children. Eggs were found in 15/15 (100%) of the public squares, 17/90 (18.9%) of the peridomiciles, 3/13 (23.1%) of the schools, and 12/41 (29.3%) of the dogs living in the peridomiciles investigated.

  18. Seropositivity and risk factors associated with Toxoplasma gondii infection in wild birds from Spain.

    PubMed

    Cabezón, Oscar; García-Bocanegra, Ignacio; Molina-López, Rafael; Marco, Ignasi; Blanco, Juan M; Höfle, Ursula; Margalida, Antoni; Bach-Raich, Esther; Darwich, Laila; Echeverría, Israel; Obón, Elena; Hernández, Mauro; Lavín, Santiago; Dubey, Jitender P; Almería, Sonia

    2011-01-01

    Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n=610), Strigiformes (n=260), Ciconiiformes (n=156), Gruiformes (n=21), and other orders (n=32), from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1:25) were found in 282 (26.1%, IC(95%:)23.5-28.7) of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus), short-toed snake-eagle (Circaetus gallicus), Bonelli's eagle (Aquila fasciata), golden eagle (Aquila chrysaetos), bearded vulture (Gypaetus barbatus), osprey (Pandion haliaetus), Montagu's harrier (Circus pygargus), Western marsh-harrier (Circus aeruginosus), peregrine falcon (Falco peregrinus), long-eared owl (Asio otus), common scops owl (Otus scops), Eurasian spoonbill (Platalea leucorodia), white stork (Ciconia ciconia), grey heron (Ardea cinerea), common moorhen (Gallinula chloropus); in the International Union for Conservation of Nature (IUCN) "vulnerable" Spanish imperial eagle (Aquila adalberti), lesser kestrel (Falco naumanni) and great bustard (Otis tarda); and in the IUCN "near threatened" red kite (Milvus milvus). The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo) (68.1%, 98 of 144). The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is widespread and can be at a high level in

  19. Situated, strategic, and AI-Enhanced technology introduction to healthcare.

    PubMed

    Bushko, Renata G

    2005-01-01

    We work hard on creating AI-wings for physicians to let them fly higher and faster in diagnosing patients--a task that physicians do not want to automate. What we do not work hard on is determining the ENVIRONMENT in which physicians' AI wings are supposed to function. It seems to be a job for social/business analysts that have their own separate kingdom. For the sake of all of us (potential patients!) social/business consultants and their methodologies should not be treated as a separate kingdom. The most urgent task is to achieve synergy between (1) AI/Fuzzy/Neural research, (2) Applied medical AI, (3) Social/Business research on medical institutions. We need this synergy in order to assure humanistic medical technology; technology flexible and sensitive enough to facilitate healthcare work while leaving space for human pride and creativity. In order to achieve humanistic technology, designers should consider the impact of technological breakthroughs on the organizations in which this technology will function and the nature of work of humans destined to use this technology. Situated (different for each organization), Strategic (based on an in-depth knowledge of Healthcare business), and AI-Enhanced (ended with a dynamic model) method for introducing technology to Healthcare allows identifying areas where technology can make medical work easier. Using this method before automating human work will get us closer to the ideal where there is no discontinuity between design and use of programs; where the technology matches users' needs perfectly--the world with humanistic technology and healthcare workers with AI-wings.

  20. Household Socioeconomic and Demographic Correlates of Cryptosporidium Seropositivity in the United States

    PubMed Central

    Becker, Daniel J.; Oloya, James; Ezeamama, Amara E.

    2015-01-01

    Background Cryptosporidium are parasitic protozoa that infect humans, domestic animals, and wildlife globally. In the United States, cryptosporidiosis occurs in an estimated 750,000 persons annually, and is primarily caused by either of the Cryptosporidium parvum genotypes 1 and 2, exposure to which occurs through ingestion of food or water contaminated with oocytes shed from infected hosts. Although most cryptosporidiosis cases are caused by genotype 1 and are of human origin, the zoonotic sources of genotype 2, such as livestock, are increasingly recognized as important for understanding human disease patterns. Social inequality could mediate patterns of human exposure and infection by placing individuals in environments where food or water contamination and livestock contact is high or through reducing the availability of educational and sanitary resources required to avoid exposure. Methodology/Principal Findings We here analyzed data from the National Health and Nutritional Examination Survey (NHANES) between 1999 and 2000, and related seropositivity to Cryptosporidium parvum to correlates of social inequality at the household and individual scale. After accounting for the complex sampling design of NHANES and confounding by individual demographics and household conditions, we found impaired household food adequacy was associated with greater odds of Cryptosporidium seropositivity. Additionally, we identified individuals of non-white race and ethnicity and those born outside the United States as having significantly greater risk than white, domestic-born counterparts. Furthermore, we provide suggestive evidence for direct effects of family wealth on Cryptosporidium seropositivity, in that persons from low-income households and from families close to the poverty threshold had elevated odds of seropositivity relative to those in high-income families and in households far above the poverty line. Conclusions/Significance These results refute assertions that

  1. A Spatial Analysis of Rift Valley Fever Virus Seropositivity in Domestic Ruminants in Tanzania.

    PubMed

    Sindato, Calvin; Pfeiffer, Dirk U; Karimuribo, Esron D; Mboera, Leonard E G; Rweyemamu, Mark M; Paweska, Janusz T

    2015-01-01

    Rift Valley fever (RVF) is an acute arthropod-borne viral zoonotic disease primarily occurring in Africa. Since RVF-like disease was reported in Tanzania in 1930, outbreaks of the disease have been reported mainly from the eastern ecosystem of the Great Rift Valley. This cross-sectional study was carried out to describe the variation in RVF virus (RVFV) seropositivity in domestic ruminants between selected villages in the eastern and western Rift Valley ecosystems in Tanzania, and identify potential risk factors. Three study villages were purposively selected from each of the two Rift Valley ecosystems. Serum samples from randomly selected domestic ruminants (n = 1,435) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM), using RVF enzyme-linked immunosorbent assay methods. Mixed effects logistic regression modelling was used to investigate the association between potential risk factors and RVFV seropositivity. The overall RVFV seroprevalence (n = 1,435) in domestic ruminants was 25.8% and species specific seroprevalence was 29.7%, 27.7% and 22.0% in sheep (n = 148), cattle (n = 756) and goats (n = 531), respectively. The odds of seropositivity were significantly higher in animals sampled from the villages in the eastern than those in the western Rift Valley ecosystem (OR = 1.88, CI: 1.41, 2.51; p<0.001), in animals sampled from villages with soils of good than those with soils of poor water holding capacity (OR = 1.97; 95% CI: 1.58, 3.02; p< 0.001), and in animals which had been introduced than in animals born within the herd (OR = 5.08, CI: 2.74, 9.44; p< 0.001). Compared with animals aged 1-2 years, those aged 3 and 4-5 years had 3.40 (CI: 2.49, 4.64; p< 0.001) and 3.31 (CI: 2.27, 4.82, p< 0.001) times the odds of seropositivity. The findings confirm exposure to RVFV in all the study villages, but with a higher prevalence in the study villages from the eastern Rift Valley ecosystem.

  2. Isolation and molecular characterization of Brucella melitensis from seropositive goats in Peninsula Malaysia.

    PubMed

    Bamaiyi, P H; Hassan, L; Khairani-Bejo, S; Zainal Abidin, M; Ramlan, M; Krishnan, N; Adzhar, A; Abdullah, N; Hamidah N, H M; Norsuhanna, M M; Hashim, S N

    2012-12-01

    A study was carried out to isolate Brucella melitensis using established bacteriological and PCR techniques in Brucella seropositive goats in farms in Selangor, Negeri Sembilan, Melaka and Pulau Pinang. Brucella melitensis was isolated from 7 of 134 reactors with the highest isolation from the vaginal swabs (57.14%) followed by the spleen (28.57%), uterine fluid (14.29%). No Brucella was isolated from the lymph nodes. PCR confirmed all the seven isolates as B. melitensis and isolates were phylogenetically related to other isolates from India, Iran, and Israel but most closely related to isolates from Singapore.

  3. A Spatial Analysis of Rift Valley Fever Virus Seropositivity in Domestic Ruminants in Tanzania

    PubMed Central

    Sindato, Calvin; Pfeiffer, Dirk U.; Karimuribo, Esron D.; Mboera, Leonard E. G.; Rweyemamu, Mark M.; Paweska, Janusz T.

    2015-01-01

    Rift Valley fever (RVF) is an acute arthropod-borne viral zoonotic disease primarily occurring in Africa. Since RVF-like disease was reported in Tanzania in 1930, outbreaks of the disease have been reported mainly from the eastern ecosystem of the Great Rift Valley. This cross-sectional study was carried out to describe the variation in RVF virus (RVFV) seropositivity in domestic ruminants between selected villages in the eastern and western Rift Valley ecosystems in Tanzania, and identify potential risk factors. Three study villages were purposively selected from each of the two Rift Valley ecosystems. Serum samples from randomly selected domestic ruminants (n = 1,435) were tested for the presence of specific immunoglobulin G (IgG) and M (IgM), using RVF enzyme-linked immunosorbent assay methods. Mixed effects logistic regression modelling was used to investigate the association between potential risk factors and RVFV seropositivity. The overall RVFV seroprevalence (n = 1,435) in domestic ruminants was 25.8% and speciesspecific seroprevalence was 29.7%, 27.7% and 22.0% in sheep (n = 148), cattle (n = 756) and goats (n = 531), respectively. The odds of seropositivity were significantly higher in animals sampled from the villages in the eastern than those in the western Rift Valley ecosystem (OR = 1.88, CI: 1.41, 2.51; p<0.001), in animals sampled from villages with soils of good than those with soils of poor water holding capacity (OR = 1.97; 95% CI: 1.58, 3.02; p< 0.001), and in animals which had been introduced than in animals born within the herd (OR = 5.08, CI: 2.74, 9.44; p< 0.001). Compared with animals aged 1–2 years, those aged 3 and 4–5 years had 3.40 (CI: 2.49, 4.64; p< 0.001) and 3.31 (CI: 2.27, 4.82, p< 0.001) times the odds of seropositivity. The findings confirm exposure to RVFV in all the study villages, but with a higher prevalence in the study villages from the eastern Rift Valley ecosystem. PMID:26162089

  4. Seroprevalence and Risk Factors for Leptospira Seropositivity in Beef Cattle, Sheep and Deer Farmers in New Zealand.

    PubMed

    Sanhueza, J M; Heuer, C; Wilson, P R; Benschop, J; Collins-Emerson, J M

    2016-12-05

    Leptospirosis is a global zoonosis that in New Zealand affects primarily people occupationally exposed to livestock. The objective of this study was to estimate the seroprevalence of five Leptospira serovars in farmers working on cattle, sheep and deer farms that had the serological status of animals previously assessed and to identify risk factors for farmer seropositivity. A total of 178 farmers from 127 properties participated in the study. Blood samples were tested using the microscopic agglutination test (MAT) for the presence of antibodies to Leptospira. Samples with a MAT titre ≥48 were considered seropositive. Using Bayesian statistical analysis, the median seroprevalence of Leptospira, all serovars combined, was estimated to be 6.6% (95% probability interval (PI) 3.6-10.9%). Risk factors associated with seropositivity were assisting deer or cattle calving, farming deer, having ≥25% of flat terrain and high abundance of wild deer on farm, while high possum abundance on farm was negatively associated with seropositivity. No association was observed between farmer serostatus and previously recorded livestock serology. Leptospira seropositivity was associated with influenza-like illness of farmers (RR = 1.7; 95% PI 1.0-2.5). Assuming a causal relationship, this suggested an annual risk of 1.3% (95% PI 0.0-3.0%) of influenza-like illnesses due to Leptospira infection in the population of farmers. The association between seropositivity and disease can be used to estimate the public health burden of leptospirosis in New Zealand. Identifying and understanding risk factors for Leptospira seropositivity can inform preventive measures, hence contributing to the reduction of leptospirosis incidence in farmers.

  5. SEROPOSITIVITY FOR ASCARIOSIS AND TOXOCARIOSIS AND CYTOKINE EXPRESSION AMONG THE INDIGENOUS PEOPLE IN THE VENEZUELAN DELTA REGION

    PubMed Central

    Araujo, Zaida; Brandes, Sietze; Pinelli, Elena; Bochichio, María A.; Palacios, Andrea; Wide, Albina; Rivas-Santiago, Bruno; Jiménez, Juan Carlos

    2015-01-01

    The present study aimed at measuring seropositivities for infection by Ascaris suum and Toxocara canis using the excretory/secretory (E/S) antigens from Ascaris suum (AES) and Toxocara canis (TES) within an indigenous population. In addition, quantification of cytokine expressions in peripheral blood cells was determined. A total of 50 Warao indigenous were included; of which 43 were adults and seven children. In adults, 44.1% were seropositive for both parasites; whereas children had only seropositivity to one or the other helminth. For ascariosis, the percentage of AES seropositivity in adults and children was high; 23.3% and 57.1%, respectively. While that for toxocariosis, the percentage of TES seropositivity in adults and children was low; 9.3% and 14.3%, respectively. The percentage of seronegativity was comparable for AES and TES antigens in adults (27.9%) and children (28.6%). When positive sera were analyzed by Western blotting technique using AES antigens; three bands of 97.2, 193.6 and 200.2 kDas were mostly recognized. When the TES antigens were used, nine major bands were mostly identified; 47.4, 52.2, 84.9, 98.2, 119.1, 131.3, 175.6, 184.4 and 193.6 kDas. Stool examinations showed that Blastocystis hominis, Hymenolepis nana and Entamoeba coli were the most commonly observed intestinal parasites. Quantification of cytokines IFN-γ, IL-2, IL-6, TGF-β, TNF-α, IL-10 and IL-4 expressions showed that there was only a significant increased expression of IL-4 in indigenous with TES seropositivity (p < 0.002). Ascaris and Toxocara seropositivity was prevalent among Warao indigenous. PMID:25651326

  6. Frame synchronization of satellite based on AIS signals

    NASA Astrophysics Data System (ADS)

    Ma, Shexiang; Zhao, Dawei

    2016-10-01

    Frame synchronization play a very important role in coding of AIS. There are much arithmetic like maximum-likelihood, correlation and so on. But most of those cannot achieve good performance with large frequency offset. As satellite-based AIS system exist larger time delay and Doppler frequency offset, this paper propose arithmetic of frame synchronization. It is based on folding auto-correlation, where the top half and second half of training sequence have largest correlation after it is modulated by GMSK. Simulation experiments indicate that this arithmetic has good anti-frequency-offset performance.

  7. Rapid prototyping and AI programming environments applied to payload modeling

    NASA Technical Reports Server (NTRS)

    Carnahan, Richard S., Jr.; Mendler, Andrew P.

    1987-01-01

    This effort focused on using artificial intelligence (AI) programming environments and rapid prototyping to aid in both space flight manned and unmanned payload simulation and training. Significant problems addressed are the large amount of development time required to design and implement just one of these payload simulations and the relative inflexibility of the resulting model to accepting future modification. Results of this effort have suggested that both rapid prototyping and AI programming environments can significantly reduce development time and cost when applied to the domain of payload modeling for crew training. The techniques employed are applicable to a variety of domains where models or simulations are required.

  8. Diverter AI based decision aid, phases 1 and 2

    NASA Technical Reports Server (NTRS)

    Sexton, George A.; Bayles, Scott J.; Patterson, Robert W.; Schulke, Duane A.; Williams, Deborah C.

    1989-01-01

    It was determined that a system to incorporate artificial intelligence (AI) into airborne flight management computers is feasible. The AI functions that would be most useful to the pilot are to perform situational assessment, evaluate outside influences on the contemplated rerouting, perform flight planning/replanning, and perform maneuver planning. A study of the software architecture and software tools capable of demonstrating Diverter was also made. A skeletal planner known as the Knowledge Acquisition Development Tool (KADET), which is a combination script-based and rule-based system, was used to implement the system. A prototype system was developed which demonstrates advanced in-flight planning/replanning capabilities.

  9. AiGERM: A logic programming front end for GERM

    NASA Technical Reports Server (NTRS)

    Hashim, Safaa H.

    1990-01-01

    AiGerm (Artificially Intelligent Graphical Entity Relation Modeler) is a relational data base query and programming language front end for MCC (Mission Control Center)/STP's (Space Test Program) Germ (Graphical Entity Relational Modeling) system. It is intended as an add-on component of the Germ system to be used for navigating very large networks of information. It can also function as an expert system shell for prototyping knowledge-based systems. AiGerm provides an interface between the programming language and Germ.

  10. Detection of rotaviruses and intestinal lesions in broiler chicks from flocks with runting and stunting syndrome (RSS).

    PubMed

    Otto, Peter; Liebler-Tenorio, Elisabeth M; Elschner, Mandy; Reetz, Jochen; Löhren, Ulrich; Diller, Roland

    2006-09-01

    The intestinal tract and intestinal contents were collected from 34 stunted, 5-to-14-day-old broiler chicks from eight flocks with runting and stunting syndrome (RSS) in Northern Germany to investigate intestinal lesions and the presence of enteric pathogens with a special focus on rotaviruses (RVs). Seven chicks from a healthy flock were used as controls. Severe villous atrophy was seen in chicks from six flocks with RSS but not in the control flock. Lesions were often "regionally" distributed in the middle-to-distal small intestine. Transmission electron microscopy (TEM), polyacrylamide-gel electrophoresis (PAGE), reverse-transcriptase polymerase chain reaction (RT-PCR), and seminested RT-PCR were used for detection and characterization of RVs. The PAGE allows discrimination of different RV groups, and the RT-PCR was used to verify the presence of group (gp) A RVs. RVs were detected (by all methods) in 32 of 34 chicks from the flocks with RSS. By TEM (negative staining), RV particles were observed in intestinal contents of 28 chicks from the flocks with RSS. PAGE analysis showed four RV groups: gpA, gpD, gpF, and gpG. Group A RVs were detected in four chicks from two flocks with RSS, without intestinal lesions. GpD RVs were detected in 12 chicks of five flocks with RSS, 10 of them with severe villous atrophy. GpF RVs were confirmed in four chicks from three flocks with RSS and in two birds in the control flock. GpG RVs were verified in two chicks from two flocks with RSS, one with, and one without, intestinal lesions. At present, PCR methods are only available for detection of gpA RVs. Using RT-PCR, gpA RVs were identified in samples from 22 chicks including samples of two chicks from the control flock. Statistical analysis revealed a positive correlation between presence of gpD RV and severe villous atrophy in flocks with RSS. The results suggest that gpD RV plays a major role in the pathogenesis of RSS.

  11. 9 CFR 146.4 - General provisions for all participating flocks and slaughter plants.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 9 Animals and Animal Products 1 2013-01-01 2013-01-01 false General provisions for all participating flocks and slaughter plants. 146.4 Section 146.4 Animals and Animal Products ANIMAL AND PLANT... and slaughter plants. (a) Records that establish the identity of products handled shall be...

  12. 9 CFR 146.4 - General provisions for all participating flocks and slaughter plants.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 9 Animals and Animal Products 1 2010-01-01 2010-01-01 false General provisions for all participating flocks and slaughter plants. 146.4 Section 146.4 Animals and Animal Products ANIMAL AND PLANT... and slaughter plants. (a) Records that establish the identity of products handled shall be...

  13. 9 CFR 146.4 - General provisions for all participating flocks and slaughter plants.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 9 Animals and Animal Products 1 2014-01-01 2014-01-01 false General provisions for all participating flocks and slaughter plants. 146.4 Section 146.4 Animals and Animal Products ANIMAL AND PLANT... and slaughter plants. (a) Records that establish the identity of products handled shall be...

  14. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... control procedures. (g) U.S. H5/H7 Avian Influenza Clean. This program is intended to be the basis from... subtypes of avian influenza. It is intended to determine the presence of the H5/H7 subtypes of avian influenza in breeding turkeys through routine surveillance of each participating breeding flock. A...

  15. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... Official State Agency and approved by the Service in lieu of annual blood testing. (b) U.S. Avian Influenza... program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine...

  16. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... Official State Agency and approved by the Service in lieu of annual blood testing. (b) U.S. Avian Influenza... program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine...

  17. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Official State Agency and approved by the Service in lieu of annual blood testing. (b) U.S. Avian Influenza... program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine...

  18. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... control procedures. (g) U.S. H5/H7 Avian Influenza Clean. This program is intended to be the basis from... subtypes of avian influenza. It is intended to determine the presence of the H5/H7 subtypes of avian influenza in breeding turkeys through routine surveillance of each participating breeding flock. A...

  19. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... control procedures. (g) U.S. H5/H7 Avian Influenza Clean. This program is intended to be the basis from... subtypes of avian influenza. It is intended to determine the presence of the H5/H7 subtypes of avian influenza in breeding turkeys through routine surveillance of each participating breeding flock. A...

  20. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... Official State Agency and approved by the Service in lieu of annual blood testing. (b) U.S. Avian Influenza... program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine...

  1. 9 CFR 145.63 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... Official State Agency and approved by the Service in lieu of annual blood testing. (b) U.S. Avian Influenza... program for the prevention and control of avian influenza. It is intended to determine the presence of avian influenza in all ostrich, emu, rhea, and cassowary breeding flocks through routine...

  2. 9 CFR 146.4 - General provisions for all participating flocks and slaughter plants.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... participating flocks and slaughter plants. 146.4 Section 146.4 Animals and Animal Products ANIMAL AND PLANT... and slaughter plants. (a) Records that establish the identity of products handled shall be maintained... classification may include in their advertising reference to associated or franchised slaughter or...

  3. Swabbing for respiratory viral infections in older patients: a comparison of rayon and nylon flocked swabs.

    PubMed

    Hernes, S S; Quarsten, H; Hagen, E; Lyngroth, A L; Pripp, A H; Bjorvatn, B; Bakke, P S

    2011-02-01

    The purpose of this study was to compare the sampling efficacy of rayon swabs and nylon flocked swabs, and of oropharyngeal and nasopharyngeal specimens for the detection of respiratory viruses in elderly patients. Samples were obtained from patients 60 years of age or above who were newly admitted to Sorlandet Hospital Arendal, Norway. The patients were interviewed for current symptoms of a respiratory tract infection. Using rayon swabs and nylon flocked swabs, comparable sets of mucosal samples were harvested from the nasopharynx and the oropharynx. The samples were analysed using real-time polymerase chain reaction (PCR) methods. A total of 223 patients (mean age 74.9 years, standard deviation [SD] 9.0 years) were swabbed and a virus was recovered from 11% of the symptomatic patients. Regardless of the sampling site, a calculated 4.8 times higher viral load (95% confidence interval [CI] 1.3-17, p = 0.017) was obtained using the nylon flocked swabs as compared to the rayon swabs. Also, regardless of the type of swab, a calculated 19 times higher viral load was found in the samples from the nasopharynx as compared to the oropharynx (95% CI 5.4-67.4, p < 0.001). When swabbing for respiratory viruses in elderly patients, nasopharyngeal rather than oropharyngeal samples should be obtained. Nylon flocked swabs appear to be more efficient than rayon swabs.

  4. Monitoring chicken flock behaviour provides early warning of infection by human pathogen Campylobacter

    PubMed Central

    Colles, Frances M.; Cain, Russell J.; Nickson, Thomas; Smith, Adrian L.; Roberts, Stephen J.; Maiden, Martin C. J.; Lunn, Daniel; Dawkins, Marian Stamp

    2016-01-01

    Campylobacter is the commonest bacterial cause of gastrointestinal infection in humans, and chicken meat is the major source of infection throughout the world. Strict and expensive on-farm biosecurity measures have been largely unsuccessful in controlling infection and are hampered by the time needed to analyse faecal samples, with the result that Campylobacter status is often known only after a flock has been processed. Our data demonstrate an alternative approach that monitors the behaviour of live chickens with cameras and analyses the ‘optical flow’ patterns made by flock movements. Campylobacter-free chicken flocks have higher mean and lower kurtosis of optical flow than those testing positive for Campylobacter by microbiological methods. We show that by monitoring behaviour in this way, flocks likely to become positive can be identified within the first 7–10 days of life, much earlier than conventional on-farm microbiological methods. This early warning has the potential to lead to a more targeted approach to Campylobacter control and also provides new insights into possible sources of infection that could transform the control of this globally important food-borne pathogen. PMID:26740618

  5. Comparison of Campylobacter populations isolated from a free-range broiler flock before and after slaughter.

    PubMed

    Colles, Frances M; McCarthy, Noel D; Sheppard, Samuel K; Layton, Ruth; Maiden, Martin C J

    2010-02-28

    Relatively little is known about the Campylobacter genotypes colonizing extensively reared broiler flocks and their survival through the slaughter process, despite the increasing demand for free-range and organic products by the consumer. Campylobacter isolates from a free-range boiler flock, sampled before and after slaughter, were genotyped by MLST (multilocus sequence typing) and sequence analysis of the flaA short variable region (SVR). The Campylobacter genotypes isolated before and after slaughter were diverse, with up to five sequence types (STs) (seven-locus allelic profiles resulting from MLST) identified per live bird, up to eight STs identified per carcass and 31 STs identified in all. The majority (72.0%) of isolates sampled from carcasses post-slaughter were indistinguishable from those isolated from the live flock before slaughter by ST and flaA SVR type, however, sampling 'on-farm' failed to capture all of the diversity seen post-slaughter. There were statistically significant increases in the genetic diversity of Campylobacter (p=0.005) and the proportion of C. coli (p=0.002), with some evidence for differential survival of genotypes contaminating the end product. C. coli genotypes isolated after slaughter were more similar to those from free-range and organic meat products sampled nationally, than from the live flock sampled previously. This study demonstrated the utility of MLST in detecting genetic diversity before and after the slaughter process.

  6. Monitoring chicken flock behaviour provides early warning of infection by human pathogen Campylobacter.

    PubMed

    Colles, Frances M; Cain, Russell J; Nickson, Thomas; Smith, Adrian L; Roberts, Stephen J; Maiden, Martin C J; Lunn, Daniel; Dawkins, Marian Stamp

    2016-01-13

    Campylobacter is the commonest bacterial cause of gastrointestinal infection in humans, and chicken meat is the major source of infection throughout the world. Strict and expensive on-farm biosecurity measures have been largely unsuccessful in controlling infection and are hampered by the time needed to analyse faecal samples, with the result that Campylobacter status is often known only after a flock has been processed. Our data demonstrate an alternative approach that monitors the behaviour of live chickens with cameras and analyses the 'optical flow' patterns made by flock movements. Campylobacter-free chicken flocks have higher mean and lower kurtosis of optical flow than those testing positive for Campylobacter by microbiological methods. We show that by monitoring behaviour in this way, flocks likely to become positive can be identified within the first 7-10 days of life, much earlier than conventional on-farm microbiological methods. This early warning has the potential to lead to a more targeted approach to Campylobacter control and also provides new insights into possible sources of infection that could transform the control of this globally important food-borne pathogen.

  7. Campylobacter detection in broiler ceca at processing - a three year 211 flock survey

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter is associated with live broilers and chicken meat products. There is some discussion in the literature about the possibility that Campylobacter prevalence in broilers could be affected by season or weather conditions. The objective of this study was to measure the flock prevalence of...

  8. Identification and phylogenetic diversity of parvovirus circulating in commercial chicken and turkey flocks in Croatia.

    PubMed

    Bidin, M; Lojkić, I; Bidin, Z; Tiljar, M; Majnarić, D

    2011-12-01

    Phylogenetic diversity of parvovirus detected in commercial chicken and turkey flocks is described. Nine chicken and six turkey flocks from Croatian farms were tested for parvovirus presence. Intestinal samples from one turkey and seven chicken flocks were found positive, and were sequenced. Natural parvovirus infection was more frequently detected in chickens than in turkeys examined in this study. Sequence analysis of 400 nucleotide fragments of the nonstructural gene (NS) showed that our sequences had more similarity with chicken parvovirus (ChPV) (92.3%-99.7%) than turkey parvovirus (TuPV) (89.5%-98.9%) strains. Phylogenetic analysis grouped our sequences in two clades. Also, the higher prevalence of ChPV than TuPV in tested flocks was defined. The necropsy findings suggested a malabsorption syndrome followed by a preascitic condition. Further research of parvovirus infection, pathogenesis, and the possibility of its association with poult enteritis and mortality syndrome (PEMS) and runting and stunting syndrome (RSS) is needed to clarify its significance as an agent of enteric disease.

  9. Emergence of collective changes in travel direction of starling flocks from individual birds' fluctuations.

    PubMed

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Jelic, Asja; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Shen, Edward; Viale, Massimiliano

    2015-07-06

    One of the most impressive features of moving animal groups is their ability to perform sudden coherent changes in travel direction. While this collective decision can be a response to an external alarm cue, directional switching can also emerge from the intrinsic fluctuations in individual behaviour. However, the cause and the mechanism by which such collective changes of direction occur are not fully understood yet. Here, we present an experimental study of spontaneous collective turns in natural flocks of starlings. We employ a recently developed tracking algorithm to reconstruct three-dimensional trajectories of each individual bird in the flock for the whole duration of a turning event. Our approach enables us to analyse changes in the individual behaviour of every group member and reveal the emergent dynamics of turning. We show that spontaneous turns start from individuals located at the elongated tips of the flocks, and then propagate through the group. We find that birds on the tips deviate from the mean direction of motion much more frequently than other individuals, indicating that persistent localized fluctuations are the crucial ingredient for triggering a collective directional change. Finally, we quantitatively verify that birds follow equal-radius paths during turning, the effects of which are a change of the flock's orientation and a redistribution of individual locations in the group.

  10. Liver pathology associated with increased mortality in turkey breeder and meat turkey flocks.

    PubMed

    Popp, Christina; Hauck, Rüdiger; Vahlenkamp, Thomas W; Lüschow, Dörte; Kershaw, B Olivia; Hoferer, Marc; Hafez, Hafez M

    2014-09-01

    Between 2006 and 2011 a series of disease conditions characterized by raised mortality and liver disorders occurred in turkey breeder flocks and in meat turkey flocks in Germany. The flocks were between 12 and 23 wk of age, and mostly hens were affected. Clinical signs were nonspecific and accompanied by mortality varying between 1% and 7%. Affected birds displayed swollen livers that were marbled with black and red spots and yellowish areas. The pericardium was filled with an amber fluid, and the coronary groove was extensively filled with fat. Spleens were swollen, and a serous fluid that seemed to leak from the liver was present in the body cavity. Histopathological findings in all but one case included fatty degeneration of hepatocytes with parenchymal collapse and associated hemorrhages. Some animals showed cholangitis and hepatitis with intranuclear inclusion bodies. In three cases with breeders, electron microscopy detected virus particles that were between 23 and 30 nm and similar to parvo- or picornavirus. In addition, picornavirus RNA was detected in the livers of one meat turkey flock. Investigations by PCR for circovirus, polyomavirus parvovirus, and aviadenovirus yielded negative results in all cases, but an aviadenovirus was isolated from livers twice and a reovirus from the intestines once. Supplementation with vitamin E and selenium seemed to improve the situation. The most likely diagnosis is lipidosis, a metabolic disorder with complex etiology, which has rarely been described in turkeys.

  11. Detection of Campylobacter in 100 commercial flocks - evaluation of plating media and filtration method

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Campylobacter is a natural member of the gut microflora in many commercial broilers and as such can become a contaminant on edible surfaces during processing. Culturing gut contents or feces can be a means to determine flock status prior to live-haul. The wide variety of non-Campylobacter backgrou...

  12. 9 CFR 145.73 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... of Salmonella enteritidis. (1) A flock and the hatching eggs and chicks produced from it which have... died within 7 days after hatching are examined bacteriologically for salmonella at an authorized... products produced under the Animal Protein Products Industry (APPI) Salmonella Education/Reduction...

  13. 9 CFR 145.73 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... of Salmonella enteritidis. (1) A flock and the hatching eggs and chicks produced from it which have... died within 7 days after hatching are examined bacteriologically for salmonella at an authorized... products produced under the Animal Protein Products Industry (APPI) Salmonella Education/Reduction...

  14. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... certified free of Salmonella enteritidis. (1) A flock and the hatching eggs and chicks produced from it... group D Salmonella samples have been serotyped: (A) A 25-gram sample of meconium from the chicks in the... process; (B) Mash feed may contain animal protein if the finished feed is treated with a...

  15. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... the level of salmonella through compliance with sanitation and management practices as described in... authorized laboratory for Salmonella. (2) The poults for the candidate breeding flock are placed in a... presence of Salmonella, as described in § 147.12 of this subchapter. (3) Feed for turkeys in the...

  16. 9 CFR 145.43 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... the level of salmonella through compliance with sanitation and management practices as described in... authorized laboratory for Salmonella. (2) The poults for the candidate breeding flock are placed in a... presence of Salmonella, as described in § 147.12 of this subchapter. (3) Feed for turkeys in the...

  17. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... certified free of Salmonella enteritidis. (1) A flock and the hatching eggs and chicks produced from it... group D Salmonella samples have been serotyped: (A) A 25-gram sample of meconium from the chicks in the... process; (B) Mash feed may contain animal protein if the finished feed is treated with a...

  18. 9 CFR 145.33 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... Salmonella organisms in hatching eggs and chicks through an effective and practical sanitation program at the... to reduce the incidence of Salmonella in their products. (1) A flock and the hatching eggs and chicks...) Salmonella Education/Reduction Program or the Fishmeal Inspection Program of the National Marine...

  19. 9 CFR 145.53 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... POULTRY Special Provisions for Waterfowl, Exhibition Poultry, and Game Bird Breeding Flocks and Products... typhoid infection; (vii) All poultry, including exhibition, exotic, and game birds, but excluding... examination monitoring program for game birds acceptable to the Official State Agency and approved by...

  20. 9 CFR 145.53 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... POULTRY Special Provisions for Waterfowl, Exhibition Poultry, and Game Bird Breeding Flocks and Products... typhoid infection; (vii) All poultry, including exhibition, exotic, and game birds, but excluding... examination monitoring program for game birds acceptable to the Official State Agency and approved by...

  1. Emergence of collective changes in travel direction of starling flocks from individual birds' fluctuations

    PubMed Central

    Attanasi, Alessandro; Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Jelic, Asja; Melillo, Stefania; Parisi, Leonardo; Pohl, Oliver; Shen, Edward; Viale, Massimiliano

    2015-01-01

    One of the most impressive features of moving animal groups is their ability to perform sudden coherent changes in travel direction. While this collective decision can be a response to an external alarm cue, directional switching can also emerge from the intrinsic fluctuations in individual behaviour. However, the cause and the mechanism by which such collective changes of direction occur are not fully understood yet. Here, we present an experimental study of spontaneous collective turns in natural flocks of starlings. We employ a recently developed tracking algorithm to reconstruct three-dimensional trajectories of each individual bird in the flock for the whole duration of a turning event. Our approach enables us to analyse changes in the individual behaviour of every group member and reveal the emergent dynamics of turning. We show that spontaneous turns start from individuals located at the elongated tips of the flocks, and then propagate through the group. We find that birds on the tips deviate from the mean direction of motion much more frequently than other individuals, indicating that persistent localized fluctuations are the crucial ingredient for triggering a collective directional change. Finally, we quantitatively verify that birds follow equal-radius paths during turning, the effects of which are a change of the flock's orientation and a redistribution of individual locations in the group. PMID:26236825

  2. Detection of enteric pathogens in Turkey flocks affected with severe enteritis, in Brazil.

    PubMed

    Moura-Alvarez, Joelma; Nuñez, Luis F N; Astolfi-Ferreira, Claudete S; Knöbl, Terezinha; Chacón, Jorge L; Moreno, Andrea M; Jones, Richard C; Ferreira, Antonio J Piantino

    2014-08-01

    Twenty-two flocks of turkeys affected by enteric problems, with ages between 10 and 104 days and located in the Southern region of Brazil, were surveyed for turkey by PCR for turkey astrovirus type 2 (TAstV-2), turkey coronavirus (TCoV), hemorrhagic enteritis virus (HEV), rotavirus, reovirus, Salmonella spp., and Lawsonia intracellularis (Li) infections. Eleven profiles of pathogen combination were observed. The most frequently encountered pathogen combinations were TCoV-Li, followed by TCoV-TAstV-2-Li, TCoV-TastV-2. Only TCoV was detected as the sole pathogen in three flocks. Eight and 19 flocks of the 22 were positive for TAstV-2 and TCoV, respectively. Six were positive for Salmonella spp. and L. intracellularis was detected in 12 turkey flocks. Reovirus and HEV were not detected in this survey. These results throw new light on the multiple etiology of enteritis in turkeys. The implications of these findings and their correlation with the clinical signs are comprehensively discussed, illustrating the complexity of the enteric diseases.

  3. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... POULTRY Special Provisions for Primary Meat-Type Chicken Breeding Flocks and Products § 145.83 Terminology... qualifying by means of a blood test shall be tested within the past 12 months, except that the retesting of a... induction of molt. (See § 145.14 relating to the official blood test where applicable.) (1) It has...

  4. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... POULTRY Special Provisions for Primary Meat-Type Chicken Breeding Flocks and Products § 145.83 Terminology... qualifying by means of a blood test shall be tested within the past 12 months, except that the retesting of a... induction of molt. (See § 145.14 relating to the official blood test where applicable.) (1) It has...

  5. 9 CFR 145.83 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... POULTRY Special Provisions for Primary Meat-Type Chicken Breeding Flocks and Products § 145.83 Terminology... qualifying by means of a blood test shall be tested within the past 12 months, except that the retesting of a... induction of molt. (See § 145.14 relating to the official blood test where applicable.) (1) It has...

  6. Space-time patterns of Campylobacter spp. colonization in broiler flocks, 2002-2006.

    PubMed

    Jonsson, M E; Norström, M; Sandberg, M; Ersbøll, A K; Hofshagen, M

    2010-09-01

    This study was performed to investigate space-time patterns of Campylobacter spp. colonization in broiler flocks in Norway. Data on the Campylobacter spp. status at the time of slaughter of 16 054 broiler flocks from 580 farms between 2002 and 2006 was included in the study. Spatial relative risk maps together with maps of space-time clustering were generated, the latter by using spatial scan statistics. These maps identified the same areas almost every year where there was a higher risk for a broiler flock to test positive for Campylobacter spp. during the summer months. A modified K-function analysis showed significant clustering at distances between 2.5 and 4 km within different years. The identification of geographical areas with higher risk for Campylobacter spp. colonization in broilers indicates that there are risk factors associated with Campylobacter spp. colonization in broiler flocks varying with region and time, e.g. climate, landscape or geography. These need to be further explored. The results also showed clustering at shorter distances indicating that there are risk factors for Campylobacter spp. acting in a more narrow scale as well.

  7. 9 CFR 145.33 - Terminology and classification; flocks and products.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... SERVICE, DEPARTMENT OF AGRICULTURE LIVESTOCK IMPROVEMENT NATIONAL POULTRY IMPROVEMENT PLAN FOR BREEDING POULTRY Special Provisions for Multiplier Meat-Type Chicken Breeding Flocks and Products § 145.33... applicable.) (1) It has been officially blood tested with no reactors. (2) It is a multiplier breeding...

  8. Associations between vaccinations against protozoal and viral infections and Salmonella in broiler flocks

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Reducing the burden of Salmonella in broiler flocks presents a challenge for public health and for sustainability of the industry. A number of other infections are simultaneously controlled in grow-out broilers world-wide by vaccination. The purpose of this exploratory analysis was to test, in a f...

  9. Backyard chickens in the United States: a survey of flock owners.

    PubMed

    Elkhoraibi, C; Blatchford, R A; Pitesky, M E; Mench, J A

    2014-11-01

    Although it has become increasingly popular to keep backyard chickens in the United States, few studies have provided information about these flocks. An online survey of backyard chicken owners was conducted, advertised through Master Gardeners' websites, social platforms, and other sites. The survey had 56 questions about flock history, husbandry, health care, and owner attitudes and demographics. Surveys received (n = 1,487) came almost equally from urban, suburban, and rural areas. Most (71%) respondents owned fewer than 10 chickens and had kept chickens for less than 5 yr (70%). Major reasons for keeping chickens were as food for home use (95%), gardening partners (63%), pets (57%), or a combination of these. Rural respondents had larger flocks (P ≤ 0.001) and were more likely to keep chickens as a source of income or for show (P ≤ 0.001) than urban and suburban respondents. Owners thought that eggs/meat from their chickens were more nutritious (86%), safer to consume (84%), and tasted better (95%) than store-bought products, and also that the health and welfare of their chickens was better (95%) than on commercial farms. The majority (59%) indicated no flock health problems in the last 12 mo. However, there was a lack of awareness about some poultry health conditions. Many knew either little or nothing about exotic Newcastle or Marek's disease, and most (61%) did not vaccinate against Marek's. Respondents wanted to learn more about various flock management topics, especially how to detect (64%) and treat (66%) health problems. The Internet was the main source of information (87%) used by backyard flock owners, followed by books/magazines (62%) and feed stores (40%). Minimizing predation was the most cited challenge (49%), followed by providing adequate feed at low cost (28%), dealing with soil management (25%), and complying with zoning regulations (23%). The evidence obtained from this survey will help to determine what information and resources are

  10. Strong Association Between Human and Animal Brucella Seropositivity in a Linked Study in Kenya, 2012-2013.

    PubMed

    Osoro, Eric Mogaka; Munyua, Peninah; Omulo, Sylvia; Ogola, Eric; Ade, Fredrick; Mbatha, Peter; Mbabu, Murithi; Ng'ang'a, Zipporah; Kairu, Salome; Maritim, Marybeth; Thumbi, Samuel M; Bitek, Austine; Gaichugi, Stella; Rubin, Carol; Njenga, Kariuki; Guerra, Marta

    2015-08-01

    Brucellosis is a common bacterial zoonotic infection but data on the prevalence among humans and animals is limited in Kenya. A cross-sectional survey was conducted in three counties practicing different livestock production systems to simultaneously assess the seroprevalence of, and risk factors for brucellosis among humans and their livestock (cattle, sheep, camels, and goats). A two-stage cluster sampling method with random selection of sublocations and households was conducted. Blood samples were collected from humans and animals and tested for Brucella immunoglobulin G (IgG) antibodies. Human and animal individual seroprevalence was 16% and 8%, respectively. Household and herd seroprevalence ranged from 5% to 73% and 6% to 68%, respectively. There was a 6-fold odds of human seropositivity in households with a seropositive animal compared with those without. Risk factors for human seropositivity included regular ingestion of raw milk (adjusted odds ratio [aOR] = 3.5, 95% confidence interval [CI] = 2.8-4.4), exposure to goats (herding, milking, and feeding) (aOR = 3.1, 95% CI = 2.5-3.8), and handling of animal hides (aOR = 1.8, 95% CI = 1.5-2.2). Attaining at least high school education and above was a protective factor for human seropositivity (aOR = 0.3, 95% CI = 0.3-0.4). This linked study provides evidence of a strong association between human and animal seropositivity at the household level.

  11. Strong Association between Human and Animal Brucella Seropositivity in a Linked Study in Kenya, 2012–2013

    PubMed Central

    Osoro, Eric Mogaka; Munyua, Peninah; Omulo, Sylvia; Ogola, Eric; Ade, Fredrick; Mbatha, Peter; Mbabu, Murithi; Ng'ang'a, Zipporah; Kairu, Salome; Maritim, Marybeth; Thumbi, Samuel M.; Bitek, Austine; Gaichugi, Stella; Rubin, Carol; Njenga, Kariuki; Guerra, Marta

    2015-01-01

    Brucellosis is a common bacterial zoonotic infection but data on the prevalence among humans and animals is limited in Kenya. A cross-sectional survey was conducted in three counties practicing different livestock production systems to simultaneously assess the seroprevalence of, and risk factors for brucellosis among humans and their livestock (cattle, sheep, camels, and goats). A two-stage cluster sampling method with random selection of sublocations and households was conducted. Blood samples were collected from humans and animals and tested for Brucella immunoglobulin G (IgG) antibodies. Human and animal individual seroprevalence was 16% and 8%, respectively. Household and herd seroprevalence ranged from 5% to 73% and 6% to 68%, respectively. There was a 6-fold odds of human seropositivity in households with a seropositive animal compared with those without. Risk factors for human seropositivity included regular ingestion of raw milk (adjusted odds ratio [aOR] = 3.5, 95% confidence interval [CI] = 2.8–4.4), exposure to goats (herding, milking, and feeding) (aOR = 3.1, 95% CI = 2.5–3.8), and handling of animal hides (aOR = 1.8, 95% CI = 1.5–2.2). Attaining at least high school education and above was a protective factor for human seropositivity (aOR = 0.3, 95% CI = 0.3–0.4). This linked study provides evidence of a strong association between human and animal seropositivity at the household level. PMID:26101275

  12. Deconstructing stigma: perceptions of HIV-seropositive mothers and their disclosure to children.

    PubMed

    Letteney, Susan; LaPorte, Heidi Heft

    2004-01-01

    This study addressed the perceptions of stigma and disclosure behavior of HIV-seropositive mothers. Eighty-eight HIV-seropositive women in New York City completed two independent measures of stigma, the Perceived Stigma Scale and the Devaluation-Discrimination Measure. Disclosers (67%) and nondisclosers (33%) were similar in most sociodemographic characteristics-marital status, race, religion and employment, with the exception of age and education. Significant differences were found between disclosure groups in the use of secrecy as a stigmamanagement tool and in perceived devaluation-discrimination associated with an HIV diagnosis. Nondisclosers to children were significantly more likely than disclosers to use secrecy as a stigma management tool (t =-2.76; p =.01), and to feel devalued and discriminated against as a result of HIV serostatus (t = 3.11; p =.01). Disclosure of parental HIV serostatus to children is an important aspect of continuous care and custody planning. Secrecy and perceptions of devaluation and discrimination related to HIV diagnosis should be seen as barriers to disclosure of serostatus to children.

  13. Long-Term Survival of an Urban Fruit Bat Seropositive for Ebola and Lagos Bat Viruses

    PubMed Central

    Hayman, David T. S.; Emmerich, Petra; Yu, Meng; Wang, Lin-Fa; Suu-Ire, Richard; Fooks, Anthony R.; Cunningham, Andrew A.; Wood, James L. N.

    2010-01-01

    Ebolaviruses (EBOV) (family Filoviridae) cause viral hemorrhagic fevers in humans and non-human primates when they spill over from their wildlife reservoir hosts with case fatality rates of up to 90%. Fruit bats may act as reservoirs of the Filoviridae. The migratory fruit bat, Eidolon helvum, is common across sub-Saharan Africa and lives in large colonies, often situated in cities. We screened sera from 262 E. helvum using indirect fluorescent tests for antibodies against EBOV subtype Zaire. We detected a seropositive bat from Accra, Ghana, and confirmed this using western blot analysis. The bat was also seropositive for Lagos bat virus, a Lyssavirus, by virus neutralization test. The bat was fitted with a radio transmitter and was last detected in Accra 13 months after release post-sampling, demonstrating long-term survival. Antibodies to filoviruses have not been previously demonstrated in E. helvum. Radio-telemetry data demonstrates long-term survival of an individual bat following exposure to viruses of families that can be highly pathogenic to other mammal species. Because E. helvum typically lives in large urban colonies and is a source of bushmeat in some regions, further studies should determine if this species forms a reservoir for EBOV from which spillover infections into the human population may occur. PMID:20694141

  14. HIV seropositivity rates in outreach-based counseling and testing services: program evaluation.

    PubMed

    DiFranceisco, W; Holtgrave, D R; Hoxie, N; Reiser, W J; Resenhoeft, R; Pinkerton, S D; Vergeront, J

    1998-11-01

    A common assumption is that outreach-based HIV counseling and testing services reach a clientele with a higher HIV seroprevalence than clinic-based counseling and testing. To examine this assumption, we analyzed Wisconsin's anonymous counseling and testing client records for 62,299 contacts (testing episodes) from 1992 to 1995. Bivariate analysis of counseling and testing service setting (outreach-based or clinic-based) and HIV test results suggested that outreach contacts were 23% (odds ratio [OR], 1.23; 95% confidence interval [95% CI], 1.0-1.5) more likely to test HIV-seropositive than clinic-based contacts. Relations between HIV test outcome and variables for client age, race, gender, previous testing history, mode of risk exposure, and region, as well as service setting, were examined by logistic regression. An inverted relation between service setting and seropositivity (OR, 0.65; 95% CI, 0.5-0.8) indicated that, within some subpopulations, outreach contacts were significantly less likely to test HIV-positive than clinic-based contacts. Analysis of interactions among the covariates identified race as a critical codeterminant in the relation between service setting and test outcome. These results support retargeting outreach services to enhance their overall effectiveness. Specific recommendations include the need for aggressive strategies to better "market" HIV counseling and testing to nonwhite populations, and to focus resources more selectively on gay/bisexual men of all races.

  15. Distribution of Hepatitis C virus (HCV) genotypes in seropositive patients in the state of Alagoas, Brazil

    PubMed Central

    Gonzaga, Rosa Maria S.; Rodart, Itatiana F.; Reis, Mitermayer Galvão; Ramalho Neto, Cícero Eduardo; Silva, Denise Wanderlei

    2008-01-01

    We determined the frequency of hepatitis C virus (HCV) genotypes in anti-HCV seropositive patients in the state of Alagoas, Brazil, by means of nested-reverse transcription-polymerase chain reaction (RT-nested-PCR) followed by restriction fragment length polymorphism (RFLP) of amplified fragments of the 5´NCR. The nested-PCR with genotype-specific primers from the core region was carried out when detection was not possible by the first approach. Detectable HCV-RNA was present in 115 (74.7%) of 154 serum samples. Genotype 1 was the most frequent (77.4%), against 20.9% of genotype 3 and 0.8% of genotype 2. Subtype 1b was predominant (65.2%), followed by subtypes 1a (8.7%), and 3a (6.1%). Coinfection (1a/3a) was detected in 0.8% of the samples. Indeed, there was no significant differences in the prevalence of genotype 1 compared to what has been obtained from anti-HCV seropositive patients from other locations in Brazil. Here we report for the first time the genotype 2 in the state of Alagoas. PMID:24031281

  16. Predictors of sharing injection equipment by HIV-seropositive injection drug users.

    PubMed

    Latkin, Carl A; Buchanan, Amy S; Metsch, Lisa R; Knight, Kelly; Latka, Mary H; Mizuno, Yuko; Knowlton, Amy R

    2008-12-01

    Among HIV-positive injection drug users (IDUs), we examined baseline predictors of lending needles and syringes and sharing cookers, cotton, and rinse water in the prior 3 months at follow-up. Participants were enrolled in Intervention for Seropositive Injectors-Research and Evaluation, a secondary prevention intervention for sexually active HIV-positive IDUs in 4 US cities during 2001-2005. The analyses involved 357 participants who reported injecting drugs in the prior 6 months at either the 6- or 12-month follow-up visit. About half (49%) reported at least 1 sharing episode. In adjusted analyses, peer norms supporting safer injection practices and having primary HIV medical care visits in the prior 6 months were associated with reporting no sharing of injection equipment. Higher levels of psychological distress were associated with a greater likelihood of reporting drug paraphernalia sharing. These findings suggest that intervention approaches for reducing HIV-seropositive IDUs' transmission of blood-borne infections should include peer-focused interventions to alter norms of drug paraphernalia sharing and promoting primary HIV care and mental health services.

  17. [Particulars of crisis intervention in seropositive persons or the existential crisis of HIV].

    PubMed

    Ritchot, P; Sauriol, P

    1992-01-01

    This article presents a vision of crisis intervention for seropositive persons following an approach inspired by existential psychology. Persons who intervene must view crisis intervention for HIV-positive persons as an exploration of the close relation that exists between life and death. They must investigate the interrelations with the dimensions who intervene must view crisis intervention for HIV-positive persons as an exploration of the close relation that exists between life and death. They must investigate the interrelations with the dimensions of time, space, world and body. They must also examine the characteristics of the seropositive experience that are specific to the different infected clienteles. The welcoming process, the urgency of the situation and the therapeutic complementarity must be considered as the main guidelines for this type of crisis intervention which, in addition, must take into account the various life experiences that are particular to each of the HIV-positive persons. This approach requires that the person who intervenes and plays a supporting role must put into question their own attitudes toward the phenomenon at hand. Finally, life with the infection can also bring certain intervenors and clients to discover and profit from a number of unsuspected benefits.

  18. Melanocyte biology and function with reference to oral melanin hyperpigmentation in HIV-seropositive subjects.

    PubMed

    Feller, Liviu; Chandran, Rakesh; Kramer, Beverley; Khammissa, Razia A G; Altini, Mario; Lemmer, Johan

    2014-09-01

    The color of normal skin and of oral mucosa is not determined by the number of melanocytes in the epithelium but rather by their melanogenic activity. Pigmented biopolymers or melanins are synthesized in melanosomes. Tyrosinase is the critical enzyme in the biosynthesis of both brown/black eumelanin and yellow/red pheomelanin. The number of the melanosomes within the melanocytes, the type of melanin within the melanosomes, and the efficacy of the transfer of melanosomes from the melanocytes to the neighboring keratinocytes all play an important role in tissue pigmentation. Melanin production is regulated by locally produced factors including proopiomelanocortin and its derivative peptides, particularly alpha-melanocyte-stimulating hormone (α-MSH), melanocortin 1 receptor (MC1R), adrenergic and cholinergic agents, growth factors, cytokines, and nitric oxide. Both eumelanin and pheomelanin can be produced by the same melanocytes, and the proportion of the two melanin types is influenced by the degree of functional activity of the α-MSH/MC1R intracellular pathway. The cause of HIV oral melanosis is not fully understood but may be associated with HIV-induced cytokine dysregulation, with the medications commonly prescribed to HIV-seropositive persons, and with adrenocortical dysfunction, which is not uncommon in HIV-seropositive subjects with AIDS. The purpose of this article is to discuss some aspects of melanocyte biology and HIV-associated oral melanin hyperpigmentation.

  19. Passive tick surveillance, dog seropositivity, and incidence of human Lyme disease

    USGS Publications Warehouse

    Johnson, Jaree L.; Ginsberg, Howard S.; Zhioua, Elyes; Whitworth, Ulysses G.; Markowski, Daniel; Hyland, Kerwin E.; Hu, Renjie

    2004-01-01

    Data on nymphal Ixodes scapularis ticks submitted by the public to the University of Rhode Island Tick Research Laboratory for testing from 1991 to 2000 were compared with human case data from the Rhode Island Department of Health to determine the efficacy of passive tick surveillance at assessing human risk of Lyme disease. Numbers of ticks submitted were highly correlated with human cases by county (r = 0.998, n = 5 counties) and by town (r = 0.916, n = 37 towns), as were the numbers of positive ticks submitted (r = 0.989 by county, r = 0.787 by town). Human cases were correlated with ticks submitted by town each year, and with positive ticks in all but 2 years. Thus, passive tick surveillance effectively assessed geographical risk of human Lyme disease. In contrast, tick submissions through time were not correlated with human cases from year to year. Dog seropositivity was significantly correlated with human cases by county in both years tested, but by town in only one of two years. Numbers of ticks submitted were correlated with dog seropositivity by county but not by town, apparently because of high variability among towns with small sample sizes. Our results suggest that passive tick surveillance, using ticks submitted by the public for Lyme spirochete testing, can be used to assess the geographical distribution of Lyme disease risk, but cannot reliably predict Lyme incidence from year to year.

  20. Acceptability and use of sexual barrier products and lubricants among HIV-seropositive Zambian men.

    PubMed

    Jones, D L; Weiss, S M; Chitalu, N; Mumbi, M; Shine, A; Vamos, S; Villar, O

    2008-12-01

    This study assessed the acceptability and preference for sexual barrier and lubricant products among men in Zambia following trial and long-term use. It also examined the role of men's preferences as facilitators or impediments to product use for HIV transmission reduction within the Zambian context. HIV-seropositive and -serodiscordant couples were recruited from HIV voluntary counseling and testing centers in Lusaka between 2003 and 2006; 66% of those approached agreed to participate. HIV seropositive male participants participated in a product exposure group intervention (n = 155). Participants were provided with male and female condoms and vaginal lubricants (Astroglide [BioFilm, Inc., Vista, CA] & KY gels [Johnson & Johnson, Langhorne, PA], Lubrin suppositories [Kendwood Therapuetics, Fairfield, NJ]) over three sessions; assessments were conducted at baseline, monthly over 6 months and at 12 months. At baseline, the majority of men reported no previous exposure to lubricant products or female condoms and high (79%) levels of consistent male condom use in the last 7 days. Female condom use increased during the intervention, and male condom use increased at 6 months and was maintained over 12 months. The basis for decisions regarding lubricant use following product exposure was most influenced by a preference for communicating with partners; participant preference for lubricant products was distributed between all three products. Results illustrate the importance of development of a variety of products for prevention of HIV transmission and of inclusion of male partners in interventions to increase sexual barrier product use to facilitate barrier acceptability and use in Zambia.

  1. Risk Factors for Seropositivity to Kaposi Sarcoma–Associated Herpesvirus Among Children in Uganda

    PubMed Central

    Webb, Emily L.; Sebina, Ismail; Nalwoga, Angela; Muhangi, Lawrence; Miley, Wendell; Johnston, W. Thomas; Ndibazza, Juliet; Whitby, Denise; Newton, Robert; Elliott, Alison M.

    2013-01-01

    Background: Determinants of Kaposi sarcoma–associated herpesvirus (KSHV) seropositivity among children living in sub-Saharan African populations where infection is endemic are not well understood. Local environmental factors, including other infectious agents, may be key. Methods: Within the context of a well-characterized birth cohort, we examined associations between various factors and antibodies against KSHV, measured in stored plasma samples from 1823 mother–child pairs in Entebbe, Uganda. Results: Seroprevalence increased with increasing age of the child (P = 0.0003) and was higher among those with KSHV seropositive mothers than in those without (12% vs 9%; odds ratio: 1.4, 95% confidence interval: 1.1 to 2.0). It was also higher among children with HIV infection (29% vs 10%; odds ratio: 3.1, 95% confidence interval: 1.2 to 8.3) or malaria parasitemia (30% vs 10%; odds ratio: 4.1, 95% confidence interval: 2.4 to 7.0) than in children without. These associations were not explained by socioeconomic status. Conclusions: The finding that KSHV serostatus is associated with malaria parasitemia in children is novel. In a country endemic for KSHV, malaria may be a cofactor for KSHV infection or reactivation among children. PMID:23403859

  2. Focal epithelial hyperplasia (Heck disease) related to highly active antiretroviral therapy in an HIV-seropositive child. A report of a case, and a review of the literature.

    PubMed

    Feller, L; Khammissa, R A G; Wood, N H; Malema, V; Meyerov, R; Lemmer, J

    2010-05-01

    Focal epithelial hyperplasia is increasingly frequently observed in rural South African communities. HIV-seropositive subjects have a higher prevalence of oral human papillomavirus (HPV) infections than immunocompetent subjects; and paradoxically, the introduction of highly active antiretroviral therapy for treatment of HIV-seropositive subjects is associated with increased frequency of focal epithelial hyperplasia. We describe a case of focal epithelial hyperplasia in an HIV-seropositive child receiving highly active antiretroviral therapy, who was successfully treated by using diode laser ablation.

  3. AI in the Elementary, Middle, and Secondary Classroom.

    ERIC Educational Resources Information Center

    Kirkpatrick, Susan N.; Biglan, Barbara

    1990-01-01

    Describes activities that present concepts and applications of artificial intelligence (AI) for elementary and secondary school students. The use of Logo with elementary students is discussed; appropriate software is described; programing activities using Logo, BASIC, and Prolog are examined; and the field of robotics is discussed. (four…

  4. AI in CALL--Artificially Inflated or Almost Imminent?

    ERIC Educational Resources Information Center

    Schulze, Mathias

    2008-01-01

    The application of techniques from artificial intelligence (AI) to CALL has commonly been referred to as intelligent CALL (ICALL). ICALL is only slightly older than the "CALICO Journal", and this paper looks back at a quarter century of published research mainly in North America and by North American scholars. This "inventory…

  5. New directions for Artificial Intelligence (AI) methods in optimum design

    NASA Technical Reports Server (NTRS)

    Hajela, Prabhat

    1989-01-01

    Developments and applications of artificial intelligence (AI) methods in the design of structural systems is reviewed. Principal shortcomings in the current approach are emphasized, and the need for some degree of formalism in the development environment for such design tools is underscored. Emphasis is placed on efforts to integrate algorithmic computations in expert systems.

  6. Artificial Intelligence: Is the Future Now for A.I.?

    ERIC Educational Resources Information Center

    Ramaswami, Rama

    2009-01-01

    In education, artificial intelligence (AI) has not made much headway. In the one area where it would seem poised to lend the most benefit--assessment--the reliance on standardized tests, intensified by the demands of the No Child Left Behind Act of 2001, which holds schools accountable for whether students pass statewide exams, precludes its use.…

  7. State Revolving Fund American Iron and Steel (AIS) Requirement

    EPA Pesticide Factsheets

    The AIS provision requires CWSRF and DWSRF assistance recipients to use iron and steel products that are produced in the U.S. It applies to projects for the construction, alteration, maintenance, or repair of a public water system or treatment work.

  8. Automatic Identification System (AIS) Transmit Testing in Louisville Phase 2

    DTIC Science & Technology

    2014-08-01

    project. Two of the captains were Capt. David Williams and Capt. Spencer Kennedy. After leaving SCI, the team members went to Crounse Inc. and met...team members had a phone conference with Herbert Taylor (VP Operations, Kongsberg Maritime Simulation Inc.) to discuss the integration of AIS data in

  9. 33 CFR 164.46 - Automatic Identification System (AIS).

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... forth in IMO SN/Circ.227 (incorporated by reference, see § 164.03). Not all AIS units are able to broadcast position, course, and speed without the input of an external positioning device (e.g. dGPS); the use of other external devices (e.g. transmitting heading device, gyro, rate of turn indicator)...

  10. AI in Reverse: Computer Tools That Become Cognitive.

    ERIC Educational Resources Information Center

    Salomon, Gavriel

    The question of whether human thinking can come to simulate computer intelligence--i.e., AI in reverse--is addressed in this paper. Examples are given of three computer tools which perform several functions that constitute an intellectual partnership between student and tool. Such functions include: (1) assuming part of the intellectual burden in…

  11. AI/Simulation Fusion Project at Lawrence Livermore National Laboratory

    SciTech Connect

    Erickson, S.A.

    1984-04-25

    This presentation first discusses the motivation for the AI Simulation Fusion project. After discussing very briefly what expert systems are in general, what object oriented languages are in general, and some observed features of typical combat simulations, it discusses why putting together artificial intelligence and combat simulation makes sense. We then talk about the first demonstration goal for this fusion project.

  12. Prevalence and antimicrobial susceptibility of Campylobacter in broiler flocks in Japan.

    PubMed

    Haruna, M; Sasaki, Y; Murakami, M; Ikeda, A; Kusukawa, M; Tsujiyama, Y; Ito, K; Asai, T; Yamada, Y

    2012-06-01

    Campylobacter was isolated from 67 (47.2%) of 142 broiler flocks between September 2009 and February 2010. The prevalence of Campylobacter in broiler flocks was significantly lower during January and February than it was from September to December. Campylobacter colonization was more common in flocks that were not provided with a disinfected water supply, which was consistent with the findings of a previous study. The prevalence of antimicrobial drug-resistant Campylobacter spp. was investigated, and the minimum inhibitory concentrations of eight antimicrobial agents were determined for 122 Campylobacter jejuni isolates and 46 Campylobacter coli isolates from broiler flocks between 2007 and 2010. In this study, 29.5% (36/122) of C. jejuni isolates and 41.3% (19/46) of C. coli isolates were resistant to enrofloxacin (ERFX), whereas all isolates were susceptible to erythromycin. Furthermore, the ERFX-resistant isolates were tested for susceptibility to other classes of antimicrobial agents, and 55.6% (20/36) of ERFX-resistant C. jejuni isolates and 47.4% (9/19) of ERFX-resistant C. coli isolates were resistant to at least one of aminobenzyl penicillin, dihydrostreptomycin and oxytetracycline. To avoid an impact of antimicrobial drug-resistant Campylobacter spp. on the efficacy of antimicrobial treatment for human campylobacteriosis, prudent use of antimicrobial agents is a requisite. The use of antimicrobial agents should be accompanied by various approaches such as prevention of Campylobacter colonization in broiler flocks with the aim of lowering the occurrence of Campylobacter infection in humans.

  13. Effects of habitat fragmentation and degradation on flocks of African ant-following birds.

    PubMed

    Peters, Marcell K; Likare, Smith; Kraemer, Manfred

    2008-06-01

    Tropical rain forests are rapidly cleared, fragmented, and degraded in sub-Saharan Africa; however, little is known about the response of species and even of key ecological groups to these processes. One of the most intriguing (but often neglected) ecological phenomena in African rain forests is the interaction between swarm-raiding army ants and ant-following birds. Similar to their well-known Neotropical representatives, ant-following birds in Africa track the massive swarm raids of army ants and feed on arthropods flushed by the ants. In this study we analyzed the effect of habitat fragmentation and degradation of a mid-altitude Congo-Guinean rain forest in western Kenya on the structure of ant-following bird flocks. Significant numbers of swarm raids were located in all forest fragments and in both undegraded and degraded forest. Fifty-six different species of birds followed army ant raids, forming bird flocks of one to 15 species. We quantitatively differentiated the bird community into five species of specialized ant-followers and 51 species of opportunistic ant-followers. Species richness and size of bird flocks decreased with decreasing size of forest fragments and was higher in undegraded than in degraded habitat. This was caused by the decrease of the species richness and number of specialized ant-followers at swarms, while the group of opportunistic ant-followers was affected little by habitat fragmentation and degradation. The composition of bird flocks was more variable in small fragments and degraded forest, compared to undegraded habitat in large fragments. The effect of habitat fragmentation on flock structure was best explained by the strong decline of the abundance of specialized ant-followers in small forest fragments. To conserve the association of army ants and ant-following birds in its natural state, vast areas of unfragmented and undegraded tropical rain forest are necessary.

  14. Collective decision making and social interaction rules in mixed-species flocks of songbirds

    PubMed Central

    Farine, Damien R.; Aplin, Lucy M.; Garroway, Colin J.; Mann, Richard P.; Sheldon, Ben C.

    2014-01-01

    Associations in mixed-species foraging groups are common in animals, yet have rarely been explored in the context of collective behaviour. Despite many investigations into the social and ecological conditions under which individuals should form groups, we still know little about the specific behavioural rules that individuals adopt in these contexts, or whether these can be generalized to heterospecifics. Here, we studied collective behaviour in flocks in a community of five species of woodland passerine birds. We adopted an automated data collection protocol, involving visits by RFID-tagged birds to feeding stations equipped with antennae, over two winters, recording 91 576 feeding events by 1904 individuals. We demonstrated highly synchronized feeding behaviour within patches, with birds moving towards areas of the patch with the largest proportion of the flock. Using a model of collective decision making, we then explored the underlying decision rule birds may be using when foraging in mixed-species flocks. The model tested whether birds used a different decision rule for conspecifics and heterospecifics, and whether the rules used by individuals of different species varied. We found that species differed in their response to the distribution of conspecifics and heterospecifics across foraging patches. However, simulating decisions using the different rules, which reproduced our data well, suggested that the outcome of using different decision rules by each species resulted in qualitatively similar overall patterns of movement. It is possible that the decision rules each species uses may be adjusted to variation in mean species abundance in order for individuals to maintain the same overall flock-level response. This is likely to be important for maintaining coordinated behaviour across species, and to result in quick and adaptive flock responses to food resources that are patchily distributed in space and time. PMID:25214653

  15. Post-coital vaginal sampling with nylon flocked swabs improves DNA typing.

    PubMed

    Benschop, Corina C G; Wiebosch, Danielle C; Kloosterman, Ate D; Sijen, Titia

    2010-02-01

    In the examination of sexual assault cases, DNA typing of vaginal samples mostly occurs after differential DNA extraction. Notwithstanding the differential extraction method, the DNA profiles from the seminal fraction often show the male alleles at low-level in combination with female alleles. This unfavorable ratio male to female DNA is due to a limited amount of sperm cells and an overwhelming quantity of female cells. In this study, we compared standard cotton and nylon flocked swabs for post-coital vaginal sampling. Twelve couples donated 88 vaginal swabs - 44 cotton, 44 nylon flocked - which were taken with a time since intercourse (TSI) up to 84 h. These vaginal swabs were sorted into categories on the basis of the TSI and submitted to (1) microscopic examination for the presence of male cells, (2) presumptive tests for the detection of seminal fluid and (3) DNA typing. Cellular elution was found to be 6-fold more efficient from the nylon flocked swabs. This makes microscopic analysis less time consuming as the higher cell yield and better cell morphology simplify detection of male cells. Both swab types reveal similar results regarding presumptive tests and male DNA typing. Positive presumptive tests (RSID-semen and PSA) were obtained up to 60 h TSI and male autosomal profiles up to 72 h TSI. Interestingly, over 50% of the samples negative for both presumptive tests resulted in informative male STR profiles. After differential extraction, less DNA was left on the nylon flocked swabs and more male DNA was isolated. Our results imply that the use of nylon flocked swabs for vaginal sampling will improve microscopic analysis and DNA typing in the medical forensic investigation of sexual assault cases.

  16. Three-dimensional trajectories and network analyses of group behaviour within chimney swift flocks during approaches to the roost.

    PubMed

    Evangelista, Dennis J; Ray, Dylan D; Raja, Sathish K; Hedrick, Tyson L

    2017-02-22

    Chimney swifts (Chaetura pelagica) are highly manoeuvrable birds notable for roosting overnight in chimneys, in groups of hundreds or thousands of birds, before and during their autumn migration. At dusk, birds gather in large numbers from surrounding areas near a roost site. The whole flock then employs an orderly, but dynamic, circling approach pattern before rapidly entering a small aperture en masse We recorded the three-dimensional trajectories of ≈1 800 individual birds during a 30 min period encompassing flock formation, circling, and landing, and used these trajectories to test several hypotheses relating to flock or group behaviour. Specifically, we investigated whether the swifts use local interaction rules based on topological distance (e.g. the n nearest neighbours, regardless of their distance) rather than physical distance (e.g. neighbours within x m, regardless of number) to guide interactions, whether the chimney entry zone is more or less cooperative than the surrounding flock, and whether the characteristic subgroup size is constant or varies with flock density. We found that the swift flock is structured around local rules based on physical distance, that subgroup size increases with density, and that there exist regions of the flock that are less cooperative than others, in particular the chimney entry zone.

  17. Three-dimensional trajectories and network analyses of group behaviour within chimney swift flocks during approaches to the roost

    PubMed Central

    Ray, Dylan D.; Raja, Sathish K.

    2017-01-01

    Chimney swifts (Chaetura pelagica) are highly manoeuvrable birds notable for roosting overnight in chimneys, in groups of hundreds or thousands of birds, before and during their autumn migration. At dusk, birds gather in large numbers from surrounding areas near a roost site. The whole flock then employs an orderly, but dynamic, circling approach pattern before rapidly entering a small aperture en masse. We recorded the three-dimensional trajectories of ≈1 800 individual birds during a 30 min period encompassing flock formation, circling, and landing, and used these trajectories to test several hypotheses relating to flock or group behaviour. Specifically, we investigated whether the swifts use local interaction rules based on topological distance (e.g. the n nearest neighbours, regardless of their distance) rather than physical distance (e.g. neighbours within x m, regardless of number) to guide interactions, whether the chimney entry zone is more or less cooperative than the surrounding flock, and whether the characteristic subgroup size is constant or varies with flock density. We found that the swift flock is structured around local rules based on physical distance, that subgroup size increases with density, and that there exist regions of the flock that are less cooperative than others, in particular the chimney entry zone. PMID:28202812

  18. A longitudinal study of the risks for introduction of severe footrot into sheep flocks in the south west of Norway.

    PubMed

    Grøneng, Gry M; Green, Laura E; Kaler, Jasmeet; Vatn, Synnøve; Hopp, Petter

    2014-02-01

    In 2008, ovine footrot was detected in Norway for the first time since 1948. By December 2012 it had spread to 99 flocks, all in the county of Rogaland in the south west of Norway, and 42% of which were located in the municipality of Rennesøy in Rogaland. The aim of this study was to investigate risk factors for contracting severe footrot in flocks of sheep. A flock was considered positive for severe footrot based on positive virulence test or by clinical signs in addition to a positive PCR test. A retrospective longitudinal study was performed with a questionnaire as the main data source. All sheep farmers (107) in the municipality of Rennesøy were selected for inclusion in the study. The questions focused on direct and indirect contacts between sheep in different sheep flocks and general information about the farm. The questions covered the years 2007-2011. Data were analysed using discrete time survival modelling. A total of 81 (76%) farmers responded to the questionnaire including 29 of 41 (71%) farmers with flocks positive for severe footrot. Factors that increased the risk of a flock becoming positive for severe footrot in the final multivariable survival model were sheep that trespassed boundary fences and came into contact with a flock positive for severe footrot (odds ratio 11.5, 95% confidence interval 4.1-32.2) and at least one flock with severe footrot within 0-1km radius of a farm (odds ratio 8.6, 95% confidence interval 2.3-32.6). This study highlights the importance of upgrading and maintaining boundary fences and encouraging farmers to avoid direct and indirect contact between nearby flocks.

  19. Detection of autoinducer (AI-2)-like activity in food samples.

    PubMed

    Sivakumar, Kirthiram K; Jesudhasan, Palmy R; Pillai, Suresh D

    2011-01-01

    The contamination, survival, and possible foodborne disease outbreaks are major issues confronting the food industry. However, from a microbial perspective, any food whether natural or processed is just another environmental niche that is available for colonization. Quorum sensing or cell-cell communication is a process by which microorganisms are thought to communicate with each other using a variety of small molecules termed autoinducers. The autoinducer AI-2 is thought to be a universal signaling molecule due to its ability to modulate the gene expression of a number of different bacterial species and genera. Pathogens such as Pseudomonas aeruginosa, Aeromonas hydrophila, Vibrio anguillarum, Streptococcus sp., and Burkholderia cepacia form biofilms on a variety of man-made and natural surfaces using cell-cell mechanisms. It is important to detect and study autoinducers and their activities in foods, since a better understanding of these molecules in food and food ingredients may help in designing new approaches to thwart microbial persistence and biofilm formation. The autoinducer AI-2 is thought to be involved in microbial attachment and biofilm formation leading to food spoilage. To better understand microbial cell-cell signaling in foods especially as it relates to pathogen persistence, biofilm formation, and food spoilage, methods to process, extract, and purify autoinducer molecules need to be developed. This chapter details methods to process food samples to obtain cell-free supernatants (CFS), which could subsequently be tested for the presence of AI-2 or "AI-2-like activity" in the extracted CFS using autoinducer bioassays. Additionally, the method of synthesizing AI-2 in the laboratory is also provided. The methods that are presented in this chapter are based on previously published research articles from the authors' laboratory.

  20. Providing ART to HIV Seropositive Persons Who Use Drugs: Progress in New York City, Prospects for "Ending the Epidemic".

    PubMed

    Jarlais, Don C Des; Arasteh, Kamyar; McKnight, Courtney; Feelemyer, Jonathan; Hagan, Holly; Cooper, Hannah L F; Campbell, Aimee N C; Tross, Susan; Perlman, David C

    2016-02-01

    New York City has experienced the largest HIV epidemic among persons who use psychoactive drugs. We examined progress in placing HIV seropositive persons who inject drugs (PWID) and HIV seropositive non-injecting drug users (NIDU) onto antiretroviral treatment (ART) in New York City over the last 15 years. We recruited 3511 PWID and 3543 NIDU from persons voluntarily entering drug detoxification and methadone maintenance treatment programs in New York City from 2001 to 2014. HIV prevalence declined significantly among both PWID and NIDU. The percentage who reported receiving ART increased significantly, from approximately 50 % (2001-2005) to approximately 75 % (2012-2014). There were no racial/ethnic disparities in the percentages of HIV seropositive persons who were on ART. Continued improvement in ART uptake and TasP and maintenance of other prevention and care services should lead to an "End of the AIDS Epidemic" for persons who use heroin and cocaine in New York City.

  1. PRNP genetic variability and molecular typing of natural goat scrapie isolates in a high number of infected flocks.

    PubMed

    Fragkiadaki, Eirini G; Vaccari, Gabriele; Ekateriniadou, Loukia V; Agrimi, Umberto; Giadinis, Nektarios D; Chiappini, Barbara; Esposito, Elena; Conte, Michela; Nonno, Romolo

    2011-09-30

    One hundred and four scrapie positive and 77 negative goats from 34 Greek mixed flocks were analysed by prion protein gene sequencing and 17 caprine scrapie isolates from 11 flocks were submitted to molecular isolate typing. For the first time, the protective S146 variant was reported in Greece, while the protective K222 variant was detected in negative but also in five scrapie positive goats from heavily infected flocks. By immunoblotting six isolates, including two goat flockmates carrying the K222 variant, showed molecular features slightly different from all other Greek and Italian isolates co-analysed, possibly suggesting the presence of different scrapie strains in Greece.

  2. Gastrointestinal and urinary tract pathogenic infections among HIV seropositive patients at the Komfo Anokye Teaching Hospital in Ghana

    PubMed Central

    2012-01-01

    Background Gastrointestinal and urinary tract pathogenic infections are aggravating the incidence and progression of the Human Immunodeficiency Virus (HIV) infection into Acquired Immune Deficiency Syndrome (AIDS) more especially in the developing countries. This study was conducted to assess the common gastrointestinal and urinary infections among HIV/AIDS patients at the Komfo Anokye Teaching Hospital (KATH) in Ghana between April and December 2008. Findings This work reports on gastrointestinal and urinary tract pathogenic infections among 500 HIV seropositive and 300 HIV seronegative patients. There was a 35% (175/500) prevalence of intestinal parasites among HIV seropositive patients compared to 4.3% (13/300) in HIV seronegative patients. Giardia lamblia and Cryptosporidium accounted for 19% (95/500) and 14% (70/500) respectively, while Schistosoma mansoni, Strongyloides stercoralis and hookworm together accounted for 2% (10/500) of intestinal parasitic infections among the HIV seropositive patients. There was no significant difference (p > 0.05) in urinary parasitic infection between HIV seropositive 1% (2/500) and seronegative patients 0.7% (2/300). Most, 60 (86%) out of 70, of the urinary tract infection among the HIV seropositive patients was due to bacteria with E. coli being the most predominant isolate, 28 (47%) out of 60. There was no significant difference in infections based on age and gender. Conclusion G. lamblia and Cryptosporidium were the most common gastrointestinal parasites detected while bacteria accounted for majority of the urinary tract infections among the HIV seropositive patients at the hospital. PMID:22909315

  3. HPV16 Seropositivity and Subsequent HPV16 Infection Risk in a Naturally Infected Population: Comparison of Serological Assays

    PubMed Central

    Lin, Shih-Wen; Ghosh, Arpita; Porras, Carolina; Markt, Sarah C.; Rodriguez, Ana Cecilia; Schiffman, Mark; Wacholder, Sholom; Kemp, Troy J.; Pinto, Ligia A.; Gonzalez, Paula; Wentzensen, Nicolas; Esser, Mark T.; Matys, Katie; Meuree, Ariane; Quint, Wim; van Doorn, Leen-Jan; Herrero, Rolando; Hildesheim, Allan; Safaeian, Mahboobeh

    2013-01-01

    Background Several serological assays have been developed to detect antibodies elicited against infections with oncogenic human papillomavirus (HPV) type 16. The association between antibody levels measured by various assays and subsequent HPV infection risk may differ. We compared HPV16-specific antibody levels previously measured by a virus-like particle (VLP)-based direct enzyme-linked immunoassay (ELISA) with levels measured by additional assays and evaluated the protection against HPV16 infection conferred at different levels of the assays. Methodology/Principal Findings Replicate enrollment serum aliquots from 388 unvaccinated women in the control arm of the Costa Rica HPV vaccine trial were measured for HPV16 seropositivity using three serological assays: a VLP-based direct ELISA; a VLP-based competitive Luminex immunoassay (cLIA); and a secreted alkaline phosphatase protein neutralization assay (SEAP-NA). We assessed the association of assay seropositivity and risk of subsequent HPV16 infection over four years of follow-up by calculating sampling-adjusted odds ratios (OR) and HPV16 seropositivity based on standard cutoff from the cLIA was significantly associated with protection from subsequent HPV16 infection (OR = 0.48, CI = 0.27–0.86, compared with seronegatives). Compared with seronegatives, the highest seropositive tertile antibody levels from the direct ELISA (OR = 0.53, CI = 0.28–0.90) as well as the SEAP-NA (OR = 0.20, CI = 0.06, 0.64) were also significantly associated with protection from HPV16 infection. Conclusions/Significance Enrollment HPV16 seropositivity by any of the three serological assays evaluated was associated with protection from subsequent infection, although cutoffs for immune protection were different. We defined the assays and seropositivity levels after natural infection that better measure and translate to protective immunity. PMID:23301022

  4. Associations of cigarette smoking with viral immune and cognitive function in human immunodeficiency virus–seropositive women

    PubMed Central

    Wojna, Valerie; Robles, Lizbeth; Skolasky, Richard L; Mayo, Raul; Selnes, Ola; de la Torre, Tania; Maldonado, Elizabeth; Nath, Avindra; Meléndez, Loyda M.; Lasalde-Dominicci, Jose

    2016-01-01

    Cigarette smoking alters the immune system and may improve cognitive deficits in neuropsychiatric disorders. Smoking prevalence is high in human immunodeficiency virus (HIV)–infected patients; however, its effect on HIV-associated cognitive impairment remains unknown in the era of antiretroviral treatment. The authors examined associations of smoking with viral immune profile and cognitive function in a cohort of HIV-seropositive women. This observational cross-sectional study included 56 women (36 HIV-seropositive and 20 HIV-seronegative) surveyed with a tobacco questionnaire: the Fagerström Test for Nicotine Dependency. Viral immune status was obtained 6 to 12 months before questioned. Neurocognitive testing (NP) assessed verbal memory, frontal/executive function, psychomotor speed, and motor speed. A reference group of HIV-seronegative women was used to calculate standardized z-scores. Cognitive impairment was classified using a modified American Academy of Neurology criteria, adding an asymptomatic group based on NP tests. Statistics included parametric and nonparametric tests. HIV-seropositive women were more likely to report a history of smoking (P = 0.028). Among them, current smoking correlated with higher plasma viral load (P = 0.048), and history of smoking correlated with lower CD4 cell count (P = 0.027). The authors observed no associations between cognitive impairment and either current or past history of smoking and no differences in neurocognitive domain scores between HIV-seropositive and -seronegative women or between those with and without a history of smoking. However, restricting analysis to HIV-seropositives showed a significant better performance on the frontal/executive domain in those with history of smoking. In summary, history of smoking correlated with better frontal/executive cognitive domain performance in HIV-seropositive women and with worse viral immune profile. PMID:18097887

  5. Chlamydia trachomatis IgG3 seropositivity is a predictor of reproductive outcomes in infertile women with patent fallopian tubes

    PubMed Central

    Steiner, Anne Z.; Diamond, Michael P.; Legro, Richard S.; Schlaff, William D.; Barnhart, Kurt T.; Casson, Peter R.; Christman, Gregory M.; Alvero, Ruben; Hansen, Karl R.; Geisler, William M.; Thomas, Tracey; Santoro, Nanette; Zhang, Heping; Eisenberg, Esther

    2015-01-01

    Objective To determine if Chlamydia trachomatis (Ct) seropositivity as detected by the Ct elementary body (EB)-based enzyme linked immunosorbent assay (Ct EB ELISA) predicts pregnancy and pregnancy outcome among infertile women with documented tubal patency. Design Cohort study Setting Outpatient clinics participating in the reproductive medicine network Patients 1250 infertile women with documented tubal patency enrolled in one of two randomized controlled trials: PPCOSII and AMIGOS Intervention Sera were analyzed for anti-Ct IgG1 and IgG3 antibodies using a research Ct EB ELISA. OD405 readings ≥0.35 and ≥0.1 were considered positive for IgG1 and IgG3, respectively. Main Outcome Measures Primary outcomes included pregnancy, live birth, and ectopic pregnancy. Log linear regression was used to determine the relative risk after adjusting for age, race, treatment medication, smoking status, and current alcohol use. Results 243 (19%) women were seropositive for anti-Ct IgG3. They tended to be non-White and smokers. Anti-Ct IgG3 seropositive women were significantly less likely to conceive (RR 0.65, 95% CI 0.52-0.83) or to have a live birth (RR 0.59, 95% 0.43-0.80); these associations were weakened after adjusting for number of HSG-documented patent tubes (RR 0.73, 95% CI 0.56-0.97) and (0.73, 95% CI: 0.50-1.04), respectively. Anti-Ct IgG3 seropositive women who conceived had 2.7 (95% CI: 1.40-5.34) times the risk of ectopic pregnancy. Conclusions Even in the presence of tubal patency, anti-Ct IgG3 seropositivity is associated with lower likelihood of pregnancy. Anti-Ct IgG3 seropositive women have up to 3 times the risk of ectopic pregnancy. PMID:26413816

  6. Decline in human immunodeficiency virus seropositivity and seroconversion in US Navy enlisted personnel: 1986 to 1989. Navy HIV Working Group.

    PubMed Central

    Garland, F C; Gorham, E D; Cunnion, S O; Miller, M R; Balazs, L L

    1992-01-01

    The US Navy administered 1,795,578 enzyme-linked immunosorbent assay (ELISA) tests to 848,632 active-duty Navy enlisted personnel during 1986 to 1989. This study identified 2438 human immunodeficiency virus (HIV)-seropositive active-duty enlisted Navy personnel, including 778 seroconverters. Three types of quarterly rates of HIV seropositivity and seroconversion were determined. All three rates declined. This decline could not be explained by changes in the population tested according to age, race, sex, occupation, or geographic location of home port. PMID:1546779

  7. Seropositivity and Risk Factors Associated with Toxoplasma gondii Infection in Wild Birds from Spain

    PubMed Central

    Cabezón, Oscar; García-Bocanegra, Ignacio; Molina-López, Rafael; Marco, Ignasi; Blanco, Juan M.; Höfle, Ursula; Margalida, Antoni; Bach-Raich, Esther; Darwich, Laila; Echeverría, Israel; Obón, Elena; Hernández, Mauro; Lavín, Santiago; Dubey, Jitender P.; Almería, Sonia

    2011-01-01

    Toxoplasma gondii is a zoonotic intracellular protozoan parasite of worldwide distribution that infects many species of warm-blooded animals, including birds. To date, there is scant information about the seropositivity of T. gondii and the risk factors associated with T. gondii infection in wild bird populations. In the present study, T. gondii infection was evaluated on sera obtained from 1079 wild birds belonging to 56 species (including Falconiformes (n = 610), Strigiformes (n = 260), Ciconiiformes (n = 156), Gruiformes (n = 21), and other orders (n = 32), from different areas of Spain. Antibodies to T. gondii (modified agglutination test, MAT titer ≥1∶25) were found in 282 (26.1%, IC95%:23.5–28.7) of the 1079 birds. This study constitute the first extensive survey in wild birds species in Spain and reports for the first time T. gondii antibodies in the griffon vulture (Gyps fulvus), short-toed snake-eagle (Circaetus gallicus), Bonelli's eagle (Aquila fasciata), golden eagle (Aquila chrysaetos), bearded vulture (Gypaetus barbatus), osprey (Pandion haliaetus), Montagu's harrier (Circus pygargus), Western marsh-harrier (Circus aeruginosus), peregrine falcon (Falco peregrinus), long-eared owl (Asio otus), common scops owl (Otus scops), Eurasian spoonbill (Platalea leucorodia), white stork (Ciconia ciconia), grey heron (Ardea cinerea), common moorhen (Gallinula chloropus); in the International Union for Conservation of Nature (IUCN) “vulnerable” Spanish imperial eagle (Aquila adalberti), lesser kestrel (Falco naumanni) and great bustard (Otis tarda); and in the IUCN “near threatened” red kite (Milvus milvus). The highest seropositivity by species was observed in the Eurasian eagle owl (Bubo bubo) (68.1%, 98 of 144). The main risk factors associated with T. gondii seropositivity in wild birds were age and diet, with the highest exposure in older animals and in carnivorous wild birds. The results showed that T. gondii infection is

  8. Risk factors for Brucella seropositivity in goat herds in eastern and western Uganda.

    PubMed

    Kabagambe, E K; Elzer, P H; Geaghan, J P; Opuda-Asibo, J; Scholl, D T; Miller, J E

    2001-12-03

    Cross-sectional prevalences and risk factors for Brucella seropositivity in goats in eastern and western Uganda were investigated. Serum was collected from 1518 goats randomly selected from 145 herds which had been identified using multistage sampling. The brucellosis card test (CT) and the Brucella melitensis tube-agglutination test (TAT) were used in parallel to detect antibodies against B. abortus and B. melitensis, respectively. Interviewer-administered questionnaires were used to collect information on goat health and management. This information was used in multivariable logistic-regression models to determine the risk factors for Brucella seropositivity in goat herds. For each analysis, a herd was considered positive if at least one goat in the herd tested positive for antibodies against Brucella and negative if none was positive. Four percent (55/1480) of the goats screened with the CT had antibodies against Brucella. The reactors were distributed in 13% (19/145) of the herds. The most-important herd-level risk factors identified were use of a hired caretaker as the primary manager of the operation compared to owner/family members (adjusted odds ratio (OR)=8.1; 95% CI 1.6, 39.7), keeping sheep in addition to goats (OR=6.0; CI 1.5, 23.7) compared to having no sheep, and free browsing (OR=4.7; 95% CI 1.0, 20.7) when compared to tethering or zero-grazing. Using the TAT, 10% (141/1446) of the goats tested positive. The positives were distributed in 43% (63/145) of the herds. Free browsing (OR=6.7; 95% CI 2.7, 16.9) when compared to tethering or zero-grazing and lack of veterinary care (OR=2.9; CI 1.3, 6.7) were the most-important factors identified in the multivariable model for B. melitensis herd seropositivity. To explore/reduce the risk of misclassification in a secondary analysis, herds were reclassified as positive if at least one goat tested positive on both tests and negative if none of the goats was positive on any of the two tests. Using this

  9. Relationship between Toxoplasma gondii seropositivity and acoustic startle response in an inner-city population.

    PubMed

    Massa, Nick M; Duncan, Erica; Jovanovic, Tanja; Kerley, Kimberly; Weng, Lei; Gensler, Lauren; Lee, Samuel S; Norrholm, Seth; Powers, Abigail; Almli, Lynn M; Gillespie, Charles F; Ressler, Kerry; Pearce, Bradley D

    2017-03-01

    Toxoplasma gondii (TOXO) is a neuroinvasive protozoan parasite that induces the formation of persistent cysts in mammalian brains. It infects approximately 1.1million people in the United States annually. Latent TOXO infection is implicated in the etiology of psychiatric disorders, especially schizophrenia (SCZ), and has been correlated with modestly impaired cognition. The acoustic startle response (ASR) is a reflex seen in all mammals. It is mediated by a simple subcortical circuit, and provides an indicator of neural function. We previously reported the association of TOXO with slowed acoustic startle latency, an index of neural processing speed, in a sample of schizophrenia and healthy control subjects. The alterations in neurobiology with TOXO latent infection may not be specific to schizophrenia. Therefore we examined TOXO in relation to acoustic startle in an urban, predominately African American, population with mixed psychiatric diagnoses, and healthy controls. Physiological and diagnostic data along with blood samples were collected from 364 outpatients treated at an inner-city hospital. TOXO status was determined with an ELISA assay for TOXO-specific IgG. A discrete titer was calculated based on standard cut-points as an indicator of seropositivity, and the TOXO-specific IgG concentration served as serointensity. A series of linear regression models were used to assess the association of TOXO seropositivity and serointensity with ASR magnitude and latency in models adjusting for demographics and psychiatric diagnoses (PTSD, major depression, schizophrenia, psychosis, substance abuse). ASR magnitude was 11.5% higher in TOXO seropositive subjects compared to seronegative individuals (p=0.01). This effect was more pronounced in models with TOXO serointensity that adjusted for sociodemographic covariates (F=7.41, p=0.0068; F=10.05, p=0.0017), and remained significant when psychiatric diagnoses were stepped into the models. TOXO showed no association with

  10. Maternal Immunization Earlier in Pregnancy Maximizes Antibody Transfer and Expected Infant Seropositivity Against Pertussis

    PubMed Central

    Eberhardt, Christiane S.; Blanchard-Rohner, Geraldine; Lemaître, Barbara; Boukrid, Meriem; Combescure, Christophe; Othenin-Girard, Véronique; Chilin, Antonina; Petre, Jean; de Tejada, Begoña Martinez; Siegrist, Claire-Anne

    2016-01-01

    Background. Maternal immunization against pertussis is currently recommended after the 26th gestational week (GW). Data on the optimal timing of maternal immunization are inconsistent. Methods. We conducted a prospective observational noninferiority study comparing the influence of second-trimester (GW 13–25) vs third-trimester (≥GW 26) tetanus-diphtheria-acellular pertussis (Tdap) immunization in pregnant women who delivered at term. Geometric mean concentrations (GMCs) of cord blood antibodies to recombinant pertussis toxin (PT) and filamentous hemagglutinin (FHA) were assessed by enzyme-linked immunosorbent assay. The primary endpoint were GMCs and expected infant seropositivity rates, defined by birth anti-PT >30 enzyme-linked immunosorbent assay units (EU)/mL to confer seropositivity until 3 months of age. Results. We included 335 women (mean age, 31.0 ± 5.1 years; mean gestational age, 39.3 ± 1.3 GW) previously immunized with Tdap in the second (n = 122) or third (n = 213) trimester. Anti-PT and anti-FHA GMCs were higher following second- vs third-trimester immunization (PT: 57.1 EU/mL [95% confidence interval {CI}, 47.8–68.2] vs 31.1 EU/mL [95% CI, 25.7–37.7], P < .001; FHA: 284.4 EU/mL [95% CI, 241.3–335.2] vs 140.2 EU/mL [95% CI, 115.3–170.3], P < .001). The adjusted GMC ratios after second- vs third-trimester immunization differed significantly (PT: 1.9 [95% CI, 1.4–2.5]; FHA: 2.2 [95% CI, 1.7–3.0], P < .001). Expected infant seropositivity rates reached 80% vs 55% following second- vs third-trimester immunization (adjusted odds ratio, 3.7 [95% CI, 2.1–6.5], P < .001). Conclusions. Early second-trimester maternal Tdap immunization significantly increased neonatal antibodies. Recommending immunization from the second trimester onward would widen the immunization opportunity window and could improve seroprotection. PMID:26797213

  11. 78 FR 17232 - Meeting of the SANE/SART AI/AN Initiative Committee

    Federal Register 2010, 2011, 2012, 2013, 2014

    2013-03-20

    ... Indian/ Alaska Native (AI/AN) Sexual Assault Nurse Examiner (SANE)--Sexual Assault Response Team (SART.../Alaskan Native (AI/AN) Sexual Assault Nurse Examiner (SANE)--Sexual Assault Response Team...

  12. An association exists between bovine herpesvirus-4 seropositivity and abortion in cows.

    PubMed

    Czaplicki, G; Thiry, E

    1998-01-01

    The prevalence of cattle seropositive to bovine herpesvirus-4 (BHV-4) is high in Belgium. In Belgian farms, clinical signs associated with BHV-4 infection essentially involve the genital tract and consist mainly of postpartum metritis or metroperitonitis. The role of BHV-4 in abortion has not been definitively demonstrated but epidemiological and experimental facts suggest its involvement. A seroepidemiological investigation was therefore conducted as a case-control study to compare the seroprevalences of BHV-4 infections in the aborted-cow population and in a randomly selected control group in the province of Liège (Belgium). The seroprevalence (17.2%) in aborted cows was significantly higher than that of the control group (10.0%). The odds ratio (OR) was 1.87 (1.06 < 3.30). BHV-4 infection is therefore considered as a risk factor for abortion in cows.

  13. PARSONAGE-TURNER SYNDROME: CASE REPORT OF A HIV-SEROPOSITIVE PATIENT.

    PubMed

    Oliveira, Saulo Gomes de; Pombo, Eduardo Hosken; Batista, Priscila Rossi de; Cardoso, Igor Machado; Rezende, Rodrigo

    2010-01-01

    Parsonage-Turner Syndrome is a rare disease that affects the musculature of the scapular girdle, leading to muscle atrophy and large motor deficit. The etiology is uncertain, but it is believed that infectious and autoimmune factors are involved. The diagnosis is made by exclusion, and the main differential diagnoses are cervical disc hernias, rotator cuff injuries and rheumatic diseases. During diagnostic investigations, we perform laboratory tests, radiographs and MRI on the shoulders and cervical spine, with emphasis on electroneuromyography to help in making a definitive diagnosis. This case report is presented because it shows a disease that is rarely associated with HIV seropositivity and the importance of early diagnosis for better treatment of these patients.

  14. Influenza A and Parvovirus B19 Seropositivity Rates in Gabonese Infants.

    PubMed

    Gabor, Julian J; Schwarz, Norbert G; Esen, Meral; Kremsner, Peter G; Grobusch, Martin P

    2015-08-01

    Clinical and epidemiological data from Central Africa on influenza A and parvovirus B19 infections are limited. We analyzed 162 blood samples of infants 3, 9, 15, and 30 months of age for IgG antibodies against both pathogens. Antibody responses were 0, 3.7%, 12.3%, and 20.4% against influenza A; and 1.2%, 2.5%, 3.1%, and 9.3% against parvovirus B19, respectively. Seropositivity rates were 89.5 (95% confidence interval [CI]: 59-120.1) and 38.2 (95% CI: 18.9-57.6)/1,000 person-years at risk for influenza A and parvovirus B19, respectively. Our data add to the understanding of the epidemiology of both conditions.

  15. Internalized stigma, social distance, and disclosure of HIV seropositivity in rural Uganda

    PubMed Central

    Tsai, Alexander C.; Bangsberg, David R.; Kegeles, Susan M.; Katz, Ingrid T.; Haberer, Jessica E.; Muzoora, Conrad; Kumbakumba, Elias; Hunt, Peter W.; Martin, Jeffrey N.; Weiser, Sheri D.

    2013-01-01

    Background HIV is highly stigmatized, compromising both treatment and prevention in resource-limited settings. Purpose To study the relationship between internalized HIV-related stigma and serostatus disclosure and to determine the extent to which this association varies with the degree of social distance. Methods We fit multivariable Poisson regression models, with cluster-correlated robust estimates of variance, to data from 259 persons with HIV enrolled in an ongoing cohort study in rural Uganda. Results Persons with more internalized stigma were less likely to disclose their seropositivity. The magnitude of association increased with social distance such that the largest association was observed for public disclosures and the smallest association was observed for disclosures to sexual partners. Conclusions Among persons with HIV in rural Uganda, internalized stigma was negatively associated with serostatus disclosure. The inhibiting effect of stigma was greatest for the most socially distant ties. PMID:23690283

  16. Genetic identification of avian hepatitis E virus (HEV) from healthy chicken flocks and characterization of the capsid gene of 14 avian HEV isolates from chickens with hepatitis-splenomegaly syndrome in different geographical regions of the United States.

    PubMed

    Sun, Z F; Larsen, C T; Dunlop, A; Huang, F F; Pierson, F W; Toth, T E; Meng, X-J

    2004-03-01

    Avian hepatitis E virus (HEV), a novel virus identified from chickens with hepatitis-splenomegaly (HS) syndrome, is genetically and antigenically related to human HEV. Recently, it was found that avian HEV antibody is also prevalent in healthy chickens. A prospective study was done on a known seropositive but healthy chicken farm to identify avian HEV isolates from healthy chickens. Fourteen chickens were randomly selected, tagged and monitored under natural conditions for 19 weeks. All 14 chickens were seronegative at the beginning of the study at 12 weeks of age. By 21 weeks of age, all 14 chickens had seroconverted to avian HEV antibody. None of the chickens had any sign of HS syndrome. Partial helicase gene and capsid gene sequences of avian HEV isolates recovered from a healthy chicken were determined and found to share 75-97 % nucleotide sequence identity with the corresponding regions of avian HEV isolates from chickens with HS syndrome. Thus far, only one strain of avian HEV from a chicken with HS syndrome has been genetically characterized for its capsid gene, therefore the capsid gene region of an additional 14 isolates from chickens with HS syndrome were also characterized. The capsid genes of avian HEV isolates from chickens with HS syndrome were found to be heterogeneic, sharing 76-100 % nucleotide sequence identity with each other. This study indicates that avian HEV is enzootic in chicken flocks and spreads subclinically among chickens in the United States and that the virus is heterogeneic.

  17. A positive role of multiplicative noise on the emergence of flocking in a stochastic Cucker-Smale system

    SciTech Connect

    Sun, Yongzheng; Lin, Wei

    2015-08-15

    In this article, we investigate the flocking of a stochastic Cucker-Smale system with multiplicative measurement noise. We show that there is a noise strength, below which the flocking occurs and the convergence time is a decreasing function of noise strength. Specifically, we find a power-law relationship between the convergence time and the density of group. We also investigate the influence of control parameter and an optimal value is found that minimizes the convergence time.

  18. 10 CFR 1017.28 - Processing on Automated Information Systems (AIS).

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 4 2010-01-01 2010-01-01 false Processing on Automated Information Systems (AIS). 1017.28... UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.28 Processing on Automated Information Systems (AIS). UCNI may be processed or produced on any AIS that complies with the guidance in...

  19. 10 CFR 1017.28 - Processing on Automated Information Systems (AIS).

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 4 2014-01-01 2014-01-01 false Processing on Automated Information Systems (AIS). 1017.28... UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.28 Processing on Automated Information Systems (AIS). UCNI may be processed or produced on any AIS that complies with the guidance in...

  20. 10 CFR 1017.28 - Processing on Automated Information Systems (AIS).

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 4 2011-01-01 2011-01-01 false Processing on Automated Information Systems (AIS). 1017.28... UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.28 Processing on Automated Information Systems (AIS). UCNI may be processed or produced on any AIS that complies with the guidance in...

  1. 10 CFR 1017.28 - Processing on Automated Information Systems (AIS).

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 4 2012-01-01 2012-01-01 false Processing on Automated Information Systems (AIS). 1017.28... UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.28 Processing on Automated Information Systems (AIS). UCNI may be processed or produced on any AIS that complies with the guidance in...

  2. 10 CFR 1017.28 - Processing on Automated Information Systems (AIS).

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 4 2013-01-01 2013-01-01 false Processing on Automated Information Systems (AIS). 1017.28... UNCLASSIFIED CONTROLLED NUCLEAR INFORMATION Physical Protection Requirements § 1017.28 Processing on Automated Information Systems (AIS). UCNI may be processed or produced on any AIS that complies with the guidance in...

  3. Oil spills and AI: How to manage resources through simulation

    SciTech Connect

    Giribone, P.; Bruzzone, A.G.; Caddeo, S.

    1995-12-31

    Today, in the Mediterranean theater of the Upper Tyrrhenian, the ecological risk involving oil installations is still quite high. This is due to the fact that valuable environmental and tourist areas exist together with large industrial and port structures; in particular, recent events have demonstrated the danger involving oil spills along the Ligurian coastline. This study proposes an approach to plan the operations that should be performed when accidents occur, based on the use of AI techniques.

  4. AiResearch QCGAT engine performance and emissions tests

    NASA Technical Reports Server (NTRS)

    Norgren, W. M.

    1980-01-01

    Results of aerodynamic performance and emission tests, conducted on a specially designed QCGAT engine in the 17,793-N (4,000 lb) thrust class, are presented. Performance of the AiResearch QCGAT engine was excellent throughout all testing. No serious mechanical malfunctions were encountered, and no significant test time was lost due to engine-related problems. Emissions were drastically reduced over similar engines, and the engine exhibited good smoke performance.

  5. Artificial intelligence (AI) systems for interpreting complex medical datasets.

    PubMed

    Altman, R B

    2017-02-09

    Advances in machine intelligence have created powerful capabilities in algorithms that find hidden patterns in data, classify objects based on their measured characteristics, and associate similar patients/diseases/drugs based on common features. However, artificial intelligence (AI) applications in medical data have several technical challenges: complex and heterogeneous datasets, noisy medical datasets, and explaining their output to users. There are also social challenges related to intellectual property, data provenance, regulatory issues, economics, and liability.

  6. The AIS: A Spectrograph/Imager Ensemble for Space Flight

    DTIC Science & Technology

    1990-05-17

    emissions in the vicinity of spacecraft. It includes nine spectrographs, which cover the spectral range from 115 to 1100 snm#.Vlithpe- tralI ...designations, wavelength ranges, and fields of view. 10 3. Spectrograph parameters and calibration results . 26 4. Imager parameters and calibration... results . 28 BI Weights and Dimensions of the boxes that comprise the AIS 42 Accession For NTIS GRA& DTIC TAB 0 Unamotced E0 Just ificat1o by Distrlbution

  7. Flocking of Second-Order Multiagent Systems With Connectivity Preservation Based on Algebraic Connectivity Estimation.

    PubMed

    Fang, Hao; Wei, Yue; Chen, Jie; Xin, Bin

    2017-04-01

    The problem of flocking of second-order multiagent systems with connectivity preservation is investigated in this paper. First, for estimating the algebraic connectivity as well as the corresponding eigenvector, a new decentralized inverse power iteration scheme is formulated. Then, based on the estimation of the algebraic connectivity, a set of distributed gradient-based flocking control protocols is built with a new class of generalized hybrid potential fields which could guarantee collision avoidance, desired distance stabilization, and the connectivity of the underlying communication network simultaneously. What is important is that the proposed control scheme allows the existing edges to be broken without violation of connectivity constraints, and thus yields more flexibility of motions and reduces the communication cost for the multiagent system. In the end, nontrivial comparative simulations and experimental results are performed to demonstrate the effectiveness of the theoretical results and highlight the advantages of the proposed estimation scheme and control algorithm.

  8. An outbreak of blindness due to retinopathy in nine flocks of guinea fowl.

    PubMed

    Cecchinato, M; Lupini, C; Bolognesi, P G; Marzadori, F; Raffini, E; Frasnelli, M; Poppi, L; Shivaprasad, H L; Catelli, E

    2014-06-01

    Blindness was observed in 10- to 14-day-old guinea fowl. The incidence ranged from 25% to 80% in nine flocks within a total population of 110,000 guinea fowls. Clinical signs of blindness in birds included aimless wandering, failure to find feed and water, lateral recumbency, loss of weight, and increased mortality. The birds lacked papillary reflexes to light, and there were no gross lesions in the eyes. Histologically there was degeneration and disorganization of photoreceptors in the retina. The guinea fowl came from three different breeder sources but all of the birds were given the same feed. The condition was not observed in the subsequent flocks that came from the same breeder sources but that were given different feed. Based on these observations, toxicity of an unknown ingredient in the feed is suspected as the cause of blindness in the guinea fowl.

  9. Route-dependent switch between hierarchical and egalitarian strategies in pigeon flocks

    PubMed Central

    Zhang, Hai-Tao; Chen, Zhiyong; Vicsek, Tamás; Feng, Guanjun; Sun, Longsheng; Su, Riqi; Zhou, Tao

    2014-01-01

    The mechanisms that underlie fascinating inter-individual interactions among animal groups have attracted increasing attention from biologists, physicists, and system scientists. There are two well-known types of interaction patterns: hierarchical and egalitarian. In the former type, individuals follow their leaders, whereas they follow their neighbors in the latter. Using high-resolution spatiotemporal data derived from the free flights of a flock of pigeons, we show that pigeon flocks actually adopt a mode that switches between the two aforementioned strategies. To determine its flight direction, each pigeon tends to follow the average of its neighbors while moving along a smooth trajectory, whereas it switches to follow its leaders when sudden turns or zigzags occur. By contrast, when deciding how fast to fly, each pigeon synthesizes the average velocity of its neighbors. This switching mechanism is promising for possible industrial applications in multi-robot system coordination, unmanned vehicle formation control, and other areas. PMID:25055832

  10. Route-dependent switch between hierarchical and egalitarian strategies in pigeon flocks

    NASA Astrophysics Data System (ADS)

    Zhang, Hai-Tao; Chen, Zhiyong; Vicsek, Tamás; Feng, Guanjun; Sun, Longsheng; Su, Riqi; Zhou, Tao

    2014-07-01

    The mechanisms that underlie fascinating inter-individual interactions among animal groups have attracted increasing attention from biologists, physicists, and system scientists. There are two well-known types of interaction patterns: hierarchical and egalitarian. In the former type, individuals follow their leaders, whereas they follow their neighbors in the latter. Using high-resolution spatiotemporal data derived from the free flights of a flock of pigeons, we show that pigeon flocks actually adopt a mode that switches between the two aforementioned strategies. To determine its flight direction, each pigeon tends to follow the average of its neighbors while moving along a smooth trajectory, whereas it switches to follow its leaders when sudden turns or zigzags occur. By contrast, when deciding how fast to fly, each pigeon synthesizes the average velocity of its neighbors. This switching mechanism is promising for possible industrial applications in multi-robot system coordination, unmanned vehicle formation control, and other areas.

  11. Route-dependent switch between hierarchical and egalitarian strategies in pigeon flocks.

    PubMed

    Zhang, Hai-Tao; Chen, Zhiyong; Vicsek, Tamás; Feng, Guanjun; Sun, Longsheng; Su, Riqi; Zhou, Tao

    2014-07-24

    The mechanisms that underlie fascinating inter-individual interactions among animal groups have attracted increasing attention from biologists, physicists, and system scientists. There are two well-known types of interaction patterns: hierarchical and egalitarian. In the former type, individuals follow their leaders, whereas they follow their neighbors in the latter. Using high-resolution spatiotemporal data derived from the free flights of a flock of pigeons, we show that pigeon flocks actually adopt a mode that switches between the two aforementioned strategies. To determine its flight direction, each pigeon tends to follow the average of its neighbors while moving along a smooth trajectory, whereas it switches to follow its leaders when sudden turns or zigzags occur. By contrast, when deciding how fast to fly, each pigeon synthesizes the average velocity of its neighbors. This switching mechanism is promising for possible industrial applications in multi-robot system coordination, unmanned vehicle formation control, and other areas.

  12. Extracting uranium from seawater: Promising AI series adsorbents

    DOE PAGES

    Das, Sadananda; Oyola, Y.; Mayes, Richard T.; ...

    2015-11-10

    A series of adsorbent (AI10 through AI17) were successfully developed at ORNL by radiation induced graft polymerization (RIGP) of acrylonitrile (AN) and vinylphosphonic acid (VPA) (at different mole/mole ratios) onto high surface area polyethylene fiber, with higher degree of grafting which ranges from 110 300%. The grafted nitrile groups were converted to amidoxime groups by reaction with 10 wt% hydroxylamine at 80 C for 72 hours. The amidoximated adsorbents were then conditioned with 0.44M KOH at 80 C followed by screening at ORNL with simulated seawater spiked with 8 ppm uranium. Uranium adsorption capacity in simulated seawater screening ranged frommore » 171-187 g-U/kg-ads irrespective of %DOG. The performance of the adsorbents for uranium adsorption in natural seawater was also carried out using flow-through-column at Pacific Northwest National Laboratory (PNNL). The three hours KOH conditioning was better for higher uranium uptake than one hour. The adsorbent AI11 containing AN and VPA at the mole ration of 3.52, emerged as the potential candidate for higher uranium adsorption (3.35 g-U/Kg-ads.) after 56 days of exposure in the seawater in the flow-through-column. The rate vanadium adsorption over uranium was linearly increased throughout the 56 days exposure. The total vanadium uptake was ~5 times over uranium after 56 days.« less

  13. Extracting Uranium from Seawater: Promising AI Series Adsorbents

    SciTech Connect

    Das, S.; Oyola, Y.; Mayes, R. T.; Janke, C. J.; Kuo, L. -J.; Gill, G.; Wood, J. R.; Dai, S.

    2016-04-20

    A new series of adsorbents (AI10 through AI17) were successfully developed at ORNL by radiation induced graft polymerization (RIGP) of acrylonitrile (AN) and vinylphosphonic acid (VPA) (at different mole to mole ratios) onto high surface area polyethylene fiber, with high degrees of grafting (DOG) varying from 110 to 300%. The grafted nitrile groups were converted to amidoxime groups by reaction with 5 wt % hydroxylamine at 80 °C for 72 h. The amidoximated adsorbents were then conditioned with 0.44 M KOH at 80 °C followed by screening at ORNL with prescreening brine spiked with 8 ppm uranium. Uranium adsorption capacities in prescreening ranged from 171 to 187 g-U/kg-ads irrespective of percent DOG. The performance of the adsorbents with respect to uranium adsorption in natural seawater was also investigated using flow-throughcolumn testing at the Pacific Northwest National Laboratory (PNNL). Three hours of KOH conditioning led to higher uranium uptake than 1 h of conditioning. The adsorbent AI11, containing AN and VPA at the mole ratio of 3.52, emerged as the potential candidate for the highest uranium adsorption (3.35 g-U/kg-ads.) after 56 days of exposure in seawater flow-through-columns. The rate of vanadium adsorption over uranium linearly increased throughout the 56 days of exposure. The total mass of vanadium uptake was ~5 times greater than uranium after 56 days.

  14. Functional subdivisions in low-frequency primary auditory cortex (AI).

    PubMed

    Wallace, M N; Palmer, A R

    2009-04-01

    We wished to test the hypothesis that there are modules in low-frequency AI that can be identified by their responsiveness to communication calls or particular regions of space. Units were recorded in anaesthetised guinea pig AI and stimulated with conspecific vocalizations and a virtual motion stimulus (binaural beats) presented via a closed sound system. Recording tracks were mainly oriented orthogonally to the cortical surface. Some of these contained units that were all time-locked to the structure of the chutter call (14/22 tracks) and/or the purr call (12/22 tracks) and/or that had a preference for stimuli from a particular region of space (8/20 tracks with four contralateral, two ipsilateral and two midline), or where there was a strong asymmetry in the response to beats of different direction (two tracks). We conclude that about half of low-frequency AI is organized into modules that are consistent with separate "what" and "where" pathways.

  15. LUT observations of the mass-transferring binary AI Dra

    NASA Astrophysics Data System (ADS)

    Liao, Wenping; Qian, Shengbang; Li, Linjia; Zhou, Xiao; Zhao, Ergang; Liu, Nianping

    2016-06-01

    Complete UV band light curve of the eclipsing binary AI Dra was observed with the Lunar-based Ultraviolet Telescope (LUT) in October 2014. It is very useful to adopt this continuous and uninterrupted light curve to determine physical and orbital parameters of the binary system. Photometric solutions of the spot model are obtained by using the W-D (Wilson and Devinney) method. It is confirmed that AI Dra is a semi-detached binary with secondary component filling its critical Roche lobe, which indicates that a mass transfer from the secondary component to the primary one should happen. Orbital period analysis based on all available eclipse times suggests a secular period increase and two cyclic variations. The secular period increase was interpreted by mass transfer from the secondary component to the primary one at a rate of 4.12 ×10^{-8}M_{⊙}/yr, which is in agreement with the photometric solutions. Two cyclic oscillations were due to light travel-time effect (LTTE) via the presence of two cool stellar companions in a near 2:1 mean-motion resonance. Both photometric solutions and orbital period analysis confirm that AI Dra is a mass-transferring binary, the massive primary is filling 69 % of its critical Roche lobe. After the primary evolves to fill the critical Roche lobe, the mass transfer will be reversed and the binary will evolve into a contact configuration.

  16. Extracting uranium from seawater: Promising AI series adsorbents

    SciTech Connect

    Das, Sadananda; Oyola, Y.; Mayes, Richard T.; Janke, Christopher James; Kuo, Li-Jung; Gill, Gary; Wood, Jordana; Dai, Sheng

    2015-11-10

    A series of adsorbent (AI10 through AI17) were successfully developed at ORNL by radiation induced graft polymerization (RIGP) of acrylonitrile (AN) and vinylphosphonic acid (VPA) (at different mole/mole ratios) onto high surface area polyethylene fiber, with higher degree of grafting which ranges from 110 300%. The grafted nitrile groups were converted to amidoxime groups by reaction with 10 wt% hydroxylamine at 80 C for 72 hours. The amidoximated adsorbents were then conditioned with 0.44M KOH at 80 C followed by screening at ORNL with simulated seawater spiked with 8 ppm uranium. Uranium adsorption capacity in simulated seawater screening ranged from 171-187 g-U/kg-ads irrespective of %DOG. The performance of the adsorbents for uranium adsorption in natural seawater was also carried out using flow-through-column at Pacific Northwest National Laboratory (PNNL). The three hours KOH conditioning was better for higher uranium uptake than one hour. The adsorbent AI11 containing AN and VPA at the mole ration of 3.52, emerged as the potential candidate for higher uranium adsorption (3.35 g-U/Kg-ads.) after 56 days of exposure in the seawater in the flow-through-column. The rate vanadium adsorption over uranium was linearly increased throughout the 56 days exposure. The total vanadium uptake was ~5 times over uranium after 56 days.

  17. The AI Bus architecture for distributed knowledge-based systems

    NASA Technical Reports Server (NTRS)

    Schultz, Roger D.; Stobie, Iain

    1991-01-01

    The AI Bus architecture is layered, distributed object oriented framework developed to support the requirements of advanced technology programs for an order of magnitude improvement in software costs. The consequent need for highly autonomous computer systems, adaptable to new technology advances over a long lifespan, led to the design of an open architecture and toolbox for building large scale, robust, production quality systems. The AI Bus accommodates a mix of knowledge based and conventional components, running on heterogeneous, distributed real world and testbed environment. The concepts and design is described of the AI Bus architecture and its current implementation status as a Unix C++ library or reusable objects. Each high level semiautonomous agent process consists of a number of knowledge sources together with interagent communication mechanisms based on shared blackboards and message passing acquaintances. Standard interfaces and protocols are followed for combining and validating subsystems. Dynamic probes or demons provide an event driven means for providing active objects with shared access to resources, and each other, while not violating their security.

  18. Hereditary apolipoprotein AI-associated renal amyloidosis: A diagnostic challenge.

    PubMed

    Samillán-Sosa, Kelly Del Rocío; Sención-Martínez, Gloria; Lopes-Martín, Vanessa; Martínez-González, Miguel Angel; Solé, Manel; Arostegui, Jose Luis; Mesa, Jose; García-Díaz, Juan de Dios; Rodríguez-Puyol, Diego; Martínez-Miguel, Patricia

    2015-01-01

    Hereditary renal amyloidosis is an autosomal dominant condition with considerable overlap with other amyloidosis types. Differential diagnosis is complicated, but is relevant for prognosis and treatment. We describe a patient with nephrotic syndrome and progressive renal failure, who had a mother with renal amiloidosis. Renal biopsy revealed amyloid deposits in glomerular space, with absence of light chains and protein AA. We suspected amyloidosis with fibrinogen A alpha chain deposits, which is the most frequent cause of hereditary amyloidosis in Europe, with a glomerular preferential affectation. However, the genetic study showed a novel mutation in apolipoprotein AI. On reviewing the biopsy of the patient's mother similar glomerular deposits were found, but there were significant deposits in the renal medulla as well, which is typical in APO AI amyloidosis. The diagnosis was confirmed by immunohistochemistry. Apo AI amyloidosis is characterized by slowly progressive renal disease and end-stage renal disease occurs aproximately 3 to 15 years from initial diagnosis. Renal transplantation offers an acceptable graft survival and in these patients with hepatorenal involvement simultaneous liver and kidney transplantation could be considered.

  19. Artificial Intelligence (AI) Based Tactical Guidance for Fighter Aircraft

    NASA Technical Reports Server (NTRS)

    McManus, John W.; Goodrich, Kenneth H.

    1990-01-01

    A research program investigating the use of Artificial Intelligence (AI) techniques to aid in the development of a Tactical Decision Generator (TDG) for Within Visual Range (WVR) air combat engagements is discussed. The application of AI programming and problem solving methods in the development and implementation of the Computerized Logic For Air-to-Air Warfare Simulations (CLAWS), a second generation TDG, is presented. The Knowledge-Based Systems used by CLAWS to aid in the tactical decision-making process are outlined in detail, and the results of tests to evaluate the performance of CLAWS versus a baseline TDG developed in FORTRAN to run in real-time in the Langley Differential Maneuvering Simulator (DMS), are presented. To date, these test results have shown significant performance gains with respect to the TDG baseline in one-versus-one air combat engagements, and the AI-based TDG software has proven to be much easier to modify and maintain than the baseline FORTRAN TDG programs. Alternate computing environments and programming approaches, including the use of parallel algorithms and heterogeneous computer networks are discussed, and the design and performance of a prototype concurrent TDG system are presented.

  20. Structural Ecosystems Therapy for HIV-Seropositive African American Women: Effects on Psychological Distress, Family Hassles, and Family Support

    ERIC Educational Resources Information Center

    Szapocznik, Jose; Feaster, Daniel J.; Mitrani, Victoria B.; Prado, Guillermo; Smith, Lila; Robinson-Batista, Carleen; Schwartz, Seth J.; Mauer, Magaly H.; Robbins, Michael S.

    2004-01-01

    This study tests the efficacy of Structural Ecosystems Therapy (SET), a family-ecological intervention, in improving psychosocial functioning when compared with an attention-comparison person-centered condition and a community control condition. A sample of 209 HIV-seropositive, urban, low-income, African American women was randomized into 1 of…

  1. Rubella reimmunization: comparative analysis of the immunoglobulin G response to rubella virus vaccine in previously seronegative and seropositive individuals.

    PubMed Central

    Mitchell, L A; Ho, M K; Rogers, J E; Tingle, A J; Marusyk, R G; Weber, J M; Duclos, P; Tepper, M L; Lacroix, M; Zrein, M

    1996-01-01

    Rubella virus (RV)-specific immunoglobulin G (IgG) antibodies were studied in military recruits undergoing unselected immunization with live attenuated measles, mumps, and rubella virus (MMR) vaccine. Three different whole-RV enzyme immunoassays (EIAs) and an epitope-specific EIA with a synthetic peptide (BCH-178c) representing a heutralization domain on the RV E1 envelope protein were used. Before vaccination, 84.2, 87.7, and 84.5% of the subjects tested (n = 399) were found to be seropositive (> 10 IU/ml or assay equivalent) by the three whole-RV EIAs, respectively, while only 82.5% were seropositive by the BCH-178c EIA. Although prevaccination seropositivity rates were similar for the whole-RV EIAs (sensitivity, 94 to 100%), many sera considered seropositive by the whole-RV EIAs had E1 peptide EIA antibody levels of < 10 IU/ml (sensitivity, 77.4 to 80.7%). One month after vaccination, 97.8, 97.2, and 93.5% of the subjects who were followed (n = 356) were seropositive by the three whole-RV EIAs, respectively, while 89% had BCH-178c peptide-specific IgG titers of > 10 IU/ml. After vaccination, depending on the assay used, up to 20.6% of initially seropositive individuals exhibited a greater than fourfold increase in RV-specific IgG, while up to 47.3% showed a greater than twofold increase. Increased antibody titers after vaccination (seroboosting) were most frequently associated with low levels of BCH-178c peptide-specific IgG before vaccination. RV protein-specific IgG was also studied by immunoblot assays in a subset (n = 56) of individuals receiving the MMR vaccine. Of these, 89.4 and 91.1% exhibited RV protein (E1, E2, and C protein)-specific IgG before and after vaccination, respectively. Seroboosting (two- to fourfold increase in EIA titers of individuals seropositive by the whole-RV EIA before vaccination) was usually accompanied by a shift in the IgG immunoblot pattern from a single (E1) to multiple (E1-E1, E1-C, or E1-E2-C) specificities, suggesting

  2. A Q-Learning Approach to Flocking With UAVs in a Stochastic Environment.

    PubMed

    Hung, Shao-Ming; Givigi, Sidney N

    2017-01-01

    In the past two decades, unmanned aerial vehicles (UAVs) have demonstrated their efficacy in supporting both military and civilian applications, where tasks can be dull, dirty, dangerous, or simply too costly with conventional methods. Many of the applications contain tasks that can be executed in parallel, hence the natural progression is to deploy multiple UAVs working together as a force multiplier. However, to do so requires autonomous coordination among the UAVs, similar to swarming behaviors seen in animals and insects. This paper looks at flocking with small fixed-wing UAVs in the context of a model-free reinforcement learning problem. In particular, Peng's Q(λ) with a variable learning rate is employed by the followers to learn a control policy that facilitates flocking in a leader-follower topology. The problem is structured as a Markov decision process, where the agents are modeled as small fixed-wing UAVs that experience stochasticity due to disturbances such as winds and control noises, as well as weight and balance issues. Learned policies are compared to ones solved using stochastic optimal control (i.e., dynamic programming) by evaluating the average cost incurred during flight according to a cost function. Simulation results demonstrate the feasibility of the proposed learning approach at enabling agents to learn how to flock in a leader-follower topology, while operating in a nonstationary stochastic environment.

  3. Prevalence and on-farm risk factors for diarrhoea in meat lamb flocks in Western Australia.

    PubMed

    Sweeny, Joshua P A; Ryan, U M; Robertson, I D; Jacobson, C

    2012-06-01

    Diarrhoea is a widespread problem for sheep enterprises worldwide. A cross-sectional epidemiological study was conducted using a questionnaire to determine the prevalence of diarrhoea and associated risk factors where there was evidence of recent diarrhoea (active diarrhoea or fresh faecal soiling of breech fleece) for meat lambs on farms in southern Western Australia during 2010. The response rate was 41.4% (139/336). Evidence of recent diarrhoea was reported on 64.8% of farms, with a mean of 6.9% lambs affected per farm. Location of a farm and a higher annual rainfall were associated with an increased diarrhoea prevalence. Binary logistic regression analysis suggested that the drinking water source was associated with the incidence of diarrhoea, since lamb flocks supplied with dam water were 117 times (95% CI: 18.2, 754.8) more likely to have observed diarrhoea or fresh breech fleece faecal soiling than lamb flocks supplied with other sources of water. Faecal worm egg counts were used by 65% of respondents to determine whether an anthelmintic treatment was warranted and 74% of respondents administered a treatment to their meat lambs. In response to a range of diarrhoea scenarios presented to respondents (5%, 25% and 50% of the flock with evidence of recent diarrhoea), 15.1% would have elected to administer an anthelmintic treatment regardless of differences in prevalence.

  4. Isolation, identification and antimicrobial sensitivity of Ornithobacterium rhinotracheale in broilers chicken flocks of Khuzestan, Iran

    PubMed Central

    Mayahi, Mansour; Gharibi, Darioush; Ghadimipour, Rahim; Talazadeh, Forough

    2016-01-01

    Ornithobacterium rhinotracheale (ORT) is a bacterium associated with respiratory disease, growth retardation, decreased egg production and mortality in chickens and turkeys. The objective of this study was isolation, identification and evaluation of antimicrobial susceptibility of ORT bacterium in slaughtered broilers chicken flocks based on cultural and molecular tests in Khuzestan province, south-west of Iran. A total of 210 tracheal swab samples were collected from 21 broiler flocks slaughtered in abattoirs of the province. The results of cultural and biochemical tests showed that 23 (10.95%) isolates from tracheal swabs of 4 flocks (19.04%) were identified as ORT, but according to molecular characterization, 18 (8.57%) ORT isolates were positive in PCR assay and produced the predicted 784 bp amplification product. Finally, using the disk diffusion method, the drug resistance patterns of ORT isolates were determined against a panel of commonly used antimicrobial agents. Antimicrobial susceptibility test revealed that all isolates (100%) were sensitive to tetracycline, florfenicol and cephalexin. The highest antimicrobial resistance (89.00%) was seen for fosfomycin, sultrim and gentamicin. The results of present research showed that there was significant difference between the isolation rates of ORT from various areas of the province. As well, our findings indicated that the simultaneous use of both cultural and molecular techniques results in more comprehensive outcomes in the isolation and identification of the organismfrom understudy hosts. PMID:28144427

  5. Diversity and Prevalence of Ectoparasites on Backyard Chicken Flocks in California.

    PubMed

    Murillo, Amy C; Mullens, Bradley A

    2016-05-01

    Peridomestic ("backyard") chicken flocks are gaining popularity in the developed world (e.g., North America or Europe), yet little is known regarding prevalence or severity of their ectoparasites. Therefore, five birds on each of 20 properties throughout southern California were surveyed in summer for on-host (permanent) and off-host dwelling (temporary) ectoparasites. Only four premises (20%) were entirely free of ectoparasites. In declining order of prevalence (% of premises), permanent ectoparasites included six chicken louse species: Menacanthus stramineus (Nitzsch) (50%), Goniocotes gallinae (De Geer) (35%), Lipeurus caponis (L.) (20%), Menopon gallinae (L.) (15%), Menacanthus cornutus (Schömmer) (5%), and Cuclotogaster heterographus (Nitzsch) (5%). Only one flea species, Echidnophaga gallinacea (Westwood) (20%), was found. Three parasitic mite species were observed: Ornithonyssus sylviarum (Canestrini & Fanzago) (15%), Knemidocoptes mutans (Robin & Lanquetin) (10%), and Dermanyssus gallinae (De Geer) (5%). Many infestations consisted of a few to a dozen individuals per bird, but M. stramineus, G. gallinae, M. cornutus, and E. gallinacea were abundant (dozens to hundreds of individuals) on some birds, and damage by K. mutans was severe on two premises. Off-host dwelling ectoparasites were rare (D. gallinae) or absent (Cimex lectularius L., Argasidae). Parasite diversity in peridomestic flocks greatly exceeds that is routinely observed on commercial chicken flocks and highlights a need for increased biosecurity and development of ectoparasite control options for homeowners.

  6. Epidemiological survey on Mycoplasma synoviae infection in Portuguese broiler breeder flocks.

    PubMed

    Moreira, Fernando Alberto; Cardoso, Luís; Coelho, Ana Cláudia

    2015-01-01

    Since modernization and expansion of the poultry industry, infections with Mycoplasma spp. bacteria have been reported as a cause of considerable economic losses. The prevalence of Mycoplasma synoviae infection in 974,000 Portuguese broiler breeders, belonging to 36 flocks, was investigated from December 2008 to March 2012. This study was conducted using a commercial indirect enzyme-linked immunosorbent assay (ELISA) for the analysis of serum antibodies, and a polymerase chain reaction (PCR) for the tracheal tissue. Twenty-four flocks were simultaneously found positive by ELISA and PCR [66.7%, 95% confidence interval (CI): 43.5-76.9%]. The M. synoviae prevalence among chickens averaged 40.3% (483/1,200), with values ranging from 0.0 to 83.3% per flock. The prevalence of farms where M. synoviae positive birds have been found was determined in different poultry categories such as density, biosecurity, strains, offspring quality, premises'age, and others husbandry factors. Prevalence values were significantly higher among birds housed in new facilities (less than 3 years old) and were also significantly higher in the production period. The high prevalence of M. synoviae infection detected in the present study suggests the need to adopt appropriate control measures.

  7. Flocking and Turning: a New Model for Self-organized Collective Motion

    NASA Astrophysics Data System (ADS)

    Cavagna, Andrea; Del Castello, Lorenzo; Giardina, Irene; Grigera, Tomas; Jelic, Asja; Melillo, Stefania; Mora, Thierry; Parisi, Leonardo; Silvestri, Edmondo; Viale, Massimiliano; Walczak, Aleksandra M.

    2015-02-01

    Birds in a flock move in a correlated way, resulting in large polarization of velocities. A good understanding of this collective behavior exists for linear motion of the flock. Yet observing actual birds, the center of mass of the group often turns giving rise to more complicated dynamics, still keeping strong polarization of the flock. Here we propose novel dynamical equations for the collective motion of polarized animal groups that account for correlated turning including solely social forces. We exploit rotational symmetries and conservation laws of the problem to formulate a theory in terms of generalized coordinates of motion for the velocity directions akin to a Hamiltonian formulation for rotations. We explicitly derive the correspondence between this formulation and the dynamics of the individual velocities, thus obtaining a new model of collective motion. In the appropriate overdamped limit we recover the well-known Vicsek model, which dissipates rotational information and does not allow for polarized turns. Although the new model has its most vivid success in describing turning groups, its dynamics is intrinsically different from previous ones in a wide dynamical regime, while reducing to the hydrodynamic description of Toner and Tu at very large length-scales. The derived framework is therefore general and it may describe the collective motion of any strongly polarized active matter system.

  8. Short-range interactions versus long-range correlations in bird flocks

    NASA Astrophysics Data System (ADS)

    Cavagna, Andrea; Del Castello, Lorenzo; Dey, Supravat; Giardina, Irene; Melillo, Stefania; Parisi, Leonardo; Viale, Massimiliano

    2015-07-01

    Bird flocks are a paradigmatic example of collective motion. One of the prominent traits of flocking is the presence of long range velocity correlations between individuals, which allow them to influence each other over the large scales, keeping a high level of group coordination. A crucial question is to understand what is the mutual interaction between birds generating such nontrivial correlations. Here we use the maximum entropy (ME) approach to infer from experimental data of natural flocks the effective interactions between individuals. Compared to previous studies, we make a significant step forward as we retrieve the full functional dependence of the interaction on distance, and find that it decays exponentially over a range of a few individuals. The fact that ME gives a short-range interaction even though its experimental input is the long-range correlation function, shows that the method is able to discriminate the relevant information encoded in such correlations and single out a minimal number of effective parameters. Finally, we show how the method can be used to capture the degree of anisotropy of mutual interactions.

  9. Absolute parameters for AI Phoenicis using WASP photometry

    NASA Astrophysics Data System (ADS)

    Kirkby-Kent, J. A.; Maxted, P. F. L.; Serenelli, A. M.; Turner, O. D.; Evans, D. F.; Anderson, D. R.; Hellier, C.; West, R. G.

    2016-06-01

    Context. AI Phe is a double-lined, detached eclipsing binary, in which a K-type sub-giant star totally eclipses its main-sequence companion every 24.6 days. This configuration makes AI Phe ideal for testing stellar evolutionary models. Difficulties in obtaining a complete lightcurve mean the precision of existing radii measurements could be improved. Aims: Our aim is to improve the precision of the radius measurements for the stars in AI Phe using high-precision photometry from the Wide Angle Search for Planets (WASP), and use these improved radius measurements together with estimates of the masses, temperatures and composition of the stars to place constraints on the mixing length, helium abundance and age of the system. Methods: A best-fit ebop model is used to obtain lightcurve parameters, with their standard errors calculated using a prayer-bead algorithm. These were combined with previously published spectroscopic orbit results, to obtain masses and radii. A Bayesian method is used to estimate the age of the system for model grids with different mixing lengths and helium abundances. Results: The radii are found to be R1 = 1.835 ± 0.014 R⊙, R2 = 2.912 ± 0.014 R⊙ and the masses M1 = 1.1973 ± 0.0037 M⊙, M2 = 1.2473 ± 0.0039 M⊙. From the best-fit stellar models we infer a mixing length of 1.78, a helium abundance of YAI = 0.26 +0.02-0.01 and an age of 4.39 ± 0.32 Gyr. Times of primary minimum show the period of AI Phe is not constant. Currently, there are insufficient data to determine the cause of this variation. Conclusions: Improved precision in the masses and radii have improved the age estimate, and allowed the mixing length and helium abundance to be constrained. The eccentricity is now the largest source of uncertainty in calculating the masses. Further work is needed to characterise the orbit of AI Phe. Obtaining more binaries with parameters measured to a similar level of precision would allow us to test for relationships between helium

  10. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests.

    PubMed

    Yoganandan, Narayan; Pintar, Frank A; Humm, John R; Stadter, Gregory W; Curry, William H; Brasel, Karen J

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990-1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m(2). Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data.

  11. Comparison of AIS 1990 update 98 versus AIS 2005 for describing PMHS injuries in lateral and oblique sled tests

    PubMed Central

    Yoganandan, Narayan; Pintar, Frank A.; Humm, John R.; Stadter, Gregory W.; Curry, William H.; Brasel, Karen J.

    2013-01-01

    This study analyzed skeletal and organ injuries in pure lateral and oblique impacts from 20 intact post mortem human surrogate (PMHS) sled tests at 6.7 m/s. Injuries to the shoulder, thorax, abdomen, pelvis and spine were scored using AIS 1990–1998 update and 2005. The Injury Severity Scores (ISS) were extracted for both loadings from both versions. Mean age, stature, total body mass and body mass index for pure lateral and oblique tests: 58 and 55 years, 1.7 and 1.8 m, 69 and 66 kg, and 24 and 21 kg/m2. Skeletal injuries (ribs, sternum) occurred in both impacts. However, oblique impacts resulted in more injuries. Pure lateral and oblique impacts ISS: 0 to 16 and 0 to 24, representing a greater potential for injury-related consequences in real-world situations in oblique impacts. Internal organs were more involved in oblique impacts. ISS decreased in AIS 2005, reflecting changes to scoring and drawing attention to potential effects for pre-hospital care/medical aspects. Mean AIS scores for the two load vectors and two AIS coding schemes are included. From automotive crashworthiness perspectives, decreases in injury severities might alter injury risk functions with a shift to lower metrics for the same risk level than current risk estimations. This finding influences dummy-based injury criteria and occupant safety as risk functions are used for countermeasure effectiveness and cost-benefit analyses by regulatory bodies. Increase in organ injuries in oblique loading indicate the importance of this vector as current dummies and injury criteria used in regulations are based on pure lateral impact data. PMID:24406958

  12. Features of anti-aquaporin 4 antibody-seropositive Chinese patients with neuromyelitis optica spectrum optic neuritis.

    PubMed

    Li, Hongyang; Wang, Yanling; Xu, Quangang; Zhang, Aidi; Zhou, Huanfen; Zhao, Shuo; Kang, Hao; Peng, Chunxia; Cao, Shanshan; Wei, Shihui

    2015-10-01

    The detection of anti-aquaporin-4 autoantibody (AQP-4 Ab) is crucial to detect patients who will develop neuromyelitis optica (NMO); however, there are few studies on the AQP-4 Ab serostatus of patients with neuromyelitis optica spectrum ON. We analyzed the clinical and paraclinical features of neuromyelitis optica spectrum ON patients in China according to the patients' AQP4-Ab serostatus. 125 patients with recurrent and bilateral ON with simultaneous attacks were divided into AQP-4 Ab-seropositive and -seronegative groups. Demographic, clinical, serum autoantibody data, connective tissue disorders (CTDs), visual performance were compared. A Visual Acuity (VA) of less than 0.1 during acute ON attacks occurred more frequently in the seropositive group (p = 0.023); however, there was not a significant difference between groups on VA recovery after the first attack. The seropositive group experienced the worst outcome during the last attack (p = 0.017). Other co-existing autoimmunity antibodies (p < 0.001) and CTDs (p < 0.001) were more prevalent in seropositive patients. There were no significant differences on VA recovery and RNFLT combined with other autoantibodies or CTDs. The two groups did not differ significantly with regard to time to relapse, annualized relapse rates, time of diagnosis NMO, or RNFL. There were no significant differences on VA recovery and RNFLT combined with other autoantibodies or CTDs. RNFLT was thinner in NMO seropositive patients. Although AQP-4 Ab expression predicted poor visual outcome, positive patients were usually associated with mild symptoms at first onset. Anti-SSA/SSB antibody or Sjögren syndrome may be associated with AQP-4 Ab in neuromyelitis optica spectrum ON.

  13. Prevalence and risk factors for Brucella seropositivity among sheep and goats in a peri-urban region of Tajikistan.

    PubMed

    Rajala, Elisabeth Lindahl; Grahn, Cecilia; Ljung, Isabel; Sattorov, Nosirjon; Boqvist, Sofia; Magnusson, Ulf

    2016-03-01

    This cross-sectional study aimed to estimate the seroprevalence of Brucella infection among sheep and goats on small-scale farms in a peri-urban area of Tajikistan and identify factors associated with seropositivity. The study population was 667 female sheep and goats >6 months of age from 21 villages in four districts surrounding the capital city, Dushanbe. Individual blood samples were collected during October and November 2012 and analysed with indirect enzyme linked immunosorbent assay (ELISA). Positive samples were confirmed with competitive ELISA. To identify factors associated with seropositivity at an individual level, a generalised linear mixed model was applied to account for clustering of individuals within villages and districts. The true individual seroprevalence was 6.7 % and ranged from 1.0 to 15.6 % between the four districts. Fourteen villages had at least one seropositive sheep or goat, resulting in apparent prevalence of 67 % at village level. The seroprevalence at individual level was significantly lower in Rudaki district (odds ratio (OR) = 0.1; 95 % confidence interval (CI) 0.03-0.4) and Varzob district (OR = 0.3; 95 % CI 0.09-0.8) than in Vahdat district. Sheep were more likely than goats to be seropositive (OR = 2.7; 95 % CI 1.3-5.5). Increasing age was significantly associated with seropositivity (OR = 1.4; 95 % CI 1.2-1.6). These results indicate high prevalence of Brucella infection among sheep and goats in the peri-urban area of the capital city in Tajikistan. Given the dense human population in such areas, this could constitute a threat to public health, besides causing significant production losses.

  14. Anti-hepatitis C virus seropositivity is not associated with metabolic syndrome irrespective of age, gender and fibrosis.

    PubMed

    Cheng, Yuan-Lung; Wang, Yuan-Chen; Lan, Keng-Hsin; Huo, Teh-Ia; Huang, Yi-Hsiang; Su, Chien-Wei; Lin, Han-Chieh; Lee, Fa-Yauh; Wu, Jaw-Ching; Lee, Shou-Dong

    2015-01-01

    Although many studies have tried to clarify the association between hepatitis C virus (HCV) infection and metabolic syndrome, few studies have comprehensively assessed their relationship stratified by different demographic characteristics. We aimed to investigate the correlation between metabolic syndrome and anti-HCV seropositivity in Taiwan. This study enrolled consecutive subjects who had received health check-up services at Taipei Veterans General Hospital from 2002 to 2009. Metabolic syndrome was diagnosed according to the criteria defined by the International Diabetes Federation Task Force on Epidemiology and Prevention. Among the 30616 subjects enrolled in this study, the prevalence of positive anti-HCV serology was 2.7%, and 28.8% were diagnosed with metabolic syndrome. By multivariate analysis, metabolic syndrome was associated with higher body mass index, older age, male sex, a higher level of alanine aminotransferase, gamma-glutamyltransferase, platelet count and the presence of fatty liver whereas anti-HCV seropositivity was not an independent variable for metabolic syndrome. Further stratifying the subjects by age and sex, and there was still no significant difference in HCV status between those with and without metabolic syndrome. Moreover, the stage of liver fibrosis represented by aspartate aminotransferase to platelet ratio index was also not correlated with metabolic syndrome in the subjects with anti-HCV seropositivity. In conclusion, although subjects with anti-HCV seropositivity had higher fasting glucose levels and lower cholesterol and triglyceride levels compared to those with negative anti-HCV test, anti-HCV seropositivity was not associated with metabolic syndrome based on the current diagnostic criteria irrespective of age, gender and the stage of hepatic fibrosis.

  15. Factors influencing variation of bulk milk antibiotic residue occurrence, somatic cell count, and total bacterial count in dairy sheep flocks.

    PubMed

    Gonzalo, C; Carriedo, J A; García-Jimeno, M C; Pérez-Bilbao, M; de la Fuente, L F

    2010-04-01

    To study the variations of bulk tank milk variables in dairy ewe flocks and to identify the main target practices and flock groups to improve milk quality and safety, a total of 71,228 records of antibiotic residue (AR) and milk yield and 68,781 records of somatic cell count (SCC) and total bacterial count (TBC) were obtained over 5 yr from the same 209 dairy ewe flocks of the Assaf breed belonging to the Consortium for Ovine Promotion of Castilla-León (Spain). Based on a logistic regression model, year, month, semester, SCC, TBC, dry therapy, and milk yield significantly contributed to AR variation. High SCC was associated with increased AR violations. When antibiotic dry therapy was implemented, AR occurrence was higher than when this practice was not used. A polynomial monthly distribution throughout the year was observed for AR occurrence; the highest values were in autumn, coinciding with low milk yields per flock. Yearly occurrences drastically diminished from 2004 (1.36%) to 2008 (0.30%), probably as a result of effective educational programs. The mixed-model ANOVA of factors influencing variation in SCC and TBC indicated that year, month, AR, dry therapy group, milking type, and year interactions were significant variation factors for SCC and TBC; mathematical model accounted for 74.1 and 35.4% of total variance for each variable, respectively. Differences in management and hygiene practice caused significant SCC and TBC variations among flocks and within flocks throughout the 5-yr study. Over time, continuously dry treated flocks showed lower logSCC (5.80) and logTBC (4.92) than untreated (6.10 and 5.18, respectively) or discontinuously dry treated (6.01 and 5.05, respectively) flocks. Continuously dry treated flocks had lower AR occurrences than did discontinuously dry treated flocks. As a whole, AR occurrence and SCC and TBC bulk tank milk variables can be used for monitoring mammary health and milk hygiene and safety in dairy sheep throughout time.

  16. The species flocks of East African cichlid fishes: recent advances in molecular phylogenetics and population genetics

    NASA Astrophysics Data System (ADS)

    Salzburger, Walter; Meyer, Axel

    With more than 3,000 species, the fish family Cichlidae is one of the most species-rich families of vertebrates. Cichlids occur in southern and central America, Africa, Madagascar, and India. The hotspot of their biodiversity is East Africa, where they form adaptive radiations composed of hundreds of endemic species in several lakes of various sizes and ages. The unparalleled species richness of East African cichlids has been something of a conundrum for evolutionary biologists and ecologists, since it has been in doubt whether these hundreds of species arose by allopatric speciation or whether it is necessary to invoke somewhat less traditional models of speciation, such as micro-allopatric, peripatric, or even sympatric speciation or evolution through sexual selection mediated by female choice. Ernst Mayr's analyses of these evolutionary uniquely diverse species assemblages have contributed to a more direct approach to this problem and have led to a deeper understanding of the patterns and processes that caused the formation of these huge groups of species. We review here recent molecular data on population differentiation and phylogenetics, which have helped to unravel, to some extent, the patterns and processes that led to the formation and ecological maintenance of cichlid species flocks. It is becoming apparent that sexually selected traits do play an important role in speciation in micro-allopatric or even sympatric settings. Species richness seems to be roughly correlated with the surface area, but not the age, of the lakes. We observe that the oldest lineages of a species flock of cichlids are often less species-rich and live in the open water or deepwater habitats. While the species flocks of the Lake Malawai and the Lake Victoria areas were shown to be monophyletic, the cichlid assemblage of Lake Tanganyika seems to consist of several independent species flocks. Cichlids emerge as an evolutionary model system in which many fundamental questions in

  17. Flocking and feeding in the fiddler crab ( UCA tangeri): Prey availability as risk-taking behaviour

    NASA Astrophysics Data System (ADS)

    Ens, B. J.; Klaassen, M.; Zwarts, L.

    For a full understanding of prey availability, it is necessary to study risk-taking behaviour of the prey. Fiddler crabs are ideally suited for such a study, as they have to leave their safe burrow to feed on the surface of the intertidal flats during low tide, thereby exposing themselves to avian predators. A study in an intertidal area along the coast of Mauritania showed that small crabs always stayed in the vicinity of their burrow, but large crabs wandered in large flocks (also referred to as droves) to feed on sea-grass beds downshore. Transplanting downshore feeding substrate to the burrowing zone of the small crabs proved that they too preferred to feed on it. Since small crabs can be preyed upon by more species of birds, this suggests that the decision not to leave the burrowing zone might be related to the risk of being fed upon by birds. We calculated predation risk from measurements on the density and feeding activity of the crabs, as well as the feeding density, the intake rate and the size selection of the avian predators. Per hour on the surface, crabs in a flock were more at risk than crabs feeding near their burrow. Thus, though flocking crabs may have benefited from 'swamping the predator' by emerging in maximum numbers during some tides only, this did not reduce their risk of predation below that of non-flocking crabs. Furthermore we found that irrespective of activity, large crabs suffered a higher mortality per tide from avian predators than small crabs. This suggests that large crabs could not sufficiently reduce their foraging time to compensate for the increased risk while foraging in a flock, even though they probably experienced better feeding conditions than small crabs staying near their burrow. The greater energy demands of large crabs were reflected in a greater surface area grazed. Thus, with increasing size a fiddler crab has to feed further away from its burrow and so may derive less protection from staying near to it. It seems that

  18. QML-AiNet: An immune network approach to learning qualitative differential equation models.

    PubMed

    Pang, Wei; Coghill, George M

    2015-02-01

    In this paper, we explore the application of Opt-AiNet, an immune network approach for search and optimisation problems, to learning qualitative models in the form of qualitative differential equations. The Opt-AiNet algorithm is adapted to qualitative model learning problems, resulting in the proposed system QML-AiNet. The potential of QML-AiNet to address the scalability and multimodal search space issues of qualitative model learning has been investigated. More importantly, to further improve the efficiency of QML-AiNet, we also modify the mutation operator according to the features of discrete qualitative model space. Experimental results show that the performance of QML-AiNet is comparable to QML-CLONALG, a QML system using the clonal selection algorithm (CLONALG). More importantly, QML-AiNet with the modified mutation operator can significantly improve the scalability of QML and is much more efficient than QML-CLONALG.

  19. QML-AiNet: An immune network approach to learning qualitative differential equation models

    PubMed Central

    Pang, Wei; Coghill, George M.

    2015-01-01

    In this paper, we explore the application of Opt-AiNet, an immune network approach for search and optimisation problems, to learning qualitative models in the form of qualitative differential equations. The Opt-AiNet algorithm is adapted to qualitative model learning problems, resulting in the proposed system QML-AiNet. The potential of QML-AiNet to address the scalability and multimodal search space issues of qualitative model learning has been investigated. More importantly, to further improve the efficiency of QML-AiNet, we also modify the mutation operator according to the features of discrete qualitative model space. Experimental results show that the performance of QML-AiNet is comparable to QML-CLONALG, a QML system using the clonal selection algorithm (CLONALG). More importantly, QML-AiNet with the modified mutation operator can significantly improve the scalability of QML and is much more efficient than QML-CLONALG. PMID:25648212

  20. Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada.

    PubMed

    Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

    2016-01-01

    An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry.

  1. Drug use and antimicrobial resistance among Escherichia coli and Enterococcus spp. isolates from chicken and turkey flocks slaughtered in Quebec, Canada

    PubMed Central

    Boulianne, Martine; Arsenault, Julie; Daignault, Danielle; Archambault, Marie; Letellier, Ann; Dutil, Lucie

    2016-01-01

    An observational study was conducted of chicken and turkey flocks slaughtered at federal processing plants in the province of Quebec, Canada. The objectives were to estimate prevalence of drug use at hatchery and on farm and to identify antimicrobial resistance (AMR) in cecal Escherichia coli and Enterococcus spp. isolates and factors associated with AMR. Eighty-two chicken flocks and 59 turkey flocks were sampled. At the hatchery, the most used antimicrobial was ceftiofur in chickens (76% of flocks) and spectinomycin in turkeys (42% of flocks). Virginiamycin was the antimicrobial most frequently added to the feed in both chicken and turkey flocks. At least 1 E. coli isolate resistant to third-generation cephalosporins was present in all chicken flocks and in a third of turkey flocks. Resistance to tetracycline, streptomycin, and sulfisoxazole was detected in > 90% of flocks for E. coli isolates. Antimicrobial resistance (AMR) was observed to bacitracin, erythromycin, lincomycin, quinupristin-dalfopristin, and tetracycline in both chicken and turkey flocks for Enterococcus spp. isolates. No resistance to vancomycin was observed. The use of ceftiofur at hatchery was significantly associated with the proportion of ceftiofur-resistant E. coli isolates in chicken flocks. In turkey flocks, ceftiofur resistance was more frequent when turkeys were placed on litter previously used by chickens. Associations between drug use and resistance were observed with tetracycline (turkey) in E. coli isolates and with bacitracin (chicken and turkey), gentamicin (turkey), and tylosin (chicken) in Enterococcus spp. isolates. Further studies are needed to provide producers and veterinarians with alternative management practices and tools in order to reduce the use of antimicrobial feed additives in poultry. PMID:26733732

  2. Workability and Muscle Strength in Patients With Seropositive Rheumatoid Arthritis: Survey Study Protocol

    PubMed Central

    Erlacher, Ludwig; Quittan, Michael; Fenzl, Karl Heinrich; Dorner, Thomas Ernst

    2017-01-01

    Background Rheumatoid arthritis (RA) and other rheumatic conditions not only fundamentally affect patients’ quality of life and physiological needs but are also negatively associated with work ability. The costs of poor work ability, which, in sum, are more than treatment costs, pose an economic burden to society and patients. Work ability in RA appears to be multifactorial; symptoms such as pain, swelling, and stiffness play a major role, as these directly affect functional disability. Also, RA patients typically suffer from reduced muscle strength. Lower extremity function and grip strengths especially impair their quality of life. However, the role of muscle strength and disease activity as determinants of work ability have not yet been studied. Objective The primary objective of this study is to compare work ability in working-age participants with seropositive RA and with high and low disease activity; the secondary objective is to evaluate the association of muscle strength, functional ability, and frailty with work ability. Methods This monocentric cross-sectional study will be conducted at a rheumatologic outpatient clinic and day hospital with approximately 100 seropositive RA patients aged <65 years. A clinical disease activity index as a measure for rheumatoid disease activity will be assessed during the patients’ routine visits at the clinic. Work ability, frailty, and functional disability will be evaluated with (self-reported) questionnaires as well as with physical tests (Work Ability Index/Score; Health Assessment Questionnaire Disability Index; Survey of Health, Ageing, and Retirement in Europe Frailty Instrument; Short Physical Performance Battery). Muscle strength will be determined with dynamometer measurements of isometric hand grip strength and quadriceps femoris muscle contraction strength. Sleep quality (Medical Outcomes Study Sleep Scale) and sexual functioning as physiological needs will additionally be determined with self

  3. Human Papillomavirus at Multiple Sites Associated with Anal Squamous Intraepithelial Lesions in HIV-Seropositive Individuals

    PubMed Central

    Chuang, Eleanore; Lim, Eunjung; Milne, Cris; Zhu, Xuemei; Agsalda, Melissa; Killeen, Jeffrey; Miller, F DeWolfe; Hernandez, Brenda Y.; Shiramizu, Bruce

    2016-01-01

    Objective HIV-Seropositive patients have higher risk of HPV infection even on anti-retroviral therapy. Infection with high-risk HPV genotypes can cause dysplasia leading to cancer. This study assessed HPV at different anatomical sites in HIV-seropositive individuals and factors associated with anal squamous intraepithelial lesions (ASIL). Methods Specimens were obtained from multiple anatomical sites for each participant in conjunction with routine screening for anal dysplasia. Female specimens included cervical and anal cytologies and oral wash. Male specimens included anal cytologies, oral wash, and exfoliated cells from penile head, penile shaft, scrotum, and from uncircumcised subjects, inner foreskin. Demographic and clinical characteristics were recorded. Following DNA extraction, HIV DNA copy was assessed by qPCR; HPV was genotyped. Statistical analyses included calculation of odds ratios (OR) and 95% confidence intervals (CI), t-tests or Mann-Whitney tests. Results Males were more likely to have ASIL: 29/50 (58%) compared to 1/11 females (9%) (OR=13.81, 95% CI: 1.64–116.32). HPV 6 or 11 in anal specimens was significantly associated with ASIL (OR= 6.29, 95% CI: 1.49–26.44). Number of HPV genotypes in anal specimens was also significant: ASIL+ (3.4 ± 3.1) versus ASIL− (1.6 ± 3.1) (p=0.009). Among 44 males, HPV was detected from at least one anatomical site for 33 participants (75%): 27 anus (61%), 19 oral wash (44%), 17 penile shaft (39%), 11 scrotum (26%), 10 penile head (23%), 0 foreskin. Detection of HPV in penile shaft specimens was significantly associated with ASIL (OR=6.79, 95% CI: 1.57–29.36) as was number of HPV genotypes in penile shaft specimens: ASIL+ (2.4 ± 4.0) versus ASIL− (0.6 ± 1.7) (p=0.025). Only 1/11 females had ASIL; only 1/11 females had cervical dysplasia: OR was not estimable due to small numbers. Conclusions Males were more prone to ASIL than females. HPV at anal as well as non-anal sites may be indicative of ASIL. PMID

  4. [Preliminary results of the heparin treatment in anticardiolipin and antihistone antibodies seropositive pregnant women].

    PubMed

    Horák, S; Grettka, K; Ogrodnik, M

    2000-06-01

    The presence of elevated titres of anticardiolipin antibodies (ACA) and antihistone antibodies (AHA) in the blood serum is considered as one of serious reasons of repeated pregnancy losses. According to some reports, heparin significantly improves live birth rates in these cases. The aim of the work is an evaluation of the results of the heparin therapy in pregnant women with elevated titres of ACA and/or AHA in blood and bad obstetric anamnesis, or after sterility treatment. Our material consisted of three groups: the first one was composed of 25 ACA- and/or AHA-seropositive pregnant women 30.0 +/- 4.1 years old with 1-5 early miscarriages in past, the second one of six seropositive patients 31.3 +/- 2.8 years old, actually pregnant after the treatment of unexplained sterility (two of them after assisted reproduction) and, finally, in the third group were placed five pregnant ACA- and AHA-seronegative pregnant women 30.8 +/- 2.2 years old with 2-4 abortions of unexplained etiology in past. The ACA IgA, IgM and IgG and AHA IgG levels in blood sera were determined by ELISA. As a positive titre ACA in the class IgA was considered > 7 APL/ml, in the class IgM > 4 MPL/ml, IgG > 7 GPL/ml and in case of AHA IgG > 25 GPL/ml. The patients were treated by heparin 7500-30,000 units daily during all the pregnancy under the control of kaolin-kephalin time. In the first group, where 53 pregnancies from 56 were miscarried (94.6%), after the heparin therapy in 10 women 9 pregnancies of 11 (81.8%) were terminated by live birth (p < 0.001). One of the patients died three days after cesarean section because of myocardial infarction, probably due to sudden stopping of heparin. In the second group three women after heparin treatment delivered live babies, but three untreated aborted. In the last group only two women treated by heparin delivered live babies and three, despite treatment, miscarried. It should be concluded, that heparin therapy in ACA- and/or AHA-positive pregnant women

  5. Increased Toxoplasma gondii positivity relative to age in 125 Scottish sheep flocks; evidence of frequent acquired infection

    PubMed Central

    2011-01-01

    Toxoplasma gondii seroprevalence was determined in 3333 sheep sera from 125 distinct sheep flocks in Scotland, with the majority of flocks being represented by 27 samples, which were collected between July 2006 and August 2008. The selected farms give a representative sample of 14 400 sheep holdings identified in the Scottish Government census data from 2004. Overall T. gondii seroprevalence, at individual sheep level, was determined to be 56.6%; each flock tested, had at least a single positive animal and in four flocks all ewes tested positive. The seroprevalence of sheep increased from 37.7% in one year old stock to 73.8% in ewes that were older than six years, showing that acquired infections during the life of the animals is frequent and that environmental contamination by T. gondii oocysts must be significant. The median within-flock seroprevalence varied significantly across Scotland, with the lowest seroprevalence of 42.3% in the South and the highest seroprevalence of 69.2% in the far North of Scotland and the Scottish Islands, while the central part of Scotland had a seroprevalence of 57.7%. This distribution disequilibrium may be due to the spread and survival of oocysts on pasture and lambing areas. A questionnaire accompanying sampling of flocks identified farms that used Toxovax®, a commercial vaccine that protects sheep from abortion due to T. gondii infection. Only 24.7% of farmers used the vaccine and the vaccine did not significantly affect the within flock seroprevalence for T. gondii. The implications for food safety and human infection are discussed. PMID:22189159

  6. Pavlovian, Skinner, and Other Behaviourists' Contributions to AI. Chapter 9

    NASA Technical Reports Server (NTRS)

    Kosinski, Withold; Zaczek-Chrzanowska, Dominika

    2007-01-01

    A version of the definition of intelligent behaviour will be supplied in the context of real and artificial systems. Short presentation of principles of learning, starting with Pavlovian s classical conditioning through reinforced response and operant conditioning of Thorndike and Skinner and finishing with cognitive learning of Tolman and Bandura will be given. The most important figures within behaviourism, especially those with contribution to AI, will be described. Some tools of artificial intelligence that act according to those principles will be presented. An attempt will be made to show when some simple rules for behaviour modifications can lead to a complex intelligent behaviour.

  7. An AIS-Based E-mail Classification Method

    NASA Astrophysics Data System (ADS)

    Qing, Jinjian; Mao, Ruilong; Bie, Rongfang; Gao, Xiao-Zhi

    This paper proposes a new e-mail classification method based on the Artificial Immune System (AIS), which is endowed with good diversity and self-adaptive ability by using the immune learning, immune memory, and immune recognition. In our method, the features of spam and non-spam extracted from the training sets are combined together, and the number of false positives (non-spam messages that are incorrectly classified as spam) can be reduced. The experimental results demonstrate that this method is effective in reducing the false rate.

  8. AiResearch QCGAT engine, airplane, and nacelle design features

    NASA Technical Reports Server (NTRS)

    Heldenbrand, R. W.

    1980-01-01

    The quiet, clean, general aviation turbofan engine and nacelle system was designed and tested. The engine utilized the core of the AiResearch model TFE731-3 engine and incorporated several unique noise- and emissions-reduction features. Components that were successfully adapted to this core include the fan, gearbox, combustor, low-pressure turbine, and associated structure. A highly versatile workhorse nacelle incorporating interchangeable acoustic and hardwall duct liners, showed that large-engine attenuation technology could be applied to small propulsion engines. The application of the mixer compound nozzle demonstrated both performance and noise advantages on the engine. Major performance, emissions, and noise goals were demonstrated.

  9. Urban, Forest, and Agricultural AIS Data: Fine Spectral Structure

    NASA Technical Reports Server (NTRS)

    Vanderbilt, V. C.

    1985-01-01

    Spectra acquired by the Airborne Imaging Spectrometer (AIS) near Lafayette, IN, Ely, MN, and over the Stanford University campus, CA were analyzed for fine spectral structure using two techniques: the ratio of radiance of a ground target to the radiance of a standard and also the correlation coefficient of radiances at adjacent wavelengths. The results show ramp like features in the ratios. These features are due to the biochemical composition of the leaf and to the optical scattering properties of its cuticle. The size and shape of the ramps vary with ground cover.

  10. Helicobacter pylori Seropositivity in Patients with Interleukin-1 Polymorphisms Is Significantly Associated with ST-Segment Elevation Myocardial Infarction

    PubMed Central

    Tabata, Noriaki; Sueta, Daisuke; Akasaka, Tomonori; Arima, Yuichiro; Sakamoto, Kenji; Yamamoto, Eiichiro; Izumiya, Yasuhiro; Yamamuro, Megumi; Tsujita, Kenichi; Kojima, Sunao; Kaikita, Koichi; Morita, Kazunori; Oniki, Kentaro; Saruwatari, Junji; Nakagawa, Kazuko; Hokimoto, Seiji

    2016-01-01

    Background Helicobacter pylori infection and interleukin-1 polymorphisms are associated with an increased risk of gastric cancer. We examined the prevalence of Helicobacter pylori seropositivity and interleukin-1 polymorphisms between ST-segment elevation myocardial infarction and non-ST-segment elevation acute coronary syndrome patients. Methods We recruited consecutive acute coronary syndrome patients, and 101 non-ST-segment elevation acute coronary syndrome patients and 103 ST-segment elevation myocardial infarction patients were enrolled. Interleukin-1 polymorphism analyses were performed for single nucleotide polymorphism in interleukin-1 beta-511 and the variable number of tandem repeats polymorphism in the interleukin-1 receptor antagonist by polymerase chain reaction. Immunoglobulin G antibodies against Helicobacter pylori and high sensitivity C-reactive protein were also measured. Results The rates of the simultaneous presence of interleukin-1 polymorphisms and Helicobacter pylori-seropositivity between non-ST-segment elevation acute coronary syndrome and ST-segment elevation myocardial infarction groups were 25.7% and 42.7%, respectively (P = 0.012). Helicobacter pylori-seropositive subjects with interleukin-1 polymorphisms showed significantly higher levels of high sensitivity C-reactive protein (0.04–0.12 vs. 0.02–0.05; P<0.001). Multivariate logistic regression analysis revealed that the carriage of Helicobacter pylori-seropositivity and interleukin-1 polymorphisms was significantly associated with ST-segment elevation myocardial infarction (odds ratio, 2.32; 95% confidence interval, 1.23–4.37; P = 0.009). The C-statistic of conventional risk factors was 0.68 (P<0.001) and that including Helicobacter pylori-seropositivity and interleukin-1 polymorphisms was 0.70 (P<0.001); continuous net reclassification improvement was 34% (P = 0.0094) and integrated discrimination improvement was 3.0% (P = 0.014). Conclusions The coincidence of Helicobacter

  11. Serological and virological BVDV prevalence and risk factor analysis for herds to be BVDV seropositive in Belgian cattle herds.

    PubMed

    Sarrazin, Steven; Veldhuis, Anouk; Méroc, Estelle; Vangeel, Ilse; Laureyns, Jozef; Dewulf, Jeroen; Caij, Ann Brigitte; Piepers, Sofie; Hooyberghs, Jozef; Ribbens, Stefaan; Van Der Stede, Yves

    2013-01-01

    Bovine viral diarrhoea virus (BVDV) is a worldwide spread virus that most commonly infects cattle and can cause considerable economic losses. To determine the prevalence of BVDV in Belgium, a cross-sectional study was performed between November 2009 and March 2010. Young stock aged between 6 and 12 months from 773 randomly selected Belgian cattle herds were tested for BVDV-specific antibodies and antigen. With a target and maximum of 10 animals per sampled herd, a total of 5246 animals were selected. Additionally a questionnaire including different herd management topics and questions about participation in animal health programmes, including BVDV, was sent to 1100 Belgian cattle herds, including the 773 herds for BVDV testing. This paper focuses on results regarding these 773 herds. The true prevalence of BVDV-specific antibodies and antigen at herd level was respectively 47.4% and 4.4%, while at animal level this was respectively 32.9% and 0.3%. In 44.4% of the herds where BVDV-specific antibodies were detected at least 60% of the sampled young stock was BVDV seropositive. Interestingly, 83.4% of these farmers stated not to have suffered from problems related to BVDV. Moreover, only 8.4% of all farmers who completed the questionnaire (n=895) reported problems possibly related to BVDV the past 3 years. This demonstrates that farmers are often unaware of the presence of BVDV in their herd. Risk factors for a herd to be BVDV seropositive were identified by means of a multivariable logistic regression model. Large herds were significantly more likely to be BVDV seropositive (OR=1.004, p<0.01). The interaction between "Antigen positive animal detected in this study" and "BVDV vaccination in 2009" was significant (p<0.01). In non-vaccinating herds, the detection of antigen positive animals was significantly associated with BVDV seropositive herds (OR=13.8, p<0.01). In herds with no antigen positive animals detected, vaccination resulted in a significant risk factor to

  12. Toxocara and Ascaris seropositivity among patients suspected of visceral and ocular larva migrans in the Netherlands: trends from 1998 to 2009.

    PubMed

    Pinelli, E; Herremans, T; Harms, M G; Hoek, D; Kortbeek, L M

    2011-07-01

    Toxocara canis, Toxocara cati and Ascaris suum are roundworms of dogs, cats and pigs, respectively, that can also infect humans. These zoonotic helminths have a worldwide distribution and are also endemic in the Netherlands. Infection with Toxocara sp. may result in visceral larva migrans (VLM) or ocular larva migrans (OLM) caused by the migrating larvae. Although A. suum has been reported to occasionally mature to the adult stage in humans, clinical cases of VLM suspected to be caused by A. suum have been described. Diagnosis of these helminth infections relies mainly on serology. Here we analyse the results from the Toxocara and Ascaris IgG-ELISA from a total of 2,838 serum samples from VLM and OLM suspected patients that were sent to our institution from 1998 to 2009. Results indicate that for each year the Ascaris seropositivity is significantly higher compared to the Toxocara seropositivity. Furthermore, while Toxocara seropositivity has decreased over time, the Ascaris seropositivity has not significantly changed for the past 12 years. The Ascaris and Toxocara seropositivity was also shown to increases with age and, while gender has no influence on the Ascaris seropositivity, males showed higher Toxocara seropositivity.

  13. A study of chest infections in HIV seropositive patients in Kuala Lumpur.

    PubMed

    Wood, E; Cheong, I; Lee, C

    1998-01-01

    A retrospective study of 144 adults with HIV infection was conducted to investigate the prevalence of upper and lower respiratory tract infections (URTIs and LRTIs). The patients were divided into two groups: those with acquired HIV through intravenous drug abuse (IVDA), and those who had acquired HIV through 'other' risk behaviours. LRTIs were more prevalent than URTIs overall, and LRTIs were significantly more common (p < 0.001) in IVDAs than in the other-risk group. Tuberculosis (40%) and bacterial pneumonias (33%) comprised the majority of LRTIs among IVDAs, while Pneumocystis carinii pneumonia (40%) was the commonest LRTI in the other-risk group. Analysis of CD4 T-lymphocyte counts indicated that HIV-seropositive IVDAs are at greater risk of developing chest infections at higher CD4 counts than other-risk patients. The IVDAs were also found to have a much higher rate of co-infection with hepatitis C and B, which may be a factor accelerating the progression from HIV infection to AIDS. The mean time averaged for the two groups from known seroconversion to development of respiratory tract infection is only 1.37 years, which suggests HIV-infected patients are presenting late for treatment in Malaysia.

  14. Ovine catarrhal fever (Bluetongue): analysis of Culicoides species in seropositive farms.

    PubMed

    Guercio, A; Di Marco, P; Manno, C; Di Bella, C; Purpari, G; Torina, A

    2010-04-01

    Bluetongue (BT) is an orbiviral disease of wild and domestic ruminants, mainly sheep. In Sicily, the first Bluetongue outbreak occurred in October 2000; there have been 76 recorded outbreaks so far. The National Surveillance Plan, based on European Union Commission Decision 138/2001/CE, establishes serological and entomological surveys. This plan consists of controls of seronegative cattle, called 'sentry' as indicators for the presence and circulation of virus in defined areas. To check the seroconversions, the regional territory has been subdivided in 400 km(2) areas including 58 seronegative cattle, periodically checked by serological tests. All positive sera have been tested to detect the specific serotype by the National Reference Centre for Exotic Diseases (CESME) at the Istituto Zooprofilattico Sperimentale Abruzzo e Molise in Teramo (IZS Teramo). Moreover, entomological surveillance has been implemented in seropositive herds, to investigate the presence of insect vectors belonging to Culicoides genus. The goal of the present communication is to report on the different species of Culicoides found in the farms with Bluetongue virus and to investigate on the probable role of new competent vectors. This paper concerns data analysis of 581 light-trap catches collected in 321 farms from 2003 to 2008. We observed that 82% of checked farms were positive for Culicoides spp., and only 10% of the farms were positive for Culicoides imicola.

  15. Mental health of HIV-seropositive women during pregnancy and postpartum period: a comprehensive literature review.

    PubMed

    Kapetanovic, Suad; Dass-Brailsford, Priscilla; Nora, Diana; Talisman, Nicholas

    2014-06-01

    With growing numbers of HIV-seropositive (HIV+) women of child-bearing age and increased access to effective clinical protocols for preventing mother-to-child transmission (MTCT) of HIV, mental health-related factors have become increasingly relevant due to their potential to affect the women's quality of life, obstetric outcomes and risk of MTCT. This review synthesizes evidence from 53 peer-reviewed publications examining mental health-related variables in pregnant and postpartum HIV+ women. The presentation of results is organized by the level of socioeconomic resources in the countries where studies were conducted (i.e., high-, middle-, and low-income countries). It is concluded that psychiatric symptoms, particularly depression, and mental health vulnerabilities (e.g., inadequate coping skills) are widespread among pregnant HIV+ women globally and have a potential to affect psychological well-being, quality of life and salient clinical outcomes. The current body of evidence provides rationale for developing and evaluating clinical and structural interventions aimed at improving mental health outcomes and their clinical correlates in pregnant HIV+ women.

  16. Seropositivity to Helicobacter pylori: lack of association with length of hospitalization.

    PubMed

    Thoene, J G; Burken, M I; Hopkins, R J; Russell, R G; Morris, J G

    1991-07-01

    To examine the possibility of nosocomial spread of Helicobacter pylori, a serosurvey (n = 238) was conducted at Perry Point Department of Veterans Affairs Medical Center, an institution providing both acute and chronic care. We hypothesized that if significant nosocomial transmission was occurring, seropositivity (as measured by enzyme-linked immunosorbent assay [ELISA]) would correlate with length of stay in the facility. Whether treated as a continuous or dichotomous variable, the ELISA results did not correlate significantly with length of stay even after adjustments were made for age, race, antibiotic use, gastrointestinal instrumentation, and diagnoses by using multiple-regression models. Age was found to be a significant risk factor for a higher ELISA optical density value. A history of chronic obstructive pulmonary disease was significantly protective among internal medicine ward patients in adjusted analysis; black race was a significant risk factor among psychiatry ward patients. Our results confirm the association of H. pylori infection with age but provide no indication that extended hospitalization is a risk factor for infection.

  17. Psychiatric and Substance Abuse Comorbidity among HIV Seropositive and HIV Seronegative Prisoners in Malaysia

    PubMed Central

    Zahari, Muhammad Muhsin; Bae, Woong Hwan; Zainal, Nor Zuraida; Habil, Hussain; Kamarulzaman, Adeeba; Altice, Frederick L.

    2016-01-01

    Objective To examine the association between HIV infection and psychiatric disorders among prisoners, where mental illness, substance abuse, and HIV are disproportionately represented. Design Cross-sectional study. Methods Using a sequential randomization scheme, 200 HIV-seropositive and 200 HIV-seronegative prisoners were selected for evaluation of psychiatric illnesses with the Structured Clinical Interview for Diagnostic Statistical Manual of Mental Disorders-IV (SCID-I). Results The prevalence of mental illness and substance use disorders, particularly opioid dependence, was extremely high. HIV infection was significantly correlated with age, ethnicity, marital status, history of injection drug use, lifetime duration of incarceration, substance abuse, and polysubstance drug use. After controlling for potential confounders, HIV infection was significantly associated with non-substance-induced psychiatric disorders (AOR 1.92; 95% CI: 1.03–3.59). While prisoners with a triple diagnosis (psychiatric disorders, substance use disorders, and HIV) spent 46.7 more cumulative lifetime months in prison than those with only a psychiatric diagnosis (p < .01), those with a dual diagnosis (psychiatric plus substance use disorders) were comparable to those with one psychiatric diagnosis only. Neither HIV infection nor triple diagnosis was associated with violent offenses. Conclusion These findings suggest that a public health approach that simultaneously addresses psychiatric illnesses, substance abuse, and HIV infection is needed in both the correctional and the community settings in order to provide adequate care for triply-diagnosed patients and prevent them from returning to prison. PMID:20141394

  18. Longitudinal psychomotor speed performance in human immunodeficiency virus-seropositive individuals: impact of age and serostatus.

    PubMed

    Sacktor, Ned; Skolasky, Richard L; Cox, Christopher; Selnes, Ola; Becker, James T; Cohen, Bruce; Martin, Eileen; Miller, Eric N

    2010-10-01

    Older human immunodeficiency virus-seropositive (HIV+) individuals (greater than age 50 years) are twice as likely to develop HIV dementia compared to younger HIV+ individuals. The objective of this study was to examine the impact of both age and serostatus on longitudinal changes in psychomotor speed/executive functioning performance among HIV+ and HIV− individuals. Four hundred and seventy-seven HIV+ and 799 HIV− individuals from the Multicenter AIDS Cohort Study (MACS) were subdivided into three age groups: (1) <40 years, (2) 40-50 years, and (3) >50 years. Psychomotor speed/executive functioning test performance was measured by the Symbol Digit Modalities Test (SDMT) and the Trail Making (TM) Test Parts A and B. Changes in performance were compared among the three age groups for both HIV+ and HIV− individuals. Among HIV+ individuals, on the TM Test Part B the younger group demonstrated improvement in performance over time (P = .007). The older and middle age groups demonstrated decline in performance over time (P = .041 and .030). The older group had a significantly different trajectory relative to the younger group (P = .046). Among the HIV− individuals, there was no effect of age on longitudinal performance. In conclusion, older HIV+ individuals show greater decline over time than younger HIV+ individuals on the TM Test Part B. Our results suggest that both HIV serostatus and age together may impact longitudinal performance on this test. Mild neurocognitive changes over time among older HIV+ individuals are likely to reflect age associated pathophysiological mechanisms including cerebrovascular risk factors.

  19. Electrophysiological study (VEP, BAEP) in HIV-1 seropositive patients with and without AIDS.

    PubMed

    Pierelli, F; Soldati, G; Zambardi, P; Garrubba, C; Spadaro, M; Tilia, G; Pauri, F; Morocutti, C

    1993-01-01

    One hundred-twenty nine HIV-1 seropositive patients (39 females, 90 males) were studied by means of pattern visual evoked potential (VEP) and brainstem auditory evoked potential (BAEP) recording. Utilizing the criteria of the Centers for Disease Control the patients were clinically defined and then subdivided into four groups: group A included patients of category II (n:11); group B patients of category III (n:29); group C patients of category IVa and IVc2 (n:55) and group D patients belonging to the other subgroups of category IV (n:34). EP were altered in 26.35% of the entire group with a marked prevalence of BAEP alterations (21.7%) rather than of VEP (4.65%). A considerable amount of BAEP abnormalities (24.13%) were found in patients with persistent generalized lymphadenopathy (group B). A significant increase of BAEP mean interpeak latencies were observed in group B, C, D patients when compared with those of the control group. On the whole, EP were altered in 20.65% of the neurologically asymptomatic patients. EP alterations may precede any clinical manifestation and can be found during the earlier phases of HIV-1 infection.

  20. The relationship between adenovirus-36 seropositivity, obesity and metabolic profile in Turkish children and adults.

    PubMed

    Karamese, M; Altoparlak, U; Turgut, A; Aydogdu, S; Karamese, S Aksak

    2015-12-01

    Obesity potentially arising from viral infection is known as 'infectobesity'. The latest reports suggest that adenovirus-36 (Adv36) is related to obesity in adults and children. Our aim was not only to determine the Adv36 seropositivity in both obese and non-obese children and adults, but also to investigate correlations between antibody positivity and serum lipid profiles. Both Adv36 positivity and tumour-necrosis-factor-alpha, leptin and interleukin-6 levels were detected in blood samples collected from 146 children and 130 adults by ELISA. Fasting plasma triglycerides, total cholesterol and low-density lipoprotein levels were also measured. Adv36 positivity was determined to be 27·1% and 6% in obese and non-obese children and 17·5% and 4% in obese and non-obese adults, respectively. There was no difference with regard to total cholesterol, low-density lipoprotein, triglyceride, tumour-necrosis-factor-alpha and interleukin-6 levels (P > 0·05). However, there was a significant difference between groups in terms of leptin levels (P < 0·05). We determined the prevalence of Adv36 positivity in obese children and adults. Our results showed that Adv36 may be an obesity agent for both adults and children, parallel with current literature data. However, the available data on a possible relationship between Adv36 infection and obesity both in children and adults do not completely solve the problem.

  1. A Coding Variant of ANO10, Affecting Volume Regulation of Macrophages, Is Associated with Borrelia Seropositivity.

    PubMed

    Hammer, Christian; Wanitchakool, Podchanart; Sirianant, Lalida; Papiol, Sergi; Monnheimer, Mathieu; Faria, Diana; Ousingsawat, Jiraporn; Schramek, Natalie; Schmitt, Corinna; Margos, Gabriele; Michel, Angelika; Kraiczy, Peter; Pawlita, Michael; Schreiber, Rainer; Schulz, Thomas F; Fingerle, Volker; Tumani, Hayrettin; Ehrenreich, Hannelore; Kunzelmann, Karl

    2015-02-23

    In a first genome-wide association study (GWAS) approach to anti-Borrelia seropositivity, we identified two significant single nucleotide polymorphisms (SNPs) (rs17850869, P = 4.17E-09; rs41289586, P = 7.18E-08). Both markers, located on chromosomes 16 and 3, respectively, are within or close to genes previously connected to spinocerebellar ataxia. The risk SNP rs41289586 represents a missense variant (R263H) of anoctamin 10 (ANO10), a member of a protein family encoding Cl(-) channels and phospholipid scramblases. ANO10 augments volume-regulated Cl(-) currents (IHypo) in Xenopus oocytes, HEK293 cells, lymphocytes and macrophages and controls volume regulation by enhancing regulatory volume decrease (RVD). ANO10 supports migration of macrophages and phagocytosis of spirochetes. The R263H variant is inhibitory on IHypo, RVD and intracellular Ca(2+) signals, which may delay spirochete clearance, thereby sensitizing adaptive immunity. Our data demonstrate for the first time that ANO10 has a central role in innate immune defense against Borrelia infection.

  2. Seropositive individuals willingness to communicate, self-efficacy, and assertiveness prior to HIV infection.

    PubMed

    Crowell, Tara L

    2004-01-01

    The purpose of this study was to examine possible communication similarities between human immunodeficiency virus (HIV) positive and HIV negative individuals. Forty HIV positive heterosexuals, who were infected through heterosexual sex, completed an on-line questionnaire to assess their safer sexual communication, willingness to communicate, condom self-efficacy, and assertiveness prior to HIV infection. Results indicate that prior to infection, HIV positive heterosexuals reported having similar safer sexual communication behaviors to those not infected with the virus. Participants in this study reported high levels of willingness to engage in safer sex communication, but low levels of actual communication. Further, results reveal that participants who engaged more often in safer sex communication were more likely to use condoms. Additionally, participants reported high levels of condom self-efficacy and moderate levels of assertiveness; both variables positively correlated with condom use. Finally, participants reported that they believed they did not need to discuss using condoms because they were not at risk. Previous safer sexual communication research reveals HIV negative individuals reported engaging in the same behaviors and holding the same beliefs reported by seropositive individuals. Hence, discussion of the importance of safer sexual communication and the utility of personalization to increase the communication of HIV negative individuals is explored.

  3. Characteristics of prospective memory deficits in HIV-seropositive substance-dependent individuals: preliminary observations.

    PubMed

    Martin, Eileen M; Nixon, Heather; Pitrak, David L; Weddington, William; Rains, Niles A; Nunnally, Gerald; Grbesic, Silvana; Gonzalez, Raul; Jacobus, Joanna; Bechara, Antoine

    2007-07-01

    The construct of "prospective memory" (PM) refers to a type of episodic memory for a future intention or "remembering what one must do." This function has been proposed as a candidate mechanism underlying behaviors of critical importance in HIV disease, including adherence with medication regimens and continued engagement in risk behavior. We administered tasks of time-based and event-based prospective memory and control tasks of retrospective and working memory to 31 HIV-seropositive and 35 HIV-seronegative substance-dependent individuals (SDIs). We found that compared with HIV- controls HIV+ participants showed deficits in time-based but not event-based PM. Retrospective, but not working, memory performance correlated significantly with time-based PM performance. In addition, performance on the time-based PM task was a significant predictor of scores on a self-report measure of risky sexual and injection practices. These preliminary data provide new and unique findings regarding the components of executive function mediated by prefrontal cortical systems that are impaired among HIV+ SDIs and their relevance to "real-world" behaviors.

  4. Delay discounting is greater among drug users seropositive for hepatitis C but not HIV

    PubMed Central

    Martin, Eileen; Gonzalez, Raul; Vassileva, Jasmin; Bechara, Antoine

    2015-01-01

    Objective Substance dependent individuals (SDIs) typically overvalue immediate and undervalue (discount) delayed rewards, and level of discounting significantly predicts post-treatment relapse and other behavioral outcomes. Delay discounting has potential significance for studies of HIV prevention and adherence to antiretroviral therapy; but effects of HIV infection on delay discounting rates among SDIs are not well understood, although discounting rates are higher among individuals infected with hepatitis C virus (HCV). In this study, we investigated potential additive or interactive effects of HIV and HCV infection on delay discounting performance among a group of 239 SDIs with verified HIV and HCV serostatus. Method All participants were verified abstinent from drugs and alcohol at testing. All participants completed measures of substance abuse characteristics and comorbid disorders, and the Monetary Choice Questionnaire, a well-known measure used to derive k coefficients, which index discounting rates. Results Groups were comparable on demographic, substance use, and comorbid characteristics. Compared to uninfected controls, discounting rates were significantly higher among individuals seropositive for HCV but not HIV. Additionally, no significant group differences in discounting rates were observed among HCV+ individuals with or without coinfection with HIV. Group differences could not be attributed to aging or nonspecific effects of drug addiction. Additionally, increased discounting rates were associated with riskier injection practices. Conclusions Potential mechanisms contributing to this discrepancy in discounting rates between HIV+ and HCV+ SDIs, including decision making, are discussed and await further study. PMID:25984995

  5. Diagnostic implications of Ga-67 chest-scan patterns in human immunodeficiency virus-seropositive patients

    SciTech Connect

    Kramer, E.L.; Sanger, J.H.; Garay, S.M.; Grossman, R.J.; Tiu, S.; Banner, H.

    1989-03-01

    Consecutive gallium-67 scans (n = 237) of 180 human immunodeficiency virus-seropositive patients with suspected pulmonary infections were evaluated for intensity and pattern of gallium distribution. Scan findings were correlated with the history, chest radiographic findings, and clinicopathologic diagnoses. Pneumocystis carinii pneumonia (PCP) occurred significantly more often with heterogeneous diffuse uptake than with homogeneous diffuse uptake. Heterogeneous diffuse uptake had an 87% positive predictive value for PCP, which was higher than that of other patterns. Localized pulmonary uptake was most commonly due to bacterial pneumonia or PCP; ill-defined, perihilar uptake, to cytomegalovirus or PCP; and focal (lymph node) uptake, to tuberculosis or lymphoma. The positive predictive value of any pulmonary uptake for lung pathology was 93%, and the negative predictive value of a negative scan was 96%. These findings confirm the utility of gallium scanning in the detection of lung pathology related to acquired immunodeficiency syndrome, particularly PCP. Furthermore, identification of a diffuse pattern may permit the use of a less invasive test more specifically directed at the confirmation of a diagnosis of PCP.

  6. Inhibition of apolipoprotein A-I gene expression by obesity-associated endocannabinoids.

    PubMed

    Haas, Michael J; Mazza, Angela D; Wong, Norman C W; Mooradian, Arshag D

    2012-04-01

    Obesity is associated with increased serum endocannabinoid (EC) levels and decreased high-density lipoprotein cholesterol (HDLc). Apolipoprotein A-I (apo A-I), the primary protein component of HDL is expressed primarily in the liver and small intestine. To determine whether ECs regulate apo A-I gene expression directly, the effect of the obesity-associated ECs anandamide and 2-arachidonylglycerol on apo A-I gene expression was examined in the hepatocyte cell line HepG2 and the intestinal cell line Caco-2. Apo A-I protein secretion was suppressed nearly 50% by anandamide and 2-arachidonoylglycerol in a dose-dependent manner in both cell lines. Anandamide treatment suppressed both apo A-I mRNA and apo A-I gene promoter activity in both cell lines. Studies using apo A-I promoter deletion constructs indicated that repression of apo A-I promoter activity by anandamide requires a previously identified nuclear receptor binding site designated as site A. Furthermore, anandamide-treatment inhibited protein-DNA complex formation with the site A probe. Exogenous over expression of cannabinoid receptor 1 (CBR1) in HepG2 cells suppressed apo A-I promoter activity, while in Caco-2 cells, exogenous expression of both CBR1 and CBR2 could repress apo A-I promoter activity. The suppressive effect of anandamide on apo A-I promoter activity in Hep G2 cells could be inhibited by CBR1 antagonist AM251 but not by AM630, a selective and potent CBR2 inhibitor. These results indicate that ECs directly suppress apo A-I gene expression in both hepatocytes and intestinal cells, contributing to the decrease in serum HDLc in obese individuals.

  7. Flocking for multi-agent systems with unknown nonlinear time-varying uncertainties under a fixed undirected graph

    NASA Astrophysics Data System (ADS)

    Luo, Jie; Cao, Chengyu

    2015-05-01

    This paper presents a flocking algorithm for networked multi-agent systems with unknown, nonlinear, time-varying uncertainties by integrating cooperative control and ? adaptive control methods. An ideal multi-agent system without uncertainties is introduced first. The cooperative control law, based on an artificial potential function, is designed to make the ideal multi-agent system achieve flocking under a fixed and connected undirected graph. Information of ideal states, instead of real states, is exchanged among agents through a communication network. The presence of uncertainties will lead to the degeneration of the performance or even destabilize the entire multi-agent system. The ? adaptive control law is therefore introduced to handle unknown, nonlinear, time-varying uncertainties. By integrating the cooperative control law with the adaptive control law, the real multi-agent system stays close to the ideal multi-agent system which achieves flocking asymptotically under a connected graph. Simulation results of two-dimensional flocking with uncertainties are provided to demonstrate the presented flocking algorithm.

  8. The long-term dynamics of Campylobacter colonizing a free-range broiler breeder flock: an observational study.

    PubMed

    Colles, Frances M; McCarthy, Noel D; Bliss, Carly M; Layton, Ruth; Maiden, Martin C J

    2015-04-01

    A free-range broiler breeder flock was studied in order to determine the natural patterns of Campylobacter colonization over a period of 63 weeks. Campylobacter sequence types (STs) were not mutually exclusive and on average colonized only 17.7% of the birds tested at any time. Campylobacter STs typically reached a peak in prevalence upon initial detection in the flock before tailing off, although the ST and antigenic flaA short variable region in combination were stable over a number of months. There was evidence that, with a couple of exceptions, the ecology of C. jejuni and C. coli differed, with the latter forming a more stable population. Despite being free range, no newly colonizing STs were detected over a 6-week period in autumn and a 10-week period in winter, towards the end of the study. There was limited evidence that those STs identified among broiler chicken flocks on the same farm site were likely to colonize the breeder flock earlier (R(2) 0.16, P 0.01). These results suggest that there is natural control of Campylobacter dynamics within a flock which could potentially be exploited in designing new intervention strategies, and that the two different species should perhaps be considered separately.

  9. Collective Decision-Making in Homing Pigeons: Larger Flocks Take Longer to Decide but Do Not Make Better Decisions

    PubMed Central

    Santos, Carlos D.; Przybyzin, Sebastian; Wikelski, Martin; Dechmann, Dina K. N.

    2016-01-01

    Social animals routinely are challenged to make consensus decisions about movement directions and routes. However, the underlying mechanisms facilitating such decision-making processes are still poorly known. A prominent question is how group members participate in group decisions. We addressed this question by examining how flocks of homing pigeons (Columba livia) decide their homing direction. We released newly formed flocks varying in size and determined the time taken to choose a homing direction (decision-making period) and the accuracy of that choice. We found that the decision-making period increases exponentially with flock size, which is consistent with a participatory decision-making process. We additionally found that there is no effect of flock size on the accuracy of the decisions made, which does not match with current theory for democratic choices of flight directions. Our combined results are better explained by a participatory choice of leaders that subsequently undertake the flock directional decisions. However, this decision-making model would only entirely fit with our results if leaders were chosen based on traits other than their navigational experience. Our study provides rare empirical evidence elucidating decision-making processes in freely moving groups of animals. PMID:26863416

  10. AI techniques for a space application scheduling problem

    NASA Technical Reports Server (NTRS)

    Thalman, N.; Sparn, T.; Jaffres, L.; Gablehouse, D.; Judd, D.; Russell, C.

    1991-01-01

    Scheduling is a very complex optimization problem which can be categorized as an NP-complete problem. NP-complete problems are quite diverse, as are the algorithms used in searching for an optimal solution. In most cases, the best solutions that can be derived for these combinatorial explosive problems are near-optimal solutions. Due to the complexity of the scheduling problem, artificial intelligence (AI) can aid in solving these types of problems. Some of the factors are examined which make space application scheduling problems difficult and presents a fairly new AI-based technique called tabu search as applied to a real scheduling application. the specific problem is concerned with scheduling application. The specific problem is concerned with scheduling solar and stellar observations for the SOLar-STellar Irradiance Comparison Experiment (SOLSTICE) instrument in a constrained environment which produces minimum impact on the other instruments and maximizes target observation times. The SOLSTICE instrument will gly on-board the Upper Atmosphere Research Satellite (UARS) in 1991, and a similar instrument will fly on the earth observing system (Eos).

  11. Building distributed rule-based systems using the AI Bus

    NASA Technical Reports Server (NTRS)

    Schultz, Roger D.; Stobie, Iain C.

    1990-01-01

    The AI Bus software architecture was designed to support the construction of large-scale, production-quality applications in areas of high technology flux, running heterogeneous distributed environments, utilizing a mix of knowledge-based and conventional components. These goals led to its current development as a layered, object-oriented library for cooperative systems. This paper describes the concepts and design of the AI Bus and its implementation status as a library of reusable and customizable objects, structured by layers from operating system interfaces up to high-level knowledge-based agents. Each agent is a semi-autonomous process with specialized expertise, and consists of a number of knowledge sources (a knowledge base and inference engine). Inter-agent communication mechanisms are based on blackboards and Actors-style acquaintances. As a conservative first implementation, we used C++ on top of Unix, and wrapped an embedded Clips with methods for the knowledge source class. This involved designing standard protocols for communication and functions which use these protocols in rules. Embedding several CLIPS objects within a single process was an unexpected problem because of global variables, whose solution involved constructing and recompiling a C++ version of CLIPS. We are currently working on a more radical approach to incorporating CLIPS, by separating out its pattern matcher, rule and fact representations and other components as true object oriented modules.

  12. Discrimination of Coastal Vegetation and Biomass Using AIS Data

    NASA Technical Reports Server (NTRS)

    Gross, M. F.; Klemas, V.

    1985-01-01

    The Airborne Imaging Spectrometer (AIS) was flown over a coastal wetlands region near Lewes, Delaware, adjacent to the Delaware Bay on 16 August 1984. Using the AIS data, it was possible to discriminate between four different types of wetland vegetation canopies: (1) trees; (2) broadleaf herbaceous plants (e.g., Acnida cannabina, Hisbiscus moscheutos); (3) the low marsh grass Spartina alterniflora; and (4) the high marsh grasses Distichlis spicata and Spartina patens. The single most useful region of the spectrum was that between 1.40 and 1.90 microns, where slopes of portions of the radiance curve and ratios of radiance at particular wavelengths were significantly different for the four canopy types. The ratio between the highest digital number in the 1.40 to 1.90 microns and .84 to .94 microns regions and a similar ratio between the peaks in radiance in the 1.12 to 1.40 microns and .84 to .94 microns spectral regions were also very effective at discriminating between vegetation types. Differences in radiance values at various wavelengths between samples of the same vegetation type could potentially be used to estimate biomass.

  13. Sensor assignment to mission in AI-TECD

    NASA Astrophysics Data System (ADS)

    Ganger, Robert; de Mel, Geeth; Pham, Tien; Rudnicki, Ronald; Schreiber, Yonatan

    2016-05-01

    Sensor-mission assignment involves the allocation of sensors and other information-providing resources to missions in order to cover the information needs of the individual tasks within each mission. The importance of efficient and effective means to find appropriate resources for tasks is exacerbated in the coalition context where the operational environment is dynamic and a multitude of critically important tasks need to achieve their collective goals to meet the objectives of the coalition. The Sensor Assignment to Mission (SAM) framework—a research product of the International Technology Alliance in Network and Information Sciences (NIS-ITA) program—provided the first knowledge intensive resource selection approach for the sensor network domain so that contextual information could be used to effectively select resources for tasks in coalition environments. Recently, CUBRC, Inc. was tasked with operationalizing the SAM framework through the use of the I2WD Common Core Ontologies for the Communications-Electronics Research, Development and Engineering Center (CERDEC) sponsored Actionable Intelligence Technology Enabled Capabilities Demonstration (AI-TECD). The demonstration event took place at Fort Dix, New Jersey during July 2015, and this paper discusses the integration and the successful demonstration of the SAM framework within the AI-TECD, lessons learned, and its potential impact in future operations.

  14. Multimodal evoked potentials in HIV-1-seropositive patients: relationship between the immune impairment and the neurophysiological function.

    PubMed

    Pierelli, F; Garrubba, C; Tilia, G; Parisi, L; Fattapposta, F; Pozzessere, G; Soldati, G; Stanzione, P; D'Offizi, G; Mezzaroma, I

    1996-04-01

    Multimodal evoked potentials (PRVEP, BAEP, mSEP) were recorded in 56 HIV-1 seropositive outpatients free from opportunistic CNS pathologies and/or overt HIV-1 encephalopathy. EPs were altered in 17 of 39 (43.6%) seropositive subjects without AIDS (group A) and in 13 of 17 (76.5%) patients with AIDS (group B). A high incidence of subclinical alterations (30.8%) were found in group A patients. Significant BAEP (I-III, III-V, I-V) interpeak latency and mSEP (N9-N13, N9-N20) conduction time prolongations were found in group A and B patients. PRVEP P100 was significantly prolonged only in group B. An inverse relationship between BAEP interpeak latencies and CD4 count was found. Our findings support the hypothesis of an important role of immunodepression in the development of neurophysiologic abnormalities, together with a preferential involvement of acoustic pathways, in the course of HIV-1 infection.

  15. Seropositivity of Toxoplasma gondii in domestic donkeys (Equus asinus) and isolation of T. gondii from farm cats.

    PubMed

    Dubey, J P; Ness, S L; Kwok, O C H; Choudhary, S; Mittel, L D; Divers, T J

    2014-01-17

    Donkeys (Equus asinus) are used as both companion and working animals throughout the world and in some countries, their meat and milk are used for human consumption. Here we report the first serological survey of Toxoplasma gondii in donkeys in the United States. Serum samples from 373 donkeys from eight farms in five states were tested for T. gondii antibodies by the modified agglutination test (MAT). Twenty-four of 373 (6.4%) of donkeys were seropositive, with MAT titers ranging from 25 to ≥ 200. All seropositive donkeys were Miniature breed. Seropositivity prevalence was 7.0% in female donkeys (20/282) and 4.1% in male donkeys (4/91). No donkeys less than 24 months of age (129) were seropositive, suggesting postnatal transmission of infection. Domestic cats were present on six of the eight farms. Three cats from one farm had MAT titers of 200. Viable T. gondii was isolated from the hearts of two cats, but not from brain tissues. Genotyping of isolate DNA extracted from culture-derived tachyzoites using 10 PCR-restriction fragment length polymorphism (RFLP) markers (SAG1, SAG2, SAG3, BTUB, GRA6, c22-8, c29-2, PK1, L358 and Apico loci) revealed that both isolates were clonal Type II (ToxoDB PCR-RFLP genotype #1). This is the first serological survey for T. gondii in donkeys in the United States, and suggests that donkey milk and meat should be considered as a potential source for human infection. The role of barn cats in the transmission of T. gondii to donkeys on farms warrents further investigation.

  16. Risk factors for HIV seropositivity among people consulting for HIV antibody testing: a pilot surveillance study in Quebec.

    PubMed Central

    Alary, M; Castel, J

    1990-01-01

    The surveillance of AIDS (acquired immune deficiency syndrome) through case reporting only reflects the epidemiologic features of HIV (human immunodeficiency virus) transmission a few years earlier and not the prevalence of HIV seropositivity. HIV infection is not a notifiable condition in Quebec. We were asked by the ministère de la Santé et des Services sociaux du Québec to perform a pilot project for the surveillance of HIV seropositivity using a network of sentinel physicians. From May 15, 1988, to Sept. 30, 1989, physicians from four collaborating centres collected data on the serologic status, demographic characteristics and risk factors for 4209 patients who underwent HIV antibody testing. Of the 3899 subjects included in the study 7.9% were HIV positive. Through logistic regression analysis the following variables were found to be significantly associated with HIV seropositivity: presence of HIV-related symptoms (prevalence odds ratio [POR] 36.5), origin from an endemic area (POR 9.1), homosexuality or bisexuality (POR 8.4), intravenous drug use (POR 4.2), male sex (POR 2.8), previous HIV antibody testing (POR 2.5) and previous sexually transmitted disease (POR 1.8). Over the study period we found a large increase in HIV seroprevalence among intravenous drug users (4.2% in 1988 to 19.0% in 1989) (p = 0.02). This increase might reflect a recent change in the epidemiologic pattern of HIV transmission in Quebec. Surveillance of HIV seropositivity through a network of sentinel physicians may be a reasonable alternative to mandatory reporting. PMID:2357678

  17. Isolation of Campylobacter from Brazilian broiler flocks using different culturing procedures.

    PubMed

    Vaz, C S L; Voss-Rech, D; Pozza, J S; Coldebella, A; Silva, V S

    2014-11-01

    Conventional culturing methods enable the detection of Campylobacter in broiler flocks. However, laboratory culture of Campylobacter is laborious because of its fastidious behavior and the presence of competing nontarget bacteria. This study evaluated different protocols to isolate Campylobacter from broiler litter, feces, and cloacal and drag swabs. Samples taken from commercial Brazilian broiler flocks were directly streaked onto Preston agar (PA), Campy-Line agar (CLA), and modified charcoal cefoperazone deoxycholate agar (mCCDA) and also enriched in blood-free Bolton broth (bfBB) for 24 and 48 h followed by plating onto the different selective media. Higher numbers of Campylobacter-positive cloacal and drag swab samples were observed using either direct plating or enrichment for 24 h before plating onto PA, compared with enrichment for 48 h (P < 0.05). Furthermore, direct plating was a more sensitive method to detect Campylobacter in broiler litter and feces samples. Analysis of directly plated samples revealed that higher Campylobacter levels were detected in feces streaked onto PA (88.8%), cloacal swabs plated onto mCCDA (72.2%), drag swabs streaked onto CLA or mCCDA (69.4%), and litter samples inoculated onto PA (63.8%). Preston agar was the best agar to isolate Campylobacter from directly plated litter samples (P < 0.05), but there was no difference in the efficacies of PA, mCCDA, and CLA in detecting Campylobacter in other samples. The isolated Campylobacter strains were phenotypically identified as Campylobacter jejuni or Campylobacter coli. The predominant contaminant observed in the Campylobacter cultures was Proteus mirabilis, which was resistant to the majority of antimicrobial agents in selective media. Together, these data showed that direct plating onto PA and onto either CLA or mCCDA as the second selective agar enabled the reliable isolation of thermophilic Campylobacter species from broiler samples. Finally, Campylobacter was detected in all

  18. Step selection techniques uncover the environmental predictors of space use patterns in flocks of Amazonian birds

    PubMed Central

    Potts, Jonathan R; Mokross, Karl; Stouffer, Philip C; Lewis, Mark A

    2014-01-01

    Understanding the behavioral decisions behind animal movement and space use patterns is a key challenge for behavioral ecology. Tools to quantify these patterns from movement and animal–habitat interactions are vital for transforming ecology into a predictive science. This is particularly important in environments undergoing rapid anthropogenic changes, such as the Amazon rainforest, where animals face novel landscapes. Insectivorous bird flocks are key elements of avian biodiversity in the Amazonian ecosystem. Therefore, disentangling and quantifying the drivers behind their movement and space use patterns is of great importance for Amazonian conservation. We use a step selection function (SSF) approach to uncover environmental drivers behind movement choices. This is used to construct a mechanistic model, from which we derive predicted utilization distributions (home ranges) of flocks. We show that movement decisions are significantly influenced by canopy height and topography, but depletion and renewal of resources do not appear to affect movement significantly. We quantify the magnitude of these effects and demonstrate that they are helpful for understanding various heterogeneous aspects of space use. We compare our results to recent analytic derivations of space use, demonstrating that the analytic approximation is only accurate when assuming that there is no persistence in the animals' movement. Our model can be translated into other environments or hypothetical scenarios, such as those given by proposed future anthropogenic actions, to make predictions of spatial patterns in bird flocks. Furthermore, our approach is quite general, so could potentially be used to understand the drivers of movement and spatial patterns for a wide variety of animal communities. PMID:25558353

  19. Deletion variant near ZNF389 is associated with control of ovine lentivirus in multiple sheep flocks

    PubMed Central

    White, S N; Mousel, M R; Reynolds, J O; Herrmann-Hoesing, L M; Knowles, D P

    2014-01-01

    Ovine lentivirus (OvLV) is a macrophage-tropic lentivirus found in many countries that causes interstitial pneumonia, mastitis, arthritis and cachexia in sheep. There is no preventive vaccine and no cure, but breed differences suggest marker-assisted selective breeding might improve odds of infection and control of OvLV post-infection. Although variants in TMEM154 have consistent association with odds of infection, no variant in any gene has been associated with host control of OvLV post-infection in multiple animal sets. Proviral concentration is a live-animal diagnostic measure of OvLV control post-infection related to severity of OvLV-induced lesions. A recent genome-wide association study identified a region including four zinc finger genes associated with proviral concentration in one Rambouillet flock. To refine this region, we tested additional variants and identified a small insertion/deletion variant near ZNF389 that showed consistent association with proviral concentration in three animal sets (P < 0.05). These animal sets contained Rambouillet, Polypay and crossbred sheep from multiple locations and management conditions. Strikingly, one flock had exceptionally high prevalence (>87%, including yearlings) and mean proviral concentration (>950 copies/μg), possibly due to needle sharing. The best estimate of proviral concentration by genotype, obtained from all 1310 OvLV-positive animals tested, showed insertion homozygotes had less than half the proviral concentration of other genotypes (P < 0.0001). Future work will test additional breeds, management conditions and viral subtypes, and identify functional properties of the haplotype this deletion variant tracks. To our knowledge, this is the first genetic variant consistently associated with host control of OvLV post-infection in multiple sheep flocks. PMID:24303974

  20. Erysipelothrix rhusiopathiae contamination in the poultry house environment during erysipelas outbreaks in organic laying hen flocks.

    PubMed

    Eriksson, Helena; Bagge, Elisabeth; Båverud, Viveca; Fellström, Claes; Jansson, Désirée S

    2014-01-01

    This study investigated organic laying hen farms for the presence of Erysipelothrix rhusiopathiae in the house environment and from potential carriers (i.e. insects and mice) during ongoing erysipelas outbreaks, and compared the obtained isolates with those from laying hens. The samples were investigated by selective culture followed by species-specific polymerase chain reaction on cultures. E. rhusiopathiae was isolated from the spleen, jejunal contents, manure, dust and swabs from water nipples. Three more samples from the house environment tested positive by polymerase chain reaction compared with selective culture alone. Selected isolates were investigated by pulsed-field gel electrophoresis (PFGE) and matrix-assisted laser desorption/ionization time-of-flight mass spectrometry (MALDI-TOF MS). One farm was represented by isolates from laying hens only, and one of these isolates differed in one PFGE band from the others. Different banding patterns were observed for isolates from laying hens and manure on one farm. On the remaining two farms, the isolates from the house environment and laying hens were identical but differed between farms. Outbreaks reoccurred in the next flock on two of the farms, and different PFGE types were isolated from consecutive flocks. Our results suggest an external source of infection, which would explain the previously reported increased risk of outbreaks in free-range flocks. Contaminated manure and dust may represent sources of transmission. For the isolates, MALDI-TOF MS and biochemical typing results were in agreement but, since the type strain of Erysipelothrix tonsillarum was typed as E. rhusiopathiae using MALDI-TOF MS, further studies into this method are needed.

  1. High prevalence of turkey parvovirus in turkey flocks from Hungary experiencing enteric disease syndromes.

    PubMed

    Palade, Elena Alina; Demeter, Zoltán; Hornyák, Akos; Nemes, Csaba; Kisary, János; Rusvai, Miklós

    2011-09-01

    Samples collected in 2008 and 2009, from 49 turkey flocks of 6 to 43 days in age and presenting clinical signs of enteric disease and high mortality, were tested by polymerase chain reaction and reverse transcription-polymerase chain reaction for the presence of viruses currently associated with enteric disease (ED) syndromes: astrovirus, reovirus, rotavirus, coronavirus, adenovirus, and parvovirus. Turkey astroviruses were found in 83.67% of the cases and turkey astrovirus 2 (TAst-2) in 26.53%. The investigations directly demonstrated the high prevalence of turkey parvovirus (TuPV) in 23 flocks (46.9%) experiencing signs of ED, making this pathogen the second most identified after astroviruses. Phylogenetic analysis on a 527 base pair-long region from the NS1 gene revealed two main clusters, a chicken parvovirus (ChPV) and a TuPV group, but also the presence of a divergent branch of tentatively named "TuPV-like ChPV" strains. The 23 Hungarian TuPV strains were separately positioned in two groups from the American origin sequences in the TuPV cluster. An Avail-based restriction fragment length polymorphism assay has also been developed for the quick differentiation of TuPV, ChPV, and divergent TuPV-like ChPV strains. As most detected enteric viruses have been directly demonstrated in healthy turkey flocks as well, the epidemiology of this disease complex remains unclear, suggesting that a certain combination of pathogens, environmental factors, or both are necessary for the development of clinical signs.

  2. Flock-level case-control study of slaughter-lamb pneumonia in New Zealand.

    PubMed

    Goodwin-Ray, K A; Stevenson, M; Heuer, C

    2008-06-15

    Subclinical pneumonia is common in production lambs, and causes reductions in growth rate. We selected farms from meat-inspection records of three New Zealand abattoirs from December 2000 to May 2001 to study risk factors for flocks having >or=3% of their lambs with >or=10% of the lung surface with lesions, compared to flocks with a zero lamb-level prevalence of such pneumonia. A questionnaire of management practices was mailed to participating managers of case and control farms and we received responses from 132/192 (69%) cases and 181/300 (60%) in control farms. Risk factors for case farms were shearing lambs on the day of weaning (OR 6.4), breeding ewe replacements on-farm (OR 4.0), and the percentage of lambs sold between March and May (OR 1.0 for <23% sold (reference category), OR 3.9 for 23-42% sold, OR 2.7 for 43-64% sold, OR 4.3 for >64% sold). Protective factors included: grazing lambs at a fixed stocking rate after weaning (OR 0.4), injecting lambs with vitamin B12 at the time of docking (OR 0.4), and at the time of weaning (OR 0.3). Path analysis was used to show important associations between risk and protective factors differentiated according to time (e.g. before and after birth, at weaning and during growth on pasture). Flocks breeding their own ewe replacements were more likely to shear lambs at weaning, were less likely to buy lambs post-weaning and more likely to have ill-thrift present in >5% of lambs post-weaning. The purchase of lambs post-weaning was indirectly associated with greater odds of pneumonia at slaughter.

  3. Oocyst output and transmission rates during successive infections with Eimeria acervulina in experimental broiler flocks.

    PubMed

    Velkers, Francisca C; Bouma, Annemarie; Stegeman, J Arjan; de Jong, Mart C M

    2012-06-08

    The infection dynamics of Eimeria species determine the clinical manifestation of the disease coccidiosis in poultry flocks, and a better understanding of the dynamics may contribute to improvement of control measures. Our aim was to study the course of infection and the transmission of Eimeria acervulina in groups of broilers by quantifying the transmission rate parameter and oocyst output. Three transmission experiments were carried out with groups of 20 male SPF broilers. At 2 days of age, one bird in each trial was orally inoculated with five sporulated E. acervulina oocysts (D0 post-inoculation, pi). One day after inoculation (D1 pi), the inoculated bird was housed with 19 non-inoculated contact birds. Individual faecal droppings were examined daily from D3-D32 pi to quantify the number of oocysts per gram faeces. The inoculated bird started shedding oocysts at D5 pi and contact birds between D10 and D17 pi. Contact birds that became infected due to oocyst excretion by the inoculated bird were characterized as first generation contact birds (C1). Contact birds excreting from D15 pi onwards (C2) became infected after the first C1 birds had started shedding and were considered to belong to a successive generation of the flock infection. Oocyst output was significantly lower for C1 compared to C2 birds, but the transmission rate parameter remained constant for both infection generations. These results suggest that although oocyst load increases, the transmission rate of E. acervulina remains constant between successive generations of infection in a flock.

  4. Prevalence of Abnormalities in Vestibular Function and Balance among HIV-Seropositive and HIV-Seronegative Women and Men

    PubMed Central

    Cohen, Helen S.; Cox, Christopher; Springer, Gayle; Hoffman, Howard J.; Young, Mary A.; Margolick, Joseph B.; Plankey, Michael W.

    2012-01-01

    Background Most HIV-seropositive subjects in western countries receive highly active antiretroviral therapy (HAART). Although many aspects of their health have been studied, little is known about their vestibular and balance function. The goals of this study were to determine the prevalences of vestibular and balance impairments among HIV-seropositive and comparable seronegative men and women and to determine if those groups differed. Methods Standard screening tests of vestibular and balance function, including head thrusts, Dix-Hallpike maneuvers, and Romberg balance tests on compliant foam were performed during semiannual study visits of participants who were enrolled in the Baltimore and Washington, D. C. sites of the Multicenter AIDS Cohort Study and the Women's Interagency HIV Study. Results No significant differences by HIV status were found on most tests, but HIV-seropositive subjects who were using HAART had a lower frequency of abnormal Dix-Hallpike nystagmus than HIV-seronegative subjects. A significant number of nonclassical Dix-Hallpike responses were found. Age was associated with Romberg scores on foam with eyes closed. Sex was not associated with any of the test scores. Conclusion These findings suggest that HAART-treated HIV infection has no harmful association with vestibular function in community-dwelling, ambulatory men and women. The association with age was expected, but the lack of association with sex was unexpected. The presence of nonclassical Dix-Hallpike responses might be consistent with central nervous system lesions. PMID:22675462

  5. Short-term declines in CD4 levels associated with cocaine use in HIV-1 seropositive, minority injecting drug users.

    PubMed Central

    Siddiqui, N. S.; Brown, L. S.; Makuch, R. W.

    1993-01-01

    This study evaluates the association of cocaine use with short-term change in CD4 counts among human immunodeficiency virus type 1 (HIV-1) seropositive, minority injecting drug users prior to the introduction of zidovudine (AZT). Ninety-eight HIV-1 seropositive subjects were recruited from six inner-city, methadone maintenance clinics. A baseline assessment included a short questionnaire regarding drug behavior and quantitation of CD4 cell counts. These measures were repeated on all subjects 3 to 4 months later. Thirty-eight subjects reported using cocaine between baseline and 4-month follow-up evaluations. Males and African Americans were more likely to be cocaine users (P < .01). Cocaine users were more likely to engage in heroin and needle use (P < .001). Cocaine users experienced a significant decline in CD4 cells compared with nonusers (P = .013); no marked difference in CD4 decline was noted between heroin users and nonusers (P = .19). Multivariate analysis showed that a decline in CD4 counts was 2.82 times more likely to occur in cocaine users than in cocaine nonusers (90% two-sided confidence interval of 1.08, 7.37). These findings support the hypothesis of a possible link between cocaine use and short-term CD4 decline in HIV-1 seropositive injecting drug users. PMID:8478971

  6. Antibody response to Newcastle disease vaccination in a flock of young partridges (Rhynchotus rufescens).

    PubMed

    Sousa, R L; Cardoso, T C; Paulillo, A C; Montassier, H J; Pinto, A A

    1999-09-01

    Ten young partridges (Rhynchotus rufescens) were vaccinated with the lentogenic strain of Newcastle disease virus. Another eight unvaccinated birds were kept in close contact with the treated flock. Antibodies levels were measured over the course of 3 mo in all birds using the hemagglutination inhibition (HI) test and the liquid-phase blocking enzyme-linked immunosorbent assay (LPB-ELISA). The LPB-ELISA was standardized, and the results were compared with those obtained with the HI test. Antibodies increased after 23 days postvaccination in 16 birds with no side effects as determined by both the HI test and the LPB-ELISA.

  7. A simple system for recording lamb mortality used to improve flock management.

    PubMed

    Eales, F A; Small, J; Gilmour, J S; Armstrong, R H; Gittus, G D

    1986-03-01

    Many commercial sheep farmers do not record either the extent or the causes of their lamb losses but this information is essential if losses are to be reduced in the future. The major causes of death in newborn lambs are reviewed together with the common predisposing factors. The development and practical application of a simple system for recording lamb deaths is described. It is concluded that the application of this type of system, initiated, supervised and interpreted by the farmer's own veterinary surgeon, would indicate how to reduce the losses of lambs and would be a useful component of any flock health scheme.

  8. An outbreak of duck virus enteritis (duck plague) in a captive flock of mixed waterfowl

    USGS Publications Warehouse

    Montgomery, R.D.; Stein, G.; Novilla, M.N.; Hurley, Sarah S.; Fink, R.J.

    1981-01-01

    An outbreak of duck virus enteritis occurred in a flock of captive waterfowl composed of mallards (Anas platyrhynchos), black ducks (Anas rubripes), and Canada geese (Branta canadensis). Although all three species were housed together, morbidity and mortality were confined to the 227 black ducks and Canada geese, of which 180 died and the rest were left in a weakened condition. Lesions are given for 20 black ducks and 4 Canada geese dying from DVE. In addition, both horizontal and vertical transmission are discussed as possible sources of the virus that caused this outbreak.

  9. Reanalysis of the hydrodynamic theory of fluid, polar-ordered flocks.

    PubMed

    Toner, John

    2012-09-01

    I reanalyze the hydrodynamic theory of fluid, polar-ordered flocks. I find new linear terms in the hydrodynamic equations which slightly modify the anisotropy, but not the scaling, of the damping of sound modes. I also find that the nonlinearities allowed in equilibrium do not stabilize long-ranged order in spatial dimensions d=2, in accord with the Mermin-Wagner theorem. Nonequilibrium nonlinearities do stabilize long-ranged order in d=2, as argued by earlier work. Some of these were missed by earlier work; it is unclear whether or not they change the scaling exponents in d=2.

  10. Sticktight fleas associated with fowl pox in a backyard chicken flock in California.

    PubMed

    Gustafson, C R; Bickford, A A; Cooper, G L; Charlton, B R

    1997-01-01

    A mixed breed rooster, from a backyard flock of 13 chickens, was received at California Veterinary Diagnostic Laboratory System-Turlock Branch for postmortem examination. The bird presented with thickened, featherless, scab-encrusted skin around the head region. Numerous sticktight fleas were found attached to the encrusted skin. Microscopic evaluation of the skin revealed a lymphoplasmacytic reaction in the dermis with visible embedded flea mouthparts. Also noted histologically in this region were epidermal hyperplasia and ballooned epidermal cells containing intracytoplasmic inclusions indicative of fowl poxvirus.

  11. Novel therapies to increase apolipoprotein AI and HDL for the treatment of atherosclerosis.

    PubMed

    Wong, Norman Cw

    2007-09-01

    Apolipoprotein AI (apoAI) is the major protein component of HDL, and thus has an important role in the treatment of atherosclerosis. This review summarizes the various approaches being examined for raising levels of apoAI/HDL, including increasing the synthesis of apoAI and altering the metabolism of HDL. In addition, the currently available drugs used to increase apoAI/HDL are discussed, with a focus on the potential sites of action of these drugs on HDL metabolism. The outcome of further investigational studies into this field should provide effective therapies to increase apoAI/HDL levels and thus be of use in the treatment of cardiovascular disease.

  12. Is traumatic axonal injury (AI) associated with an early microglial activation? Application of a double-labeling technique for simultaneous detection of microglia and AI.

    PubMed

    Oehmichen, M; Theuerkauf, I; Meissner, C

    1999-05-01

    The aim of the present study was to determine whether axonal injury (AI) induces a microglial reaction within 15 days after brain trauma. In 40 selected cases of confirmed AI, the topographical relation of AI and microglial reaction was assessed using an immunohistochemical double-labeling technique for simultaneous demonstration of AI using beta-amyloid precursor protein (beta-APP) antibody and of microglia using CD68 antibody. Although traumatic injury was usually followed by a moderate early diffuse rise in the number of CD68-reactive cells in the white matter, increases in macrophages in areas of AI accumulation were only sporadic and did not occur until after 4 days. At survival intervals of 5-15 days a moderate microglial reaction in regions of beta-APP-positive injured axons was detected, at maximum, in half of the case material. During this interval AI-associated satellitosis-like clusters or stars described by other authors after a survival time of more than 7 weeks were an isolated phenomenon. The prolonged microglial reaction as well as the reduction of beta-APP-positive AI during longer survival periods supports the hypothesis that AI is not primarily chemotactically attractive and that the damage to a portion of beta-APPstained axons may be partly reversible. Most cases clearly require a prolonged interval of more than 15 days before initiation of the final scavenger reaction. For forensic purposes the increase in the number of microglial cells within the region of AI accumulation after a survival time of more than 5 days and the multiple and distinct demonstration of star-like microglial reactions within the white matter after survival times exceeding 7 weeks may provide valuable postmortem information on the timing of a traumatic event.

  13. Early warning of footpad dermatitis and hockburn in broiler chicken flocks using optical flow, bodyweight and water consumption.

    PubMed

    Dawkins, M S; Roberts, S J; Cain, R J; Nickson, T; Donnelly, C A

    2017-02-27

    Footpad dermatitis and hockburn are serious welfare and economic issues for the production of broiler (meat) chickens. The authors here describe the use of an inexpensive camera system that monitors the movements of broiler flocks throughout their lives and suggest that it is possible to predict, even in young birds, the cross-sectional prevalence at slaughter of footpad dermatitis and hockburn before external signs are visible. The skew and kurtosis calculated from the authors' camera-based optical flow system had considerably more power to predict these outcomes in the 50 flocks reported here than water consumption, bodyweight or mortality and therefore have the potential to inform improved flock management through giving farmers early warning of welfare issues. Further trials are underway to establish the generality of the results.

  14. A novel alignment repulsion algorithm for flocking of multi-agent systems based on the number of neighbours per agent

    NASA Astrophysics Data System (ADS)

    Kahani, R.; Sedigh, A. K.; Mahjani, M. Gh.

    2015-12-01

    In this paper, an energy-based control methodology is proposed to satisfy the Reynolds three rules in a flock of multiple agents. First, a control law is provided that is directly derived from the passivity theorem. In the next step, the Number of Neighbours Alignment/Repulsion algorithm is introduced for a flock of agents which loses the cohesion ability and uniformly joint connectivity condition. With this method, each agent tries to follow the agents which escape its neighbourhood by considering the velocity of escape time and number of neighbours. It is mathematically proved that the motion of multiple agents converges to a rigid and uncrowded flock if the group is jointly connected just for an instant. Moreover, the conditions for collision avoidance are guaranteed during the entire process. Finally, simulation results are presented to show the effectiveness of the proposed methodology.

  15. Cytomegalovirus prevention strategies in seropositive kidney transplant recipients: an insight into current clinical practice.

    PubMed

    Fernández-Ruiz, Mario; Arias, Manuel; Campistol, Josep M; Navarro, David; Gómez-Huertas, Ernesto; Gómez-Márquez, Gonzalo; Díaz, Juan Manuel; Hernández, Domingo; Bernal-Blanco, Gabriel; Cofan, Frederic; Jimeno, Luisa; Franco-Esteve, Antonio; González, Esther; Moreso, Francesc J; Gómez-Alamillo, Carlos; Mendiluce, Alicia; Luna-Huerta, Enrique; Aguado, José María

    2015-09-01

    There is notable heterogeneity in the implementation of cytomegalovirus (CMV) prevention practices among CMV-seropositive (R+) kidney transplant (KT) recipients. In this prospective observational study, we included 387 CMV R+ KT recipients from 25 Spanish centers. Prevention strategies (antiviral prophylaxis or preemptive therapy) were applied according to institutional protocols at each site. The impact on the 12-month incidence of CMV disease was assessed by Cox regression. Asymptomatic CMV infection, acute rejection, graft function, non-CMV infection, graft loss, and all-cause mortality were also analyzed (secondary outcomes). Models were adjusted for a propensity score (PS) analysis for receiving antiviral prophylaxis. Overall, 190 patients (49.1%) received preemptive therapy, 185 (47.8%) antiviral prophylaxis, and 12 (3.1%) no specific intervention. Twelve-month cumulative incidences of CMV disease and asymptomatic infection were 3.6% and 39.3%, respectively. Patients on prophylaxis had lower incidence of CMV disease [PS-adjusted HR (aHR): 0.10; 95% confidence interval (CI): 0.01-0.79] and asymptomatic infection (aHR: 0.46; 95% CI: 0.29-0.72) than those managed preemptively, with no significant differences according to the duration of prophylaxis. All cases of CMV disease in the prophylaxis group occurred after prophylaxis discontinuation. There were no differences in any of the secondary outcomes. In conclusion, antiviral prophylaxis was associated with a lower occurrence of CMV disease in CMV R+ KT recipients, although such benefit should be balanced with the risk of late-onset disease.

  16. Oral shedding of Bartonella in cats: correlation with bacteremia and seropositivity.

    PubMed

    Namekata, David Y; Kasten, Rickie W; Boman, Dawn A; Straub, Mary H; Siperstein-Cook, Laurie; Couvelaire, Karen; Chomel, Bruno B

    2010-12-15

    Cats are the main reservoirs of zoonotic Bartonella henselae, B. clarridgeiae and B. koehlerae, transmitted among cats by cat fleas. No study has investigated the presence of Bartonella in the saliva of bacteremic and non-bacteremic cats to correlate it to the level of bacteremia and the presence or absence of oral lesions. Shelter cats from northern California (n=130) and Michigan (n=50) were tested for Bartonella bacteremia by blood culture, presence of Bartonella antibodies and Bartonella DNA in oral swabs. Bacteremia was detected in 45 (25%) cats, mainly from northern California (n=40), which were highly flea infested and were 4 times more likely to be bacteremic than the non-flea-infested cats from Michigan. Overall, 69 (38.3%) cats had Bartonella PCR positive oral swabs. Bacteremic cats were almost 3 times (P=0.003) more likely to have PCR positive oral swabs (59%, 26/44) than non-bacteremic cats (32.5%, 44/135). However, there was no correlation between cats being bacteremic and having oral lesions. Antibody prevalences for B. henselae and B. clarridgeiae were 30% and 42.8%. B. henselae and B. clarridgeiae seropositive cats were almost 4 times (P=0.0001) and 3 times (P=0.003) more likely to have oral lesions than seronegative cats. Despite a higher prevalence (odds ratio=1.73; 95% confidence interval=0.88-3.38) of oral lesions in cats with oral swabs testing PCR positive, no statistical association could be demonstrated in this cat population.

  17. Age-associated Epstein–Barr virus-specific T cell responses in seropositive healthy adults

    PubMed Central

    Cárdenas Sierra, D; Vélez Colmenares, G; Orfao de Matos, A; Fiorentino Gómez, S; Quijano Gómez, S M

    2014-01-01

    Epstein–Barr virus (EBV) is present in 95% of the world's adult population. The immune response participates in immune vigilance and persistent infection control, and this condition is maintained by both a good quality (functionality) and quantity of specific T cells throughout life. In the present study, we evaluated EBV-specific CD4+ and CD8+ T lymphocyte responses in seropositive healthy individuals younger and older than 50 years of age. The assessment comprised the frequency, phenotype, functionality and clonotypic distribution of T lymphocytes. We found that in both age groups a similar EBV-specific T cell response was found, with overlapping numbers of tumour necrosis factor (TNF)-α+ T lymphocytes (CD4+ and CD8+) within the memory and effector cell compartments, in addition to monofunctional and multi-functional T cells producing interleukin (IL)-2 and/or interferon (IFN)-γ. However, individuals aged more than 50 years showed significantly higher frequencies of IL-2-producing CD4+ T lymphocytes in association with greater production of soluble IFN-γ, TNF-α and IL-6 than subjects younger than 50 years. A polyclonal T cell receptor (TCR)-variable beta region (Vβ) repertoire exists in both age groups under basal conditions and in response to EBV; the major TCR families found in TNF-α+/CD4+ T lymphocytes were Vβ1, Vβ2, Vβ17 and Vβ22 in both age groups, and the major TCR family in TNF-α+/CD8+ T cells was Vβ13·1 for individuals younger than 50 years and Vβ9 for individuals aged more than 50 years. Our findings suggest that the EBV-specific T cell response (using a polyclonal stimulation model) is distributed throughout several T cell differentiation compartments in an age-independent manner and includes both monofunctional and multi-functional T lymphocytes. PMID:24666437

  18. Mononuclear phagocyte system Fc-receptor function in patients with seropositive rheumatoid arthritis.

    PubMed

    Lobatto, S; Breedveld, F C; Camps, J A; Pauwels, E K; Westedt, M L; Daha, M R; van Es, L A

    1987-03-01

    Mononuclear phagocyte system (MPS) Fc-receptor function in 20 patients with seropositive rheumatoid arthritis (RA) was investigated using radiolabelled autologous erythrocytes coated with an average of 5,800 molecules of anti-rhesus IgG (E. IgG). Although clearance times (T1/2) of E. IgG tended to be longer in RA patients than those in healthy controls (46 +/- 6 min vs 38 +/- 5 min, mean +/- s.e.m., P = 0.38), this did not reach statistical significance. Liver spleen uptake ratios (LS ratios) were increased in patients with RA (13/100 +/- 1/100 vs 7/100 +/- 1/100, P less than 0.05). There was no correlation of T1/2 or LS ratios with articular disease activity, vasculitis, ESR, IgM containing immune complex levels or Clq-binding immune complex levels. Although Clq-binding immune complex levels were significantly higher in patients with vasculitis than in those without (P less than 0.01), T1/2 and LS ratios did not differ in these two groups of patients. The T1/2 and LS ratios of E.IgG did not reveal a defect in MPS Fc-receptor function and did not correlate with one of the above-mentioned clinical and immunological parameters. We suggest that in order to establish a possible defect in Fc-receptor function correlating with disease activity and immune complex levels in RA patients, soluble immune complexes or immune complex-like material should be used as probes.

  19. Antibody response in seropositive multiple sclerosis patients vaccinated with attenuated live varicella zoster virus

    PubMed Central

    Ross, RT; Dawood, MR; Cheang, Mary; Nicolle, Lindsay E

    1996-01-01

    OBJECTIVE: To determine the safety and effectiveness of live attenuated varicella zoster virus (VZV) vaccine (OKA/Merck) on 50 patients with chronic progressive multiple sclerosis (MS), based on the hypothesis that VZV might be the antigen or antigen mimic of MS plus the fact that repeated high antigen doses have produced ‘antigen paralysis’ in experimental allergic encephalomyelitis mice. DESIGN: Fifty patients were randomly selected without controls. They were assessed clinically at entry and on four other occasions over 14 months. Enhanced cranial magnetic resonance imaging (MRI) was performed at entry and at six and 12 months post entry. All were vaccinated after initial assessment and again six weeks later. SETTING: All clinical and laboratory assessments were performed at the Health Sciences Centre, Winnipeg, in the out-patient department. All MRI examinations were performed at the St Boniface General Hospital, Winnipeg, Manitoba. Both are tertiary care hospitals. POPULATION STUDIED: Fifty randomly selected patients with chronic progressive MS, age 18 to 60 years, and a disability status scale of 2.0 or greater were included. Forty-five patients completed the study. INTERVENTIONS: Two vaccinations with attenuated live VZV six weeks apart. RESULTS: All patients were VZV seropositive at entry and all showed an increased antibody level following vaccination. No one was harmed by the vaccine. There may have been some changes in the MS of 15 patients. CONCLUSIONS: It may be reasonable and safe to challenge the process of MS using large doses of the immunogenic proteins of the VZV to induce ‘immune paralysis’. PMID:22514454

  20. A Case-Control Study of Risk Factors for Bovine Brucellosis Seropositivity in Peninsular Malaysia

    PubMed Central

    Anka, Mukhtar Salihu; Hassan, Latiffah; Khairani-Bejo, Siti; Zainal, Mohamed Abidin; Mohamad, Ramlan bin; Salleh, Annas; Adzhar, Azri

    2014-01-01

    Bovine brucellosis was first reported in Peninsular Malaysia in 1950. A subsequent survey conducted in the country revealed that the disease was widespread. Current knowledge on the potential risk factors for brucellosis occurrence on cattle farms in Malaysia is lacking. Therefore, we conducted a case-control study to identify the potential herd-level risk factors for bovine brucellosis occurrence in four states in the country, namely Kelantan, Pahang, Selangor and Negeri Sembilan. Thirty-five cases and 36 controls of herds were selected where data on farm management, biosecurity, medical history and public health were collected. Multivariable logistic regression identified that Brucella seropositive herds were more likely to; have some interaction with wildlife (OR 8.9, 95% CI = 1.59–50.05); originated from farms where multiple species such as buffalo/others (OR 41.8, 95% CI = 3.94–443.19) and goat/sheep (OR 8.9, 95%Cl = 1.10–71.83) were reared, practice extensive production system (OR 13.6, 95% CI 1.31–140.24) and have had episodes of abortion in the past (OR 51.8, 95% CI = 4.54–590.90) when compared to seronegative herds. Considering the lack of information on the epidemiology of bovine brucellosis in peninsular Malaysia and absence of information on preventing the inception or spread of the disease, this report could contribute to the on-going area-wise national brucellosis eradication program. PMID:25265020