Crop -glucanase activity limits the effectiveness of a recombinant cellulase used to supplement a barley-based feed for free-range broilers

1. The supplementation of diets rich in soluble polysaccharides with microbial cellulases and hemicellulases decreases digesta viscosity and promotes broiler performance. 2. In contrast, recent experiments suggest that polysaccharidases are ineffective for improving the nutritive value of pasture biomass used by free-range broilers. However, the feasibility of using cellulases and hemicellulases to improve the utilisation of cereal-based feeds by pastured poultry remains to be established. 3. A study was undertaken to investigate the capacity of a recombinant cellulase from Clostridium thermocellum to improve the nutritive value of a barley-based feed for free-range pastured broilers of the RedBro Cou Nu RedBro M genotype. 4. The results show that supplementation of a barley-based diet with a recombinant -glucanase had no effect on the performance of free-range broilers, foraging in legume-based diets from d 28 to 56. In addition, the results confirm that the lack of effect of the recombinant enzyme in improving the nutritive value of the barley-based feed does not result from enzyme proteolysis or inhibition in the gastrointestinal tract. 5. Significantly, -glucanase activity was identified in the crop of non-supplemented animals. The data suggest that endogenous cellulases originated both from the barley-based feed and from the crop microflora. 6. The results presented here suggest that in older birds of slow-growing genotypes associated with free-range production systems, previously unknown sources of -glucanases, such as the feed and microbial symbiotic microflora, can affect the effectiveness of exogenous enzymes added to the feed

Cytotoxic Effects Of Zoledronic Acid On Human Epithelial Cells And Gingival Fibroblasts

Bisphosphonate-induced osteonecrosis has been related to the cytotoxicity of these drugs on oral mucosa cells. A previous study showed that 5 μM of zoledronic acid (ZA), a nitrogen-containing bisphosphonate, is the highest concentration of this drug found in the oral cavity of patients under treatment. Therefore, in order to simulate an osteonecrosis clinical condition, the aim of this study was to evaluate the highest concentration of ZA applied on human epithelial cells (HaCaT) and gingival fibroblasts. For this purpose, cells (3x104 cells/cm2) were seeded in wells for 48 h using complete culture medium (cDMEM). After 48 h incubation, the cDMEM was replaced by fresh serum-free culture medium (DMEM-FBS) in which the cells were maintained for additional 24 h. Then, 5 μM ZA were added to the DMEM-FBS and the cells incubated in contact with the drug for 48 h. After this period, the number of viable cells (trypan blue), cell viability (MTT assay), total protein (TP) production and cell morphology (SEM analysis) were assessed. Data were analyzed statistically by Mann-Whitney, ANOVA and Tukey's test (α=0.05). ZA caused a significant reduction in the number of viable cells and decreased the metabolic activity of both cell lines. However, decrease of TP production occurred only in the epithelial cell cultures. Morphological alterations were observed in both cell types treated with ZA. In conclusion, ZA (5 μM) was cytotoxic to human epithelial cells and gingival fibroblast cultures, which could be associated, clinically, with the development of bisphosphonateinduced osteonecrosis.246551558Civitelli, R., Napoli, N., Armamento-Villareal, R., Use of intravenous bisphosphonates in osteoporosis (2007) Curr Osteoporos Rep, 5, pp. 8-13Cohen, S.B., An update on bisphosphonates (2004) Curr Rheumatol Rep, 6, pp. 59-65Rogers, M.J., Watts, D.J., Russel, R.G., Overview of bisphosphonates (1997) Cancer, 80, pp. 1652-1660Rogers, M.J., Gordon, S., Benford, H.L., Coxon, F.P., Luckman, S.P., Monkkonen, J., Cellular and molecular mechanisms of action of bisphosphonates (2000) Cancer Supl, 88, pp. 2961-2978Lawson, M.A., Xia, Z., Barnett, B.L., Triffitt, J.T., Phipps, R.J., Dunford, J.E., Differences between bisphosphonates in binding affinities for hydroxyapatite (2010) J Biomed Mater Res Part B: Appl Biomater, 92, pp. 149-155Allen, M.R., Burr, D.B., The pathogenesis of bisphosphonate-related osteonecrosis of the jaw: So many hypotheses, so few data (2009) J Oral Maxillofac Surg, 67, pp. 61-70Otto, S., Pautke, C., Opelz, C., Wesphal, I., Drosse, I., Swager, J., Osteonecrosis of the jaw: Effects of bisphosphonate type, local concentration, and acidic milieu on the pathomechanism (2010) J Oral Maxillofac Surg, 68, pp. 2837-2845Reid, I.R., Booland, M.J., Is bisphosphonate-associated osteonecrosis of the jaw caused by soft tissue toxicity? (2007) Bone, 41, pp. 318-320Scheper, M.A., Badros, A., Chausparat, R., Cullen, K.J., Meiller, T.F., Effect of zoledronic acid on oral fibroblasts and epithelial cells: A potential mechanism of bisphosphonate-associated osteonecrosis (2009) Br J Haematol, 144, pp. 667-676Scheper, M.A., Badros, A., Salama, A.R., Wartburton, G., Cullen, K.J., Weikel, D.S., A novel bioassay model to determine clinically significant bisphosphonate levels (2009) Support Care Cancer, 17, pp. 1553-1557Ruggiero, S.L., Mehrotra, B., Rosenberg, T.J., Engroff, S.L., Osteonecrosis of the jaws associated with the use of bisphosphonates: A review of 63 cases (2004) J Oral Maxillofac Surg, 62, pp. 527-534Walter, C., Klein, M.O., Pabst, A., Al-Nawas, B., Duscher, H., Ziebart, T., Influence of bisphosphonates on endothelial cells, fibroblasts, and osteogenic cells (2010) Clin Oral Investig, 14, pp. 35-41Kumar, S.K.S., Gorur, A., Schaauddin, C., Shuler, C.F., Costerton, J.W., Sedghizadeh, P.P., The role of microbial biofilms in osteonecrosis of the jaw associated with bisphosphonate therapy (2010) Curr Osteoporos Rep, 8, pp. 40-48Aas, J.A., Paster, B.J., Stokes, L.N., Olsen, I., Dewhirst, F.E., Defining the normal bacterial flora of the oral cavity (2005) J Clin Microbiol, 43, pp. 5721-5732Basso, F.G., Pansani, T.N., Turrioni, A.P.S., Bagnato, V.S., Hebling, J., de Souza Costa, C.A., In vitro wound healing improvement by low-level laser therapy application in cultured gingival fibroblasts (2012) Int J Dent, , [Epub ahead of print. DOI: 10.1155/2012/719452]Wiegand, C., Hipler, U., Methods for the measurement of cell and tissue compatibility including tissue regeneration process (2008) GMS Krankenhhyg Interdiszip, 3, pp. 1863-5245Basso, F.G., Oliveira, C.F., Kurachi, C., Hebling, J., de Souza Costa, C.A., Biostimulatory effect of low-level laser therapy on keratinocytes in vitro (2013) Lasers Med Sci, 28, pp. 367-374De Souza Costa, C.A., Duarte, P.T., de Souza, P.P., Giro, E.M., Hebling, J., Cytotoxic effects and pulpal response caused by a mineral trioxide aggregate formulation and calcium hydroxide (2008) Am J Dent, 21, pp. 255-261Oliveira, C.F., Basso, F.G., Lins, E.C.C., Kurachi, C., Hebling, J., Bagnato, V.S., Increased viability of odontoblast-like cells subjected to low-level laser irradiation (2010) Laser Phys, 20, pp. 1659-1666Read, S.M., Northcote, D.H., Minimization of variation in the response to different proteins of the Coomassie blue G dye-binding assay for protein (1981) Anal Biochem, 116, pp. 53-64Oliveira, C.F., Basso, F.G., Lins, E.C., Kurachi, C., Hebling, J., Bagnato, V.S., In vitro effect of low-level laser on odontoblast-like cells (2011) Laser Phys Lett, 8, pp. 155-163Simon, M.J.K., Niehoff, P., Kimming, B., Wiltfang, J., Açil, Y., Expression profile and synthesis of different collagen types I, II III and V of human gingival fibroblasts, osteoblasts, ans SaOs-2 cells after bisphosphonate treatment (2010) Clin Oral Investig, 14, pp. 51-58Migliorati, C.A., Siegel, M.A., Elting, L.S., Bisphosphonate-associated osteonecrosis: A long-term complication of bisphosphonate treatment (2006) Lancet Oncol, 7, pp. 508-514Werner, S., Krieg, T., Smola, H., Keratinocyte-fibroblast interactions in wound healing (2007) J Investigative Dermatol, 127, pp. 998-1008Ravosa, M.J., Ning, J., Liu, Y., Stack, M.S., Bisphosphonate effects on the behavior of oral epithelial cells and oral fibroblasts (2011) Arch Oral Biol, 56, pp. 491-49

Apêndices e fossetas pré-auriculares : existe alguma correlação destes achados com défict auditivo ou malformações renais em nossa população?

27

Bartonella Clarridgeiae Bacteremia Detected In An Asymptomatic Blood Donor

Human exposure to Bartonella clarridgeiae has been reported only on the basis of antibody detection. We report for the first time an asymptomatic human blood donor infected with B. clarridgeiae, as documented by enrichment blood culture, PCR, and DNA sequencing.531352356Maggi, R.G., Duncan, A.W., Breitschwerdt, E.B., Novel chemically modified liquid medium that will support the growth of seven Bartonella species (2005) J Clin Microbiol, 43, pp. 2651-2655. , http://dx.doi.org/10.1128/JCM.43.6.2651-2655.2005Drummond, M.R., Pitassi, L.H., Lania, B.G., Dos Santos, S.R., Gilioli, R., Velho, P.E., Detection of Bartonella henselae in defibrinated sheep blood used for culture media supplementation (2011) Braz J Microbiol, 42, pp. 430-432. , http://dx.doi.org/10.1590/S1517-83822011000200003Altschul, S.F., Gish, W., Miller, W., Myers, E.W., Lipman, D.J., Basic local alignment search tool (1990) J Mol Biol, 215, pp. 403-410Dalton, M.J., Robinson, L.E., Cooper, J., Regnery, R.L., Olson, J.G., Childs, J.E., Use of Bartonella antigens for serologic diagnosis of cat-scratch disease at a national referral center (1995) Arch Intern Med, 155, pp. 1670-1676Breitschwerdt, E.B., Maggi, R.G., Chomel, B.B., Lappin, M.R., Bartonellosis: An emerging infectious disease of zoonotic importance to animals and human beings (2010) J Vet Emerg Crit Care (San Antonio), 20, pp. 8-30. , http://dx.doi.org/10.1111/j.1476-4431.2009.00496.xChamberlin, J., Laughlin, L.W., Romero, S., Solorzano, N., Gordon, S., Andre, R.G., Pachas, P., Watts, D., Epidemiology of endemic Bartonella bacilliformis: A prospective cohort study in a Peruvian mountain valley community (2002) J Infect Dis, 186, pp. 983-990. , http://dx.doi.org/10.1086/344054Maggi, R.G., Ericson, M., Mascarelli, P.E., Bradley, J.M., Breitschwerdt, E.B., Bartonella henselae bacteremia in a mother and son potentially associated with tick exposure (2013) Parasit Vectors, 6, p. 101. , http://dx.doi.org/10.1186/1756-3305-6-101Scott, M.A., McCurley, T.L., Vnencak-Jones, C.L., Hager, C., McCoy, J.A., Anderson, B., Collins, R.D., Edwards, K.M., Cat scratch disease: Detection of Bartonella henselae DNA in archival biopsies from patients with clinically, serologically, and histologically defined disease (1996) Am J Pathol, 149, pp. 2161-2167Slater, L.N., Welch, D.F., Min, K.W., Rochalimaea henselae causes bacillary angiomatosis and peliosis hepatis (1992) Arch Intern Med, 152, pp. 602-606Sander, A., Zagrosek, A., Bredt, W., Schiltz, E., Piemont, Y., Lanz, C., Dehio, C., Characterization of Bartonella clarridgeiae flagellin (FlaA) and detection of antiflagellin antibodies in patients with lymphadenopathy (2000) J Clin Microbiol, 38, pp. 2943-2948Kordick, D.L., Hilyard, E.J., Hadfield, T.L., Wilson, K.H., Steigerwalt, A.G., Brenner, D.J., Breitschwerdt, E.B., Bartonella clarridgeiae, a newly recognized zoonotic pathogen causing inoculation papules, fever, and lymphadenopathy (cat scratch disease) (1997) J Clin Microbiol, 35, pp. 1813-1818Margileth, A.M., Baehren, D.F., Chest-wall abscess due to cat-scratch disease (CSD) in an adult with antibodies to Bartonella clarridgeiae: Case report and review of the thoracopulmonary manifestations of CSD (1998) Clin Infect Dis, 27, pp. 353-357. , http://dx.doi.org/10.1086/514671Chomel, B.B., Mac Donald, K.A., Kasten, R.W., Chang, C.C., Wey, A.C., Foley, J.E., Thomas, W.P., Kittleson, M.D., Aortic valve endocarditis in a dog due to Bartonella clarridgeiae (2001) J Clin Microbiol, 39, pp. 3548-3554. , http://dx.doi.org/10.1128/JCM.39.10.3548-3554.2001Gillespie, T.N., Washabau, R.J., Goldschmidt, M.H., Cullen, J.M., Rogala, A.R., Breitschwerdt, E.B., Detection of Bartonella henselae and Bartonella clarridgeiae DNA in hepatic specimens from two dogs with hepatic disease (2003) J Am Vet Med Assoc, 222, pp. 47-51. , http://dx.doi.org/10.2460/javma.2003.222.47, 35Robinson, M.T., Hillman, T., Langton, D.A., Shaw, S.E., Bartonella clarridgeiae in a cat in the UK (2009) Vet Rec, 164, pp. 58-59. , http://dx.doi.org/10.1136/vr.164.2.58Sykes, J.E., Westropp, J.L., Kasten, R.W., Chomel, B.B., Association between Bartonella species infection and disease in pet cats as determined using serology and culture (2010) J Feline Med Surg, 12, pp. 631-636. , http://dx.doi.org/10.1016/j.jfms.2010.04.003Fouch, B., Coventry, S., A case of fatal disseminated Bartonella henselae infection (cat-scratch disease) with encephalitis (2007) Arch Pathol Lab Med, 131, pp. 1591-1594Boudebouch, N., Sarih, M., Beaucournu, J.C., Amarouch, H., Hassar, M., Raoult, D., Parola, P., Bartonella clarridgeiae, B. Henselae, and Rickettsia felis in fleas from Morocco (2011) Ann Trop Med Parasitol, 105, pp. 493-498. , http://dx.doi.org/10.1179/1364859411Y.0000000038Kordick, D.L., Brown, T.T., Shin, K., Breitschwerdt, E.B., Clinical and pathologic evaluation of chronic Bartonella henselae or Bartonella clarridgeiae infection in cats (1999) J Clin Microbiol, 37, pp. 1536-1547Chomel, B.B., Carlos, E.T., Kasten, R.W., Yamamoto, K., Chang, C.C., Carlos, R.S., Abenes, M.V., Pajares, C.M., Bartonella henselae and Bartonella clarridgeiae infection in domestic cats from the Philippines (1999) Am J Trop Med Hyg, 60, pp. 593-597Dehio, C., Bartonella interactions with endothelial cells and erythrocytes (2001) Trends Microbiol, 9, pp. 279-285. , http://dx.doi.org/10.1016/S0966-842X(01)02047-9Dehio, C., Meyer, M., Berger, J., Schwarz, H., Lanz, C., Interaction of Bartonella henselae with endothelial cells results in bacterial aggregation on the cell surface and the subsequent engulfment and internalisation of the bacterial aggregate by a unique structure, the invasome (1997) J Cell Sci, 110 (18), pp. 2141-2154Braga Mdo, S., Diniz, P.P., André, M.R., Bortoli, C.P., Machado, R.Z., Molecular characterisation of Bartonella species in cats from São Luís, state of Maranhão, North-Eastern Brazil (2012) Mem Inst Oswaldo Cruz, 107, pp. 772-777. , http://dx.doi.org/10.1590/S0074-02762012000600011Eremeeva, M.E., Gerns, H.L., Lydy, S.L., Goo, J.S., Ryan, E.T., Mathew, S.S., Ferraro, M.J., Koehler, J.E., Bacteremia, fever, and splenomegaly caused by a newly recognized Bartonella species (2007) N Engl J Med, 356, pp. 2381-2387. , http://dx.doi.org/10.1056/NEJMoa065987Chomel, B.B., Boulouis, H.J., Breitschwerdt, E.B., Kasten, R.W., Vayssier-Taussat, M., Birtles, R.J., Koehler, J.E., Dehio, C., Ecological fitness and strategies of adaptation of Bartonella species to their hosts and vectors (2009) Vet Res, 40, p. 29. , http://dx.doi.org/10.1051/vetres/2009011Breitschwerdt, E.B., Maggi, R.G., Duncan, A.W., Nicholson, W.L., Hegarty, B.C., Woods, C.W., Bartonella species in blood of immunocompetent persons with animal and arthropod contact (2007) Emerg Infect Dis, 13, pp. 938-941. , http://dx.doi.org/10.3201/eid1306.061337Carson, J.L., Grossman, B.J., Kleinman, S., Tinmouth, A.T., Marques, M.B., Fung, M.K., Holcomb, J.B., Djulbegovic, B., Red blood cell transfusion: A clinical practice guideline from the AABB (2012) Ann Intern Med, 157, pp. 49-58. , http://dx.doi.org/10.7326/0003-4819-157-1-201206190-00429Ramirez-Arcos, S., Goldman, M., Blajchman, M., Bacterial contamination (2012) Transfusion Reaction, 4, pp. 153-189. , Popovsky MA (ed), American Association Of Blood Banks, Bethesda, MDVamvakas, E.C., Blajchman, M.A., Transfusion-related mortality: The ongoing risks of allogeneic blood transfusion and the available strategies for their prevention (2009) Blood, 113, pp. 3406-3417. , http://dx.doi.org/10.1182/blood-2008-10-167643Magalhães, R.F., Cintra, M.L., Barjas-Castro, M.L., Del Negro, G.M., Okay, T.S., Velho, P.E., Blood donor infected with Bartonella henselae (2010) Transfus Med, 20, pp. 280-282. , http://dx.doi.org/10.1111/j.1365-3148.2010.01001.xMagalhães, R.F., Pitassi, L.H., Salvadego, M., De Moraes, A.M., Barjas-Castro, M.L., Velho, P.E., Bartonella henselae survives after the storage period of red blood cell units: Is it transmissible by transfusion? (2008) Transfus Med, 18, pp. 287-291. , http://dx.doi.org/10.1111/j.1365-3148.2008.00871.xLin, J.W., Chen, C.M., Chang, C.C., Unknown fever and back pain caused by Bartonella henselae in a veterinarian after a needle puncture: A case report and literature review (2011) Vector Borne Zoonotic Dis, 11, pp. 589-591. , http://dx.doi.org/10.1089/vbz.2009.0217Oliveira, A.M., Maggi, R.G., Woods, C.W., Breitschwerdt, E.B., Suspected needle stick transmission of Bartonella vinsonii subspecies berkhoffii to a veterinarian (2010) J Vet Intern Med, 24, pp. 1229-1232. , http://dx.doi.org/10.1111/j.1939-1676.2010.0563.xOhl, M.E., Spach, D.H., Bartonella quintana and urban trench fever (2000) Clin Infect Dis, 31, pp. 131-135. , http://dx.doi.org/10.1086/313890Daly, J.S., Worthington, M.G., Brenner, D.J., Moss, C.W., Hollis, D.G., Weyant, R.S., Steigerwalt, A.G., O'Connor, S.P., Rochalimaea elizabethae sp. Nov. Isolated from a patient with endocarditis (1993) J Clin Microbiol, 31, pp. 872-881Oksi, J., Rantala, S., Kilpinen, S., Silvennoinen, R., Vornanen, M., Veikkolainen, V., Eerola, E., Pulliainen, A.T., Cat scratch disease caused by Bartonella grahamii in an immunocompromised patient (2013) J Clin Microbiol, 51, pp. 2781-2784. , http://dx.doi.org/10.1128/JCM.00910-13Breitschwerdt, E.B., Mascarelli, P.E., Schweickert, L.A., Maggi, R.G., Hegarty, B.C., Bradley, J.M., Woods, C.W., Hallucinations, sensory neuropathy, and peripheral visual deficits in a young woman infected with Bartonella koehlerae (2011) J Clin Microbiol, 49, pp. 3415-3417. , http://dx.doi.org/10.1128/JCM.00833-11Raoult, D., Roblot, F., Rolain, J.M., Besnier, J.M., Loulergue, J., Bastides, F., Choutet, P., First isolation of Bartonella alsatica from a valve of a patient with endocarditis (2006) J Clin Microbiol, 44, pp. 278-279. , http://dx.doi.org/10.1128/JCM.44.1.278-279.2006Welch, D.F., Carroll, K.C., Hofmeister, E.K., Persing, D.H., Robison, D.A., Steigerwalt, A.G., Brenner, D.J., Isolation of a new subspecies, Bartonella vinsonii subsp. Arupensis, from a cattle rancher: Identity with isolates found in conjunction with Borrelia burgdorferi and Babesia microti among naturally infected mice (1999) J Clin Microbiol, 37, pp. 2598-2601Probert, W., Louie, J.K., Tucker, J.R., Longoria, R., Hogue, R., Moler, S., Graves, M., Fritz, C.L., Meningitis due to a "Bartonella washoensis"-like human pathogen (2009) J Clin Microbiol, 47, pp. 2332-2335. , http://dx.doi.org/10.1128/JCM.00511-09Kosoy, M., Morway, C., Sheff, K.W., Bai, Y., Colborn, J., Chalcraft, L., Dowell, S.F., Petersen, L.R., Bartonella tamiae sp. Nov., a newly recognized pathogen isolated from three human patients from Thailand (2008) J Clin Microbiol, 46, pp. 772-775. , http://dx.doi.org/10.1128/JCM.02120-07Maggi, R.G., Kosoy, M., Mintzer, M., Breitschwerdt, E.B., Isolation of Candidatus Bartonella melophagi from human blood (2009) Emerg Infect Dis, 15, pp. 66-68. , http://dx.doi.org/10.3201/eid1501.081080Lin, E.Y., Tsigrelis, C., Baddour, L.M., Lepidi, H., Rolain, J.M., Patel, R., Raoult, D., Candidatus Bartonella mayotimonensis and endocarditis (2010) Emerg Infect Dis, 16, pp. 500-503. , http://dx.doi.org/10.3201/eid1603.081673Breitschwerdt, E.B., Maggi, R.G., Cadenas, M.B., De Paiva Diniz, P.P., A groundhog, a novel Bartonella sequence, and my father's death (2009) Emerg Infect Dis, 15, pp. 2080-2086. , http://dx.doi.org/10.3201/eid1512.AD151

Search for lepton-flavor violation at HERA

A search for lepton-flavor-violating interactions $e p \to \mu X$ and $e p\to \tau X$ has been performed with the ZEUS detector using the entire HERA I data sample, corresponding to an integrated luminosity of 130 pb^{-1}. The data were taken at center-of-mass energies, $\sqrt{s}$, of 300 and 318 GeV. No evidence of lepton-flavor violation was found, and constraints were derived on leptoquarks (LQs) that could mediate such interactions. For LQ masses below $\sqrt{s}$, limits were set on $\lambda_{eq_1} \sqrt{\beta_{\ell q}}$, where $\lambda_{eq_1}$ is the coupling of the LQ to an electron and a first-generation quark $q_1$, and $\beta_{\ell q}$ is the branching ratio of the LQ to the final-state lepton $\ell$ ($\mu$ or $\tau$) and a quark $q$. For LQ masses much larger than $\sqrt{s}$, limits were set on the four-fermion interaction term $\lambda_{e q_\alpha} \lambda_{\ell q_\beta} / M_{\mathrm{LQ}}^2$ for LQs that couple to an electron and a quark $q_\alpha$ and to a lepton $\ell$ and a quark $q_\beta$, where $\alpha$ and $\beta$ are quark generation indices. Some of the limits are also applicable to lepton-flavor-violating processes mediated by squarks in $R$-Parity-violating supersymmetric models. In some cases, especially when a higher-generation quark is involved and for the process $e p\to \tau X$, the ZEUS limits are the most stringent to date.Comment: 37 pages, 10 figures, Accepted by EPJC. References and 1 figure (Fig. 6) adde

Multijet production in neutral current deep inelastic scattering at HERA and determination of alpha_s

Multijet production rates in neutral current deep inelastic scattering have been measured in the range of exchanged boson virtualities 10 < Q2 < 5000 GeV2. The data were taken at the ep collider HERA with centre-of-mass energy sqrt(s) = 318 GeV using the ZEUS detector and correspond to an integrated luminosity of 82.2 pb-1. Jets were identified in the Breit frame using the k_T cluster algorithm in the longitudinally invariant inclusive mode. Measurements of differential dijet and trijet cross sections are presented as functions of jet transverse energy E_{T,B}{jet}, pseudorapidity eta_{LAB}{jet} and Q2 with E_{T,B}{jet} > 5 GeV and -1 < eta_{LAB}{jet} < 2.5. Next-to-leading-order QCD calculations describe the data well. The value of the strong coupling constant alpha_s(M_Z), determined from the ratio of the trijet to dijet cross sections, is alpha_s(M_Z) = 0.1179 pm 0.0013(stat.) {+0.0028}_{-0.0046}(exp.) {+0.0064}_{-0.0046}(th.)Comment: 22 pages, 5 figure

Photoproduction of D∗±D^{*\pm} mesons associated with a leading neutron

The photoproduction of $D^{*\pm} (2010)$ mesons associated with a leading neutron has been observed with the ZEUS detector in $ep$ collisions at HERA using an integrated luminosity of 80 pb$^{-1}$. The neutron carries a large fraction, {$x_L>0.2$}, of the incoming proton beam energy and is detected at very small production angles, {$\theta_n<0.8$ mrad}, an indication of peripheral scattering. The $D^*$ meson is centrally produced with pseudorapidity {$|\eta| 1.9$ GeV}, which is large compared to the average transverse momentum of the neutron of 0.22 GeV. The ratio of neutron-tagged to inclusive $D^*$ production is $8.85\pm 0.93({\rm stat.})^{+0.48}_{-0.61}({\rm syst.})\%$ in the photon-proton center-of-mass energy range {$130 <W<280$ GeV}. The data suggest that the presence of a hard scale enhances the fraction of events with a leading neutron in the final state.Comment: 28 pages, 4 figures, 2 table