Patterns in random walks and Brownian motion

We ask if it is possible to find some particular continuous paths of unit length in linear Brownian motion. Beginning with a discrete version of the problem, we derive the asymptotics of the expected waiting time for several interesting patterns. These suggest corresponding results on the existence/non-existence of continuous paths embedded in Brownian motion. With further effort we are able to prove some of these existence and non-existence results by various stochastic analysis arguments. A list of open problems is presented.Comment: 31 pages, 4 figures. This paper is published at http://link.springer.com/chapter/10.1007/978-3-319-18585-9_

Anemia mielotísica por osteopetrose em um cão: relato de caso

A osteopetrose é uma doença rara, caracterizada pelo aumento generalizado da densidade óssea. Tem como característica principal, a reabsorção osteoclástica defeituosa, resultando no acúmulo de massa óssea. Além disso, pode ocorrer retardo do crescimento, desnutrição progressiva, anemia e caquexia. O presente relato descreve o caso de uma cadela, com aproximadamente nove meses de idade, sem raça definida, com histórico de apatia e disorexia. Hemogramas seriados demonstraram pancitopenia persistente. Vários exames laboratoriais foram realizados para excluir doenças como erliquiose, leishmaniose e cinomose, porém todos foram negativos. O mielograma constatou hipocelularidade relativa por provável aplasia/hipoplasia medular. Exames radiográficos evidenciaram o aumento da radiopacidade óssea e hipertrofia da região cortical, e a necropsia confirmou a redução do canal medular. O exame histopatológico confirmou a osteopetrose. Conclui-se que a osteopetrose pode causar comprometimento na produção de células sanguíneas, sendo uma causa rara de anemia mielotísica, além de alterações neurológicas secundárias à má-formação dos ossos do crânio

Eficácia dos colírios ciclosporina e tacrolimo no tratamento de ceratoconjuntivite seca em cães

RESUMO O objetivo deste estudo foi avaliar os efeitos do tacrolimo e da ciclosporina na produção lacrimal de cães com ceratoconjuntivite seca (CCS) durante 90 dias. Para tanto, foram utilizados colírios de tacrolimo 0,02% (TcL) e ciclosporina 0,1% (CsA) em 14 cães com CCS. Os animais foram distribuídos em dois grupos e avaliados antes do início do tratamento (T0) e aos 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) e 90 (T6) dias após o início do tratamento. Na avaliação clínica, observou-se maior redução da secreção ocular, da opacidade e do edema corneano e da vascularização conjuntival. no grupo tacrolimo. No teste de Schirmer, verificou-se produção basal de 6(4,07 e 5,86(2,85mm/min no TcL e CsA, respectivamente, com aumento significativo da produção lacrimal em ambos os grupos, contudo houve aumento significativo da produção lacrimal a partir dos 15 dias de tratamento no grupo TcL (17,88(5,51mm/min), mas apenas a partir dos 45 dias no grupo CsA (11,86(4,74mm/min). Conclui-se que o uso do colírio tacrolimo aumentou em 68,83% a produção lacrimal em 90 dias de tratamento, comparado com a ciclosporina (56,82%), além de diminuir as manifestações clínicas inerentes à CCS, quando comparado à terapia com ciclosporina

Matriz porosa do BV60S no tratamento de defeitos ósseos críticosem rádios de cães

O objetivo deste estudo foi avaliar o efeito da matriz porosa do biovidro de composição molar 60% SiO2 - 36% CaO - 4% P2O5 (BV60S) no tratamento de defeitos ósseos críticos de cães. Foram utilizados 20 cães, machos, sem raça definida, com dois anos e massa corporal média de 25kg. Foram constituídos três grupos experimentais: defeitos ósseos preenchidos com BV60S (BV), com osso autógeno (C+) e defeitos não preenchidos (C-). A regeneração óssea foi avaliada por meio de exames radiográficos, densitométricos e histomorfométricos ao longo de 90 dias. A matriz do BV60S mostrou rápida reabsorção com redução média de 12,62% a cada 15 dias. A regeneração foi completa no grupo C+ e incompleta nos grupos BV e C-, aos 90 dias. A área de neoformação óssea foi semelhante entre os grupos BV e C-, em todos os tempos estudados. Conclui-se que a matriz porosa do BV60S possui rápida reabsorção, não sendo eficiente no tratamento de defeitos ósseos críticos em rádios de cães

Efeito da fluidoterapia transcirúrgica sobre o hematócrito pós-cirúrgico em cadelas submetidas a ovariossalpingo-histerectomia eletiva

RESUMO Apesar dos inúmeros benefícios da fluidoterapia transcirúrgica, sobrecarga de volume pode trazer efeitos deletérios, como a alteração de parâmetros hematimétricos. Dessa maneira, o presente trabalho teve como objetivo avaliar duas diferentes taxas de infusão de solução cristaloide no período transanestésico e seus efeitos até 24 horas pós-operatório. Foram utilizados dois grupos de seis animais cada, um deles recebeu solução de cloreto de sódio 0,9% a 10mL/kg/h (G10) e o outro a 5mL/kg/h (G5). Os valores de hematócrito foram avaliados no período de 24 horas em 10 diferentes momentos. Os resultados não apontaram diferenças significativas entre os grupos, porém foi observada redução significativa do hematócrito após indução anestésica. Foi ainda observada redução de hematócrito após o término da cirurgia em ambos os grupos, e o retorno aos valores basais de hematócrito ocorreu de forma significativa 12 horas após o procedimento cirúrgico em G10, e após oito horas em G5, mostrando uma tendência à hemodiluição mais persistente em G10

Delay From Fracture To Hospital Admission: A New Risk Factor For Hip Fracture Mortality?

Summary: The relationship between surgical timing and hip fracture mortality is unknown in the context of developing countries where large delays to surgery are common. We observed that delay from fracture to hospital admission is associated with decreased survival after a hip fracture. Introduction: To examine the relationship between the time interval from fracture to surgery as well as its subcomponents (time from fracture to hospital admission and time from admission to surgery) and hip fracture survival. Methods: The medical records of all patients aged 60 years and older admitted to a public university hospital in the city of Rio de Janeiro with a primary diagnosis of hip fracture between 1995 and 2000 were reviewed. Survival to hospital discharge and at 1 year were examined. Results: Among 343 patients included in the study, there were 18 (5.3%) in-hospital deaths, and 297 (86.6%) patients remained alive 1 year after surgery. Very long delays from the time of fracture to hospital admission (mean 3 days) and from hospital admission to surgery (mean 13 days) were identified. Increased time from fracture to hospital admission was associated with reduced survival to hospital discharge (hazard ratio [HR] 1.09, 95% CI 1.03-1.15, p00.005) and reduced survival at 1 year after surgery (HR 1.07, 95% CI 1.03-1.10, p< 0.001). The interval of time from hospital admission to surgery was not associated with reduced survival to hospital discharge (HR 1.03, 95% CI 0.96-1.10, p00.379) or at 1 year after surgery (HR 1.03, 95% CI 0.99-1.07, p00.185). Conclusions: If the association estimated in our study is causal, our results provide evidence that some hip fracturerelated deaths could be prevented by improved patient access to appropriate and timely hospital care in the context of a developing country. © International Osteoporosis Foundation and National Osteoporosis Foundation 2012.231228472853Johnell, O., Kanis, J., Epidemiology of osteoporotic fractures (2005) Osteoporosis International, 16 (SUPPL. 2), pp. S3-S7. , DOI 10.1007/s00198-004-1702-6Cummings, S.R., Melton, L.J., Epidemiology and outcomes of osteoporotic fractures (2002) Lancet, 359 (9319), pp. 1761-1767Hiligsmann, M., Bruyere, O., Ethgen, O., Gathon, H.J., Reginster, J.Y., Lifetime absolute risk of hip and other osteoporotic fracture in Belgian women (2008) Bone, 43 (6), pp. 991-994Haentjens, P., Magaziner, J., Colon-Emeric, C.S., Vanderschueren, D., Milisen, K., Velkeniers, B., Boonen, S., Meta-analysis: Excess mortality after hip fracture among older women and men (2010) Ann Intern Med, 152 (6), pp. 380-390Vidan, M.T., Sanchez, E., Gracia, Y., Maranon, E., Vaquero, J., Serra, J.A., Causes and effects of surgical delay in patients with hip fracture: A cohort study (2011) Ann Intern Med, 155 (4), pp. 226-233Majumdar, S.R., Beaupre, L.A., Johnston, D.W.C., Dick, D.A., Cinats, J.G., Jiang, H.X., Lack of association between mortality and timing of surgical fixation in elderly patients with hip fracture: Results of a retrospective population-based cohort study (2006) Medical Care, 44 (6), pp. 552-559. , DOI 10.1097/01.mlr.0000215812.13720.2e, PII 0000565020060600000010Novack, V., Jotkowitz, A., Etzion, O., Porath, A., Does delay in surgery after hip fracture lead to worse outcomes? A multicenter survey (2007) International Journal for Quality in Health Care, 19 (3), pp. 170-176. , DOI 10.1093/intqhc/mzm003Shiga, T., Wajima, Z., Ohe, Y., Is operative delay associated with increased mortality of hip fracture patients? Systematic review, meta-analysis, and meta-regression (2008) Canadian Journal of Anesthesia, 55 (3), pp. 146-154Kahn, S.K., Kalra, S., Khanna, A., Thiruvengada, M.M., Parker, M.J., Timing of surgery for hip fractures: A systematic review of 52 published studies involving 291, 413 patients (2009) Injury, 40 (7), pp. 692-697Leung, F., Lau, T.W., Kwan, K., Chow, S.P., Kung, A.W.C., Does timing of surgery matter in fragility hip fractures? (2010) Osteoporos Int, 21 (SUPPL. 4), pp. S529-S534Vidal, E.I., Moreira-Filho, D.C., Coeli, C.M., Camargo, K.R., Fukushima, F.B., Blais, R., Hip fracture in the elderly: Does counting time from fracture to surgery or from hospital admission to surgery matter when studying in-hospital mortality? (2009) Osteoporos Int, 20 (5), pp. 723-729Gullberg, B., Johnell, O., Kanis, J.A., World-wide projections for hip fracture (1997) Osteoporosis International, 7 (5), pp. 407-413. , DOI 10.1007/PL00004148Computerised record linkage: Compared with traditional patient follow-up methods in clinical trials and illustrated in a prospective epidemiological study. West of Scotland Coronary Prevention Study Group (1995) J Clin Epidemiol., 48 (12), pp. 1441-1452Jaro, M., Probabilistic linkage of large public health data files (1995) Stat Med, 14 (5-7), pp. 491-498Vidal, E.I.O., Coeli, C.M., Pinheiro, R.S., Camargo Jr., K.R., Mortality within 1 year after hip fracture surgical repair in the elderly according to postoperative period: A probabilistic record linkage study in Brazil (2006) Osteoporosis International, 17 (10), pp. 1569-1576. , DOI 10.1007/s00198-006-0173-3Shannon, H.S., Jamieson, E., Walsh, C., Julian, J.A., Fair, M.E., Buffet, A., Comparison of individual follow-up and computerized record linkage using the Canadian Mortality Data Base (1989) Canadian Journal of Public Health, 80 (1), pp. 54-57Coutinho, E.S.F., Coeli, C.M., Accuracy of the probabilistic record linkage methodology to ascertain deaths in survival studies (2006) Cadernos de Saude Publica, 22 (10), pp. 2249-2252. , http://www.scielo.br/pdf/csp/v22n10/24.pdfCamargo Jr., K.R., Coeli, C.M., Reclink: An application for database linkage implementing the probabilistic record linkage method (2000) Cad Saude Publica, 16 (2), pp. 439-447Charlson, M.E., Pompei, P., Ales, K.A., MacKenzie, C.R., A new method of classifying prognostic comorbidity in longitudinal studies: Development and validation (1987) Journal of Chronic Diseases, 40 (5), pp. 373-383. , DOI 10.1016/0021-9681(87)90171-8Grambsch, P., Therneau, T., Proportional hazards tests and diagnostics based on weighted residuals (1994) Biometrika, 81 (3), pp. 515-526R: A language and environment for statistical computing (2009) R Foundation for Statistical Computing, , R Development Core Team, Vienna, AustriaOrosz, G.M., Hannan, E.L., Magaziner, J., Koval, K., Gilbert, M., Aufses, A., Straus, E., Siu, A.L., Hip fracture in the older patient: Reasons for delay in hospitalization and timing of surgical repair (2002) J Am Geriatr Soc, 50 (8), pp. 1336-1340Hefley Jr., W.F., Nelson, C.L., Puskarich-May, C.L., Effect of delayed admission to the hospital on the preoperative prevalence of deep-vein thrombosis associated with fractures about the hip (1996) Journal of Bone and Joint Surgery - Series A, 78 (4), pp. 581-583Grimes, J.P., Gregory, P.M., Noveck, H., Butler, M.S., Carson, J.L., The effects of time-to-surgery on mortality and morbidity in patients following hip fracture (2002) American Journal of Medicine, 112 (9), pp. 702-709. , DOI 10.1016/S0002-9343(02)01119-1, PII S0002934302011191Beaupre, L.A., Jones, C.A., Saunders, L.D., Johnston, D.W.C., Buckingham, J., Majumdar, S.R., Best practices for elderly hip fracture patients: A systematic overview of the evidence (2005) Journal of General Internal Medicine, 20 (11), pp. 1019-1025. , DOI 10.1111/j.1525-1497.2005.00219.xOrosz, G.M., Magaziner, J., Hannan, E.L., Morrison, R.S., Koval, K., Gilbert, M., McLaughlin, M., Siu, A.L., Association of Timing of Surgery for Hip Fracture and Patient Outcomes (2004) Journal of the American Medical Association, 291 (14), pp. 1738-1743. , DOI 10.1001/jama.291.14.1738Bhandari, M., Tornetta III, P., Ellis, T., Audige, L., Sprague, S., Kuo, J.C., Swiontkowski, M.F., Hierarchy of evidence: Differences in results between non-randomized studies and randomized trials in patients with femoral neck fractures (2004) Archives of Orthopaedic and Trauma Surgery, 124 (1), pp. 10-16. , DOI 10.1007/s00402-003-0559-zMcGuire, K., Bernstein, J., Polsky, D., Silber, J., Delays until surgery after hip fracture increases mortality (2004) Clin Orthop Rel Res, 428, pp. 294-301Zuckerman, J.D., Skovron, M.L., Koval, K.J., Aharonoff, G., Frankel, V.H., Postoperative complications and mortality associated with operative delay in older patients who have a fracture of the hip (1995) J Bone Joint Surg Am, 77 (10), pp. 1551-155

Efficacy of cyclosporine and tacrolimus drops in the treatment of keratoconjunctivitis sicca in dogs

<p></p><p>ABSTRACT The objective of this study was to evaluate the effects of tacrolimus and cyclosporine on the lacrimal production of dogs with ketaroconjunctivitis sicca (KCS) for 90 days. Tacrolimus 0.02% (TcL) and 0.1% cyclosporine (CsA) eye drops were used in 14 dogs with KCS. The animals were randomly assigned to two groups and evaluated before treatment (T0) and at 15 (T1), 30 (T2), 45 (T3), 60 (T4), 75 (T5) and 90 (T6) days after initiation of treatment. Clinical evaluation showed significant reduction of ocular secretion, corneal opacity and edema and conjunctival vascularization in the tacrolimus group. Schirmer test showed basal lacrimal production of 6(4.07 and 5.86(2.85mm/min for TcL and CsA, respectively, with significant increase in lacrimal production in both groups. There was a significant increase in lacrimal production after 15 days of treatment in the TcL group (17.88(5.51mm/min), but only after 45 days in the CsA group (11.86(4.74mm/min). Tacrolimus drops increased lacrimal production in 68.83% after 90 days of treatment, compared to cyclosporine (56.82%), and also reduced clinical manifestations related to KCS when compared to cyclosporine.</p><p></p