Until recently, most studies on the role of hormones in plant-pathogen interactions focused on salicylic acid (SA), jasmonic acid (JA), and ethylene (ET). It is now clear that pathogen-induced modulation of signaling via other hormones contributes to virulence. A picture is emerging of complex crosstalk and induced hormonal changes that modulate disease and resistance, with outcomes dependent on pathogen lifestyles and the genetic constitution of the host. Recent progress has revealed intriguing similarities between hormone signaling mechanisms, with gene induction responses often achieved by derepression. Here, we report on recent advances, updating current knowledge on classical defense hormones SA, JA, and ET, and the roles of auxin, abscisic acid (ABA), cytokinins (CKs), and brassinosteroids in molding plant-pathogen interactions. We highlight an emerging theme that positive and negative regulators of these disparate hormone signaling pathways are crucial regulatory targets of hormonal crosstalk in disease and defense.

Hormone Crosstalk in Plant Disease and Defense: More Than Just JASMONATE-SALICYLATE Antagonism

Many ``real-world'' networks are clearly defined while most ``social'' networks are to some extent subjective. Indeed, the accuracy of empirically-determined social networks is a question of some concern because individuals may have distinct perceptions of what constitutes a social link. One unambiguous type of connection is sexual contact. Here we analyze data on the sexual behavior of a random sample of individuals, and find that the cumulative distributions of the number of sexual partners during the twelve months prior to the survey decays as a power law with similar exponents $\alpha \approx 2.4$ for females and males. The scale-free nature of the web of human sexual contacts suggests that strategic interventions aimed at preventing the spread of sexually-transmitted diseases may be the most efficient approach.

The Web of Human Sexual Contacts

Hormone balance and abiotic stress tolerance in crop plants

Tick-borne rickettsioses are caused by obligate intracellular bacteria belonging to the spotted fever group of the genus Rickettsia. These zoonoses are among the oldest known vector-borne diseases. However, in the past 25 years, the scope and importance of the recognized tick-associated rickettsial pathogens have increased dramatically, making this complex of diseases an ideal paradigm for the understanding of emerging and reemerging infections. Several species of tick-borne rickettsiae that were considered nonpathogenic for decades are now associated with human infections, and novel Rickettsia species of undetermined pathogenicity continue to be detected in or isolated from ticks around the world. This remarkable expansion of information has been driven largely by the use of molecular techniques that have facilitated the identification of novel and previously recognized rickettsiae in ticks. New approaches, such as swabbing of eschars to obtain material to be tested by PCR, have emerged in recent years and have played a role in describing emerging tick-borne rickettsioses. Here, we present the current knowledge on tick-borne rickettsiae and rickettsioses using a geographic approach toward the epidemiology of these diseases.

Update on Tick-Borne Rickettsioses around the World: a Geographic Approach

During most of the 20th century, the epidemiology of tick-borne rickettsioses could be summarized as the occurrence of a single pathogenic rickettsia on each continent. An element of this paradigm suggested that the many other characterized and noncharacterized rickettsiae isolated from ticks were not pathogenic to humans. In this context, it was considered that relatively few tick-borne rickettsiae caused human disease. This concept was modified extensively from 1984 through 2005 by the identification of at least 11 additional rickettsial species or subspecies that cause tick-borne rickettsioses around the world. Of these agents, seven were initially isolated from ticks, often years or decades before a definitive association with human disease was established. We present here the tick-borne rickettsioses described through 2005 and focus on the epidemiological circumstances that have played a role in the emergence of the newly recognized diseases.

Tick-Borne Rickettsioses around the World: Emerging Diseases Challenging Old Concepts

Improvements in veterinary medicine have resulted in a significant benefit in the life of pets in the last 20 years, and increased pet life expectancy led to an increased prevalence of canine neoplasia. Cancer epidemiology and spatial analysis tools, although well developed for human oncology research, is just beginning to be explored in veterinary oncology. Sao Paulo city, capital of the state of Sao Paulo, Brazil, is divided into five regions: North, South, East, West and downtown. The Veterinary Hospital of the School of Veterinary Medicine and Animal Science, University of Sao Paulo (HOVET-SVMAS-USP), is located in the West region of Sao Paulo, Brazil, and admits cases of small and large animals. Canine mammary tumors are so numerous that they are not routinely treated at the HOVET. The aim of this work was to perform a cartographic study to describe the spatial distribution of prevalent cases of neoplasms in dogs from the HOVET. Of the 3,620 cases seen in 2002 and 2003, 380 cases (10.5%) were of dogs affected with benign and malignant neoplasms. No statistical difference was found for the 380 addresses distributed among the five regions of the city. These results showed that the HOVET receives canine patients from all regions of Sao Paulo and there is a homogeneous spatial distribution of neoplasms. Authors encourage additional broader studies, involving several veterinary hospitals, clinics or laboratories in order to obtain more accurate data on distribution of canine neoplasms in Sao Paulo, SP, Brazil.

/pdf/cartografia-das-neoplasias-em-caes-das-diferentes-regioes-da-iutvnxyuv9.pdf

Cartografia das neoplasias em cães das diferentes regiões da cidade de São Paulo, SP, Brasil: um levantamento (2002-2003) dos dados do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Brasil

/pdf/situacao-epidemiologica-da-brucelose-no-brasil-2b07c3ryy5.pdf

Situação epidemiológica da brucelose no Brasil

Carrapatos infestando capivaras em cinco áreas do Estado de São Paulo

In light of recent efforts in Brazil to increase B19 strain vaccine coverage of heifers, this study proposes a standardized methodology for the calculation of vaccination coverage among the Federal Units. To illustrate its use, the method was applied to data from the state of Mato Grosso to calculate vaccination coverage from 2006 to 2010. The results provide the best estimate based on data currently available in most states and can be easily adapted to situations in which the cattle registries use different age categories from those used in the state of Mato Grosso.

Method for determining bovine brucellosis vaccination coverage

/pdf/fatores-de-risco-para-brucelose-bovina-no-brasil-uerbudjg7x.pdf

Fernando Ferreira

Papers

Cartografia das neoplasias em cães das diferentes regiões da cidade de São Paulo, SP, Brasil: um levantamento (2002-2003) dos dados do Hospital Veterinário da Faculdade de Medicina Veterinária e Zootecnia da Universidade de São Paulo, Brasil

Situação epidemiológica da brucelose no Brasil

Carrapatos infestando capivaras em cinco áreas do Estado de São Paulo

Method for determining bovine brucellosis vaccination coverage

Fatores de risco para brucelose bovina no Brasil