Surveillance studies of Lymphocystis disease virus in farmed gilthead seabream (Sparus aurata) by real-time PCR

Lymphocystis disease (LCD) is the main viral infection reported to affect cultured gilthead seabream (Sparus aurata) in Southern Atlantic and Mediterranean aquaculture. Its etiological agent is the Lymphocystis disease virus (LCDV), a member of the family Iridoviridae (genus Lymphocystivirus). The only adequate measures for LCD prevention in the aquaculture systems are general prophylactic practices, such as the control of fish to be introduced in the farm facilities in order to detect carrier fish. These animals may pose a risk for the introduction of LCDV in fish farms, as direct contact between fish specimens is considered the main route of LCDV spreading. More recently, asymptomatic carrier breeders, as well as virus contaminated-live food, have been involved in LCDV transmission to fish larvae. The detection of subclinical viral infections in carrier fish requires the use of sensitive diagnostic methods. In this context, the objective of this study was to establish the applicability of a real-time PCR assay for LCDV diagnosis in surveillance studies. In addition, the assay has been evaluated with samples from a gilthead seabream hatchery, in order to prove its utility to trace the origin of LCDV in fish farms. Juvenile fish were collected at four farms with different background regarding to LCD. LCDV was detected in all farms, and 30 to 100% of fish were identified as LCDV-infected. Estimated viral load in caudal fin of asymptomatic fish was two to five orders of magnitude lower than in diseased fish. Carrier fish were also identified in the broodstock from a farm with LCD records by analysing caudal fin samples by qPCR. In this farm, the q-PCR assay developed in this study allowed the quantitative detection of LCDV in all samples collected in the hatchery, including fertilized eggs, larvae and fingerlings, and also rotifer cultures and artemia metanauplii and cysts used for larval rearing.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Teachers’ Perception of College and Career Education Exposure on Middle School Students

Properly preparing middle school students for their transition to high school and postsecondary endeavors requires early exposure to college and career information and resources. Across the United States, high school students have access to a scattered array of programs and resources aimed at career development and college preparation. Unfortunately, none of these college and career resources are integrated into the K-12 student experience in any systemic or holistic way. Furthermore, very few of these resources are even directed at K-12 students prior to their time in high school. This gap in college and career education is due to a lack of focus and absence of research on the early exposure of college and career education as a means to improve student achievement and prepare K-12 students for their transition into life post-graduation. The gap in literature and research aimed at understanding the impact of early exposure of College and Career Education (CCE) has led to the development of this study. This study seeks to assess middle school teachers’ perceptions to gather input for the development and publication of an engaging web-based resource center geared toward providing students with early exposure to college and career development resources

Course of infection with Lymphocystis disease virus in gilthead seabream (Sparus aurata)

Lymphocystis disease virus (LCDV) is the etiological agent of lymphocystis disease (LCD), a pathology that affects a wide variety of fish species. Data about LCDV pathogenesis are very short, and mainly limited to histopathological studies of skin lesions. Recent studies on viral genome detection (both by PCR or DNA-DNA in situ hybridization) suggest that LCDV establish a systemic and persistent infection in gilthead seabream (Sparus aurata), but further studies are necessary to prove if this infection is productive or not. In the present study viral quantification and viral mRNA detection (by qPCR and RT-qPCR) have been used to investigate LCDV multiplication in different organs of juvenile gilthead seabream. In addition, a histopathological study was carried out. Animals were collected from two commercial farms in Southwestern Spain. In one farm, where no LCD outbreaks have been recorded, apparently healthy fish were collected, whereas in the other farm, diseased and recovered (two months after LCD symptoms disappearance) fish were sampled. All the animals were LCDV-infected, and viral gene expression was detected in every organ analysed (caudal fin, intestine, liver, spleen, kidney and brain). In asymptomatic animals, both apparently healthy and recovered, a low-titre infection was observed, with the highest viral copy numbers detected in brain and kidney. In diseased fish, viral loads were significantly higher than in subclinical infected animals, being maximal in caudal fin, where lymphocysts were present in the dermis. Different histological alterations were observed in the internal organs from diseased fish analysed, although no hypertrophied cells were detected in any of them. In recovered fish, most of the organs examined presented similar histological features to those in healthy animals. Thus, pathological changes were only detected in the intestine and liver, although they were less severe than those observed in diseased fish. The results presented showed that LCDV establishes a systemic infection in juvenile gilthead seabream, which can be subclinical. In addition, although the disease is self-limiting, the virus is not removed after disease recovery, but produces a persistent infection.Universidad de Málaga. Campus de Excelencia Internacional Andalucía Tec

Основные модели национальной школы в современном российском образовании

Card issuers have mainly relied on rewards programs as their main strategy to increase usage. However, there is scarce evidence on the effectiveness of these programs. This paper is addressing two topics which could have important managerial and public policy implications: (i) it estimates the impact of rewards on the use of cards and (ii) it quantifies their economic effects in terms of the cash substitution. We find that rewards may significantly modify choice for card payments. Their economic impact also varies significantly across types of rewards and merchant activities. Additionally, rewards seem to be more effective for debit cards