Challenges in controlling viral diseases of poultry

As in many countries including Malaysia, poultry industry has become a major contributor to the country’s economy primarily due to the rapid revolutionary of the industry and advances made in poultry management, nutrition, genetics and better diagnosis and control of diseases. As the poultry industry is expanding, much is needed to be done to improve the efficiency of production, which directly depends on the control and prevention of diseases. Infectious diseases are one of the major causes of economic losses in poultry industries. In many instances, no specific signs are associated with a particular disease. Besides clinical signs and findings from post mortem examinations, diagnostic tools based on serological and molecular detection are used to confirm the causative agents. However, the identification of causative agents and the detection of specific antibody responses in relation to a clinical problem are complicated due to the concurrent infections and improper use of vaccines. Currently, the poultry industry is threatened by more virulent viruses of endemic diseases or by exotic and emerging diseases that can cause major economic losses to this sector. The emergence and re-emergence of avian influenza virus (AIV), particularly the highly pathogenic avian influenza (HPAI) H5N1, the presence of endemic low pathogenic avian influenza (LPAI) H9N2 in poultry flock and recently the detection of novel H7H9 posed significant threat to the poultry industry and public health sector. Catastrophic diseases such as HPAI H5N1 is not easy to overlook, the real challenge is to confront H7N9, H9N2 and other LPAI which act in concert with other factors such as management, environment, nutrition and concurrent infections which form continuous threat to the entire poultry production system. The repeated outbreaks of diseases caused by variant strains of infectious bronchitis virus (IBV), velogenic Newcastle disease viruses (NDV) and more virulent viruses of infectious bursal disease virus (IBDV), infectious laryngotracheitis virus (ILTV) and Marek’s disease virus (MDV) in well managed poultry flocks have prompted the need to evaluate the underlying factors contributing to the failure of vaccination to provide complete protection against clinical infections and transmission of disease. Vaccination failure can be classified as primary vaccination failure where the chickens do not develop adequate antibody titer and succumbed to a field disease outbreak. However, in secondary vaccination failure, the chickens develop adequate immune response but then immunity wanes over time. In the field, vaccination failure is complex involving various factors associated with the vaccine strains and vaccination program, the virulence of field pathogens and the host immune competence. In many situations, immunosuppressive agents primarily MDV, IBDV, and chicken anemia virus play an important role in increasing the susceptibility of chickens to opportunistic infections and/or suppressing effective vaccine induced responses.There is no doubt diagnostic tools, vaccines and vaccination equipment have improved over the years. However, despite these advancements, conventional laboratory diagnosis using serological tests and conventional live and killed vaccines are used extensively in health and disease management of poultry. As the poultry industry become more intensive, accurate, economical and practical laboratory diagnostic tools are important for effective control of disease outbreaks. The advancements in the use of molecular detection method using real-time PCR approach, highly automated instruments for antibody detection and development of rapid on site antigen capture assays for virus antigen detection may have significant impact in the field of disease prevention and control. In the area of vaccinology, most of the advances in the development of the so called recombinant vaccines against poultry disease are based on the development of recombinant protein or synthetic peptide vaccines, recombinant vector vaccines using selected virus or bacteria as carriers and DNA plasmids as genetic vaccines. However, very few recombinant vaccines are available commercially. The majority of these newer vaccines are live recombinant viral vectors based on fowlpox virus and herpesvirus designed to deliver specific gene(s) to stimulate the host’ immune system. Recently, a few new live recombinant viral vector vaccines based on avian adenovirus and reverse genetic NDV and AIV are making their way in several countries. However, the use of vaccines against field viruses also contribute to the emergence of variant or more virulent viruses that are able to escape existing vaccine induced immunity as what have been reported for several RNA viruses namely AIV, IBV and IBDV. Similar phenomenon was also reported for DNA viruses such as MDV and ILT, where the use of different live attenuated ILT vaccine strains contribute to the emergence of new pathogenic ILT strain affecting poultry. It is clear that progress has been made in the control and prevention of viral diseases of poultry. However, a comprehensive approach is needed for disease control requiring consideration of the interactions between management, nutrition, poultry genetics and immune functions against infectious disease. It is envisioned that the progress in functional characterization of the chicken genome, avian transgenic technology and further improvement of poultry vaccines and therapeutics will further increase the global competitiveness of poultry industry

An Investigation of Arab Students’ Motivation for Learning English

This study investigated what factors motivate L1 Arab learners of English at the University of Huddersfield, whether Arab students‘ motivation changes during their university course, and, if there is any change, how it influences students‘ second language proficiency level. In particular, this study aimed to examine the relationship between students‘ level of motivation and their proficiency level in English. In order to investigate these factors, I adopted the mixed method represented by the quantitative and qualitative research techniques which have been applied sequentially at two points (1) at the start of their English language course (2) and at the end of the course. The data were collected from Arab students enrolled on the ESUS Course, English Skills for University Study, at the International Study Centre at University of Huddersfield (N=42). The findings showed that of the multiple factors which motivate L1 Arab students to learn English, the first among them are an interest in foreign languages and instrumental motivation to find a job and pass exams. This research introduced a new definition of Integrativeness. The traditional concept of integrativeness states that the L2 student learns English because they have a positive attitude towards the native speakers or want to be a part of the native community. This was not reflected in the research as the students were learning English to become a part of the international community (whose members speak English). Students in this research were learning English to become a part of the international community whose members speak English. The data collected in this research showed that there was no correlation between students‘ L2 motivation and their proficiency level. Students‘ motivation scores at the beginning and the end of their English course were compared to their entry and final exam results and no statistically significant correlation was found. In addition, students‘ change in motivation was compared with their entry, final and change in exam performance and no statistically significant correlation was found here either. This suggests that the traditional role of L2 motivation in learning a target language has changed over the last few decades. The traditional role played by motivation in learning a second language has been minimized during the last few decades. The considerations of more important factors such as the personal differences, teaching style in schools and universities and the openness of some closed regions to the English civilization and lifestyle have limited the influence of motivation on the L2 learning process

Actinobacillosis of the omentum in A Cow

Satu kes actinobacillosis luar biasa menglibatkan omentum lembu dihuraikan. Walaupun pendapatan histologi lesi adalah menyerupai penyakit ini dengan tepat, bakteria penyebabnya Actinobacillus lignieresi tidak diperolehi dalam kajian kultura. Perimustahaknya penyakit ini dalam segi pemeriksaan daging praktik dibincangkan

DIGITAL TECHNOLOGY AND SECOND LANGUAGE ACQUISITION IN PRE-SCHOOL AGE

This paper presents a study investigating the use of digital technology - tablets and mobile phones by six pre-school children in Požega, Croatia and the way this technology facilitated the English language learning process through its content. The children involved were two boys and four girls aged between four to five. The paper’s introduction reflects on today’s widespread use of digital technology amongst the young learners. The study itself was conducted using two quantitative research methods – contextual interviews with the pre-school children and interviews with the children’s parents. The study findings indicated that the children preferred multimodal content such as cartoons and video games with colourful themes or characters, that prompt or ask questions, i.e. encourage participation. A strong preference for English speakers changing pitch and tone within the content was also indicated in the findings. The findings pointed to children’s preference towards music videos – nursery rhymes teaching letters, numbers or colours. Finally, gaming videos and tutorials were a common choice of content for all six children, where they were mostly exposed to visual and aural prompts. In conclusion, the children independently selected multimodal content: cartoons, videos games, tutorials, gaming videos and nursery rhymes which all shared visual, aural, linguistic and spatial modes of communication. The research provided a valuable insight into the type of digital content that pre-school children opt for in non-educational environment and how they acquire basic communication skills in English as a result

Investigation of path loss prediction in different multi-floor stairwells at 900MHz and 1800MHz

Wireless communication along the stairwell in a high rise building is important to ensure immediate response to take place via consistent relaying of necessary information or data in emergency situations. Thus, a good understanding of signal wave attenuation along the stairwell is necessary to allow a better wireless network planning. This paper presents empirical path loss prediction model for multi-floor stairwell environment. The proposed model is based on measurement at 4 different stairwells, at 900MHz and 1800 MHz which are near public safety communication bands. The model incorporates the effect of different floor heights and unique path loss-to-distance relation on selected stair flights observed during measurement campaign. The proposed model demonstrates higher accuracy than 3 standard path loss models at 2 other stairwell

LINUX Based Application Layer for Vehicle Based Road/Environment Condition Warning System using Vehicular Ad hoc Networks (VANETs)

The number of accidents in Malaysia that increases annually is a severe problem that needs to be addressed aggressively [1]. Of the many factors that cause accidents, the reduced concentration of driver during a driving session is one of the main factors that add up to the number of road accident and this is more so during bad weather such as during rain fall, fog or snow. There is an urgency to develop something to help and increase the safety of the driver by warning the driver of the driving situation ahead. This project addresses this urgency by developing a safety application that is used to alert the driver of road/environment abnormality and spread the information to other drivers nearby. The vehicle to vehicle communication is done by implementing a platform for Vehicle Ad Hoc Networks (VANETs). This networks works by automatically forming networks between vehicles in real time. Currently the communication is done using the standard WiFi network. This project is strictly being developed on the application layer using JAVA. For the next stage of this project, the application can be linked to vehicle sensors and external sensors where the data obtained can be processed and broadcasted to other vehicles

Detection of organochlorine compound in puyu, sepat and haruan fish caught from irrigation canals in paddy fields in Selangor and Perak, Malaysia

A case study was conducted to investigate the concentration of organochlorine pesticide residues in fish samples collected from irrigation canals in paddy fields in Tanjong Karang and Sekinchan, Selangor and Seberang Perak, Perak, Malaysia. The samples comprised of three fish species, namely puyu (Anabas testudineus), haruan (Channa striatus) and sepat (Tricogaster pectoralis). Samples were chopped and homogenized and later digested and extracted using QuEChERS method and characterised for organochlorine compounds using gas chromatography. Seven organochlorine compounds, namely aldrin, dieldrin, endrin, endosulfan, o,p-DDT, o,p-DDD and p,p-DDT were identified and quantified. The water samples taken from the irrigation canals were analysed only for endosulfan at 0.04 mg/kg, which exceeded the maximum residue level for endosulfan pesticide residue for water sewage by Environment Protection Administration of the Republic of China on Taiwan (2000) at 0.03 mg/kg. However, the concentrations of endosulfan in all fish samples were below the Codex Alimentary Maximum Residue Limit of 0.2 mg/kg for meat

Poultry viruses: from threat to therapy

Infectious diseases are one of the major causes of economic losses in poultry industries. In many instances, there are no specific signs that are associated with a particular disease. Besides clinical signs and findings from post mortem examinations, diagnostic tools based on serological and molecular detections are used to confirm the causative agents. However, the identification of causative agents and the detection of specific antibody responses in relation to a clinical problem are complicated due to the concurrent infections and improper use of vaccines. Currently, the poultry industry is threatened by more virulent viruses of endemic diseases or by exotic and emerging diseases that can cause major economic losses to this sector. The emergence and re-emergence of avian influenza virus (AIV), particularly the highly pathogenic avian influenza (HPAI) H5N1, the presence of endemic low pathogenic avian influenza (LPAI) H9N2 in poultry flock and recently the detection of the novel H7H9 and H10N8 in certain regions in China posed threats to the poultry industry and public health sector. Infection with HPAI such as H5N1 is easy to diagnose. However, the real challenge is to confront H7N9, H9N2, H10N8 and other LPAI which act in concert with other factors such as management, environment, nutrition and concurrent infections which possess a continuous threat to the entire poultry production system. The repeated outbreaks of diseases caused by variant strains of infectious bronchitis virus (IBV), velogenic Newcastle disease viruses (NDV) and more virulent viruses of infectious bursal disease virus (IBDV), infectious laryngotracheitis virus (ILTV) and Marek’s disease virus (MDV) in well managed poultry flocks have prompted the need to evaluate the underlying factors contributing to the failure of vaccinations to provide protection against clinical infections and transmission of disease. In the field, vaccination failure is a complex event involving various factors associated with vaccine strains and vaccination program, the virulence of field pathogens and the host immune competence. In many situations, immunosuppressive agents, primarily the MDV, IBDV and chicken anemia virus play an important role in increasing the susceptibility of chickens to opportunistic infections and/or suppressing effective vaccine induced responses. Vaccination is the most cost-effective method available in preventing economic losses and increasing the lifespan of animals. Undoubtedly, diagnostic tools, vaccines and vaccination equipment have improved over the years through the use of innovative technology. However, vaccine is not evolution-proof and it may enhance virus evolution especially in the absence of sterilizing immunity allowing wild type viruses to be transmitted through vaccinated chickens.Despite advancements in genetic engineered tools, conventional laboratory diagnosis using serological tests and conventional vaccines are used extensively in health and disease management of poultry. Nearly all poultry vaccines are conventional vaccines which consist of live-attenuated and killed vaccines that have generally worked well. However, avian pathogens continue to change and develop ways to evade the immunity induced by the current vaccines. In addition, as the poultry industry become more intensive, accurate, economical and practical laboratory diagnostic tools are important for the effective control of disease outbreaks. The advancements in the use of molecular detection method using real-time PCR approach, highly automated instruments for antibody detection and development of rapid on site assays for virus antigen detection may have significant impact in the field of disease prevention and control. In the area of vaccinology, most of the advances in the development of recombinant vaccines against poultry diseases are based on the development of recombinant viral vectored, DNA plasmid and reverse genetic vaccines. However, it is anticipated that more recombinant based vaccines will be used in the field in the near future. In addition, the advancement on “omic” technology are paving novel approaches for the development of new generation adjuvants and vaccines as well as breeding for disease resistance based on our improving knowledge of the chicken immunogenomic response to disease. However, the development and delivery of new or improved poultry diagnostics, vaccines and pharmaceutical which fulfill the industry, regulatory and public acceptance is a challenging process. Although the majority of poultry viruses are pathogenic to chickens, some of them especially NDV has the potential to act as a live saver in humans due to its unique properties as viral vectored vaccine against other infectious diseases and selective oncolytic properties on human cancer cells. The continuous encouraging results of NDV oncolytic virotherapy in human clinical trials will facilitate the approval of NDV as ancillary therapy of human cancer in the near future. Innovative research on the use of NDV as human vaccines and therapeutics should be explored via multi-disciplinary approach by various expert groups. In conclusion, as the poultry industry is expanding and the globalization of poultry and poultry by products, much is needed to improve the control and prevention of diseases. The emerging and emerging of diseases especially transboundary diseases can impact socioeconomic of a country and global food security. The strengthening our scientific and technical capacity, especially through innovative technology and strategy, will help to meet the current challenges and ever changing needs of the nation and the world