Validation of a screening tool for identifying three-year- old Cantonese-speaking children with language impairment

A dissertation submitted in partial fulfilment of the requirements for the Bachelor of Science (Speech and Hearing Sciences), The University of Hong Kong, June 30, 2007.Also available in print.Thesis (B.Sc)--University of Hong Kong, 2007.published_or_final_versionSpeech and Hearing SciencesBachelorBachelor of Science in Speech and Hearing Science

Partial characterisation of ATP-binding cassette encoding genes in Cryptosporidium parvum

Cryptosporidium parvum is an intestinal parasitic protozoa which causes self-limited diarrhoea in immunocompetent individuals and devastating and fulminant diarrhoea in immunocompromised patients (Griffiths, 1998)

Molecular epidemiology of Plasmodium species prevalent in Yemen based on 18 s rRNA

<p>Abstract</p> <p>Background</p> <p>Malaria is an endemic disease in Yemen and is responsible for 4.9 deaths per 100,000 population per year and 43,000 disability adjusted life years lost. Although malaria in Yemen is caused mainly by <it>Plasmodium falciparum </it>and <it>Plasmodium vivax</it>, there are no sequence data available on the two species. This study was conducted to investigate the distribution of the <it>Plasmodium </it>species based on the molecular detection and to study the molecular phylogeny of these parasites.</p> <p>Methods</p> <p>Blood samples from 511 febrile patients were collected and a partial region of the 18 s ribosomal RNA (18 s rRNA) gene was amplified using nested PCR. From the 86 positive blood samples, 13 <it>Plasmodium falciparum </it>and 4 <it>Plasmodium vivax </it>were selected and underwent cloning and, subsequently, sequencing and the sequences were subjected to phylogenetic analysis using the neighbor-joining and maximum parsimony methods.</p> <p>Results</p> <p>Malaria was detected by PCR in 86 samples (16.8%). The majority of the single infections were caused by <it>P. falciparum </it>(80.3%), followed by <it>P. vivax </it>(5.8%). Mixed infection rates of <it>P. falciparum </it>+ <it>P. vivax </it>and <it>P. falciparum </it>+ <it>P. malariae </it>were 11.6% and 2.3%, respectively. All <it>P. falciparum </it>isolates were grouped with the strain 3D7, while <it>P. vivax </it>isolates were grouped with the strain Salvador1. Phylogenetic trees based on 18 s rRNA placed the <it>P. falciparum </it>isolates into three sub-clusters and <it>P. vivax </it>into one cluster. Sequence alignment analysis showed 5-14.8% SNP in the partial sequences of the 18 s rRNA of <it>P. falciparum</it>.</p> <p>Conclusions</p> <p>Although <it>P. falciparum </it>is predominant, <it>P. vivax</it>, <it>P. malariae </it>and mixed infections are more prevalent than has been revealed by microscopy. This overlooked distribution should be considered by malaria control strategy makers. The genetic polymorphisms warrant further investigation.</p

Recombinant Dense Granular Protein (GRA5) for Detection of Human Toxoplasmosis by Western Blot

Toxoplasma gondii infects all warm-blooded animals, including humans, causing serious public health problems and great economic loss for the food industry. Commonly used serological tests require costly and hazardous preparation of whole Toxoplasma lysate antigens from tachyzoites. Here, we have evaluated an alternative method for antigen production, which involved a prokaryotic expression system. Specifically, we expressed T. gondii dense granular protein-5 (GRA5) in Escherichia coli and isolated it by affinity purification. The serodiagnostic potential of the purified recombinant GRA5 (rGRA5) was tested through Western blot analysis against 212 human patient serum samples. We found that rGRA5 protein was 100% specific for analysis of toxoplasmosis-negative human sera. Also, rGRA5 was able to detect acute and chronic T. gondii infections (sensitivities of 46.8% and 61.2%, resp.)

PLASER: Pronunciation Learning via Automatic Speech Recognition

PLASER is a multimedia tool with instant feedback designed to teach English pronunciation for high-school students of Hong Kong whose mother tongue is Cantonese Chinese. The objective is to teach correct pronunciation and not to assess a student&apos;s overall pronunciation quality. Major challenges related to speech recognition technology include: allowance for non-native accent, reliable and corrective feedbacks, and visualization of errors

Genetic assemblage of Sarcocystis spp. in Malaysian snakes

Abstract Background: Sarcocystis species are protozoan parasites with a wide host range including snakes. Although there were several reports of Sarcocytis species in snakes, their distribution and prevalence are still not fully explored. Methods: In this study, fecal specimens of several snake species in Malaysia were examined for the presence of Sarcocystis by PCR of 18S rDNA sequence. Microscopy examination of the fecal specimens for sporocysts was not carried as it was difficult to determine the species of the infecting Sarcocystis. Results: Of the 28 snake fecal specimens, 7 were positive by PCR. BLASTn and phylogenetic analyses of the amplified 18S rDNA sequences revealed the snakes were infected with either S. nesbitti, S. singaporensis, S. zuoi or undefined Sarcocystis species. Conclusion: This study is the first to report Sarcocystis infection in a cobra, and S. nesbitti in a reticulated python

A preliminary investigation of China Ginger and Kuching Local Ginger species : Oil extracts and synthesis towards potential greener insect repellent

Ginger essential oil (Zingiber officinale) is the volatile oil extracted from ginger rhizome. Compared to chemical synthetic repellent, green insect (in particular mosquito) repellent would be favoured by the public as it is environmentally friendly and does not cause harm to the human’s health. The focus of this study is on the comparison study between China Ginger and Kuching Local Ginger essential oil aim towards utilization as the greener mosquito repellent. In this study, the ginger essential oils are extracted greener method i.e. via hydro distillation process for 7 h. The percentage oil yield for China and Kuching Local Ginger are 0.158 wt% and 0.264 wt%, respectively. The extracted ginger essential oils are further subject to Fourier Transform Infrared Spec�troscopy (FTIR) and Gas Chromatography- Mass spectrometry (GC-MS) analysis. Based on the FTIR spectrum graph generated, both types of ginger essential oils essentially having the similar function groups including phenolic compounds, alcohol primer, alkena methyl group, aromatic compound, carbonyl compound, carboxylic acid, hydroxyl group. From the GC-MS results it revealed that the most abundant chemical constituents presented in both China Gniger and Kuching Local Ginger essential are: α-Zingiberene (7.88% and 7.03%), α-Curcumene (6.04% and 6.49%), α-Citral or Genarial (3.81% and 7.86%), β-Bisabolene (3.06% and 4.62%), β-esqui�phellandrene (5.83% and 5.95%), β-Sesquisabinene (0.07% and 0.51%), β-Selinenol (3.97% and 2.26%), Zin�giberenol (5.16% and 1.64%), [6]-Shogaol (0.33% and 0.23%), trans-Sesquisabinene hydrate (1.72% and 2.87%), trans-Geranylgeraniol (3.51% and 2.81%), Camphene (1.17% and 0.56%), Eucalyptol (2.68% and 1.81%), Citronellol (1.76% and 1.55%), Neral (2.82% and 6.03%), and Geraniol (1.62% and 2.29%) respectively. Kuching Local Ginger essential oil is found marginally superior insect repellent characteristics due to its higher monoterpene compounds in the essential oil

Perspectives of vector management in the control and elimination of vector-borne zoonoses

The complex transmission profiles of vector-borne zoonoses (VZB) and vector-borne infections with animal reservoirs (VBIAR) complicate efforts to break the transmission circuit of these infections. To control and eliminate VZB and VBIAR, insecticide application may not be conducted easily in all circumstances, particularly for infections with sylvatic transmission cycle. As a result, alternative approaches have been considered in the vector management against these infections. In this review, we highlighted differences among the environmental, chemical, and biological control approaches in vector management, from the perspectives of VZB and VBIAR. Concerns and knowledge gaps pertaining to the available control approaches were discussed to better understand the prospects of integrating these vector control approaches to synergistically break the transmission of VZB and VBIAR in humans, in line with the integrated vector management (IVM) developed by the World Health Organization (WHO) since 2004

A preliminary investigation of China Ginger and Kuching Local Ginger species: Oil extracts and synthesis towards potential greener insect repellent

Ginger essential oil (Zingiber officinale) is the volatile oil extracted from ginger rhizome. Compared to chemical synthetic repellent, green insect (in particular mosquito) repellent would be favoured by the public as it is environmentally friendly and does not cause harm to the human’s health. The focus of this study is on the comparison study between China Ginger and Kuching Local Ginger essential oil aim towards utilization as the greener mosquito repellent. In this study, the ginger essential oils are extracted greener method i.e. via hydro distillation process for 7 h. The percentage oil yield for China and Kuching Local Ginger are 0.158 wt% and 0.264 wt%, respectively. The extracted ginger essential oils are further subject to Fourier Transform Infrared Spectroscopy (FTIR) and Gas Chromatography- Mass spectrometry (GC-MS) analysis. Based on the FTIR spectrum graph generated, both types of ginger essential oils essentially having the similar function groups including phenolic compounds, alcohol primer, alkena methyl group, aromatic compound, carbonyl compound, carboxylic acid, hydroxyl group. From the GC-MS results it revealed that the most abundant chemical constituents presented in both China Gniger and Kuching Local Ginger essential are: α-Zingiberene (7.88% and 7.03%), α-Curcumene (6.04% and 6.49%), α-Citral or Genarial (3.81% and 7.86%), β-Bisabolene (3.06% and 4.62%), β-Sesquiphellandrene (5.83% and 5.95%), β-Sesquisabinene (0.07% and 0.51%), β-Selinenol (3.97% and 2.26%), Zingiberenol (5.16% and 1.64%), [6]-Shogaol (0.33% and 0.23%), trans-Sesquisabinene hydrate (1.72% and 2.87%), trans-Geranylgeraniol (3.51% and 2.81%), Camphene (1.17% and 0.56%), Eucalyptol (2.68% and 1.81%), Citronellol (1.76% and 1.55%), Neral (2.82% and 6.03%), and Geraniol (1.62% and 2.29%) respectively. Kuching Local Ginger essential oil is found marginally superior insect repellent characteristics due to its higher monoterpene compounds in the essential oil