Symbiotic systems of bats, bat flies, and gut bacteria in a fragmented forest.

PhD Theses.The effects of habitat disturbance on parasites and microbes is poorly understood despite implications for host health and conservation. In this thesis I identify landscape properties that impact epidemiological patterns, bipartite interactions and metacommunity structure of ectoparasitic arthropods of bats and their endosymbiotic bacteria across a fragmented region from the Atlantic Forest of Brazil and I compare the performance of routine molecular identification methods using conventional laboratory procedures, to a mobile laboratory including the MinION DNA sequencer. My results show that in situ experiments on portable sequencing platforms are a viable alternative to Illumina and Sanger sequencing, although there are trade-offs between sequence quality and speed that precluded immediate uptake. I found the prevalence of the bat fly Trichobius joblingi on the bat Carollia perspicillata to be higher in forest fragments than continuous forests. I also found the infection intensity of the bat fly Paratrichobius longricus on the bat Artibeus lituratus in continuous forests to be higher in females than males. Network analyses shows modularity to be positively correlated to habitat area for ectoparasitic networks, but negatively correlated to isolation in endosymbiont networks. Metacommunity structure analysis suggests bat fly assemblages in fragmented forests follow a quasi-Gleasonean structure with respect to habitat area. Overall, my research reveals that the effects of habitat fragmentation can be observed in parasitic and endosymbiotic communities, and the persistence of specialist symbiotic species rely on the presence of specific hosts, for example ectoparasitic and endosymbiotic communities in the smallest fragments remain 5 connected by interactions with disturbance tolerant hosts. My findings have implications for conservation through monitoring trends in potential disease vectors in wild populations

Short-term determinants of banking profitability and financial sustainability of banks in Bangladesh: An empirical study of COVID-19 effects

The purpose of this study is to examine the profitability and financial sustainability of banks in Bangladesh before and during COVID-19. The study compares the profitability and financial sustainability of 23 listed private commercial banks. The data for short-term periods before the COVID-19 and during the COVID-19 crisis we used. Financial ratios, descriptive statistics, correlation matrix and linear regression model estimations are used for the analysis of data. The mean values of ROA, ROE and NIM are found before the COVID-19 crisis as 0.0019, 0.0270 and 0.0054, and during the COVID-19 as 0.00128, 0.01856 and 0.00321 respectively. On the other hand, the mean values of NFLR, CCR, ICR, and OSR are found before COVID-19 as 2.0936, 6.852, 0.9314 and 0.4751, and during COVID-19 as -2.5961, 5.879, 0.7673 and 0.3587 respectively. The findings construe a significant impact of the unprecedented pandemic. Within a short period of time, sample banks’ profitability and financial sustainability deteriorated significantly. A key implication of our study is that the private-sector commercial banks in Bangladesh experienced severe financial difficulties during COVID-19 which impacted their profitability and financial sustainability. The findings of the study suggest that adverse economic events have substantial effects on the financial realities of financial institutions. The findings of the study are expected to be useful to both academics and policymakers

SARS-CoV-2 genomic surveillance in Malaysia: displacement of B.1.617.2 with AY lineages as the dominant Delta variants and the introduction of Omicron during the fourth epidemic wave

Objectives This study reported SARS-CoV-2 whole genome sequencing results from June 2021 to January 2022 from seven genome sequencing centers in Malaysia as part of the national surveillance program. Methods COVID-19 samples that tested positive by reverse transcription polymerase chain reaction and with cycle threshold values <30 were obtained throughout Malaysia. Sequencing of SARS-CoV-2 complete genomes was performed using Illumina, Oxford Nanopore, or Ion Torrent platforms. A total of 6163 SARS-CoV-2 complete genome sequences were generated over the surveillance period. All sequences were submitted to the Global Initiative on Sharing All Influenza Data database. Results From June 2021 to January 2022, Malaysia experienced the fourth wave of COVID-19 dominated by the Delta variant of concern, including the original B.1.617.2 lineage and descendant AY lineages. The B.1.617.2 lineage was identified as the early dominant circulating strain throughout the country but over time, was displaced by AY.59 and AY.79 lineages in Peninsular (west) Malaysia, and the AY.23 lineage in east Malaysia. In December 2021, pilgrims returning from Saudi Arabia facilitated the introduction and spread of the BA.1 lineage (Omicron variant of concern) in the country. Conclusion The changing trends of circulating SARS-CoV-2 lineages were identified, with differences observed between west and east Malaysia. This initiative highlighted the importance of leveraging research expertise in the country to facilitate pandemic response and preparedness

SARS-CoV-2 genomic surveillance in Malaysia: displacement of B.1.617.2 with AY lineages as the dominant Delta variants and the introduction of Omicron during the fourth epidemic wave

Objectives: This study reported SARS-CoV-2 whole genome sequencing results from June 2021 to January 2022 from seven genome sequencing centers in Malaysia as part of the national surveillance program. Methods: COVID-19 samples that tested positive by reverse transcription polymerase chain reaction and with cycle threshold values <30 were obtained throughout Malaysia. Sequencing of SARS-CoV-2 complete genomes was performed using Illumina, Oxford Nanopore, or Ion Torrent platforms. A total of 6163 SARS-CoV-2 complete genome sequences were generated over the surveillance period. All sequences were submitted to the Global Initiative on Sharing All Influenza Data database. Results: From June 2021 to January 2022, Malaysia experienced the fourth wave of COVID-19 dominated by the Delta variant of concern, including the original B.1.617.2 lineage and descendant AY lineages. The B.1.617.2 lineage was identified as the early dominant circulating strain throughout the country but over time, was displaced by AY.59 and AY.79 lineages in Peninsular (west) Malaysia, and the AY.23 lineage in east Malaysia. In December 2021, pilgrims returning from Saudi Arabia facilitated the introduction and spread of the BA.1 lineage (Omicron variant of concern) in the country. Conclusion: The changing trends of circulating SARS-CoV-2 lineages were identified, with differences observed between west and east Malaysia. This initiative highlighted the importance of leveraging research expertise in the country to facilitate pandemic response and preparedness