Unfinished journeys: narratives of slavery from Olaudah Equiano to Toni Morrison

Despite the obvious way in which slave narrative is 'married' to historical context as both public testimony and personal, imaginative expression of a specific experience, slave narrative presents the reader w ith unfinished journeys. The narratives which are the focus of this study are partial autobiographies, to the extent that Olaudah Equiano, H arriet Jacobs and Frederick Douglass each lived beyond the experiences about which they wrote. This is most obvious in the case of Douglass, who wrote three autobiographies. We are fortunate that Douglass wrote and re-wrote his life, and it is not unreasonable to wish, however fancifully, that Equiano and Jacobs had done the same. It is impossible to predict what their imaginary autobiographies would contain, beyond details of their lives in freedom which have come to us through historical sources, but it seems safe to assume that, like Douglass, Equiano and Jacobs would have opened doors that remained closed in the first narratives, in order to re-vision the past and shed light on the present. Indeed, the very act of imagining the slave narrator as creative agent beyond his or her journey to freedom, opens readers' minds to the possibilities of slave narrative. This is the imaginative journey performed by the fictional narratives of slavery, Dessa Rose and Beloved, into the world the slaves made, to probe and specify experiences in slavery and freedom. For the slave narrator, 'storying' his or her life was a beginning, not an end: their lives in freedom awaited them, and that longawaited and cherished freedom was no more predictable or pre-determined than was the experience of slavery. 'Storying' slavery was a cathartic process through which the past was given meaning and order, and through which the storyteller could return to an image of the unrealised self in order to make it whole. Slave narrative is an engaged body of writing— it participates in contexts which precede it, if African cultural practice is acknowledged as a vital presence in the slaves' lives, and in the narratives through which many ex-slaves were able account for their experiences in slavery. Slave narrative reflects mythic dimensions which transcend it, if realms of family, community and religion shaping childhood, adolescent struggle, and adult dilemmas are acknowledged as significant in slave narrative. The unfinished journey of slave narrative also is immediately evident in black creative traditions which acknowledge the slave's voice— spoken, sung and written— as its first utterance

Preparation of Polyclonal Antiserum to the Recombinant TiLV-S8 Protein and Its Application in the Detection of Naturally Tilapia Lake Virus (TiLV) Infected Tilapia

Tilapia lake virus (TiLV) is classified as a negative-sense, single-stranded RNA virus in the family Amnoonviridae. It is an enveloped virus with 10 genomic RNA segments, each coding for a protein. TiLV causes disease in tilapia, and outbreaks can lead to significant economic losses for the tilapia aquaculture industry. In this study, the gene encoding the segment 8 protein of TiLV was cloned into the expression vector pET15-b and then transformed into Escherichia coli strain BL21. After induction, the recombinant TiLV-S8 protein (rTiLV-S8), with a molecular mass of 20 kDa, was expressed, purified, and used to immunize mice. The mouse antiserum against rTiLV-S8 protein demonstrated specific immunoreactivity for the viral protein, approximately 19 kDa in TiLV-infected fish tissues, as determined by Western blotting. According to the results of the dot blotting assay, the antiserum was about 80 times less sensitive than one-step RT-PCR in detecting TiLV in homogenates of infected fish samples and showed no cross-reaction with uninfected fish tissues, other common fish viruses, or prevalent bacterial species found in aquatic animals. Furthermore, this polyclonal antiserum could be employed to identify TiLV-infected fish in the field using dot blotting assay, and the results can be confirmed by immunohistochemistry

Emergency response to emerging disease: AHPND in shrimp

Outbreaks of acute hepatopancreatic necrosis disease (AHPND) have caused great economic losses to many shrimp producing countries in Asia since its first appearance in 2009. The causative agent was first reported in 2013 as specific isolates of Vibrio parahaemolyticus (VPAHPND) that were later found to harbor a plasmid (pVA) encoding the Pir-like binary toxin genes PirvpA and PirvpB. More recent information indicates that pVA plasmid and variants occur in many Vibrio parahaemolyticus serotypes and also in other Vibrio species such as V. campbellii, V. harveyi and V. owensii. Information on such genomic and proteomic studies of different VPAHPND isolates from different countries are reviewed. A cohort study carried out in Thailand in 2014 indicated that AHPND outbreaks account for only a portion of the disease outbreaks reported by shrimp farmers as outbreaks of early mortality syndrome (EMS). It is urgent that the etiology of the other EMS-associated mortalities be investigated and not be overlooked. It is recommended that a regional research network and surveillance program for newly-emerging or re-emerging pathogens be established to speed up the process of diagnosis and the implementation of coordinated control measures and to avoid a repeat of the EMS/AHPND scenario

PbSe quantum dots-based chemiresistors for room-temperature NO2 detection

Colloidal quantum dots (CQDs) are promising building blocks for low-cost and high-performance gas sensors due to their excellent solution processability and extremely small size. Among chalcogenide CQDs, PbSe has a large exciton Bohr radius and exhibits strong confinement energies, facilitating the fast charge-carrier transport. However, CQDs-based devices are susceptible to degrade due to the poor stability of CQDs. Here, in order to obtain air-stable PbSe CQDs for gas sensing application, we synthesized PbSe CQDs using a cation exchange method with in situ chloride and cadmium passivation. The sharp absorption peak in UV–vis absorption spectra confirmed strong quantum confinement in the PbSe CQDs and their average diameter was estimated to be 2.87 ± 0.23 nm. To construct gas sensors, PbSe CQDs were spin-coated onto ceramic substrates and then Pb(NO3)2 treatment was carried out to remove the long-chain ligands surrounding PbSe CQDs. At 25 °C, the sensor was highly sensitive and selective to NO2 with a response of 22.3 at 50 ppm and a fast response time of 7 s. Moreover, the sensor response showed a 85.2% stability as the time increased up to 20 days, suggesting the potential applications of PbSe CQDs for NO2 monitoring at room temperature