Subprime Crisis, Systematic Risk and Arbitrage

Mestrado em Matemática FinanceiraThe financial market turmoil of 2007 and 2008 was the most severe recession seen after the Great Depression. The economic momentum, previous to the crisis, created a strong demand for AAA securities that was not available on single bond market. This motivated arrangers to issue high volumes of structured finance securities, collateralized by subprime Residential Mortgage-Backed Securities. Most of the AAA investors based their choices uniquely based on Credit Rating Agencies' assessment that taken into account Probabilities of Default or Expected Losses but mispriced the Systematic Risk. This fact created arbitrage opportunities for Asset-Backed Securities (ABS) and ABS Collateralized Debt Obligations (ABS CDO) arrangers. They exploited it by issuing securities with high levels of Systematic Risk. In this work I run ABS and ABS CDO simulations to exemplify how these instruments were structured to explore these features. To quantify the extent of the mispricing I compare a structured security with a single bond with the same rating. I use the results to exemplify the potential gains obtained by the arranger by taking advantage of the investor's blindness concerning Systematic Risk. I also approach other Structured Finance risks as parameter sensitivity and biased asset pool parameters in rating models

An Eternal ‘Child’ Turned Ally: Princely Minors and the Paternalistic British Raj at work in Hyderabad (1857-1884)

After the 1857 rebellion against British rule in India, British imperialists altered their mode of engagement with the princely states of India—from overt aggression exercised under the policy of “indirect rule” to restrained paternalism preached through a policy of “non-interference”. This paper seeks to illustrate how and why the goals of British imperialism evolved in the latter half of the 19th century. I undertake a case study of the largest princely state of India—Hyderabad—to illustrate that the Raj’s principle imperial agenda after 1857 was to domesticate and assimilate princely states within the colonial body politic. This was realized by rearticulating the tenets of ‘proper education’ for princely minors and selectively appropriating indigenous ritual idioms. In Hyderabad, I center the figure of the ‘princely minor’ Mehboob Ali Khan, the sixth Nizam of Hyderabad, whose minority from 1869-1884 became an opportune time for the British to reform and discipline him to mold him into an amenable ally. Leaving the policy of territorial conquest behind, after 1857, I argue that British imperialism had begun to envision novel ideological sites of colonialism

A review of rotavirus diarrhea in Pakistan: how much do we know?

Introduction: Rotavirus diarrhea has a worldwide distribution, infecting almost all children by the age of 3-5 years.EPIDEMIOLOGY: A comparable etiological 2-year survey carried out by the W.H.O Diarrheal Disease control (CDD) Program in 1991, in a multicenter study in 5 developing countries including Pakistan revealed that Rotavirus was found to be the most frequently detected pathogen in diarrheal episodes, during the first year of life, with the highest incidence (20%) occurring among 6-11 months old. Two other studies done in Pakistan, in under five children done in Lahore (between 1985 and 1991) and Rawalpindi (between May 1983 and April 1984) showed that Rotavirus was the second most common Diarrhea causing enteric pathogen following E.ColiTRANSMISSION: Rotaviruses are shed in high concentrations 2 days before and as many as 10 days after onset of symptoms in immunocompetent hosts, thus being an important source of viral transmission.CLINICAL COURSE: A multicenter study in 5 developing countries including Pakistan conducted by WHO CDD program revealed that only 1.8 % of cases presented with severe dehydration and these were mostly due to Rotavirus, V. Cholerae and ETEC13.DIAGNOSTIC TESTS: A study conducted in local hospitals in Pakistan during the period of October 1985-April 1986 compared the different diagnostic modalities for the detection of rotavirus in the faeces of children with acute diarrhea. The study all methods detected Rotavirus to varying degrees but ELISA was found to be the most sensitive method with 72.4% stools being positive. PREVENTIVE STRATEGIES: A study was conducted in Lahore (Pakistan) among 72 infants 6 weeks old in 1991 to assess safety and efficacy of RRV vaccine. It was found that of all infants given RRV with OPV, 50% had a two to four-fold rise in neutralization titers against rotavirus. RRV was found to be safe and not associated with adverse reactions in the 6 weeks old infants.CONCLUSION: With regards to Pakistan, there is a great need for defining rotavirus associated disease burden and strain prevalence. We also need to conduct Rotavirus vaccine trials to assess its efficacy and safety in our setting

Swept-source optical coherence tomography of an optic disc melanocytoma: The importance of the hyperreflective foci

Optic disc melanocytoma (ODM) has been considered as a benign tumor with few reports of malignant transformation. We present swept-source optical coherence tomography (SSOCT) imaging of a case of ODM. As attaining histopathology is impossible in most cases, we discuss the possibility of using SSOCT as a tool for ruling out choroidal invasion or juxtapapillary melanoma

Are we ready to combat the ecotoxicity of COVID-19 pharmaceuticals? An in silico aquatic risk assessment

To fight COVID-19 with uncountable medications and bioproducts throughout the world has taken us to another challenge of ecotoxicity. The indiscriminate usage followed by improper disposal of unused antibacterials, antivirals, antimalarials, immunomodulators, angiotensin II receptor blockers, corticosteroids, anthelmintics, anticoagulants etc. can lead us to an unimaginable ecotoxicity in the long run. A series of studies already identified active pharmaceutical ingredients (APIs) of the mentioned therapeutic classes and their metabolites in aquatic bodies as well as in wastewater treatment plants. Therefore, an initial ecotoxicity assessment of the majorly used pharmaceuticals is utmost requirement of the present time. The present in silico risk assessment study is focused on the aquatic toxicity prediction of 81 pharmaceuticals where 77 are most-used pharmaceuticals for COVID-19 throughout the world based on the literature along with one drug nirmatrelvir [PF-07321332] approved for emergency use by US-FDA and three other molecules under clinical trial. The ecotoxicity of the studied compounds were predicted based on the three aquatic species fish, algae and crustaceans employing the highest quality QSAR models available from the literature as well as using ECOSAR and QSAR Toolbox. To compare the toxicity thresholds, we have also used 4 control pharmaceuticals based on the worldwide occurrence from river, lake, STP, WWTPs, influent and effluent followed by high reported aquatic toxicity over the years as per the literature. Based on the statistical comparison, we have proposed top 3 pharmaceuticals used for the COVID-19 most toxic to the aquatic environment. The study will provide confident predictions of aquatic ecotoxicity data related to abundant use of COVID-19 drugs. The major aim of the study is to fill up the aquatic ecotoxicity data gap of major medications used for COVID-19

Efficacy and safety of intravitreal injection of triamcinolone-moxifloxacin after cataract surgery in a low to middle income country – a one-year audit

Objective: To evaluate the safety and efficacy of intravitreal injection of triamcinolone and moxifloxacin regime administered immediately following cataract surgery. Method: The retrospective study was conducted from January to June 2021 at a tertiary care referral centre in Karachi and comprised record of all patients who underwent dropless cataract surgery from April 2018 to June 2019. Data included slit lamp examination, dilated fundal exam, uncorrected visual acuity, best corrected visual acuity, and intraocular pressure. Cataract assessment and anterior chamber reaction were graded according to the World Health Organisation cataract grouping system. Efficacy of the regime was defined as the ability to prevent postoperative endophthalmitis. Stratification analysis was done to note if gender has any role in terms of effectiveness. Data was analysed using Microsoft Excel version 16.0 and IBM SPSS version 27. Results: Of 240 eyes of 161 patients analysed, 114(47.5%) were of men who had a mean age of 57.89±14.32 years, and 126(52.5%) were of females with a mean age of 58.02±10.85 years. Overall, 2(1.75%) male subjects and 1(0.8%) female subject developed breakthrough inflammation within one week of the procedure. They were treated with anti-inflammatory drops and in 1(33%) of the cases antibiotic drop for 1 week. At day 90, no patient had residual inflammation or new onset inflammation. Also, 15(6.25%) patients developed raised intraocular pressure from day 7 to day 30. Most cases 10(66.7%) resolved within 1 week of using intraocular pressure-lowering drops. No patient developed endophthalmitis postoperatively. Conclusion: Dropless cataract regime was found to be an effective and safe alternative that was easy to administer9. Key Words: Dropless cataract surgery, Safety of cataract surgery, Innovations in cataract surgery, Endophthalmitis after dropless

Safety of simultaneous bilateral intravitreal versus unilateral anti-vasculo-endothelial growth factors injection in an operating room setting

Objectives: Chorioretinal diseases requiring the use of anti-vascular endothelial growth (anti-VEGF) injections often occur in both eyes simultaneously. This can necessitate injecting both eyes together rather than one eye at a time. The purpose of the study was to determine whether simultaneous bilateral intravitreal injections of anti-VEGF agents are safe when administered in an operation theatre setting.Methods: Retrospective review of data was conducted. Single center study conducted in a tertiary care hospital in Karachi Pakistan. Approximately 30,000 eyes that received anti-VEGF injection during a 10-year study period were included (March 2008-February 2018). Patients who were lost to follow up prior to completion of treatment were excluded. Consecutive sampling technique was employed. The patients who received bilateral anti-VEGF injections were analysed separately from the ones who received unilateral injections. All injections were administered in operating theatre setting. The rate of endophthalmitis was measured in each group.Results: A total of 30,258 injections were administered of which 15,338 were bilateral injections. Four cases (4/30,258, 0.013%) of endophthalmitis occurred during the study period. Only one case (1/15,338, 0.0065%) of endophthalmitis occurred after the administration of simultaneous bilateral anti-VEGF injections.Conclusions: Administration of simultaneous bilateral anti-VEGF injections was safe in our population

Intelligent consensus predictions of bioconcentration factor of pharmaceuticals using 2D and fragment-based descriptors

Bioconcentration factors (BCFs) are markers of chemical substance accumulation in organisms, and they play a significant role in determining the environmental risk of various chemicals. Experiments to obtain BCFs are expensive and time-consuming; therefore, it is better to estimate BCF early in the chemical development process. The current research aims to evaluate the ecotoxicity potential of 122 pharmaceuticals and identify possible important structural attributes using BCF as the determining feature against a group of fish species. We have calculated the theoretical 2D descriptors from the OCHEM platform and SiRMS descriptor calculating software. The regression-based quantitative structure–property relationship (QSPR) modeling was used to identify the chemical features responsible for acute fish bioconcentration. Multiple models with the “intelligent consensus” algorithm were employed for the regression-based approach improving the predictive ability of the models. To ensure the robustness and interpretability of the developed models, rigorous validation was performed employing various statistical internal and external validation metrics. From the developed models, it can be specified that the presence of large lipophilic and electronegative moieties greatly enhances the bioaccumulative potential of pharmaceuticals, whereas the hydrophilic characteristics have shown a negative impact on BCF. Furthermore, the developed models were employed to screen the DrugBank database (https://go.drugbank.com/) for assessing the BCF properties of the entire database. The evidence acquired from the modeled descriptors might be used for aquatic risk assessment in the future, with the added benefit of providing an early caution of their probable negative impact on aquatic ecosystems for regulatory purposes