The Odd Inverse Rayleigh Family of Distributions: Simulation & Application to Real Data

A new family of inverse probability distributions named inverse Rayleigh family is introduced to generate many continuous distributions. The shapes of probability density and hazard rate functions are investigated. Some Statistical measures of the new generator including moments, quantile and generating functions, entropy measures and order statistics are derived. The Estimation of the model parameters is performed by the maximum likelihood estimation method. Furthermore, a simulation study is used to estimate the parameters of one of the members of the new family. The data application shows that the new family models can be useful to provide better fits than other lifetime models

On the metric dimension of rotationally-symmetric convex polytopes

Metric dimension is a~generalization of affine dimension to arbitrary metric spaces (provided a resolving set exists). Let $\mathcal{F}$ be a family of connected graphs $G_{n}$ : $\mathcal{F} = (G_{n})_{n}\geq 1$ depending on $n$ as follows: the order $|V(G)| = \varphi(n)$ and $\lim\limits_{n\rightarrow \infty}\varphi(n)=\infty$. If there exists a constant C > 0 such that $dim(G_{n}) \leq C$ for every $n \geq 1$ then we shall say that $\mathcal{F}$ has bounded metric dimension, otherwise $\mathcal{F}$ has unbounded metric dimension. If all graphs in $\mathcal{F}$ have the same metric dimension, then $\mathcal{F}$ is called a family of graphs with constant metric dimension.\\ In this paper, we study the metric dimension of some classes of convex polytopes which are rotationally-symmetric. It is shown that these classes of convex polytoes have the constant metric dimension and only three vertices chosen appropriately suffice to resolve all the vertices of these classes of convex polytopes. It is natural to ask for the characterization of classes of convex polytopes with constant metric dimension

Combined experimental and theoretical study of poly(aniline-co-pyrrole) oligomer

Quantum mechanical calculations are performed to establish the structure of an oligomer of aniline and pyrrole [Poly(Ani-co-Py)], through comparison of experimental and theoretically calculated properties, including conductivity. The copolymer was synthesized through chemical oxidative polymerization and then confirmed from the experimental IR, UV-vis, mass spectra, elemental, XRD, TGA, and SEM analysis. Quantum mechanical calculations are performed at Density Functional Theory (DFT) and Time dependent DFT (TD-DFT) methods for the electronic and spectroscopic properties of the oligomer. A very nice correlation is found between the theory and experiment which consequences the structure of Poly(Ani-co-Py). Poly(Ani-co-Py) is not explored like other conducting polymers; however, by tuning this molecular structure, the electro-active nature of this material can be enhanced adequately

Diagnosis of hepatoma using grayscale and Doppler ultrasound in patients with chronic liver disease

Wasim A Memon, Zishan Haider, Mirza Amanullah Beg, Muhammad Idris, Tanveer-ul-Haq, Waseem Akhtar, Sidra IdrisRadiology Department, Aga Khan University Hospital, Karachi, Pakistan Every author contributed equally to the workObjective: To determine the diagnostic accuracy of liver ultrasound for the detection of hepatoma in chronic liver disease (CLD) patients by either taking histopathology or serum α-fetoprotein levels or a biphasic computed tomography (CT) scan (whichever is available) as the gold standard.Study design: Cross-sectional.Place and duration of study: Radiology Department, The Aga Khan University Hospital, Karachi, Pakistan, from January 2007 to January 2010.Methods: A total of 239 patients (156 males and 83 females) with clinical suspicion or surveillance of hepatoma in CLD referred to the radiology department for ultrasound evaluation followed by either liver biopsy and histopathology or serum α-fetoprotein level or biphasic CT scan.Results: The sensitivity of ultrasound for hepatoma detection in CLD was 65%, specificity was 85%, and accuracy was 70%, and positive predictive value and negative predictive value were 92% and 45%, respectively.Conclusion: Ultrasound is a relatively quick, safe, reasonably accurate, and noninvasive imaging modality for the detection of hepatoma in CLD and can be complemented with clinical assessment of screening high-risk patients.Keywords: hepatoma, ultrasound, radiology, chronic liver diseas

Traumatic carotid-cavernous fistula: Clinical presentation and outcome

Objective:To evaluate the presentation, clinical course and outcome of traumatic carotid-cavernous fistula (CCF) withendovascular treatment at our institution during the last five years. Design: Retrospective descriptive study. Setting: The study included patients seen at Aga Khan University Hospital from January 2000 to December 2005. Methods: Retrospective analysis based on data retrieval from medical records using ICD coding system. Only those cases who had traumatic CCF and underwent endovascular treatment were included in the study. Results: A total of 8 patients were diagnosed with post-traumatic CCF and 11 procedures were done. Mean age at presentation was 35.6 years; mean duration of symptoms was 23 weeks after trauma; 6 patients were male and 2 female. Patients presented from 1 week to 2 years after the trauma; 7 had high-flow fistulas and 1 had low-flow fistula. Proptosis was the most common symptom (6 patients); decreased vision was present in 3 patients; 4 patients had an accompanying skull base fracture; and 1 patient had bilateral CCF. All patients were treated by endovascular procedures; 2 patients had recurrences, seen within 1 month of initial treatment and subsequently successfully treated. In 1 patient, the procedure failed due to the small size of the fistula. Conclusion: High success rate with minimal complications as seen in our series supports endovascular treatment as the leading option for CCF managemen

The study of removal chromium (VI) ions from aqueous solution by bimetallic ZnO/FeO nanocomposite with Siltstone: Isotherm, kinetics and reusability

In this study, nanocomposites of Baghanwala Siltstone (BSS) with ZnO (BSS/ZnO), FeO (BSS/FeO), and BSS/ZnO/FeO were successfully prepared for the removal of hexavalent chromium [(Cr (VI)] from aqueous solutions via a batch adsorption process. The characterization studies by X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and scanning electron microscopy-energy-dispersive X-ray spectroscopy (SEM-EDX) found successful synthesis of the composites and demonstrated the occurrence of different active functional groups that played an active role in Cr ion adsorption. The effect of Cr initial concentrations (25–100 mg/L), adsorbent dose (0.5–2 g/L), pH (2–8), and contact time (0–160 min) on Cr remediation from contaminated water was examined. The order of Cr ion removal was BSS/ZnO/FeO (77–87%) \u3e BSS/ZnO (74–83%) \u3e BSS/FeO (71–77%) \u3e BSS (68–74%). The as-synthesized BSS/ZnO/FeO led to successful Cr removal (87%) at a 25 mg/L Cr concentration at pH 4.0. The Cr ion adsorption by the BSS/ZnO/FeO nanocomposite was well explained by the Langmuir adsorption isotherm model (R2 \u3e 0.99), while the kinetic experimental data was well fitted with the pseudo-second-order model (R2 \u3e 0.99). Among the as-synthesized adsorbents, the BSS/ZnO/FeO nanocomposite showed excellent stability and reusability in seven sorption cycles. The results showed that the as-synthesized BSS/ZnO/FeO nanocomposite had the greatest adsorption potential for removing Cr ions from contaminated water

Synergistic effects of activated carbon and nano-zerovalent copper on the performance of hydroxyapatite-alginate beads for the removal of As\u3csup\u3e3+\u3c/sup\u3e from aqueous solution

© 2019 Elsevier Ltd In this study, activated carbon (AC) and nano-zerovalent copper (nZVCu) functionalized hydroxyapatite (HA) and alginate beads were synthesized and used for the removal of As3+ from aqueous solution. The characterization by X-ray diffraction, scanning electron microscopy, X-ray energy dispersive spectroscopy, X-ray photoelectron spectroscopy, transmission electron microscopy, high resolution transmission electron microscopy, BET surface area analysis, thermogravimetric analysis, and Fourier transform infrared spectroscopy revealed successful formation of the AC/nZVCu/HA-alginate, nZVCu/HA-alginate, AC/HA-alginate, and HA-alginate beads. The scanning electron microscopy and surface analysis revealed the prepared beads to be highly mesoporous which led to the maximum adsorption of As3+, i.e., 13.97, 29.33, 30.96, and 39.06 mg/g by HA-alginate, AC/HA-alginate, nZVCu/HA-alginate, and AC/nZVCu/HA-alginate beads, respectively. The thermogravimteric analysis showed the nZVCu/HA-alginate beads to be highly stable while the AC composite beads as the least stable to heat treatment. The HA-alginate beads achieved 39% removal of As3+, however, removal efficiency was promoted to 95% by coupling AC and nZVCu with HA-alginate beads at a reaction time of 120 min. The removal of As3+ by the prepared AC & nZVCu coupled HA-alginate beads was promoted with increasing [As3+]0 and [AC/nZVCu/HA-alginate]0. The pH of aqueous solution significantly influenced the removal of As3+ by AC/nZVCu/HA-alginate beads and maximum removal was achieved at pH 5.8. Freundlich adsorption isotherm and pseudo-second-order kinetic models were found to best fit the removal of As3+ by the synthesized beads. The high performance of AC/nZVCu/HA-alginate beads in the removal of As3+ even after seven cyclic treatment as well as least leaching of Cu ions into aqueous solution suggest enhanced reusability and stability of HA-alginate beads by coupling with AC and nZVCu. The results suggest that the synthesized beads have good potential for the removal of As3+ from aqueous solutions

Factor structure of Urdu version of the flourishing scale

Background: A great deal of research has been carried out on the assessment of the eudaimonic perspective of psychological well-being and the hedonic perspective of subjective well-being. The Flourishing Scale (FS) has been extensively used in research and practice, as it assesses the fundamental aspects of social psychological functioning. Nevertheless, the psychometric properties of Urdu versions of eudaimonic measures, such as the FS, have not yet been ascertained. The translation and validation of the FS in the Urdu language was not available, and hence this study was planned with the aim to validate the Urdu version of the FS. Methods: We assessed the psychometric properties of the FS in a sample of adults aged 18 years and above in Pakistan (N = 130) using exploratory factor analysis based on principal component analysis with varimax rotation and confirmatory factor analysis. Results: The exploratory factor analysis confirmed the unidimensional nature of the 8-item FS. We assessed that the Urdu version of the FS showed a high internal consistency reliability (α = 0.914) with a significant intraclass correlation coefficient (ICC), p < 0.001). In our study, the Kaiser–Mayer–Olkin value was 0.915 with a chi-square test value (χ2) of 637.687, and Bartlett's test of sphericity was significant (df = 28, p < 0.001). The intraclass correlation coefficients (ICCs) at test–retest for all domains were statistically significant (p < 0.001) and showed excellent agreement for all the items. The revised confirmatory factor analysis revealed a good-fit model, but with item 8—“People respect me”—removed due to its lower factor loading. Conclusions: The findings suggest that the FS is a psychometrically sound instrument for assessing social psychological functioning among adults in Pakistan. Therefore, the validated Urdu version of the FS may be used in future studies of well-being in clinical psychology and positive psychology

Protected areas: a resource or constraint for local people?

We investigated local people’s perceptions, knowledge, and attitudes toward conservation planning and management in Chitral Gol National Park in North West Frontier Province (NWFP) of Pakistan. A literature review was undertaken to unravel the historic drivers behind the formation of this protected area. Key informant interviews and questionnaire surveys were conducted to evaluate the effectiveness of current governance approaches adopted by the park management authorities. Community-based questionnaire surveys and key-informant interviews focused on local communities’ knowledge and awareness of the objectives of the park, people’s role in decision-making, social characteristics, and resource use structures. The information from these surveys was evaluated within the context of good governance and sustainability of park management. Results show a lack of awareness and a low level of participation in protected area management, but a high degree of willingness in the communities to participate in conservation activities. An analysis of the survey data suggests that the park authorities enforce strict protection measures within the park, but this approach lacks a strong vision of sustainability. The surveys reveal that the local people have a very strong sense of belonging to the place and are willing to contribute to the protection of the PA. A large majority of the respondents rely on electronic media as their main source of information, which could potentially form the best medium for conservation campaigning in the region. With these findings in mind, we propose changes to the current governance model for effective and sustainable management of the park in the future

Acute health effects of the Tasman Spirit oil spill on residents of Karachi, Pakistan

BACKGROUND: On July 27 2003, a ship carrying crude oil run aground near Karachi and after two weeks released 37,000 tons of its cargo into the sea. Oil on the coastal areas and fumes in air raised health concerns among people. We assessed the immediate health impact of oil spill from the tanker Tasman Spirit on residents of the affected coastline in Karachi, Pakistan. METHODS: We conducted a study consisting of an exposed group including adults living in houses on the affected shoreline and two control groups (A and B) who lived at the distance of 2 km and 20 km away from the sea, respectively. We selected households through systematic sampling and interviewed an adult male and female in each household about symptoms relating to eyes, respiratory tract, skin and nervous system, smoking, allergies, beliefs about the effect on their health and anxiety about the health effects. We used logistic regression procedures to model each symptom as an outcome and the exposure status as an independent variable while adjusting for confounders. We also used linear regression procedure to assess the relationship exposure status with symptoms score; calculated by summation of all symptoms. RESULTS: Overall 400 subjects were interviewed (exposed, n = 216; group A, n = 83; and group B, n = 101). The exposed group reported a higher occurrence of one or more symptoms compared to either of the control groups (exposed, 96% vs. group A, 70%, group B 85%; P < 0.001). Mean summary symptom scores were higher among the exposed group (14.5) than control group A (4.5) and control group B (3.8, P < 0.001). Logistic regression models indicated that there were statistically significant, moderate-to-strong associations (Prevalence ORs (POR) ranging from 2.3 to 37.0) between the exposed group and the symptoms. There was a trend of decreasing symptom-specific PORs with increase in distance from the spill site. Multiple linear regression model revealed strong relationship of exposure status with the symptoms score (β = 8.24, 95% CI: 6.37 – 10.12). CONCLUSION: Results suggest that the occurrence of increased symptoms among the exposed group is more likely to be due to exposure to the crude oil spill