Knowledge of primary paediatric care providers regarding attention deficit hyperactivity disorder and learning disorder: a study from Pakistan

Introduction: Attention deficit hyperactivity disorder (ADHD) and learning disorder (LD) remain prevalent globally and are also speculated to have a high occurrence in Pakistan. An early diagnosis and intervention in these disabilities is imperative for achieving good clinical and functional outcomes. This can be ensured by an effective screening at the level of primary paediatric care in the developing countries. We aimed to explore the ability of general practitioners (GPs) and paediatricians in Pakistan to screen for ADHD and LD based on their awareness regarding the risk factors and symptomatology of ADHD and LD. Methods: A total of 96 paediatricians and 98 GPs practising in Karachi, Pakistan were included in the study. Data was collected employing a self-administered questionnaire. Results: Only 13.7 percent of the GPs and 21.6 percent of the paediatricians were shown to have knowledge sufficient to effectively screen for / diagnose ADHD. Alarmingly, not a single GP was adequately familiar with the established risk factors and clinical symptoms of LD. The level of knowledge was not influenced by age, gender, and clinical practice attributes of the physicians. Doctors who regularly read medical journals and attend medical education seminars showed slightly better trends. Conclusion : We hypothesise that this demonstrated lack of knowledge at the level of primary care in Pakistan prevents an early screening of ADHD and LD. A multipronged strategy targeted at the provision of objective screening tools for primary paediatric care providers, regular continuing medical education seminars and an emphasis on paediatric mental health in undergraduate and postgraduate curricula may ensure an early detection of ADHD and LD in Pakistan

Cancer biomarker development from basic science to clinical practice

The amount of published literature on biomarkers has exponentially increased over the last two decades. Cancer biomarkers are molecules that are either part of tumour cells or secreted by tumour cells. Biomarkers can be used for diagnosing cancer (tumour versus normal and differentiation of subtypes), prognosticating patients (progression free survival and overall survival) and predicting response to therapy. However, very few biomarkers are currently used in clinical practice compared to the unprecedented discovery rate. Some of the examples are: carcino-embryonic antigen (CEA) for colon cancer; prostate specific antigen (PSA) for prostate; and estrogen receptor (ER), progesterone receptor (PR) and HER2 for breast cancer. Cancer biomarkers passes through a series of phases before they are used in clinical practice. First phase in biomarker development is identification of biomarkers which involve discovery, demonstration and qualification. This is followed by validation phase, which includes verification, prioritisation and initial validation. More large-scale and outcome-oriented validation studies expedite the clinical translation of biomarkers by providing a strong ‘evidence base’. The final phase in biomarker development is the routine clinical use of biomarker. In summary, careful identification of biomarkers and then validation in well-designed retrospective and prospective studies is a systematic strategy for developing clinically useful biomarkers

Environmental Aid and Economic Development in the Third World

Climate change has a profound impact on the planet, especially on developing countries – as highlighted by the Stern Report to the British government in 2006. One solution to mitigating environmental degradation and achieving better outcomes appears to be through the provision of aid to poor countries. Using newly available data from the PLAID (Project-Level Aid) database project, we ask what determines the level of environmental aid to developing countries – and in particular whether such aid is affected by the level of economic development of the recipient country. At the same time, we investigate whether economic development is affected by the receipt of environmental aid. Implicit in the second question, of course, is the notion that, besides addressing the ecological outcomes, environmental aid may have the potential to enhance the economic prosperity of poor countries.Economic Development; Aid; Developing Countries

The Economic Ramifications of Strategic IT Security Information Sharing in the Financial Services Industry

We investigate the economic ramifications of strategic IT security information sharing among firms in the financial services industry. An IT security information sharing system can potentially minimize security breaches. However, although the Presidential Decision Directive/NSC-63 encouraged the establishment of such a system in the form of industry based information sharing and analysis centers (ISACs), it is injudicious to assume that firms will be willing to naively share their security information with their strategic competitors. We argue that without a proper mechanism some firms will try to put in minimum effort, potentially reducing the system’s reliability, and aim to answer the following research question: “What will it take for a financial services firm to willingly share its strategic information technology security information with its competitors through an ISAC?” We use the theory of mechanism design in economics to develop an adverse selection model to address the question

Motion of a Vector Particle in a Curved Spacetime. II First Order Correction to a Geodesic in a Schwarzschild Background

The influence of spin on a photon's motion in a Schwarzschild and FRW spacetimes is studied. The first order correction to the geodesic motion is found. It is shown that unlike the world-lines of spinless particles, the photons world-lines do not lie in a plane.Comment: 14 pages, LaTeX2e, second paper in the series (the first one: gr-qc/0110067), replaced with typos and style corrected version, accepted in MPL

The maintenance of elevated active chlorine levels in the Antarctic lower stratosphere through HCl null cycles

The Antarctic ozone hole arises from ozone destruction driven by elevated levels of ozone destroying ("active") chlorine in Antarctic spring. These elevated levels of active chlorine have to be formed first and then maintained throughout the period of ozone destruction. It is a matter of debate how this maintenance of active chlorine is brought about in Antarctic spring, when the rate of formation of HCl (considered to be the main chlorine deactivation mechanism in Antarctica) is extremely high. Here we show that in the heart of the ozone hole (16–18 km or 85–55 hPa, in the core of the vortex), high levels of active chlorine are maintained by effective chemical cycles (referred to as HCl null cycles hereafter). In these cycles, the formation of HCl is balanced by immediate reactivation, i.e. by immediate reformation of active chlorine. Under these conditions, polar stratospheric clouds sequester HNO3 and thereby cause NO2 concentrations to be low. These HCl null cycles allow active chlorine levels to be maintained in the Antarctic lower stratosphere and thus rapid ozone destruction to occur. For the observed almost complete activation of stratospheric chlorine in the lower stratosphere, the heterogeneous reaction HCl + HOCl is essential; the production of HOCl occurs via HO2 + ClO, with the HO2 resulting from CH2O photolysis. These results are important for assessing the impact of changes of the future stratospheric composition on the recovery of the ozone hole. Our simulations indicate that, in the lower stratosphere, future increased methane concentrations will not lead to enhanced chlorine deactivation (through the reaction CH4 + Cl  ⟶  HCl + CH3) and that extreme ozone destruction to levels below  ≈ 0.1 ppm will occur until mid-century

Chaotic-based particle swarm optimization algorithm for optimal PID tuning in automatic voltage regulator systems

Introduction. In an electrical power system, the output of the synchronous generators varies due to disturbances or sudden load changes. These variations in output severely affect power system stability and power quality. The synchronous generator is equipped with an automatic voltage regulator to maintain its terminal voltage at rated voltage. Several control techniques utilized to improve the response of the automatic voltage regulator system, however, proportional integral derivative (PID) controller is the most frequently used controller but its parameters require optimization. Novelty. In this paper, the chaotic sequence based on the logistic map is hybridized with particle swarm optimization to find the optimal parameters of the PID for the automatic voltage regulator system. The logistic map chaotic sequence-based initialization and global best selection enable the algorithm to escape from local minima stagnation and improve its convergence rate resulting in best optimal parameters. Purpose. The main objective of the proposed approach is to improve the transient response of the automatic voltage regulator system by minimizing the maximum overshoot, settling time, rise time, and peak time values of the terminal voltage, and eliminating the steady-state error. Methods. In the process of parameter tuning, the Chaotic particle swarm optimization technique was run several times through the proposed hybrid objective function, which accommodates the advantages of the two most commonly used objective functions with a minimum number of iterations, and an optimal PID gain value was found. The proposed algorithm is compared with current metaheuristic algorithms including conventional particle swarm optimization, improved kidney algorithm, and others. Results. For performance evaluation, the characteristics of the integral of time multiplied squared error and Zwe-Lee Gaing objective functions are combined. Furthermore, the time-domain analysis, frequency-domain analysis, and robustness analysis are carried out to show the better performance of the proposed algorithm. The result shows that automatic voltage regulator tuned with the chaotic particle swarm optimization based PID yield improvement in overshoot, settling time, and function value of 14.41 %, 37.91 %, 1.73 % over recently proposed IKA, and 43.55 %, 44.5 %, 16.67 % over conventional particle swarm optimization algorithms. The improvement in transient response further improves the automatic voltage regulator system stability for electrical power systems.Вступ. В електроенергетичній системі потужність синхронних генераторів змінюється внаслідок збурень або різких змін навантаження. Ці зміни в потужності серйозно впливають на стабільність енергетичної системи та якість електроенергії. Синхронний генератор оснащений автоматичним регулятором напруги для підтримання напруги на його клемах на рівні номінальної напруги. Декілька методів управління використовуються для поліпшення реакції системи автоматичного регулятора напруги, однак пропорційний інтегральний похідний контролер (PID-контролер) є найбільш часто використовуваним контролером, але його параметри вимагають оптимізації. Новизна. У цій роботі хаотична послідовність, заснована на логістичній схемі, гібридизується за допомогою оптимізації рою частинок, щоб знайти оптимальні параметри PID для системи автоматичного регулятора напруги. Ініціалізація на основі хаотичної послідовності логістичної схеми та найкращий глобальний вибір дозволяють алгоритму вийти із локальної мінімальної стагнації та покращити швидкість збіжності, що дає найкращі оптимальні параметри. Мета. Основною метою запропонованого підходу є поліпшення перехідної реакції системи автоматичного регулятора напруги шляхом мінімізації максимального перевищення, часу встановлення, часу наростання та пікових значень напруги на клемах і усунення помилки у стаціонарного стані. Методи. У процесі настройки параметрів техніку оптимізації рою хаотичних частинок кілька разів пропускали через запропоновану гібридну цільову функцію, яка враховує переваги двох найбільш часто використовуваних цільових функцій з мінімальною кількістю ітерацій,і знайдено оптимальне значення коефіцієнту підсилення PID. Запропонований алгоритм порівнюється з сучасними метаевристичними алгоритмами, включаючи звичайну оптимізацію рою частинок, вдосконалений алгоритм нирок та інші. Результати. Для оцінки ефективності об'єднуються характеристики інтеграла у часі, помноженого на похибки у квадраті, та цільових функцій Цве-Лі Гейнга. Крім того, проводяться аналіз у часовій області, аналіз у частотної області та аналіз стійкості, щоб показати кращу ефективність запропонованого алгоритму. Результат показує, що автоматичний регулятор напруги, налаштований на хаотичну оптимізацію рою частинок, заснований на поліпшенні виходу PID в перевищеннях,часі налаштування та значенні функції перевищує на 14,41 %, 37,91 %, 1,73 % нещодавно запропонований нирковий алгоритм та на 43,55 %, 44,5 %, 16,67 % перевищує звичайні алгоритми оптимізації рою частинок. Поліпшення перехідної реакції ще більше покращує стабільність автоматичного регулятора напруги для систем електроенергетики