Mixed Non-Uniform Width / Evanescent Mode Ceramic Resonator Waveguide Filter With Wide Spurious Free Bandwidth

This paper presents a method to improve the spurious performance of integrated ceramic waveguide filters. Nonuniform width ceramic waveguide resonator and evanescent mode ceramic resonators are employed together to the resonant frequencies of higher order modes. The proposed designs give 75% improvement in stop band response when compared to uniform width ceramic waveguide filter. Simulated results of two six pole chebyshev filters are presented here with improved stop band performance

LATEST TOURNAISIAN (EARLY CARBONIFEROUS) CONODONTS FROM THE TABAI LIMESTONE, TIRAH, NORTHWESTERN PAKISTAN

A new stratigraphic unit, the Tabai Limestone of the poorly known Tirah area of northwest Pakistan, is one of several Early Carboniferous carbonate units distributed along the North Gondwana margin, some connected with transgressive interludes. The Tabai Limestone has produced latest Tournaisian (Early Carboniferous) conodonts indicative of the middle of the anchoralis-latus Zone

A descriptive analysis of research culture in Pakistan

This study addresses evolution of research culture in Pakistan. The study is descriptive in nature. The primary analysis is related to 180 Pakistani universities and 13259 PhDs produced from these universities since 1947 till 2016 along with their different contextual ratios such as geography, gender, public, and private sectors, universities and number of produced PhDs, supervisor and number of produced PhDs ratios, era wise growth of number of universities and produced PhDs. The study accounts for benchmark changes in leadership and resources as impacting factors for change in number of universities and produced number of Doctoral Researches (PhDs). The primary source for data is HEC while respective websites of the universities (if available) are also explored for the missing data. The study documents relatively recent emergence of certain assets in terms of a research culture and anticipates an opportunity to build upon these assets in future. Public universities with more experience are taking lead in almost all domains such as increase in number of universities and PhDs produced, their geographic and gender diversity, and supervisor to PhDs ratio etc. and private and relevantly new universities lag behind. If these could also start contributing soon Pakistan could muster the fruit of a rich research culture

What is the effect of riskshaw noise on its driver?

Objective: Occupational hearing loss is common in the industrialized world. Road noise is a major contributor to perceived environmental noise. The objective of this study was to assess hearing loss in rickshaw drivers due to rickshaw noise.Methods: Hearing loss in rickshaw drivers and taxi drivers of Karachi who were 50 years of age or younger was estimated, with a Smith Hearing Screening (SHS) questionnaire that was modified, translated into the national language, Urdu and field tested prior to administration.Results: Interviews for 91 rickshaw drivers and 94 taxi drivers were completed. All subjects were male; mean ages were 34 and 33 years for rickshaw and taxi drivers respectively. None of the rickshaws were fitted with silencers. Rickshaw drivers were about thrice as likely to be screened as hearing impaired by the SHS questionnaire (RR 2.9, 95% confidence interval 1.6, 5.0), twice as likely to report tinnitus (RR 2.2, 95% confidence interval, 1.1, 3.3) and two and a half times as likely to have difficulty in following telephonic conversations (RR 2.4, 95% confidence interval 1.2, 4.8).CONCLUSION: There is loss of hearing and tinnitus among rickshaw drivers that could be attributed to their trade. Use of silencers by rickshaw drivers could result in less hearing loss among rickshaw drivers and less noise in the environment for the other 11 million residents in the city

Surgical Outcome of Otogenic Brain Abscess in Chronic Suppurative Otitis Media

Objective: To determine the surgical out come of otogenic brain abscess in chronic suppurative otitis media.Material and Methods: This descriptive study was conducted at the departments of ENT, Head, Neck Surgery and Neurosurgery Postgraduate Medical Institute (PGMI) Lady Reading Hospital Peshawar from June 2004 to May 2009 with a total duration of five years. The diagnostic criteria were detailed history, thorough Neuro-otological examination and radiological investigations. These patients were admitted into ENT Department and they were put on quadruple therapy. CT scans were performed on emergency basis and as the patients were diagnosed as having otogenic brain abscess urgent evacuation of abscess was done by neurosurgeon. All the patients with established brain abscess were included in this study while those patients having small multiple abscesses, early cereberitis and non otogenic brain abscesses were excluded from study. A well informed consent was taken from patient explaining the procedure, its risks, benefits and associated complications. The abscesses were primarily treated by neurosurgeons and the ears were later on treated by ENT surgeons. There was neither intra operative nor postoperative complication.Results: This study included 22 patients in the age range of 12-51 years with mean age 25 years. Sixteen were male and six were female, with female to male ratio 1 : 2.6. These patients presented with history of discharging ear, headache, vomiting and disorientation. The signs of disease in these patients were granulation tissues/ cholesteatoma in ear and papilloedema. CT scans were performed in all 22 cases (100%) while MRI in 10 cases (45.45%). There were single brain abscess in 14 cases (63.63%) while 8 cases (44.45%) having multiple brain abscesses. Mainly abscess were found in temporal region followed by cerebellar. The patients with chronic ear disease were treated by radical mastoidectomy and modified radical mastoidectomy after treating the brain abscess by Neurosurgeon. The Neurosurgical procedures performed were capsulotmies in 13 cases (59.09%), Bur hole aspiration in 7 cases (31.81%) and Trans mastoid excision in 2 cases (9.09%). These patients were followed for 3 monthly having CT scan with contrast with bone window.Conclusion: We concluded from our study that otogenic brain abscess is a life threatening complication, so early identification with help of CT scan and prompt surgical intervention with appropriate treatment of middle ear (primary disease) is essential for better outcom

Evaluation of cadmium, lead, nickel and zinc status in biological samples of smokers and nonsmokers hypertensive patients

The objective of this study was to evaluate the association between trace and toxic elements zinc (Zn), cadmium (Cd), nickel (Ni) and lead (Pb) in biological samples (scalp hair, blood and urine) of smoker and nonsmoker hypertensive patients (n=457), residents of Hyderabad, Pakistan. For the purpose of comparison, the biological samples of age-matched healthy controls were selected as referents. The concentrations of trace and toxic elements were measured by atomic absorption spectrophotometer prior to microwave-assisted acid digestion. The validity and accuracy of the methodology were checked using certified reference materials and by the conventional wet acid digestion method on the same certified reference materials and real samples. The recovery of all the studied elements was found to be in the range of 97.8–99.3% in certified reference materials. The results of this study showed that the mean values of Cd, Ni and Pb were significantly higher in scalp hair, blood and urine samples of both smoker and nonsmoker patients than in referents (P<0.001), whereas the concentration of Zn was lower in the scalp hair and blood, but higher in the urine samples of hypertensive patients. The deficiency of Zn and the high exposure of toxic metals as a result of tobacco smoking may be synergistic with risk factors associated with hypertension