Neutral hydrogen at the present epoch: A constraint on the evolution of high redshift systems

Damped Lyman-alpha and metal absorption lines in the spectra of quasars indicate the presence of intervening gas-rich systems at high redshift (z greater than 2). These systems have characteristic size scales, velocity dispersions, and neutral hydrogen column densities (N(H1)) similar to present day spirals and are thus thought to be their progenitors. Constraints on galaxy evolution can be derived by comparing the H1 properties of high redshift systems to the present galaxy population. Good observational statistics on high redshift absorbers specify the number of these systems along the line of sight as a function of N(H1), the column density of neutral hydrogen per absorber. Similar statistics for nearby (z = 0) galaxies of which spirals are the only gas-rich systems that provide a significant cross-section for the interception of light from quasars is derived

A GPU based real-time software correlation system for the Murchison Widefield Array prototype

Modern graphics processing units (GPUs) are inexpensive commodity hardware that offer Tflop/s theoretical computing capacity. GPUs are well suited to many compute-intensive tasks including digital signal processing. We describe the implementation and performance of a GPU-based digital correlator for radio astronomy. The correlator is implemented using the NVIDIA CUDA development environment. We evaluate three design options on two generations of NVIDIA hardware. The different designs utilize the internal registers, shared memory and multiprocessors in different ways. We find that optimal performance is achieved with the design that minimizes global memory reads on recent generations of hardware. The GPU-based correlator outperforms a single-threaded CPU equivalent by a factor of 60 for a 32 antenna array, and runs on commodity PC hardware. The extra compute capability provided by the GPU maximises the correlation capability of a PC while retaining the fast development time associated with using standard hardware, networking and programming languages. In this way, a GPU-based correlation system represents a middle ground in design space between high performance, custom built hardware and pure CPU-based software correlation. The correlator was deployed at the Murchison Widefield Array 32 antenna prototype system where it ran in real-time for extended periods. We briefly describe the data capture, streaming and correlation system for the prototype array.Comment: 11 pages, to appear in PAS

Autism in Children: Clinical Features, Management and Challenges

Background: The prevalence of autism world-wide is estimated to be between 1 per 91-110 children. Awareness in the USA and many other developed countries is relatively high and increasing, information on this condition in Nigeria among the public and the medical community is sparse.Objective: This paper highlights the clinical features and management of autism. It also discusses current challenges of autism and its management.Method: Data was sourced from literature in world health organization (WHO) and published articles on autism and internet Medline publications.Results: Autism is characterized by impaired social interaction, problems with verbal and nonverbal communication, unusual repetitive or severely limited activities and interests. The impact of these behaviors can range from mild to disabling. Autism affects all races, ethnic groups and socioeconomic levels, the exact cause is unknown and there is no cure for it. Management is multidisciplinary including educational therapy,psychotherapy, drug treatment amongst others. The combined problems of malaria, malnutrition, pneumonia, HIV/AIDS and other infectious illnesses may be masking emphasis on this neurodevelopmental condition.Conclusions: Autism is a common neurodevelopmental disorder worldwide. Management of the condition is challenging. Creating awareness, improving skills in its diagnosis and optimal management will promote better outcome in affected children.Key Words: Autism, features, poor awareness, management, challenge

Alien Registration- Briggs, Frank P. (Portland, Cumberland County)

https://digitalmaine.com/alien_docs/23016/thumbnail.jp

Comparative Analysis of the Results from the Ideal Gas Assumptions with more Rigorous Calculations from Pro/II of the Production of Pharmaceutical Grade Acetone

The Chemical engineering team was assigned by Landshark Inc to investigate the production of 30,000 tonnes/yr of pharmaceutical-grade acetone with a purity of 99.9 wt.% from the dehydrogenation of isopropanol (IPA). The team was tasked with determining the necessary process and unit operation criteria to ensure the economic feasibility of the proposed plant. The major goal of this thesis is to provide a data comparison of the reactor in acetone production process when designed in Microsoft Excel and Pro/II. The first part of this thesis will introduce the base case briefly, transition into engineering optimizations and show the results found from the design process as well as some safety concerns to consider when designing these processes. The purpose of this study was to divulge in greater detail the implications of assuming ideal gas conditions for the process as compared to a more rigorous equations of state. For this study, the reactor section of the plant was analyzed in detail using Microsoft Excel for the ideal gas assumption and Pro//II for more rigorous calculations. The results of this comparative study indicated that Pro//II produced a higher conversion of IPA of 92.3%. This study also showed that results from Pro//II increased profitability and efficiency while decreasing capital and operating costs

An HI selected sample of galaxies - The HI mass function and the surface brightness distribution

Results from the Arecibo HI Strip Survey, an unbiased extragalactic HI survey, combined with optical and 21cm follow-up observations, determine the HI Mass Function and the cosmological mass density of HI at the present epoch. Both are consistent with earlier estimates, computed for the population of optically selected galaxies. This consistency occurs because, although the distribution of optical central surface brightnesses among galaxies is flat, we fail to find a population of galaxies with central surface brightnesses fainter than 24 B-mag/arcsec^2, even though there is no observational selection against them.Comment: 5 pages, including 3 encapsulated postscript figures. Presented at the workshop `HI in the Local Universe', Sydney, May 13-15 1996. Accepted for publication by PASA. Also available from http://www.atnf.csiro.au/Publications/HI_workshop/proceedings.htm

Childhood Hearing Impairment: How Do Parents Feel About It?

Background Hearing impairment or deafness is a major disabling condition worldwide. Etiology of the hearing loss   range from congenital to acquired, and includes common and preventable childhood infections like otitis  media and meningoencephalitis. Morbidity and burden of hearing impairment on the children and their parents is enormous. This is because affected children have developmental delay in many domains  including speech, cognition as well as behavioural and other aspects of psychosocial development. Early  identification and effective treatment of hearing loss improves language, other forms of communication, and cognitive skills. This study was carried out to evaluate and ascertain the  perception and attitude of parents of children with hearing impairment. Material  and Method This was a questionnaire based  study of parents' perception and attitude about children with hearing impairment in the PortHarcourt metropolis from pt June 2011 to 31"t May2012.Results Thirty seven parents of children with hearing impairment were studied. The parents demonstrated different attitudes towards the children. Majority, 34(94.59%) of them felt sad, others  expressed anger. Twenty seven (72.97%) felt hearing loss was due to punishment from the "gods" for an evil deed by a family member. The attitude and feelings of parents included sadness, self blame and  anger. Parents also believe that immediate cause is spiritual.ConclusionThe public should be enlightened about common preventable causes so as to correct all negative attitudes about hearing loss I impairment.Keyword: Hearing impairment; children; parents; perception and attitude

Drug induced aseptic meningitis: A diagnostic challenge

Drug-induced aseptic meningitis (DIAM) is a rare but important and often challenging diagnosis for the physician. Intake of antimicrobials, steroids, analgesics amongst others has been implicated. Signs and symptoms generally develop within 24-48 hours of drug ingestion. The patient often exhibits the classic symptoms of meningitis.Aim: Two cases of drug induced meningitis are presented with review of literature.Case reports:Case I: A 13 year old male with a three days history of persistent fever, vomiting, abdominal pain and poor appetite. He also had generalized throbbing headache and neck pain of a day’s duration. He had been on Bactrim® for urinary tract infection (UTI) three days prior to the onset of the present symptoms. On examination, he had altered mental status (confused), neck stiffness and a positive Kerning’s and Brudzinski's signs. Muscle tone and deep tendon reflexes were normal with no cranial nerve deficits. Other systems examinations were unremarkable.Case II: 15 year old male with no significant past medical history presented with a day’s history of altered mental status, headache with no fever. He had been on selfmedication with over the counter Ibuprofen tablets for intractable headache three days prior to presentation. Examination showed equivocal neck stiffness clouded by profound altered mental status. They were both initially managed for meningitis. Cerebrospinal fluid work-up for both cases ruled out infectious etiologies. Possible drug induced meningitis was then considered.Conclusion: Drug-induced aseptic meningitis is rare but should be considered in the differential diagnosis of patients presenting with acute or recurrent symptoms and signs of meningitis, especially after infectious causes have been ruled out