584 resultados para Telescopic gun sights


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All optical systems that operate in or through the atmosphere suffer from turbulence induced image blur. Both military and civilian surveillance, gun-sighting, and target identification systems are interested in terrestrial imaging over very long horizontal paths, but atmospheric turbulence can blur the resulting images beyond usefulness. My dissertation explores the performance of a multi-frame-blind-deconvolution technique applied under anisoplanatic conditions for both Gaussian and Poisson noise model assumptions. The technique is evaluated for use in reconstructing images of scenes corrupted by turbulence in long horizontal-path imaging scenarios and compared to other speckle imaging techniques. Performance is evaluated via the reconstruction of a common object from three sets of simulated turbulence degraded imagery representing low, moderate and severe turbulence conditions. Each set consisted of 1000 simulated, turbulence degraded images. The MSE performance of the estimator is evaluated as a function of the number of images, and the number of Zernike polynomial terms used to characterize the point spread function. I will compare the mean-square-error (MSE) performance of speckle imaging methods and a maximum-likelihood, multi-frame blind deconvolution (MFBD) method applied to long-path horizontal imaging scenarios. Both methods are used to reconstruct a scene from simulated imagery featuring anisoplanatic turbulence induced aberrations. This comparison is performed over three sets of 1000 simulated images each for low, moderate and severe turbulence-induced image degradation. The comparison shows that speckle-imaging techniques reduce the MSE 46 percent, 42 percent and 47 percent on average for low, moderate, and severe cases, respectively using 15 input frames under daytime conditions and moderate frame rates. Similarly, the MFBD method provides, 40 percent, 29 percent, and 36 percent improvements in MSE on average under the same conditions. The comparison is repeated under low light conditions (less than 100 photons per pixel) where improvements of 39 percent, 29 percent and 27 percent are available using speckle imaging methods and 25 input frames and 38 percent, 34 percent and 33 percent respectively for the MFBD method and 150 input frames. The MFBD estimator is applied to three sets of field data and the results presented. Finally, a combined Bispectrum-MFBD Hybrid estimator is proposed and investigated. This technique consistently provides a lower MSE and smaller variance in the estimate under all three simulated turbulence conditions.

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The field work was conducted in areas adjacent to White­hall, Montana, as has been the custom for the past several years. Instruction in the proper use of the telescopic and open sight alidades, and the Brunton compass for surveying geologic features was given. Advantages of pacing and speed­ometer mapping were pointed out and used.

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PURPOSE: The aim of this study was to analyze prosthetic maintenance in partially edentulous patients with removable prostheses supported by teeth and strategic implants. MATERIALS AND METHODS: Sixty patients with removable partial prostheses and combined tooth-implant support were identified within the time period from 1998 to 2006. One group consisted of 42 patients (planned group) with a reduced residual dentition and in need of removable partial dentures (RPDs) or overdentures in the maxilla and/or mandible. They were admitted consecutively for treatment. Due to missing teeth in strategic important positions, one or two implants were placed to improve symmetrical denture support and retention. The majority of residual teeth exhibited an impaired structural integrity and therefore were provided with root copings for denture retention. A few vital teeth were used for telescopic crowns. The anchorage system for the strategic implants was selected accordingly. A second group of 18 patients (repair group) wearing RPDs with the loss of one abutment tooth due to biologic or mechanical failure was identified. These abutment teeth were replaced by 21 implants, and patients continued to wear their original prostheses. The observation time for planned and repair groups was 12 months to 8 years. All patients followed a regular maintenance schedule. Technical or biologic complications with supporting teeth or implants and prosthetic service were registered regularly. RESULTS: Three maxillary implants were lost after loading and three roots with copings had to be removed. Biologic problems included caries and periodontal/peri-implant infection with a significantly higher incidence in the repair group (P < .05). Technical complications with the dentures were rather frequent in both groups, mostly related to the anchorage system (matrices) of root copings and implants. Maintenance and complications were observed more frequently in the first year after delivery of the denture than in the following 3 years (P < .05). No denture had to be remade. CONCLUSIONS: The placement of a few implants allows for maintaining a compromised residual dentition for support of RPDs. The combination of root and implant support facilitates treatment planning and enhances designing the removable denture. It also proves to be a practical rescue method. Technical problems with the anchorage system were frequent, particularly in the first year after delivery of the dentures.

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Contents25-year anniversary of ISU goldProposed Iowa gun bills could offer more protectionDivision III team ready for 1st shot at titleThe fall of the Iowa HouseHockey team finds positives in rebuilding seasonSmoothie movement helps health

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ContentsDebate brings out choiceA cold battle in AmesEating disorders affect everyoneStudents walk green carpet at SustainapoloozaConcealed gun carry: Is it time?Husband, wife gymnastics team works side by sideAdd some kick to that cupcake

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Homicide-suicides, the murder of one or several individuals followed by the suicide of the perpetrator, are rare but have devastating effects on families and communities. We did a systematic review and meta-analysis of studies comparing perpetrators of homicide-suicides with perpetrators of simple homicides and suicides and examined the proportion of firearm use and its correlation with firearm availability. We searched Medline and Embase from inception to July 2012 and identified 27 eligible studies. Perpetrators of homicide-suicides were older and more likely to be male and married to or separated from their victims than perpetrator of simple homicides or suicides. Influence of alcohol and a history of domestic violence or unemployment were less prevalent in homicide-suicides than in homicides. The proportion of firearm use in homicide-suicides varied across countries and was highest in the USA, Switzerland and South Africa, followed by Australia, Canada, The Netherlands and England and Wales, with a strong correlation between the use of firearms and the level of civilian gun ownership in the country. Our results indicate that homicide-suicides represent a distinct entity, with characteristics distinguishing them both from homicides and suicides.

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A microbiopsy system for fast excision and transfer of biological specimens from donor to high-pressure freezer was developed. With a modified, commercially available, Promag 1.2 biopsy gun, tissue samples can be excised with a size small enough (0.6 mm x 1.2 mm x 0.3 mm) to be easily transferred into a newly designed specimen platelet. A self-made transfer unit allows fast transfer of the specimen from the needle into the specimen platelet. The platelet is then fixed in a commercially available specimen holder of a high-pressure freezing machine (EM PACT, Leica Microsystems, Vienna, Austria) and frozen therein. The time required by a well-instructed (but not experienced) person to execute all steps is in the range of half a minute. This period is considered short enough to maintain the excised tissue pieces close to their native state. We show that a range of animal tissues (liver, brain, kidney and muscle) are well preserved. To prove the quality of freezing achieved with the system, we show vitrified ivy leaves high-pressure frozen in the new specimen platelet.

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In modern medico-legal literature, only a small number of publications deal with fatal injuries from black powder guns. Most of them focus on the morphological features such as intense soot soiling, blast tattooing and burn effects in close-range shots or describe the wound ballistics of spherical lead bullets. Another kind of "unusual" and potentially lethal weapons are handguns destined for firing only blank cartridges such as starter and alarm pistols. The dangerousness of these guns is restricted to very close and contact range shots and results from the gas jet produced by the deflagration of the propellant. The present paper reports on a suicide committed with a muzzle-loading percussion pistol cal. 45. An unusually large stellate entrance wound was located in the precordial region, accompanied by an imprint mark from the ramrod and a faint greenish discoloration (apparently due to the formation of sulfhemoglobin). Autopsy revealed an oversized powder cavity, multiple fractures of the anterior thoracic wall as well as ruptures of the heart, the aorta, the left hepatic lobe and the diaphragm. In total, the zone of mechanical destruction had a diameter of approx. 15 cm. As there was no exit wound and no bullet lodged in the body, the injury was caused exclusively by the inrushing combustion gases of the propellant (black powder) comparable with the gas jet of a blank cartridge gun. In contact shots to ballistic gelatine using the suicide's pistol loaded with black powder but no projectile, the formation of a nearly spherical cavity could be demonstrated by means of a high-speed camera. The extent of the temporary cavity after firing with 5 g of black powder roughly corresponded to the zone of destruction found in the suicide's body.

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INTRODUCTION Though developed for thoracic insufficiency syndrome, the spinal growth-stimulating potential and the ease of placement of vertical expandable titanium ribs (VEPTRs) has resulted in their widespread use for early-onset spine deformity. Observation of implant-related ossifications warrants further assessment, since they may be detrimental to the function-preserving non-fusion strategy. PATIENTS AND METHODS Radiographs (obtained pre and post index procedure, and at 4-year follow-up) and the records of 65 VEPTR patients from four paediatric spine centres were analysed. Ossifications were classified as type I (at anchor points), type II (along the central part) or type III (re-ossification after thoracostomy). RESULTS The average age at the index procedure was 6.5 years (min 1, max 13.7). The most prevalent spine problem was congenital scoliosis (37) with rib fusions (34), followed by neuromuscular and syndromic deformities (13 and 8, respectively). Idiopathic and secondary scoliosis (e.g. after thoracotomy) were less frequent (3 and 4, respectively). Forty-two of the 65 (65 %) patients showed ossifications, half of which were around the anchors. Forty-five percent (15/33) without pre-existing rib fusions developed a type II ossification along the implant. Re-ossifications of thoracostomies were less frequent (5/34, 15 %). The occurrence of ossifications was not associated with patient-specific factors. CONCLUSIONS Implant-related ossifications around VEPTR are common. In contrast to harmless bone formation around anchors, ossifications around the telescopic part and the rod section are troublesome in view of their possible negative impact on chest cage compliance and spinal mobility. This potential side effect needs to be considered during implant selection, particularly in patients with originally normal thoracic and spinal anatomy.

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Traces of backspatter recovered from the inside of the barrel of a gun that was used to deliver suicidal or homicidal contact shots may be a source of valuable forensic evidence and first systematic investigations of the persistence of victim DNA from inside firearms have been presented. The aim of the present study was to include victim RNA in such analyses to determine the origin of tissues in addition and parallel to standard DNA profiling for forensic identification purposes. In a first step, suitable mRNA (C1orf61) and micro-RNAs (miR-124a and miR-124*) that are primarily expressed in brain tissue were selected from potential candidates and confirmed using quantitative PCR (qPCR). Secondly, a co-extraction procedure for RNA and DNA was established and brain differentiability of the selected RNAs was demonstrated via qPCR using samples from experimental shots at ballistic models. In a third step, this procedure was successfully applied to analyse samples from real casework comprising eight cases of suicidal contact shots. In this pilot study, we are first to report the possibility of co-extracting mRNA, miRNA and DNA from ballistic trace samples collected from the inside of firearms and we demonstrate that RNA and DNA based analyses can be performed in parallel to produce informative and highly complementary evidence.

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Measurement association and initial orbit determination is a fundamental task when building up a database of space objects. This paper proposes an efficient and robust method to determine the orbit using the available information of two tracklets, i.e. their line-of-sights and their derivatives. The approach works with a boundary-value formulation to represent hypothesized orbital states and uses an optimization scheme to find the best fitting orbits. The method is assessed and compared to an initial-value formulation using a measurement set taken by the Zimmerwald Small Aperture Robotic Telescope of the Astronomical Institute at the University of Bern. False associations of closely spaced objects on similar orbits cannot be completely eliminated due to the short duration of the measurement arcs. However, the presented approach uses the available information optimally and the overall association performance and robustness is very promising. The boundary-value optimization takes only around 2% of computational time when compared to optimization approaches using an initial-value formulation. The full potential of the method in terms of run-time is additionally illustrated by comparing it to other published association methods.

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BACKGROUND In an effort to reduce firearm mortality rates in the USA, US states have enacted a range of firearm laws to either strengthen or deregulate the existing main federal gun control law, the Brady Law. We set out to determine the independent association of different firearm laws with overall firearm mortality, homicide firearm mortality, and suicide firearm mortality across all US states. We also projected the potential reduction of firearm mortality if the three most strongly associated firearm laws were enacted at the federal level. METHODS We constructed a cross-sectional, state-level dataset from Nov 1, 2014, to May 15, 2015, using counts of firearm-related deaths in each US state for the years 2008-10 (stratified by intent [homicide and suicide]) from the US Centers for Disease Control and Prevention's Web-based Injury Statistics Query and Reporting System, data about 25 firearm state laws implemented in 2009, and state-specific characteristics such as firearm ownership for 2013, firearm export rates, and non-firearm homicide rates for 2009, and unemployment rates for 2010. Our primary outcome measure was overall firearm-related mortality per 100 000 people in the USA in 2010. We used Poisson regression with robust variances to derive incidence rate ratios (IRRs) and 95% CIs. FINDINGS 31 672 firearm-related deaths occurred in 2010 in the USA (10·1 per 100 000 people; mean state-specific count 631·5 [SD 629·1]). Of 25 firearm laws, nine were associated with reduced firearm mortality, nine were associated with increased firearm mortality, and seven had an inconclusive association. After adjustment for relevant covariates, the three state laws most strongly associated with reduced overall firearm mortality were universal background checks for firearm purchase (multivariable IRR 0·39 [95% CI 0·23-0·67]; p=0·001), ammunition background checks (0·18 [0·09-0·36]; p<0·0001), and identification requirement for firearms (0·16 [0·09-0·29]; p<0·0001). Projected federal-level implementation of universal background checks for firearm purchase could reduce national firearm mortality from 10·35 to 4·46 deaths per 100 000 people, background checks for ammunition purchase could reduce it to 1·99 per 100 000, and firearm identification to 1·81 per 100 000. INTERPRETATION Very few of the existing state-specific firearm laws are associated with reduced firearm mortality, and this evidence underscores the importance of focusing on relevant and effective firearms legislation. Implementation of universal background checks for the purchase of firearms or ammunition, and firearm identification nationally could substantially reduce firearm mortality in the USA. FUNDING None.

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BACKGROUND Deep brain stimulation (DBS) is recognized as an effective treatment for movement disorders. We recently changed our technique, limiting the number of brain penetrations to three per side. OBJECTIVES The first aim was to evaluate the electrode precision on both sides of surgery since we implemented this surgical technique. The second aim was to analyse whether or not the electrode placement was improved with microrecording and macrostimulation. METHODS We retrospectively reviewed operation protocols and MRIs of 30 patients who underwent bilateral DBS. For microrecording and macrostimulation, we used three parallel channels of the 'Ben Gun' centred on the MRI-planned target. Pre- and post-operative MRIs were merged. The distance between the planned target and the centre of the implanted electrode artefact was measured. RESULTS There was no significant difference in targeting precision on both sides of surgery. There was more intra-operative adjustment of the second electrode positioning based on microrecording and macrostimulation, which allowed to significantly approach the MRI-planned target on the medial-lateral axis. CONCLUSION There was more electrode adjustment needed on the second side, possibly in relation with brain shift. We thus suggest performing a single central track with electrophysiological and clinical assessment, with multidirectional exploration on demand for suboptimal clinical responses.

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Working with CT DEP, the NOAA Office of Damage Assessment, Remediation and Restoration uses funds recovered from polluters to conduct restoration projects. Here in Connecticut, projects include the Jordan Brook Fishway in Waterford, the Remington Gun Club site at Lordship Point in Stratford, and more.

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A cohort study was conducted in Texas and Louisiana Gulf Coast area on individual workers who have been exposed to asbestos for 15 years or more. Most of these workers were employed in petrochemical industries. Of the 15,742 subjects initially selected for the cohort study, 3,258 had positive chest X-ray findings believed to be related to prolonged asbestos exposure. These subjects were further investigated. Their work out included detailed medical and occupational history, laboratory tests and spirometry. One thousand eight-hundred and three cases with positive chest X-ray findings whose data files were considered complete at the end of May 1986 were analyzed and their findings included in this report.^ The prevalence of lung cancer and cancer of the following sights: skin, stomach, oropharyngeal, pancreas and kidneys were significantly increased when compared to data from Connecticut Tumor Registry. The prevalence of other chronic conditions such as hypertension, emphysema, heart disease and peptic ulcer was also significantly high when compared to data for the U.S. and general population furnished by the National Center for Health Statistics (NCHS). In most instances the occurrence of cancer and the chronic ailment previously mentioned appeared to follow 15-25 years of exposure to asbestos. ^