16,792 research outputs found

    A comparison of forensic toolkits and mass market data recovery applications

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    Digital forensic application suites are large, expensive, complex software products, offering a range of functions to assist in the investigation of digital artifacts. Several authors have raised concerns as to the reliability of evidence derived from these products. This is of particular concern, given that many forensic suites are closed source and therefore can only be subject to black box evaluation. In addition, many of the individual functions integrated into forensic suites are available as commercial stand-alone products, typically at a much lower cost, or even free. This paper reports research which compared (rather than individually evaluated) the data recovery function of two forensic suites and three stand alone `non-forensic' commercial applications. The research demonstrates that, for this function at least, the commercial data recovery tools provide comparable performance to that of the forensic software suites. In addition, the research demonstrates that there is some variation in results presented by all of the data recovery tools

    Associations between Feeling and Judging the Emotions of Happiness and Fear: Findings from a Large-Scale Field Experiment

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    Background: How do we recognize emotions from other people? One possibility is that our own emotional experiences guide us in the online recognition of emotion in others. A distinct but related possibility is that emotion experience helps us to learn how to recognize emotions in childhood. Methodology/Principal Findings: We explored these ideas in a large sample of people (N = 4,608) ranging from 5 to over 50 years old. Participants were asked to rate the intensity of emotional experience in their own lives, as well as to perform a task of facial emotion recognition. Those who reported more intense experience of fear and happiness were significantly more accurate (closer to prototypical) in recognizing facial expressions of fear and happiness, respectively, and intense experience of fear was associated also with more accurate recognition of surprised and happy facial expressions. The associations held across all age groups. Conclusions: These results suggest that the intensity of one's own emotional experience of fear and happiness correlates with the ability to recognize these emotions in others, and demonstrate such an association as early as age 5

    Hardening electronic devices against very high total dose radiation environments

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    The possibilities and limitations of hardening silicon semiconductor devices to the high neutron and gamma radiation levels and greater than 10 to the eighth power rads required for the NERVA nuclear engine development are discussed. A comparison is made of the high dose neutron and gamma hardening potential of bipolar, metal insulator semiconductors and junction field effect transistors. Experimental data is presented on device degradation for the high neutron and gamma doses. Previous data and comparisons indicate that the JFET is much more immune to the combined neutron displacement and gamma ionizing effects than other transistor types. Experimental evidence is also presented which indicates that p channel MOS devices may be able to meet the requirements

    Neuronal Control of Swimming Behavior: Comparison of Vertebrate and Invertebrate Model Systems

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    Swimming movements in the leech and lamprey are highly analogous, and lack homology. Thus, similarities in mechanisms must arise from convergent evolution rather than from common ancestry. Despite over 40 years of parallel investigations into this annelid and primitive vertebrate, a close comparison of the approaches and results of this research is lacking. The present review evaluates the neural mechanisms underlying swimming in these two animals and describes the many similarities that provide intriguing examples of convergent evolution. Specifically, we discuss swim initiation, maintenance and termination, isolated nervous system preparations, neural-circuitry, central oscillators, intersegmental coupling, phase lags, cycle periods and sensory feedback. Comparative studies between species highlight mechanisms that optimize behavior and allow us a broader understanding of nervous system function

    Spontaneous Arrhythmias and Conduction Disturbances in Domestic Animals

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    Most of the common arrhythmias and conduction disturbances have been reported in domestic mammals. Prevalence data, however, are not available from unselected population samples, and little information is at hand on long-term studies of individual cases. A discussion of some of these disturbances, therefore, must necessarily rely more heavily upon clinical impression than is desirable. Data have been published on normal electrocardiograms in different species, which, coupled with published case series, individual case reports, and observations made at the Heart Station of the University of Pennsylvania School of Veterinary Medicine, provide the basis for this presentation. This information suggests that certain arrhythmias and conduction disturbances occur commonly in some species and should be regarded as normal variants. In animals, departures from the normal regular sinus rhythm characteristic of adult humans apparently result from a relatively greater vagal influence on the cardiac pacemaker and conduction tissues. This certainly accounts for respiratory sinus arrhythmia in dogs. In horses, high resting vagal activity is considered accountable for sinus arrhythmia (respiratory and non-respiratory), wandering pacemaker, varying P-R interval, SA block, and incomplete AV block with dropped beats. Although these arrhythmias and conduction disturbances may occur with primary heart disease, or disease primarily affecting vagal activity, their frequent occurrence in the absence of detectable heart disease and also their disappearance with increased heart rate following exercise, excitement, or atropine, support the view that vagal activity rather than primary heart disease accounts for the majority of occasions in which they are observed. Frequently, more than one of the preceding arrhythmias are observed in one individual in the same or subsequent tracings; therefore frequency data often reflect some overlapping. It is useful, however, to present them individually when discussing more specific information

    Changing Breed Predispositions in Canine Heart Disease

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    Breed predispositions for some types of congenital heart disease were recognized 30 years ago and led to breeding experiments that confirmed the genetic transmission of specific congenital heart defects in most instances. As a result, certain breeds were associated with certain diseases, and this became a legitimate consideration in the differential diagnosis of some abnormalities in the absence of more definite diagnostic studies. As an example, a significant systolic murmur in a young Newfoundland dog means sub-aortic stenosis (SAS) until proven otherwise. The diagnosis of SAS is usually confirmed by Doppler echocardiography or angiocardiography. Although cardiologists take breed into consideration, they still rely on proper examination and appropriate diagnostic procedures; however, practitioners are comes pressed to give opinions on the likelihood of particular diagnoses and prognoses without benefit of a full work-up. In this setting, knowledge of new and changing breed predispositions can be helpful. In recent years, some defects and new breeds have been found to be overrepresented in cardiology clinics across the country. All practitioners need to be alert in order to recognize new breed predispositions and counsel breeders accordingly. Of particular note is the rising frequency of SAS in Golden Retriever and Rottweiler dogs. The purpose of this presentation is to describe changing breed predispositions that have been observed in recent years and share the results of a recent tabulation of data at our institution as well as 1987- 1989 data in the national Veterinary Medical Data Base (VMDB) at Purdue University

    Tracheal Signs and Associated Vascular Anomalies in Dogs With Persistent Right Aortic Arch

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    Medical records of 55 dogs with 1 or more vascular rings around the esophagus and trachea were reviewed to determine the nature and frequency of related vascular anomalies and to determine the reliability of tracheal deviation on radiographs for the diagnosis of persistent right aortic arch (PRAA). Fifty-two (95%) of the 55 dogs had PRAA. Of the 52 dogs with PRAA, 44% had coexisting compressive arterial anomalies: 17 had retroesophageal left subclavian artery and 6 had double aortic arch with atretic left arch. Characteristic tracheal deviation was consistently present in dogs with PRAA. Moderate or marked focal leftward curvature of the trachea near the cranial border of the heart in dorsoventral (DV) or ventrodorsal (VD) radiographs was found in 100% of available radiographs of 27 dogs with PRAA. Moderate or marked focal narrowing of the trachea also was noted in 74% of DV or VD radiographs and 29% of lateral radiographs of the dogs. Tracheal position in 30 of 30 dogs with megaesophagus and 62 of 63 control dogs was midline or rightward in VD or DV radiographs. Histology in a neonatal dog with PRAA revealed evidence of tracheal deviation and compression even before birth. Focal leftward deviation of the trachea near the cranial border of the heart in DV or VD radiographs is a reliable sign of PRAA in young dogs that regurgitate after eating solid food, and contrast esophagrams are not necessary to confirm the diagnosis of vascular ring compression
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