Abnormal Instances Research Articles

A Novel Approach for Outlier Detection Using Two-Phase SVM Classifiers with Cross-Training Method for Multi-Disease Diagnosis

Data mining can be effectively used for disease diagnosis but diagnosis of complex-linked diseases, such as TB and HIV, is critical task. Outlier detection can be used on health datasets for identifying rare and abnormal instances for diagnosis purpose. Support vector machine (SVM)-based outlier detection can be used for detecting Outliers from the health dataset and it can be possible in two ways: two-class SVM and one-class SVM. But both classifiers suffer with non-availability of accurate class labels and long training time. So, the main objective of this work is to identify abnormal instances from the health datasets for multiple disease diagnosis combining both the SVM classifiers and introduced cross-training method for solving issues of both classifiers. By comparing the proposed approach with other existing classifiers such as two-class SVM and one-class SVM, the proposed classifier detects almost exact number of outliers from both the datasets with a good accuracy and less training time.

Anomaly Detection in Medical Wireless Sensor Networks using SVM and Linear Regression Models

This paper details the architecture and describes the preliminary experimentation with the proposed framework for anomaly detection in medical wireless body area networks for ubiquitous patient and healthcare monitoring. The architecture integrates novel data mining and machine learning algorithms with modern sensor fusion techniques. Knowing wireless sensor networks are prone to failures resulting from their limitations (i.e. limited energy resources and computational power), using this framework, the authors can distinguish between irregular variations in the physiological parameters of the monitored patient and faulty sensor data, to ensure reliable operations and real time global monitoring from smart devices. Sensor nodes are used to measure characteristics of the patient and the sensed data is stored on the local processing unit. Authorized users may access this patient data remotely as long as they maintain connectivity with their application enabled smart device. Anomalous or faulty measurement data resulting from damaged sensor nodes or caused by malicious external parties may lead to misdiagnosis or even death for patients. The authors' application uses a Support Vector Machine to classify abnormal instances in the incoming sensor data. If found, the authors apply a periodically rebuilt, regressive prediction model to the abnormal instance and determine if the patient is entering a critical state or if a sensor is reporting faulty readings. Using real patient data in our experiments, the results validate the robustness of our proposed framework. The authors further discuss the experimental analysis with the proposed approach which shows that it is quickly able to identify sensor anomalies and compared with several other algorithms, it maintains a higher true positive and lower false negative rate.

A linear programming solution to data description and novelty classification

Many real-world problems require the detection of abnormal instances of a physical process, and methods inspired by the Support Vector Machines have been developed that model reference or normal data well. These methods serve as a fundamental step to enable the classification of new data as normal or abnormal. They imply the solution of a quadratic programming problem, which can present difficulties in finding solutions with standard methods and program solvers when the number of points becomes large. In this paper, we present an approach that was developed in a different context and that leads to a linear programming problem to attain the computational advantages of a linear environment. Normal 0 14 false false false IT X-NONE X-NONE /* Style Definitions */ table.MsoNormalTable {mso-style-name:Tabella normale; mso-tstyle-rowband-size:0; mso-tstyle-colband-size:0; mso-style-noshow:yes; mso-style-priority:99; mso-style-qformat:yes; mso-style-parent:; mso-padding-alt:0cm 5.4pt 0cm 5.4pt; mso-para-margin:0cm; mso-para-margin-bottom:.0001pt; mso-pagination:widow-orphan; font-size:11.0pt; font-family:Calibri,sans-serif; mso-ascii-font-family:Calibri; mso-ascii-theme-font:minor-latin; mso-fareast-font-family:Times New Roman; mso-fareast-theme-font:minor-fareast; mso-hansi-font-family:Calibri; mso-hansi-theme-font:minor-latin; mso-bidi-font-family:Times New Roman; mso-bidi-theme-font:minor-bidi;}

Outlier detection from large distributed databases

In this paper, we present an innovative system, coined as DISTROD (a.k.a DISTRibuted Outlier Detector), for detecting outliers, namely abnormal instances or observations, from multiple large distributed databases. DISTROD is able to effectively detect the so-called global outliers from distributed databases that are consistent with those produced by the centralized detection paradigm. DISTROD is equipped with a number of optimization/boosting strategies which empower it to significantly enhance its speed performance and reduce its communication overhead. Experimental evaluation demonstrates the good performance of DISTROD in terms of speed and communication overhead.

Outcomes of a modified approach to transcatheter closure of perimembranous ventricular septal defects

To describe the immediate and midterm results of a modified method for transcatheter closure of perimembranous ventricular septal defects (pmVSDs). Transcatheter closure of pmVSDs has been associated with development of heart block due to impingement on the ventricular conduction system. Ventricular septal aneurysms (VSAs) are common; the VSA tissue can serve as a target for the device without necessitating direct contact with the conduction system. Between 2004 and 2011, 15 patients underwent transcatheter closure of a pmVSD utilizing a device implanted into a VSA. Catheterization reports were examined in addition to pre-closure, post-closure, and current clinical, ECG, and echocardiographic data. The median age was 20 years (4-61 years), and the most common indication for closure was increasing LV dilation. Four different Amplatzer devices were utilized. Following device implantation there was a decrease in Qp:Qs (1.7-1.1) and in RV:LV pressure ratio (0.36-0.31). There were no deaths, no device embolizations, and no new heart block or PR interval prolongation. Three patients developed a new right bundle branch block (RBBB). The median follow-up time was 1.5 years (4 months to 7.1 years). Two patients required further procedures for important residual shunting. Six continued to have a "trivial/small" residual leak, but only one had any degree (mild) of residual LV dilation. None of the complications were significantly associated with age or weight at the time of procedure, original size of the VSD, or size or type of the device used. Transcatheter closure of pmVSD with placement of the device into the VSA is safe and effective, and may result in fewer instances of atrioventricular block and valve abnormalities than have been reported with alternative methods of pmVSD device closure. Persistent VSDs and new RBBBs remain an important issue.

Abortion in Sri Lanka: The Double Standard

In Sri Lanka, women do not have access to legal abortion except under life-saving circumstances. Clandestine abortion services are, however, available and quite accessible. Although safe specialist services are available to women who can afford them, others access services under unsafe and exploitative conditions. At the time of this writing, a draft bill that will legalize abortion in instances of rape, incest, and fetal abnormalities awaits approval, amid opposition. In this article, I explore the current push for legal reform as a solution to unsafe abortion. Although a welcome effort, this amendment alone will be insufficient to address the public health consequences of unsafe abortion in Sri Lanka because most women seek abortions for other reasons. Much broader legal and policy reform will be required.

Pathways to abnormal revenge and forgiveness

The target article’s important point is easily misunderstood to claim that all revenge is adaptive. Revenge and forgiveness can overstretch (or understretch) the bounds of utility due to misperceptions, minimization of costly errors, a breakdown within our evolved revenge systems, or natural genetic and developmental variation. Together, these factors can compound to produce highly abnormal instances of revenge and forgiveness.

Oocyte and Embryo Selection in Assisted Reproductive Treatments: Methods Improving Outcome and Illuminating Aspects of Meiosis and Embryogenesis.

The introduction of in vitro fertilization (IVF) treatment over thirty years ago revolutionized the treatment of infertility and has led to the birth of more than five million babies worldwide. However, this remarkable success masks the fact that IVF treatment remains remarkably inefficient. It is still the case that most patients require more than one cycle of treatment to obtain a viable pregnancy and more than 80% of embryos transferred to the uterus fail to produce a birth. The poor success rate per embryo transferred is a consequence of the extreme variability in the competence of the oocytes and embryos produced during a typical IVF cycle, coupled with the inability of routine morphological evaluations to correctly identify the embryos having the greatest developmental potential. Innovations in genetic testing and embryo culture have recently become available, which may finally allow an accurate evaluation of embryo competence and offer the hope of significant improvements to IVF treatment. These new technologies are also shedding light on important aspects of human oogenesis and preimplantation development. Principal amongst the new methods for embryo selection are those that allow accurate screening for chromosome abnormalities. Aneuploidy is extremely common in human oocytes and embryos and is of great clinical significance, having responsibility for the majority of miscarriages and many instances of congenital abnormality and mental retardation. The application of comprehensive chromosome screening techniques has provided an insight into the frequency of aneuploidy affecting each chromosome. It has been confirmed that during female meiosis errors involving single chromatids are far more common than those affecting whole chromosomes. Lagging of chromosomes during anaphase and failure of chromosomes to migrate to the spindle both occur frequently, contributing to a preponderance of chromosome losses over gains in the polar bodies tested. It has long been known that female meiosis I is the source of most aneuploidies detected during pregnancy and that the incidence of abnormalities increases with advancing age. Data from the comprehensive chromosome screening of polar bodies confirms this to be true for younger patients. However, it is now clear that errors occurring in meiosis II increase more rapidly with advancing age than those derived from meiosis I, such that errors from the second meiotic division predominate for women over 40 years of age. Data from embryos has also provided an interesting insight into chromosome segregation during preimplantation development, confirming a remarkable level of genetic instability characterized by a high frequency of chromosomal malsegregation, mosaicism and chromosome breakage. Clinically, there is rapidly accumulating data showing that IVF outcomes (pregnancy and miscarriage rates) can be significantly improved by testing embryos for aneuploidy and transferring those found to be chromosomally normal, provided appropriate technologies are used.This lecture will review data from more than 2000 human oocytes and embryos tested in our laboratory, providing unique and sometimes unexpected information concerning the mechanisms leading to aneuploidy.

Study of Retinal Biometric Systems with Respect to Feature Classification for Recognition and Diabetic Retinopathy

A biometric system is a heterogeneous entity characterized by identification and classification of data depending on a metric along with characteristics such as disease recognition and classification. This work is mainly concentrated on biometric pattern matching of a retinal image based on its macro and micro features. During data collection, several instances of abnormalities were detected on the retina, specially diabetes. In this work 350 images (fundus data which are training data) were analyzed using Decision trees and K Nearest Neighbour clustering technique. Four groups were identified from the data: normal retinopathy, mild non-proliferative diabetic retinopathy, moderate non-proliferative diabetic retinopathy and severe non-proliferative diabetic retinopathy. The important features that were collected for the data were distances, micro-aneurysms, exudates and haemorrhages. These features were extracted depending on the shapes of the vessels and the shapes of the diabetic features. In this paper a constructive method has been designed for classifying a person based on retinal biometric. The percentage accuracy by using decision tree has been 91.3% and by using K Nearest Neighbour has been 62%.The size of the training data set has been 350 and the size of the testing data set is 150.

231 SEMINAL QUALITY IN WHOOPING CRANE (GRUS AMERICANA) IS AFFECTED BY STAGE OF BREEDING SEASON BUT NOT BY AGE OF INDIVIDUAL

The whooping crane is one of the most critically endangered species in North America. The species underwent a severe genetic bottleneck with only 16 individuals remaining in the wild as of 1942. Captive breeding began in 1966 and continues to produce chicks for release in order to establish new wild populations. However, captive birds experience poor reproduction with approximately 40% of eggs being infertile. Males have been known to reach sexual maturity at 5 years of age and continue to reproduce almost as long as the duration of their adult life (i.e. 40 years). Understanding factors affecting seminal quality may assist in identifying and correcting causes of suboptimal reproduction. Our objectives were to determine the influence of age and reproductive seasonality on seminal quality. We hypothesised that seminal quality variations among whooping cranes and ejaculates within a given individual over time were due to bird age and stage of breeding season. In 2010, twenty-nine whooping cranes of 5 age groups housed at Patuxent Wildlife Research Center (Laurel, MD, USA) were studied: ≤5 years (n = 3); 6–10 years (n = 7); 11–15 years (n = 7); 16–20 years (n = 4); >20 years old (n = 8). Semen was collected using a manual manipulation technique at 3 stages of the breeding season: early (March, n = 29) mid (April, n = 24), and late (May, n = 14). Samples were evaluated for seminal volume and sperm concentration, motility, and morphology, with data evaluated by analysis of variance. Bird age had no influence on seminal quality, whereas stage of breeding season affected seminal volume and the proportion of sperm with normal morphology (95% confidence interval). Specifically, samples collected during Mid breeding season had the highest volume (mean ± SEM; early: 42.0 ± 8.0 μL; mid: 66.0 ± 15.2 μL; late: 39.7 ± 17.8 μL), but lowest proportions of structurally normal sperm (early: 78.4 ± 3.7%: mid: 61.5 ± 3.2%; late: 69.7 ± 3.4%). There was a significant difference (P = 0.06) in sperm concentration among stages of the breeding season (early: 66.3 ± 18.8 × 106 sperm mL–1; mid: 179.2 ± 46.2 × 106 sperm mL–1; late: 91.4 ± 47.8 × 106 sperm mL–1). Sperm motility was unaffected by season (early: 36.4 ± 3.5%; mid: 45.9 ± 4.1%; late: 48.0 ± 4.9%). In summary, there is a peak in seminal quality that corresponds with higher volume and more sperm during the mid stage of the season, although with higher instances of structural abnormalities. Despite the small founder base for this species, males in this population produce sperm with no variation in seminal quality across a wide variation in age.

The Flame Photometer as Engine of Nephrology: A Biography

In the 1940s, the flame photometer made possible for the first time relatively simple and quick measurements of sodium and potassium in serum and urine. During World War II, it unexpectedly fell into the hands of John P. Peters of Yale University, who sought to understand water and electrolyte physiology and apply such knowledge to patient problems. Pupils and young associates of Peters would seed the early nephrology divisions and training programs in the United States; the flame photometer was essential to their work and that of their trainees, both Americans and international visitors. Hyponatremia and the syndrome of inappropriate antidiuretic hormone secretion became the "attribute" disorders of nephrologists. Invention of a microflame photometer fostered the revival of micropuncture and transport studies. In the 1960s, the flame photometer was linked to Leonard Skeggs' sequential automated analysis system, leading to enormous numbers of routine measurements of electrolytes. The growing number of nephrologists, then based mostly at teaching hospitals, thus found plentiful instances of sodium and potassium abnormalities to address. The autoanalyzer also catalyzed use of the anion gap, another emblem of nephrology in its early decades. Not only ideas and theories, but also the usually invisible machinery, enable the growth of a knowledge base and formation of a scientific discipline or medical specialty. Of course, the flame photometer did not itself shape the agenda of nephrology, but it allowed the most influential group of progenitors and their progeny to explore normal function and bring a strongly physiologic imperative to their daily work with patients.

Geochemical anomalies of hydrothermal plume at EPR 13°N

During the DY105-12, 14cruise (RN DAYANG YIHAO, November 2003) on East Pacific Rise (EPR) 12-13 degrees N, the submarine hydrothermal activity was investigated and the CTD hydrocast was carried out at EPR12 degrees 39 ' N - 12 degrees 54 ' N. From the temperature anomalies and the concentrations of magnesium, chlorine, bromine in seawater samples, we discover that magnesium depletes 9.3%-22.4%, chlorine and bromine enrich 10.3%-28.7% and 10.7%-29.0% respectively relative to normal seawater at the stations which have chemistry anomalies, moreover temperature and chemistry anomalies are at the same layer. The depletion of magnesium in the plume may be caused by a fluid lacking of magnesium which rises after the hydrothermal fluid reaches the equilibrium with ambient seawater, the enrichment of chlorine and bromine might be the result of inputting later brine which is generated by phase separation due to hydrothermal activity. In addition, the Br/CI ratio in the abnormal layers at the survey area is identical to that in seawater, which implies that halite dissolution (or precipitation) occurs neither when the fluid is vented nor when hydrothermal fluid entraining ambient seawater rises to form plume. From the abnormal instance at E55 station, it is very possible that there might exist a new hydrothermal vent site.

Prophylactic intravenous preloading for regional analgesia in labour.

Reduced uterine blood flow from maternal hypotension may contribute to fetal heart rate changes which are common following regional analgesia (epidural or spinal or combined spinal-epidural (CSE)) during labour. Intravenous fluid preloading may help to reduce maternal hypotension but using lower doses of local anaesthetic, and opioid only blocks, may reduce the need for preloading. To assess the effects of prophylactic intravenous fluid preloading before regional analgesia during labour on maternal and fetal well-being. We searched the Cochrane Pregnancy and Childbirth Group trials register (19 February 2004). Randomised and quasi-randomised trials comparing prophylactic intravenous preloading before regional analgesia during labour with a control group (dummy or no preloading). Two reviewers independently applied eligibility criteria, assessed trial quality and extracted data. Six studies are included (473 participants). In one epidural trial using high-dose local anaesthetic, preloading with intravenous fluids was shown to counteract the hypotension which frequently follows traditional epidural analgesia (relative risk (RR) 0.07, 95% confidence interval (CI) 0.01 to 0.53; 102 women). This trial was also associated with a reduction in fetal heart rate abnormalities (RR 0.36, 95% CI 0.16 to 0.83; 102 women); no differences were detected in other perinatal and maternal outcomes for this trial and another high-dose epidural trial. In the two epidural low-dose anaesthetic trials, no significant difference in maternal hypotension was found (RR 0.73, 95% CI 0.36 to 1.48; 260 women), although they were underpowered to detect less than a very large effect. No significant differences were seen between groups in these trials for fetal heart rate abnormalities (RR 0.64, 95% CI 0.39 to 1.05; 233 women). In the two CSE trials, no differences were reported between preloading and no preloading groups. In the spinal/opioid trial, the RR for hypotension was 0.89, 95% CI 0.43 to 1.83 (40 women) and 0.70, 95% CI 0.36 to 1.37 for fetal heart rate abnormalities (32 women). In the opioid only study (30 women), there were no instances of hypotension or fetal heart rate abnormalities in either group. Preloading prior to traditional high-dose local anaesthetic blocks may have some beneficial fetal and maternal effects in healthy women. Low-dose epidural and CSE analgesia techniques may reduce the need for preloading. The studies reviewed were too small to show whether preloading is beneficial for women having regional analgesia during labour using the lower-dose local anaesthetics or opioids. Further investigation of low-dose epidural or CSE (including opioid only) blocks, and the risks and benefits of intravenous preloading for women with pregnancy complications, is required.

Rebuttal: interooplasmic transfers in humans

There have been two known instances of chromosomal abnormalities in clinical pregnancies resulting from ooplasmic transplantation in our work (Barritt et al., 2000). One singleton pregnancy ended in a spontaneous miscarriage in the first trimester. The fetus was karyotyped as 45,XO. The rate of spontaneous miscarriage in assisted reproduction is 12–15% and such miscarriages (as in the natural population) are by standard practice not included in the calculation of congenital abnormalities (Simpson, 1990). Another ooplasmic transplantation pregnancy was analysed by ultrasonography at 15 weeks and shown to be a twin gestation with one fetus developing abnormally. Amniocentesis and analysis revealed the presence of a 45,XO karyotype. This fetus was electively reduced and the second 46,XX fetus was subsequently delivered normally. The 45,XO karyotype is the most common chromosomal abnormality associated with abnormal developmental morphology at the time of ultrasonography (Byrne et al., 1985). As much as 70% of spontaneous first trimester miscarriages are associated with chromosomal abnormalities and 45,XO is the most common single chromosome abnormality within this group with an incidence of 20–25% (Strom et al., 1992; Simpson, 1990) The overall incidence of a 45,XO karyotype in amniocentesis and chorionic villus sampling analysis is approximately 1/500 and 1/250 respectively (Gravholt et al., 1992). Press reports suggesting that the 45,XO karyotype is “rare” or “mysterious” are obviously distortions of the facts.

Subperiosteal Rejuvenation of the Midface and Periorbital Area: A Simplified Approach

A simplified approach to subperiosteal midface rejuvenation is presented. The technique was developed through experience with 60 subperiosteal face lifts over an 8-year period. Because it does not involve a lower eyelid incision, there is no risk of ectropion, yet the midfacial structures and orbicularis oculi muscle can be elevated easily and precisely. The procedure can be performed alone but is more commonly performed in conjunction with brow lift and traditional SMAS dissection of the lower face and neck. The benefits of this subperiosteal approach to the midface are powerful elevation of the midfacial structures, improvement of the nasolabial folds, enhancement of the cheek prominences, smoothing of the nasojugal folds, and tightening of the orbicularis oculi. The procedure is performed through small incisions in the temple and gingival sulcus. The operation is technically straightforward and poses little risk to neurovascular structures. Concerns over prolonged swelling have not materialized. There have been no instances of lower lid or canthal abnormalities. (Plast. Reconstr. Surg. 104: 842, 1999.)

Subperiosteal Rejuvenation of the Midface and Periorbital Area: A Simplified Approach

A simplified approach to subperiosteal midface rejuvenation is presented. The technique was developed through experience with 60 subperiosteal face lifts over an 8-year period. Because it does not involve a lower eyelid incision, there is no risk of ectropion, yet the midfacial structures and orbicularis oculi muscle can be elevated easily and precisely. The procedure can be performed alone but is more commonly performed in conjunction with brow lift and traditional SMAS dissection of the lower face and neck. The benefits of this subperiosteal approach to the midface are powerful elevation of the midfacial structures, improvement of the nasolabial folds, enhancement of the cheek prominences, smoothing of the nasojugal folds, and tightening of the orbicularis oculi. The procedure is performed through small incisions in the temple and gingival sulcus. The operation is technically straightforward and poses little risk to neurovascular structures. Concerns over prolonged swelling have not materialized. There have been no instances of lower lid or canthal abnormalities.

Oral or Vaginal Misoprostol for Induction of Labor

Objective: To compare vaginal versus oral misoprostol for induction of labor. Method: Induction of labor was carried out in 40 women near term in two equal and randomized groups (according to a computer generated table) using misoprostol. Group I received vaginal misoprostol (100 μg) every 3 h while group II patients were given the same dose via the oral route. The dose was doubled if no response was detected under continuous cardiotocographic (CTG) tracings. Result: The vaginal route of administration induced a higher success rate in a shorter time interval using a lower dose but was associated with more abnormal FHR patterns and instances of uterine hyperstimulation. Conclusion: It is recommended to use the vaginal approach with cardiotocographic monitoring.

Pediatric cardiac transplantation despite atrial and venous return anomalies

Congenital anomalies of the atrium, pulmonary venous return, and systemic venous return are often regarded as anatomical contraindications to orthotopic cardiac transplantation. Among our pediatriec transplant patients, 10 children aged 3 to 15 years, weighing 9 to 45 kg, and all previously operated on for a total of 18 interventions had 32 anomalies needing correction at the time of transplantation. Besides the 18 instances of great vessel abnormalities, 14 anomalies of the atrium and of the venous return were encountered either alone or in combination: single atrium or previous septectomy (4), hypoplastic left atrium (2), previous Mustard procedure (1), cor triatriatum (1), anomalous pulmonary venous return (3), and anomalous systemic venous return (3). The preparation of the donor heart was modified in four ways: right atrial paraseptal incision, left atrial flap technique, full-length mobilization of the pulmonary arteries, and aortic arch incision. Correction of the atrial and venous return anomalies was carried out at the time of orthotopic transplantation with the following techniques: atrial septation, atrial enlargement, superior systemic venous return reroofing, inferior systemic venous return reroofing, double venous rerouting (pulmonary and systemic), and septal realignment. One child died of pulmonary hypertension in the early postoperative period. After a follow-up ranging from 1 month to 52 months, all survivors are asymptomatic. Based on echocardiography, heart catheterization, and angiography, there are no stenoses and no shunts, and the atrial dimensions are good. Based on the results achieved with these surgical techniques, we conclude that most atrial lesions, anomalous pulmonary venous returns, and anomalous systemic venous returns are correctable at the time of orthotopic transplantation and do not preclude a successful outcome in children.

Evaluation and treatment of intradural tumours located anterior to the cervicomedullary junction by a lateral suboccipital approach

Tumours located anterior to the cervicomedullary junction have been most commonly approached via one of two routes: anterior/transoral or posterolateral. Each of these surgical corridors can pose potential pitfalls. To circumvent these problems, a lateral suboccipital approach in conjunction with an upper cervical hemilaminectomy has been used. Selecting an appropriate surgical corridor between the lower cranial nerves (IX through XII), the vertebral artery, and the posterior inferior cerebellar artery has allowed satisfactory tumour removal. A three-dimensional picture of tumour location and relationship to surrounding neural and vascular structures is obtained preoperatively from computed tomography and magnetic resonance. Arteriography is essential to determine the origin, course, and relation of each vertebral to the tumour as well as the contribution of each vertebral to the basilar. In instances of abnormalities in the posterior circulation, evaluation of the carotid contribution to the basilar is crucial. The advantages of this approach are several. First, a direct view of the anterior surface of the lower brainstem und upper cervical cord is obtained. Second, surgery is undertaken in a sterile field in which the dura can be closed watertight. Third, neither mastoidectomy nor transposition of the vertebral artery is required. The major difficulty is the necessity to operate through narrow surgical corridors bounded by the lower cranial nerves, vertebral and posterior inferior cerebellar arteries, and the lower medulla and upper cervical cord. These structures provide the major obstacles to dissection as well as the primary causes of morbidity.

Aristotle, the Fallacy of Accident, and the Nature of Predication: A Historical Inquiry

Aristotle, the Fallacy of Accident, and the Nature of Predication: A Historical Inquiry AN|BAL A. BUENO 1. In the analysis of informal fallacies in English-language logical treatises we usually find one called the fallacy of accident and another that is characterized as its converse. The latter is also usually called the fallacy a dicto secundum quid ad dictum simpliciter, or simply secundum quid. Accident is usually defined as the application of a general rule to a case in which, because of some accidental feature it possesses, the rule does not apply. Sometimes the fallacy is defined in more traditional language as inferring of a subject with an accident that which is known to be the case of the subject only. The converse fallacy is defined as generalizing from an atypical or abnormal instance, or inferring of a subject that which is true of the subject with an accident. This fallacy is sometimes called hasty generalization. ~ The preceding definitions of these fallacies lead to serious difficulties which have been analyzed by some theorists, but their objections have not yet led to a general reassessment of them. 2The main criticisms are the following. ' See Irving Copi, Introduction to Logic, 6th ed. (NewYork: Macmillan, 1982), lO6-7; Henry Byerly,A Primer ofLogic (Harper and Row, 1973),47-48; John Grier Higben, Logic. Deductive and Inductive (NewYork: Scribners, x912), 161; W. StanleyJevons, Elementary Lessons in Logic: Deductive andlnductive (NewYork and London: 19o4), 176-78. ' A discussion of these difficulties maybe found in Aristotle on Fallacies or The Sophistici Elenchi, trans, and ed. Edward Poste (London, 1866), 158. See also H. W. B. Joseph, An Introduction to Logic (Oxford, 19o6,2d ed. 1916;reprint 1931),587-88. C. L. Hamblin, Fallacies (London: x97o), 25-31 . [5] 6 JOURNAL OF THE HISTORY OF PHILOSOPHY 26:i JANUARY i988 1. There are many arguments about which we cannot tell whether the inference moves from a particular or restricted case to a more general case, or vice versa. Let us consider an example:3 A person who thrusts a knife into another person's body is guilty of a crime and should be punished. Surgeons thrust knives into other people's bodies. Therefore, surgeons are criminals and should be punished. This argument may be interpreted in two ways. We can consider the first premiss as a general rule (namely thrusting a knife without any further qualification ) and the second as a more restricted case (thrusting a knife with the intention of curing). Under this interpretation, the inference moves from a broader to a more restricted case, and the argument is a case of the fallacy of accident. But we can also interpret the first premiss as a qualified statement that refers to thrusting a knife with the intention of harming a person, and the second as the general case of thrusting a knife without any further qualification . Now the movement of meaning is reversed, and the argument becomes a case of secundum quid. In view of the fact that many arguments can be construed as one or the other fallacy, the distinction seems artificial. That it is difficult to distinguish between the two fallacies is clearly shown by the fact that a classical example of secundum quid: What you buy at the market today, you will eat tomorrow. You bought raw meat at the market today. Therefore, you will eat raw meat tomorrow. This is cited by I. Copi and by M. R. Cohen and E. Nagel in their well-known logic books as an instance of accident.4 Augustus De Morgan remarked that "this piece of meat has remained uncooked, fresh as ever, a prodigious time."5 The meat may still be fresh, but the fallacy has changed. In fact, many arguments move neither from a general to a restricted case, nor in the opposite direction, but from one special case to another. For this reason both De Morgan and W. S. Jevons proposed a third type of fallacy, namely "arguing from one special case to another special case," or a dicto secundum quid ad dictum secundum alterum quid, but this suggestion has found no acceptance. 6 3 I have borrowed this example and the...