Prostaglandin E2 induction of labor for fetal demise

Intrauterine fetal demise is a source of anxiety to both patient and physician. Heretofore, the standard treatment was either careful observation until the patient went into labor or attempt at induction of labor with oxytocin. Unfortunately, oxytocin stimulation has not proven to be uniformly successful for this problem. Prostaglandin E2 suppositories have been shown to be effective in inducing uterine evacuation after intrauterine fetal demise. In the opinion of the authors, this approach will in the future replace the sometimes dangerous and emotionally laden convention of watchful delayed therapy.     

Aldosterone secretion during high sodium cerebrospinal fluid perfusion of the brain ventricles

Conscious sheep with permanent indwelling cannulae in the lateral ventricles and the cisterna magna were Na depleted and then perfused for 9 h with an artificial CSF solution. There were 3 experimental groups: Group I (n=5) received perfusion with aritifical CSF containing NA 170 MEq./1, Group II (n=7) received perfusion with artificial CSF containing Na 145 mEq./1, Group III (n=7) received no perfusion. In Group I the blood aldosterone level fell from 26.4 +/- 7.4 to 8.6 +/- 2.3 ng/100 ml by 9 h after perfusion. There was no significant change in plasma [Na] or [K], blood angiotensin II or plasma renin concentration. Blood cortisol and corticosterone levels rose. There was also a fall in post-perfusion. Group III showed no significant change in blood aldosterone concentration. Multivariate statistical analysis showed that the fall in aldosterone levels during 170 mEq./l Na perfusion could not be accounted for by changes, either alone or together, of ACTH as evidenced by alteration in blood cortisol or corticosterone, or by change of plasma [Na], [K] or renin concentrations. This data supports the hypothesis of an additional factor which may be of CNS origin being involved in the control of aldosterone secretion.     

Cancer, emotions and mental illness: the present state of understanding

The authors review recent and current literature on the relationship between psychological factors and cancer. They discuss the roles of predisposing personality patterns and emotional stress in the development, site, and course of cancer; the influence of awareness of terminal illness on the behavior of cancer patients; and the management of psychiatric symptoms in these patients.     

To Select or To Weigh: A Comparative Study of Linear Combination Schemes for SuperParent-One-Dependence Estimators

We conduct a large-scale comparative study on linearly combining superparent-one-dependence estimators (SPODEs), a popular family of seminaive Bayesian classifiers. Altogether, 16 model selection and weighing schemes, 58 benchmark data sets, and various statistical tests are employed. This paper's main contributions are threefold. First, it formally presents each scheme's definition, rationale, and time complexity and hence can serve as a comprehensive reference for researchers interested in ensemble learning. Second, it offers bias-variance analysis for each scheme's classification error performance. Third, it identifies effective schemes that meet various needs in practice. This leads to accurate and fast classification algorithms which have an immediate and significant impact on real-world applications. Another important feature of our study is using a variety of statistical tests to evaluate multiple learning methods across multiple data sets.     

DES-GENERATED CHECKSUMS FOR ELECTRONIC SIGNATURES

Secrecy and authentication are two important features of a secure communication system. Public Key Cryptosystems, based, e.g., on the Rivest-Shamir-Adleman (RSA) algorithm, provide a very elegant solution to the problem of authenticity verification or true electronic signatures. Practical problems, however, mainly the lack of execution speed, prevent a straightforward application. In order to sign a long message it is much faster to first calculate a short digest or checksum and then sign the compressed message. For this checksum calculation the fast, inexpensive and extensively tested Data Encryption Standard (DES) can be used. But care must be taken that this additional processing step does not introduce any weakness into the signature scheme. This paper investigates two DES-based hashing methods. It is shown that neither method seems to introduce any statistical regularities in the generated checksums. The “Cipher/Message to Plain Feedback,” however, is not secure under a modification compensation attack. It is further shown how the second method, the “Cipher to Plain Feedback” proposed by Davies and Price, can be broken by a “meet in the middle attack.” This checksum method, however, can be used safely with a slight modification.