A new lower bound on the monotone network complexity of Boolean sums

Summary Neciporuk [3], Lamagna/Savage [1] and Tarjan [6] determined the monotone network complexity of a set of Boolean sums if each two sums have at most one variable in common. By this result they could define explicitely a set of n Boolean sums which depend on n variables and whose monotone complexity is of order n ^3/2. In the main theorem of this paper we prove a more general lower bound on the monotone network complexity of Boolean sums. Our lower bound is for many Boolean sums the first nontrivial lower bound. On the other side we can prove that the best lower bound which the main theorem yields is the n ^3/2-bound cited above. For the proof we use the technical trick of assuming that certain functions are given for free.     

Immune response to phi X 174 in man. 5. Primary and secondary antibody production in primary biliary cirrhosis

In primary biliary cirrhosis, the primary immune response to the bacteriophage phi X 174 is normal but the secondary response is significantly reduced. The reduction is primarily of IgG antibody, while IgM is proportionately less affected. These changes may be the result of a reduction in helper T lymphocyte function and may contribute to the increase in the ratio of serum concentration of IgM to IgG.     

Effects of pregnancy on hemoglobin AIc in normal, gestational diabetic, and diabetic women

Hemoglobin AIc, a normal minor hemoglobin, has glucose linked by a Schiff base to the N-terminal end of the beta chain. The glucose interferes with the binding of 2,3 diphosphoglycerate, probably resulting in an increased affinity of that hemoglobin for oxygen. Hb AIc is increased to twice normal levels in juvenile-onset (insulin-dependent) diabetes. In the present studies, the Hb AIc, when expressed as per cent of total hemoglobin, was found to be elevated slightly in pregnany normal (m = 6.97 per cent), pregnant nondiabetic obese (m = 6.89 per cent), and gestationally diabetic subjects (m = 8.77 per cent) above that of normal females (m = 5.68 per cent). A remarkable difference was observed between the nonpregnant diabetics (m = 12.77 per cent) and the pregnant diabetics (m = 8.46 per cent). This decrease in the level of Hb AIc in diabetics who are pregnant more than 30 weeks may reflect either a better state of diabetic control and/or a compensatory mechanism to protect the fetus by facilitating oxygen exchange from mother to fetus.     

Mental health centers and the criminal justice system

Through questionnaires, interviews, and site visits, the authors undertook to ascertain to what extent the 26 community mental health centers in Kansas were contributing to the resolution of problems that concern the criminal justice system. They found that in all large communities some reciprocal programs have developed between the two systems, but meaningful collaboration is rare in small communities. Juvenile courts, urban law enforcement agencies, and county probation officers are most receptive to collaborative programs. An evaluation of several effective programs revealed three basic conditions that attribute to their success: an urban community setting, individual initiative by staff from each system, and location of the program within the criminal justice system.     

An improved complexity hierarchy on the depth of Boolean functions

Summary Circuit depth is an important complexity measure for a Boolean function. Let some Boolean function of n variables have depth k according to an arbitrary binary basis . For each j where [log n]jk we prove the existence of a Boolean function f with the following properties. f depends essentially on n variables and the depth of f according to is exactly j Thus we state the best possible hierarchy result on the depth of all nondegenerate Boolean functions.     

Analysis and occurrence of estrogenic hormones and their glucuronides in surface water and waste water in The Netherlands

An analytical procedure was developed that enables routine analysis of four estrogenic hormones in concentrations below 1 ng/l in surface water and waste water. The recovery was 88-98% with a limit of detection of 0.1-2.4 ng/l depending on the compound and the matrix measured. This method was used to determine the occurrence of 17 beta-estradiol, 17 alpha-estradiol, estrone and 17 alpha-ethinylestradiol in the aquatic environment in The Netherlands. The data show that estrogenic hormones can be detected at low concentrations (up to 6 ng/l) at some locations in surface water. In selected effluents of waste water treatment plants estrone and 17 beta-estradiol were detected in concentrations in the ng/l range. Concentrations of 17 alpha-estradiol and the contraceptive 17 alpha-ethinylestradiol were in most of these samples below the limit of detection. Hormone glucuronides were not detected in most surface water and effluents.     

Identification of partial disjunction, parity, and threshold functions

Let F be a class of functions obtained by replacing some inputs of a Boolean function of a fixed type with some constants. The problem considered in this paper, which is called attribute efficient learning, is to identify “efficiently” a Boolean function g out of F by asking for the value of g at chosen inputs, where “efficiency” is measured in terms of the number of essential variables. We study the query complexity of attribute-efficient learning for three function classes that are, respectively, obtained from disjunction, parity, and threshold functions. In many cases, we obtain almost optimal upper and lower bound on the number of queries.     

On the choice of the offspring population size in evolutionary algorithms

Evolutionary algorithms (EAs) generally come with a large number of parameters that have to be set before the algorithm can be used. Finding appropriate settings is a difficult task. The influence of these parameters on the efficiency of the search performed by an evolutionary algorithm can be very high. But there is still a lack of theoretically justified guidelines to help the practitioner find good values for these parameters. One such parameter is the offspring population size. Using a simplified but still realistic evolutionary algorithm, a thorough analysis of the effects of the offspring population size is presented. The result is a much better understanding of the role of offspring population size in an EA and suggests a simple way to dynamically adapt this parameter when necessary.     

Ascaris suum: a revision of its early migratory path and implications for human ascariasis

The genetic diversity in a group of Escherichia coli strains belonging to serogroup O6 but expressing different H antigens was investigated by random amplification of polymorphic DNA (RAPD). Isolates of serotypes H16, H1, H31, and non-motile (NM) strains were typed using a set of 3 primers with different G + C contents. The amplified band arrays allowed the identification of 3 main clonal clusters corresponding to each O:H serotype analyzed. Based on their RAPD profiles NM strains could be assigned to either H1 or H31 serotypes. The results indicate that the flagellar antigen and the RAPD fingerprint represent reliable clonal markers in this E. coli group.