The warehouse scheduling problem: formulation and algorithms

The Warehouse Scheduling Problem is a deterministic multi-item inventory problem with a restriction on warehouse floor space available. We formulate a mixed integer nonlinear programming problem for the objective of minimizing long run inventory holding and order costs per unit of time. We integrate algorithms for staggering orders, described in companion papers, with a heuristic to choose the order sequences. The result is called Sequenced Staggering. We describe a new algorithm to generate order frequencies, called the powers-of-two-factor-of-three technique, as a generalization of Roundy's roundoff technique for powers-of-two policies. We report on a computational study of four hybrid algorithms for solving the warehouse scheduling problem, including the competing algorithm of Gallego, Queyranne, and Simchi-Levi. Based on these results, we recommend the combination of powers-of-two frequencies with Sequenced Staggering.     

Induction of superoxide dismutase isozymes by tumor necrosis factor-alpha and lipopolysaccharide in cultured normal and hyperplastic gingival fibroblasts

We studied 722 reexcision scars of benign and malignant lesions (except melanocytic lesions) excised over a 24-month period. The formalin-fixed, paraffin-embedded tissue sections were examined histologically and immunohistochemically. The histological features of melanocytic hyperplasia were present in 59 cases (8%), 56 from the sun-exposed skin of the face and neck and three from the trunk [p < 0.00001]. The most common sites were the nose and lower eyelids, but the forehead was also frequently involved. Of the 59 patients, 41 were women (p < 0.0001). Basal cell carcinoma was the most frequent original lesion in both sexes (80%). No melanocytic hyperplasia was found in 663 cases (298 on the trunk and extremities and 365 on the head and neck). We have seen this reaction pattern following reexcision of melanocytic lesions as well. Thus, interpreting reexcision margins when lentigo maligna or similar lesions are reexcised may be fraught with difficulty. It is important for pathologists and dermatopathologists to recognize this phenomenon because histologically the presence of increased numbers of large melanocytes could be misinterpreted as melanoma in situ.     

Categorical scaling of time: Implications for clock-counter models.

Pigeons partitioned time into three intervals. Responses to one key could be reinforced after a short time, to a second key after an intermediate time, and to a third key after a long time. The values of the short, intermediate, and long times and the proportion of trials ending with reinforcement were varied. Absolute and relative response rates on each key were an orderly function of time and showed approximately proportional changes with changes in the interval values, consistent with Weber's law, Gibbon's (1977) scalar expectancy theory, and Killeen and Fetterman's (1988) behavioral theory of timing (BeT). Standard deviations of the times at which subjects switched between successive keys increased more slowly within a condition than across conditions, as predicted by BeT. Increases and decreases in reinforcement probability produced both transient and longer lasting changes in timing behavior, once again, in accord with predictions of BeT. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Inhibition of 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone mouse lung tumorigenesis by arylalkynes, mechanism-based inactivators of cytochrome P450

Arylalkynes such as 4-phenyl-1-butyne (PBY), 5-phenyl-1-pentyne (PPY) and 2-ethynylnaphthalene (2-EN) are suicide inhibitors of cytochrome P450 enzymes. Arylalkyl isothiocyanates such as 6-phenylhexyl isothiocyanate (PHITC) are structurally related to arylalkynes and are known to inhibit the cytochrome P450 mediated metabolic activation and tumorigenicity of a tobacco-specific lung carcinogen, 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK). In this study, we compared the ability of PBY, PPY, 2-EN and PHITC to inhibit A/J mouse lung tumorigenesis by NNK. Groups of 20 female mice were gavaged with 5 mumol of arylalkyne or PHITC in corn oil. Two hours later they were given a single i.p. injection of 10 mumol NNK. The mice were killed 16 weeks later. PPY and PHITC were both potent inhibitors of tumorigenesis by NNK, reducing lung tumor multiplicity from 8.35 tumors per mouse to 0.40 and 0.35 respectively. PBY and 2-EN also significantly inhibited tumor multiplicity. The results of this study demonstrate that arylalkynes and PHITC are potent inhibitors of NNK induced lung tumorigenesis in A/J mice, consistent with the hypothesis that inhibition of specific cytochrome P450 enzymes is involved in inhibition of tumorigenesis.     

"Adolescent psychopathology: I. Prevalence and incidence of depression and other DSM-III—R disorders in high school students": Correction.

Reports an error in the original article by P. M. Lewinsohn et al ( Journal of Abnormal Psychology, 1993[Feb], Vol 102[1], 133–244). On page 140, in the Total Incidence columns in Table 4, the data for the Attention Deficit row should be switched with that for the Conduct row. (The following abstract of this article originally appeared in record 1993-25780-001.) Data were collected on the point and lifetime prevalences, 1-yr incidence, and comorbidity of depression with other Diagnostic and Statistical Manual of Mental Disorders-III-Revised (DSM-III-R) disorders in a randomly selected sample (n?=?1,710) of high school students at point of entry and at 1-yr follow-up (n?=?1,508). The Schedule for Affective Disorders and Schizophrenia for School-Age Children was used to collect diagnostic information; 9.6% met criteria for a current disorder, more than 33% had experienced a disorder over their lifetimes, and 31.7% of the latter had experienced a 2nd disorder. High relapse rates were found for all disorders, especially for unipolar depression (18.4%) and substance use (15.0%). Female Ss had significantly higher rates at all age levels for unipolar depression, anxiety disorders, eating disorders, and adjustment disorders; male Ss had higher rates of disruptive behavior disorders. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Generic Representation of Solid-Object Geometry for Genetic Search

Abstract: This paper examines the first stage of using genetic algorithms in design—how to encode designs as chromosomes. Generic representations capable of describing the geometry of any solid object to eliminate the unnecessary duplication of work at this stage are explored. A suitable low-parameter, spatial-partitioning representation is then proposed, using partitions consisting of six-sided polyhedra intersected by planes. Finally, the coding of the representation is examined, with the conclusion that allelic coding with control genes and user-definable, fixed-value alleles would provide the most flexible system.