The Hidden Structural Rules of the Discontinuous Lambek Calculus

The sequent calculus sL for the Lambek calculus L (lambek 58) has no structural rules. Interestingly, sL is equivalent to a multimodal calculus mL, which consists of the nonassociative Lambek calculus with the structural rule of associativity. This paper proves that the sequent calculus or hypersequent calculus hD of the discontinuous Lambek calculus (Morrill and Valent\'in), which like sL has no structural rules, is also equivalent to an omega-sorted multimodal calculus mD. More concretely, we present a faithful embedding translation between mD and hD in such a way that it can be said that hD absorbs the structural rules of mD.Comment: Submitted to Lambek Festschrift volum

Current measurements in the Salton Sea using ERTS multispectral imagery

There are no author-identified significant results in this report

A report of the neurological seminar of the marine biological laboratory, wood's holl, mass., For the season of 1899

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PhD

dissertation1. The evidence presented in this thesis indicates that mouse pancreas ribonuclease and beef pancreas ribonuclease have quite similar catalytic properties. Both enzymes cause a partial breakdown of RNA and split only secondary phosphate esters of pyrimidine-3'-phosphates. Further, both enzymes have similar pH optima and general stability to storage and handling. 2. Mouse pancreas ribonuclease can be chromatographed on columns of the carboxylic ion exchange resin IRC-50 (SE-64). When 0.2 M sodium phosphate buffer, pH 6.47, extracts of mouse pancreas are prepared and chromatographed, the enzymatically active material was eluted in two broad zones. However, when 0.25 N. sulfuric acid extracts of mouse pancreas are chromatographed, two sharp, distinct peaks of ribonuclease activity can be recognized, indicating that an alteration of the protein molecule occurred during the acid treatment. pH 7.5:5.0 ribonuclease activity ratios for the individual fractions indicate an enzymatic as well as chromatographic heterogeneity both within a given peak as well as between the peaks from a sulfuric acid extract of mouse pancreas. These chromatographic elution components have been further studied by limited rechromatography and under conditions of pH gradient elution. 3. The intracellular distribution of the ribonucleases of mouse pancreas was studied by differential centrifugation of pancreas homo-genates prepared in 0.25 M sucrose. Approximately 70 per cent of the ribonuclease activity in the tissue was associated with three (of one nuclear and nine cytoplasmic) isolated cell fractions. The highest level of ribonuclease activity was found in the cytoplasmic f" microsomal fraction (35 per cent), with lesser amounts being found in the nuclear dense granule fraction (20 per cent) and the cell "soluble" or supernatant fraction (15 per cent). 4. The effect of treating the nuclear and cytoplasmic pellets isolated from mouse pancreas homogenates with 0o25 N. sulfuric acid by the method of Hirs et al. was studied. Large decreases in the activity of the nuclear fraction as well as moderate increases in the "cytoplasmic f" microsomal fraction were observed, and the significance of these changes is discussed. 5« The cell supernatant contained a significant level of ribonuclease activity when the tissue was homogenized in sucrose, and this level could be increased four or five fold by treatment with a strong acid or by column chromatography. This inactive of "latent" ribonuclease may be bound to a protein inhibitor which is removed by an acid-inactivation or by chromatography. The relationships of these findings to other studies on cellular enzyme inhibitors are discussed. 6. Chromatographic elution studies were carried out on both the 0.2 M sodium phosphate buffer extracts and the 0.25 N. sulfuric acid extracts of four ribonuclease "rich" cell fractions. Differential analyses of the elution patterns from these cell fractions indicate, based on stability or lability to acid treatment and intracellular localization, that at least six distinct forms of the enzyme may be present in the 0o2 M sodium phosphate buffer extracts of mouse pancreas. Further, two of the six ribonucleases have specific intracellular locations, and only one of the six enzymes appears to be present in each of the fractions investigated. 7. Mouse pancreas has been incubated in vitro with a parasympathomimetic drug (pilocarpine) and with the hormone pancreozymin. Secretion (active extrusion) of both amylase and ribonuclease and an increase in respiratory rate occurred during incubation. Large differences in both the stimulated and non-stimulated extrusion of enzyme were found in different strains of mice. The means of killing the animals and pre-treatment of the tissue also affected secretion. Chromatographic analyses of the ribonuclease "actively extruded" into the incubation medium by maximal in. vitro stimulation with pilocarpine or pancreozymin suggests the following hypothesis: The enzyme associated with the nuclear fraction is contained in dense secretory granules which are selectively released on in vitro pilocarpine stimulation. In contrast, a less dense secretory granule, present in the so-called "principle zymogen fraction" of the cell, is selectively released by in vitro pancreozymin stimulation. In addition, the appearance of very large amounts of ninhydrin positive material (normally present almost exclusively in the soluble portion of the cell) in the incubation medium further suggests an involvement of the cellular cytoplasm in the secretory mechanism. 9. The cytochemical implications of the intracellular status and function of mouse pancreatic ribonuclease and the relationships of these findings to previous studies on cellular ribonucleases are discussed

THE EFFECTS OF ALTERNATE COW FRESHENING DISTRIBUTIONS ON MILK PRODUCTION AND IMPORTS IN FLORIDA

Seasonal swings in milk production in Florida result in a need to import milk on a seasonal basis. A linear programming analysis is used to analyze alternate freshening-date distributions and project the cost savings to Florida dairy farmers from reduced milk imports.Farm Management,

Global gaps in trait data for terrestrial vertebrates

AIM: Trait data are increasingly being used in studies investigating the impacts of global changes on the structure and functioning of ecological communities. Despite a growing number of trait data collations for terrestrial vertebrates, there is to date no global assessment of the gaps and biases the data present. Here, we assess whether terrestrial vertebrate trait data are taxonomically, spatially and phylogenetically biased. LOCATION: Global. TIME PERIOD: Present. MAJOR TAXA STUDIED: Terrestrial vertebrates. METHODS: We compile seven ecological traits and quantify coverage as the proportion of species for which an estimate is available. For a species, we define completeness as the proportion of non‐missing values across traits. We assess whether coverage and completeness differ across classes and examine phylogenetic biases in trait data. To investigate spatial biases, we test whether wider‐ranging species have more complete trait data than narrow‐ranging species. Additionally, we test whether species‐rich regions, which are of most concern for conservation, are less well sampled than species‐poor regions. RESULTS: Mammals and birds are well sampled even in species‐rich regions. For reptiles and amphibians (herptiles), only body size presents a high coverage (>80%), in addition to habitat‐related variables (amphibians). Herptiles are poorly sampled for other traits. The shortfalls are particularly acute in some species‐rich regions and for certain clades. Across all classes, geographically rarer species have less complete trait information. MAIN CONCLUSIONS: Trait information is less available on average in some of the most diverse areas and in geographically rarer species, both of which crucial for biodiversity conservation. Gaps in trait data might impede our ability to conduct large‐scale analyses, whereas biases can impact the validity of extrapolations. A short‐term solution to the problem is to estimate missing trait data using imputation techniques, whereas a longer‐term and more robust filling of existing gaps requires continued data‐collection efforts

Classroom enrichment through children's specialties.

Thesis (Ed.M.)--Boston Universit