Predator-prey relationships in the southeastern Ozarks–A.D. 1300

Archeological findings provide the basis for analyzing the exploitation of deer by Powers Phase Indian hunters in the southeastern Ozarks circaA.D. 1300. Predatory patterns of wolves have been documented. It is hypothesized that men and wolves were complementary, noncompetitive predators and that their predation functioned to keep the deer population within the carrying capacity of the southeastern Ozarks. A model is developed to illustrate the predator-prey relationships in the area.Powers Phase Research Project is financed by National Science Foundation Grant GS-3215 to James B. Griffin, University of Michigan.The term Powers Phase has been applied to a pre-Columbian American Indian population of Middle Mississippian cultural affiliation which occupied an area in southeast Missouri for a relatively short period of timecirca A.D. 1300.     

Genetics of esterases in Drosophila. V. Characteristics of the “pupal” esterase in D. virilis

From analysis of the properties of the pupal esterase (p-esterase) in Drosophila virilis, it is concluded that it is heat stable, its electrophoretic detection depends on culture density, its expression is stage specific, and it is not a variant of esterase 2. It was also demonstrated that p-esterase, like esterase 6, is activated by injections of the juvenile hormone into larvae. Heat treatment of heat-resistant D. virilis stocks led to decreased activities of the juvenile hormone dependent esterases but did not affect those of the heat-sensitive stocks. It is suggested that heat resistance in D. virilis is related to some functional features of the system of modifier genes controlling the phenotypic expression of esterases.     

Geitler's “Plattenband” in the diatomSynedra cf.ulna in the light of TEM investigations

The ultrastructure of the diatomSynedra cf.ulna was examined paying special attention to the Plattenband (platelet band). This structure was first described byGeitler in 1948 on the basis of LM observations and denotes a linear array of dictyosomes along the apical axis of the cell. The present investigation confirmsGeitler's observations in all essential details and demonstrates that the dictyosomes are arranged along polarized nuclear extensions running towards the cell poles. Laterally the extensions are accompanied by a number of microtubules. In large cells the total length of the nucleus thus may reach 400 µm and more. Since only the central part of the nucleus is DNA-positive with DAPI and acridine orange, the nuclear nature of the backbone of the Plattenband cannot be recognized by LM techniques. TEM investigation of serial apical and transapical sections, however, prove unambiguously the identity with extended parts of the nucleus.Dedicated to Prof. DrLothar Geitler on the occasion of his 90th birthday.     

Lepidophylloides corumbataensis sp. nov. from the Guadalupian in the Paraná Basin,southern Brazil

A new species of the isoetalean leaf genus Lepidophylloides is described. This Guadalupian species from the Paraná Basin, Lepidophylloides corumbataensis, found as silicified microphylls in the Corumbataí Formation in the municipality of Piracicaba, São Paulo state, in southern Brazil, is the first species of the genus to be formally described for Brazil, and possibly the first for Gondwanaland. This is also the first time that surviving palisade tissue has been found in a species of Lepidophylloides. The new species is compared to known species and shown to be distinct from all previously described from Euramerican and Cathaysian floras. The organization of the xylem in arch-like or crescent-shaped bundles suggests a relation to Cathaysian species. The close association with Lycopodiopsis derbyi stems (which have true leaf scars and must have suffered leaf abscission) suggests that they are different organs from the same species.     

Chromosome numbers in selectedHieracium species in the Krkonoše Mts. (the West Sudeten)

Chromosome numbers are given of 15 species of the genusHieracium L. s. str., representing seven species groups (in the sense of Flora Europaea, roughly corresponding to Zahn's “species principales”) from the Krkono?e Mts., N. Bohemia and SW Poland. For the first time chromosome numbers are reported forH. melanocephalum Tausch (2n=27),H. tubulosum Tausch (2n=36),H. schustleri Zlatník (2n=36),H. fritzei F. Schultz (2n=27),H. rohlenae Zlatník (2n=27),H. nigrescens Willd. (2n=36),H. decipiens Tausch (2n=36),H. atrellum Juxip inSchischkin etBobrov (2n=27),H. subnigrescens (Fries exNorrlin)Dahlst. (2n=36),H. sudeticum Sternberg (2n=36),H. pedunculare Tausch (2n=36),H. glandulosodentatum Uechtr. (2n=36),H. wimmeri Uechtr. (2n=27). InHieracium alpinum L. s. str. the number 2n=27 has been confirmed. The results show a high proportion of tetraploid taxa; no diploids have been found.     

Sudden unexpected improvement in the atrioventricular conduction. What is the mechanism?

The 12-lead electrocardiogram (ECG) of a 79-year-old male patient with recurrent pre-syncope showed irregular sinus rhythm with constant PR interval and left bundle branch block (LBBB) with intermittently blocked P waves. The beat following the blocked P wave had a narrower QRS with a shorter PR interval. The phenomenon of bilateral bundle branch block explains the sudden improvement in the atrioventricular conduction.     

Glycogen synthetase in the sea mussel Mytilus edulis L.—II. Seasonal changes in glycogen content and glycogen synthetase activity in the mantle tissue

• 1.1. The glycogen content of the mantle tissue reached a maximum in the summer (May–July) with levels of 41.0–53.5% of the dry tissue weight.
• 2.2. Seasonal changes in glycogen synthetase activity showed that the I-activity (independent of G6P) increased up to 10-fold in June as compared with December. The measured I-activity of glycogen synthetase was sufficient to account for the accumulation of mantle glycogen in the summer.
• 3.3. The I-activity of glycogen synthetase declined rapidly in July of each year. A possible role for the inhibition of glycogen synthetase by high levels of tissue glycogen is suggested.
• 4.4. The I-activity in the mantle tissue of mussels on the shore was higher than that for animals starved in the laboratory for 2–3 days. The differences were minimal in early May but increased markedly in late May–July. Starved mussels returned to the shore showed an increase in I-activity of glycogen synthetase.
• 5.5. Injection of 30 μmol glucose into the adductor muscle increased the concentration of glucose in the mantle fluid to 2.0–2.5 mM. A similar injection of 60 μ mol glucose resulted in a time-dependent increase in the I-activity of glycogen synthetase.
• 6.6. Injection of mussels with mammalian insulin or anti-insulin serum had no effect on the activity of glycogen synthetase. Our results are at variance with those of other workers who have used the mammalian hormone in molluscan studies (see Discussion).

     

Misunderstanding in the classification of diabetes mellitus. What's in a name?

To assess whether physicians, residents, medical students, hospital diagnosis coders, and patients properly use the designations insulin-dependent diabetes mellitus (IDDM) and non-insulin-dependent diabetes mellitus (NIDDM) that were established by criteria of the National Diabetes Data Group, we reviewed clinic and hospital records and administered questionnaires. Although essentially all cases of true IDDM were identified as such and most cases of NIDDM not requiring insulin therapy were correctly identified by all groups, patients with NIDDM on insulin therapy were misidentified as having IDDM by 38% of residents in internal medicine clinics and 68% of primary care and surgical subspecialty residents. On a survey, of 22 patients with NIDDM on insulin therapy, 17 (77%) considered themselves to have IDDM. Thus, patients who have NIDDM by the established criteria who are on insulin therapy are commonly mislabeled as having IDDM. We present an approach for dealing with this problem by adapting nomenclature focusing on insulin deficiency and resistance. It would probably also be helpful to separately identify the subset of patients with "insulin-deficient diabetes" who are ketosis-prone. It is important to use immunologic profiling (islet cell antibody testing) and insulin sensitivity or deficiency testing (C-peptide levels).     

Studies on the metabolism of steroids in the foetus. Biosynthesis of 6α-hydroxytestosterone in the human foetal liver

After incubation of testosterone with 105000g microsomes of human foetal liver, 6alpha-hydroxytestosterone was isolated and identified by t.l.c. and g.l.c.-mass spectrometry. This is the first example of 6alpha-hydroxylation of C(19) steroids in the human liver, and the finding is discussed in relation to earlier reports of 6-oxygenated C(19) and C(18) steroids in pregnant women.     

14. Are the impacts of events in the earth's history discernable in the current distributions of freshwater algae?

Freshwater microalgae, lacking a fossil record, have contributed little to the study of historical biogeography. Some of the innate difficulties are discussed, as well as some of the more hopeful possibilities, if distribution records, morphology and DNA sequence analysis are combined with knowledge of the earth's history. Examples of species within the same family showing quite different distributions are given, along with suggested explanations. These include possible examples of the role played by waterfowl in dissemination of freshwater algae.     

Tenotomy of the avian anterior latissimus dorsi muscle. II. Can regeneration from the stump occur in the pigeon?

Because the chick's anterior latissimus dorsi muscle (ALD) regenerates a fast-twitch muscular connection after tenotomy, the pigeon's ALD was tenotomized, either at the origin or through the muscle 0.5 cm from the origin, to determine whether this muscle behaves similarly to the chick muscle. These procedures were compared in pigeons operated upon at 7 weeks, versus 5 to 9 months of age. The pigeon's ALD did not regenerate a new connection, and other differences were observed between the pigeon and chick ALD. The pigeon ALD has only a single slow muscle-fiber type, has fewer fast fibers, and transforms to a fast-twitch muscle more readily than the chick ALD after tenotomy. The transformation of muscle fiber types occurred more readily in the older pigeons than those tenotomized at 7 weeks of age. Tenotomy induced morphological alterations of the muscle fiber structure in all of the pigeons, which is in contrast to the absence of changes in the tenotomized chick ALD. Therefore the pigeon and chick ALD respond completely differently to tenotomy.