THE ENDOGENOUS μ-OPIOID AGONISTS,ENDOMORPHIN 1 AND 2, HAVE VASODILATOR ACTIVITY IN THE HINDQUARTERS VASCULAR BED OF THE RAT

Endomorphin 1 and endomorphin 2 are newly-discovered endogenous ligands for the μ-opioid receptor. In the present study, responses to intra-arterial injections of endomorphin 1 and 2 were investigated in the hindquarters vascular bed of the rat. Under constant-flow conditions, endomorphin 1 and 2 induced dose-dependent decreases in hindquarters perfusion pressure when injected in doses of 3–100 nmol into the hindquarters perfusion circuit. Vasodilator responses to endomorphin 1 and 2 and met-enkephalin were attenuated by the opioid receptor antagonist naloxone (2 mg/kg i.v.) at a time when vasodilator responses to isoproterenol were not altered. In terms of relative vasodilator activity, endomorphin 1 and 2 were similar to ATP, 100-fold less potent than isoproterneol, and 10,000-fold less potent than acetylcholine. These data demonstrate that endomorphin 1 and 2 have significant naloxone-sensitive vasodilator activity in the hindquarters vascular bed of the rat. © 1997 Elsevier Science Inc.     

THE COPEPODA OF THE WU-L1 LAKE, WU-SIH, KIANGSU PROVINCE. Ⅱ. CYCLOPOIDA

This is the second part of a series of papers dealing with the Copepoda-fauna of theWu-Li Lake, Wu-Sih, Kiangsu Province, China. It comprises 21 species of Cyclopoida,of which 5 species (those marked with an asterisk in the list) are for the first time re-corded in China and two species of Tropocyclops are found to be new to science. All     

A SURVEY OF THE HOLARCTIC LINYPHIIDAE （ARANEAE）, OF THE ERIGONINE GENUS ZORNELLA JACKSON, 1932

The Holarctic erigonid genus Zornella has been surveyed. Four spedes are recognized in this genus, two Palaearctic： Z. aultrigera （L. Koch, 11879） ＆ Z. orientalis sp. nov., and two Nearcfic： Z. arrnata （Banks, 1906） ＆ Z. ayptodon Chamherlin, 1920. It is demouslrated that neither nearcfic species is agnspedtic with Z. atltrigera as was thought by Holm and other authors. Z. sp. nov. is describcd from northeastern Siberia. All of the species are illustrated and their distributions mapped.     

THE DISCOVERY OF THE CRIBRIFORM PLATE IN SINOCONODON YOUNCI (TRICONODONTA,MAMMALIA)

ThepresenceofacribriformplateinlivingplacentalsandthemarsupialsandabsenceinmonotremesmayimplythatmammalsarediphyleticandtheoriginofcribriformplatetookplacewithinthcMammalia.Buttheconc1usioncamefromthe1ivingmammalsonly,andhasnotbeensupportedbypalaeontologicalevidence.Itsappearanceinoneoftheoldestandthemostprimitivemammals,Sinoconodon,possiblysuggeststhatthecribriformplatemayoccurearlier,i.e.inthetimeofthetransitionfromtheadvancedmammal-likereptiles,Cynodontia,tothetruemammals,andthatthedistrib…     

THE MARINE COPEPODA FROM THE SPAWNING GROUNDOF PNEUMATOPHORUS JAPONICUS (HOUTTUYN)OFF CHEFOO, CHINA

Under the direction of the Committee for the Exploration of Economic Fi-sheries Resources of the Yellow Sea and Peichihli Bay, an investigation of thebreeding habits of the scomber, Pneumalophorus japonicus(Houttuyn),was carriedout in the years 1953-1955. The annual visit of the scomber to the spawning groundoff Chefoo every spring brings about a flourishing fishery there. Since the spawningmigration of marine fishes is closely related to the changes of various environ-mental factors, the plankton, considered as one of the important factors of thebiological environment, was also included in the scope of exploration. Copepods are well known as one of the most important groups of zooplankton,not only because of their numerous species, but also on account of the part they play     

WHAT CAN MULTIPLE PHYLOGENIES SAY ABOUT THE LATITUDINAL DIVERSITY GRADIENT? A NEW LOOK AT THE TROPICAL CONSERVATISM,OUT OF THE TROPICS,AND DIVERSIFICATION RATE HYPOTHESES

We reviewed published phylogenies and selected 111 phylogenetic studies representing mammals, birds, insects, and flowering plants. We then mapped the latitudinal range of all taxa to test the relative importance of the tropical conservatism, out of the tropics, and diversification rate hypotheses in generating latitudinal diversity gradients. Most clades originated in the tropics, with diversity peaking in the zone of origin. Transitions of lineages between latitudinal zones occurred at 16–22% of the tree nodes. The most common type of transition was range expansions of tropical lineages to encompass also temperate latitudes. Thus, adaptation to new climatic conditions may not represent a major obstacle for many clades. These results contradict predictions of the tropical conservatism hypothesis (i.e., few clades colonizing extratropical latitudes), but support the out‐of‐the‐tropics model (i.e., tropical originations and subsequent latitudinal range expansions). Our results suggest no difference in diversification between tropical and temperate sister lineages; thus, diversity of tropical clades was not explained by higher diversification rates in this zone. Moreover, lineages with latitudinal stasis diversified more compared to sister lineages entering a new latitudinal zone. This preserved preexisting diversity differences between latitudinal zones and can be considered a new mechanism for why diversity tends to peak in the zone of origin.     

THE SHOULDER JOINT—Observations on Comparative Anatomy,Physiology, and Treatment

In a visual study of human and simian function of the shoulder joint, manifest superiority of the latter was noted. Comparative anatomical studies tend to confirm these observations and indicate that many common affections of the shoulder in humans may stem from incomplete evolutionary adaptation.Certain anatomical clues may lead to improvements in conservative and surgical treatment.A regimen of conservative and operative treatment developed over a period of many years has been found to be clinically effective for the relief of chronic refractory shoulder pain. These techniques differ at many points from present practices of a majority of physicians who deal with diseases of the shoulder.     

THE ‘ MEDITERRANEAN ’RAMALINA PANIZZEINORTH OF THE ALPS: MORPHOLOGICAL,CHEMICAL AND rDNA SEQUENCE DATA

Ramalina panizzei De Not. is reported from Switzerland and north of the Alps for the first time. Recent collections and thalli found amongst specimens ofR. fastigiata(Pers.) Ach. are described; the species is obviously not restricted to the Mediterranean. The confusion in several herbaria around this and related corticolous species, particularlyR. subgeniculataNyl. andR. fastigiata, can be traced back to imprecise original and subsequent diagnoses, all of which lack a clear species delimitation. Similarities and differences of these species are discussed. In addition, sequences from the rDNA ITS regions were determined for two individuals ofR. panizzeiand two ofR. fastigiata, including one of each from a site where both species grow intermixed. Kimura 2-parameter genetic-distance estimates indicate thatR. panizzeiandR. fastigiataare as different from each other as either is from the reference speciesR. siliquosa(Hudson) A. L. Sm.s.l.A broad-based taxonomic revision of involved species is not possible due to the limited number of analyses, but the results demonstrate the potential for using DNA sequence data to investigate species-level questions in lichens. Based on morphology, chemistry, and DNA sequence data,R. panizzeiis retained as a distinct species.     

IS LIFE IMPOSSIBLE? INFORMATION,SEX, AND THE ORIGIN OF COMPLEX ORGANISMS

The earliest organisms are thought to have had high mutation rates. It has been asserted that these high mutation rates would have severely limited the information content of early genomes. This has led to a well‐known “paradox” because, in contemporary organisms, the mechanisms that suppress mutations are quite complex and a substantial amount of information is required to construct these mechanisms. The paradox arises because it is not clear how efficient error‐suppressing mechanisms could have evolved, and thus allowed the evolution of complex organisms, at a time when mutation rates were too high to permit the maintenance of very substantial amounts of information within genomes. Here, we use concepts from the formal theory of information to calculate the amount of genomic information that can be maintained. We identify conditions under which much higher levels of genomic information can be maintained than previously considered possible among origin‐of‐life researchers. In particular, we find that the highest levels of information are maintained when many genotypes produce identical phenotypes, and when reproduction occasionally involves recombination between multiple parental genomes. There is a good reason to believe that these conditions are relevant for very early organisms, and thus the results presented may provide a solution to a long‐standing logical problem associated with the early evolution of life.     

A NEW MACROPETALICHTHYID FROM CHINA, WITH SPECIAL REFERENCE TO THE HISTORICAL ZOOGEOGRAPHY OF THE MACROPETALICHTHYIDAE (PLACODERMI)

SudsrucodedMChy,1848OrderthytdaJaekd,1911wMarmpeytdaeEastman,l898beusHmpopsges'nov'Tpe~Hofrpetahchdnytonguaeasisgen'etSP'nov'~dsSmall-edmacropetalichthytd'Roedandpincalplatheincontac,completeymparahngthepreorbitalplaus'Posteriorpit-linesextendingposteri0riytothetal-line,and0SSficahoncenterofthenuchalplatesitUatalattheposteriorhalfoftheplate'Supia0rbitalsensorycanalnotconvergingwiththeposteri0rpit-lines'~gyHOl-(Gr')whole,enhre,COmPlete;-Petahchthy(G'),ofAnuedinthe.genencnamesofthePeta…     

THE SOUTHERN SEA LION,OTARIA BYRONIA OR OTARIA FLAVESCENS?

Abstract: The status of the specific name of the Southern sea lion is controversial; currently two names are in use: Otaria flavescens (Shaw, 1800) and Otaria byronia (de Blainville, 1820). The former was based on a two-foot-long yellowish otariid collected in the Strait of Magellan and the latter on a skull stated to have been collected on the Tinian Island (Marianas Archipelago); unfortunately both holotypes are lost. Otaria flavescens has date priority over Otaria byronia , but its identification was uncertain. This paper focuses on analyzing the main features of Shaw's holotype (body length, ear size, and hair color), which fit with the features of a Southern sea lion pup. As this was a tangible specimen from a valid locality and has priority over other available epithets, the specific name of the Southern sea lion should be Otaria flavescens (Shaw, 1800).     

THE PLIOCENE MICROMAMMALIAN FAUNA FROM JINGLE, SHANXI——A DISCUSSION OF THE AGE OF JINGLE RED CLAY

<正> The Cenozoic deposits of Jingle area was first explored by Teilhard de Chardin & Young in 1929, and six species of mammals: Hipparion houfenense, Gazella blacki Antilospira licenti, Elephas sp., Cervus sp., and Rhinocerotidae gen. indet, were found from the Red Clay in Loc. 1 (Hefeng). Based on the Jingle Fauna, Teilhard de Chardin & Young concluded that the fossil-bearing layer was situated between the typical Hipparion richthofeni Red Clay (Pontian) and the Sanmenian deposits (Polycene) (Teilhard de Chardin & Young, 1930, 1931) and called it "Upper Pontian". Since then, Jingle Formation (or Jingle Red Clay) has been widely used in the stratigraphic generalization of North China (Pei et al., 1963) although its definition and age assignment have never been cleared up. "Jinglean" was put into use for the first time as a stage name by Li et al. (1984, in Chinese) to represent Early Pliocene tentatively: "It may be equivalent to Early Pliocene, more plausibly, it is later ...... Jinglean was temporarily used here to represent Early Pliocene by tradition." In order to make clear the age of Jingle Red Clay and enrich the Hefeng Fauna, a field survey was made in the Summer of 1986 by Chen Xiaofeng and the author. An assemblage of fossil micromammals was unearthed by means of wet-sieving techniques. About 1 ton of sediments from Hefeng (Loc. 86007, or Loc. 1) and Xiagaoai (Loc. 86008, or Loc. 2) in Jingle county (see fig. 1), yielded over 1000 specimens of small mammals. The specimens are from four layers (see table 1), and the present paper only deals with the micromammals from the sand layer and the Red Clay at Hefeng (fig. 2).     

THE BREEDING STATUS OF THE CAPE VULTURE IN THE TRANSVAAL DURING 1980—1985

Benson, P. C., Tarboton, W. R., Allan, D. G. & Dobbs, J. C. 1990. The breeding status of the Cape Vulture in the Transvaal during 1980–1985. Ostrich 61: 134–142.

Ten of the 11 extant Cape Vulture Gyps coprotheres colonies in the Transvaal were censused using aerial and/or ground census techniques in the 1980–1985 breeding seasons. Minimum counts were obtained and best estimates of total numbers of “active nests” were determined using correction factors to compensate for incomplete photocoverage in the aerial technique and nest failures prior to the census dates. In 1985, the year when the most complete data were available, a minimum of 2741 and a best estimate of 2987 active nests were determined to be present in the Transvaal. At the large colonies, which were intensively monitored, breeding numbers did not fluctuate greatly from year to year, and it is thus estimated that about 3000 pairs of birds bred yearly in the Transvaal during the study period. Although the data indicate that the total numbers are greater than previously thought this is due to improved census techniques, rather than an increase in the population. Ninety-eight percent of breeding occurred at six colonies and 82% at three (Kransberg, Blouberg and Manutsa). The large colonies are associated with communal grazing (homelands) Private cattle and game farming and nature conservation areas, where the use of poison for predator control is minimal. The vulnerable status afforded the Cape Vulture in the South African Red Data Book—Birds (Brooke 1984) is justified because of the bird's disappearance from some breeding colonies, reduction in numbers at others and its vulnerability to poisoning.     

STUDIES ON THE ULTRASTRUCTURE OF THE PREMATURE OVA OF TAENIARHYNCHUS SAGIN ATUS GOEZE,1782.BY SCANNING ELECTRON MICROSCOPE

In this article, we present the observations of the ova of Taenidae whichretain(?), as seen under scanning electron microscope, the premature ova of theTacniarhynchus saginatus. An ovum comprises seven layers, which actually interpenetrate and interplay as a complete system. When the ovum becomes maturethe capsule breaks, the yolk cells and the vitelline membrane undergo degenerative thanges, but the embryophorc and the hexocanth embryo grow into completion.