Growth and Size of the Tropical Sea Cucumber Holothuria (Halodeima) atra Jager at Enewetak Atoll, Marshall Islands

In September 1975, 5031 sea cucumbers (Holothuria atra Jager) were tagged with tetracycline and returned to a gutter on the seaward reef bench of Ananij Island, Enewetak Atoll, Marshall Islands. A sample of 184 individuals was collected in September 1976. Animals were dissected and plates of the calcareous ring were examined with ultraviolet radiation for tetracycline lines. Based on 18 tagged individuals, the Brody-Bertalanffy growth constants are: K = 0.11 and P = 0.89 cm (for interradial plates). Length (L, cm) and weight (W, g) of individuals are related to plate size: L = 36.35P and W = 1950P3, giving maximum size as 32 cm and 1352 g. Length frequency distributions for the population did not change from 1975 to 1976. A preliminary estimate of annual loss is 50 to 70 percent of the total population based on the growth parameters and population size structure. Holothuria atra shows asexual reproduction by transverse fission, which appears to be the major source of recruitment at Ananij rather than from the plankton

Growth, Regeneration, and Damage Repair of Spines of the Slate-Pencil Sea Urchin Heterocentrotus mammillatus (L.) (Echinodermata: Echinoidea )

Spines of sea urchins are appendages that are associated with defense, locomotion, and food gathering. Spines are repaired when damaged, and the dynamics of repair was studied in the slate-pencil sea urchin Heterocentrotus mammillatus to provide insights not only into the processes of healing. but also into the normal growth of spines and the formation of growth lines. Regeneration of spines on tubercles following complete removal of a spine was slow and depended upon the size of the original spine. The maximum amount of regeneration occurred on tubercles with spines of intermediate size (1.6 g), which, on average, developed regenerated spines weighing 0.1, 0.3, and 0.7 g after 4, 8, and 12 months, respectively. Some large tubercles, which had original spines weighing over 3 g, failed to develop a new spine even after 8-12 months. Regeneration of a new tip on a cut stump was more rapid than production of a new spine on a tubercle. Regeneration to original size was more rapid for small spines than for large spines, but large stumps produced more calcite per unit time. In 4 months, a small spine with a removed tip weighing 0.15 g regenerated a new tip weighing 0.09 g, or 63% of its original weight. In the same time, a large spine with 2.35 g of tip removed regenerated 0.40 g of new tip, or 17% of the original weight. Holes were drilled in spines to serve as bench marks to document the production of new growth lines in response to damage. Blind holes drilled in spines caused 65% loss over 4 months, but holes drilled completely through spines caused only a 6% loss. Cutting a spine near its base did not initiate shedding of the stump. Repair of holes drilled in spines showed that major repair originated from the spine surface, and regeneration into the hole was over obtuse angles. For a slanting hole through a spine, filling of the hole carne from the distal edge for the distal opening and from the proximal edge for the proximal opening. Spines were tagged with tetracycline, but of 46 spines examined 4-12 months following treatment, only 1 displayed evidence that the spine surface had been marked. This suggests that spines usually are not growing. Abrasion of spines either by wiping with a cloth or sanding with emery paper failed to induce growth lines to form. Of 57 abraded spines and 64 unabraded spines, only 2 in each treatment category developed new growth lines. Results show that some growth lines in spines develop from trauma, but these tend to be local and do not extend from the base to the tip. Spines of Heterocentrotus mammillatus usually are not growing but occasionally undergo a growth episode that produces a growth line that extends from the milled ring to the spine tip. Such an episode is not related to damage repair from abrasion or breakage and appears to be endogenous. The SPINES OF A SEA URCHIN are morphological parts that serve as the animal's first defense against assaults from the environment (e.g., Fricke 1974, Strathmann 1981), appendages for gathering and manipulating food (e.g., Ebert 1968, Leighton 1968), and braces for wedging into crevices (e.g., Regis and Thomassin 1982). Spines form an important part of an urchin's maintenance mechanisms (Ebert 1982), and it is no surprise to find that they are repaired rapidly once damaged (Ebert 1967, Heat field 1971, Mischor 1975). Spine sizes vary greatly across taxa. For example, in St rongylocentrotus purpuratus (Stimpson 1857), calcite of a large primary spine weighs only about 0.03 g. In slate-pencil sea urchins of the genus Heterocentrotus, spines are substantially more massive. Calcite in a large H. mammillatus (Linneaus 1758) spine may weigh over 5 g, and calcite of a large primary spine of H. trigonarius (Lamarck 1816) may weigh over 11 g. Although spines from Strongylocentrotus purpuratus would be expected to be repaired rapidly (Ebert 1967, Heatfield 1971), it is less clear whether very large spines from Heterocentrotus species also would be repaired in just a few months or whether the benefits of large spines carry a potential burden of a long regeneration time. A second issue associated with damage repair focuses on growth lines in spines. In St rongylocentrotus purpuratus, lines form as a consequence of tip regeneration following breakage (Ebert 1967, Heatfield 1971 ), but growth lines in Heterocentrotus spp. have been interpreted as periodic (Dotan and Fishelson 1985, Weber 1969), an interpretation that has been disputed (Ebert 1985, 1987). The purpose of this paper is to present results of a 1-year study on Heterocentrotus mammillatus (family Echinometridae), a species with massive spines. The focus is on the responses of spines to damage, spine repair and regeneration in response to trauma, and the formation of growth lines. Data are presented on (a) regeneration following total removal of spines; (b) repair rates of calcite on cut spine stubs; (c) responses of spines to small holes drilled into or through them; (d) responses of spines to abrasion; and (e) results of tagging spines with tetracycline

Aerobic fitness and orthostatic tolerance: Evidence against an association

This presentation will focus on only one side of the debate as to whether high levels of aerobic fitness have a deleterious effect on tolerance to gravitational stress. This issue was raised in the early 1970's as a result of two research publications. The first work investigated the carotid sinus baroreflex of humans with an airtight chamber that surrounded the head and neck. The steady-state reflex changes in blood pressure that were recorded 3 minutes after application of the head and neck stimuli, were attenuated in an athletic group compared to a sedentary group of volunteers. A second report in the NASA literature indicated that five endurance-trained runners were less tolerant to LBNP than five nonrunners. These early research findings have stimulated a considerable amount of interest that has lead to a growing number of research efforts seeking an association between aerobic fitness and orthostatic tolerance in humans. I will briefly review some of the more pertinent published research information which suggests that there is no relationship between aerobic fitness and orthostatic tolerance in humans

DevOps in Practice -- A preliminary Analysis of two Multinational Companies

DevOps is a cultural movement that aims the collaboration of all the stakeholders involved in the development, deployment and operation of soft-ware to deliver a quality product or service in the shortest possible time. DevOps is relatively recent, and companies have developed their DevOps prac-tices largely from scratch. Our research aims to conduct an analysis on practic-ing DevOps in +20 software-intensive companies to provide patterns of DevOps practices and identify their benefits and barriers. This paper presents the preliminary analysis of an exploratory case study based on the interviews to relevant stakeholders of two (multinational) companies. The results show the benefits (software delivery performance) and barriers that these companies are dealing with, as well as DevOps team topology they approached during their DevOps transformation. This study aims to help practitioners and researchers to better understand DevOps transformations and the contexts where the practices worked. This, hopefully, will contribute to strengthening the evidence regarding DevOps and supporting practitioners in making better informed decisions about the return of investment when adopting DevOps.Comment: 8 pages, 1 figure, 2 tables, conferenc

Comment on the new Ds(∗)+π0D_s^{(*)+} \pi^0 resonances

We propose an explanation of the new resonances observed in $D_s^{(*)+} \pi^0$ decays. We suggest that the data can be explained by the mixing of conventional p-wave excited $D_s^+$ mesons with 4-quark states. The narrow states observed in $D_s^+ \pi^0$ and $D_s^{*+}\pi^0$ are primarily p-wave $D_{sJ}^{*}$ states, while the predominantly 4-quark states are shifted above $D^{(*)} K$ threshold and should be broad. Ranges for the mixing parameter and mass of the 4-quark state in this scenario are given. Other experimental consequences are discussed.Comment: 4 pages, 2 figures. Updated references. To appear in Phys. Lett.

Atmospheric ice nuclei in the Eyjafjallajökull volcanic ash plume

We have sampled atmospheric ice nuclei (IN) and aerosol in Germany and in Israel during spring 2010. IN were analyzed by the static vapor diffusion chamber FRIDGE, as well as by electron microscopy. During the Eyjafjallajökull volcanic eruption of April 2010 we have measured the highest ice nucleus number concentrations (>600 l−1) in our record of 2 yr of daily IN measurements in central Germany. Even in Israel, located about 5000 km away from Iceland, IN were as high as otherwise only during desert dust storms. The fraction of aerosol activated as ice nuclei at −18 °C and 119% rhice and the corresponding area density of ice-active sites per aerosol surface were considerably higher than what we observed during an intense outbreak of Saharan dust over Europe in May 2008. Pure volcanic ash accounts for at least 53–68% of the 239 individual ice nucleating particles that we collected in aerosol samples from the event and analyzed by electron microscopy. Volcanic ash samples that had been collected close to the eruption site were aerosolized in the laboratory and measured by FRIDGE. Our analysis confirms the relatively poor ice nucleating efficiency (at −18 °C and 119% ice-saturation) of such "fresh" volcanic ash, as it had recently been found by other workers. We find that both the fraction of the aerosol that is active as ice nuclei as well as the density of ice-active sites on the aerosol surface are three orders of magnitude larger in the samples collected from ambient air during the volcanic peaks than in the aerosolized samples from the ash collected close to the eruption site. From this we conclude that the ice-nucleating properties of volcanic ash may be altered substantially by aging and processing during long-range transport in the atmosphere, and that global volcanism deserves further attention as a potential source of atmospheric ice nuclei

Adipokine als metabolische Prädiktoren

Adipokine sind Proteine, die aus dem Fettgewebe freigesetzt werden. Viele dieser Fettzell-sezernierten Proteine sind bei Adipositas dysreguliert und beeinflussen das Risiko für kardiometabolische Folgeerkrankungen. Die vorliegende Arbeit untersucht daher im Speziellen die neuartigen Adipokine Angiopoietin-like protein 8/Betatrophin, Irisin, Progranulin, Adipocyte fatty acid-binding protein (AFABP) und Fibroblast growth factor 21 (FGF21) als potentiellen Link zwischen dem Fettgewebe sowie den kardiometabolischen Erkrankungen Niereninsuffizienz und Gestationsdiabetes (GDM). Die Grundlage der vorliegenden Arbeit bilden humane Studien in Patienten mit chronischer und akuter Niereninsuffizienz sowie in Patientinnen mit GDM. Zudem wurden einzelne Ergebnisse der humanen Studien in einer großen Kohortenstudie mit >1000 Probanden verifiziert. Des Weiteren wurden einzelne Adipokine in tierexperimentellen Studien genauer untersucht, um kausale Assoziationen zu detektieren. Hierdurch gelang es, bestimmte Regulationsmuster von Adipokinen in den kardiometabolischen Erkrankungen Niereninsuffizienz und GDM zu erkennen, um so mögliche pharmakologische Targets zu identifizieren. Bei Frauen mit GDM könnte insbesondere Angiopoietin-like protein 8/Betatrophin in Zukunft als pharmakologisches Target in Betracht kommen. Andere Adipokine zeigen jedoch bei GDM unterschiedliche Regulationen im Vergleich zu Diabetes mellitus Typ 2. Hier müssen zunächst weitere Untersuchungen die exakten Pathomechanismen für diese divergierenden Ergebnisse identifizieren. In den Studien zu chronischer und akuter Niereninsuffizienz konnte gezeigt werden, dass insbesondere die Adipokine Progranulin, AFABP und FGF21 direkt mit der Nierenfunktion assoziiert sind. Andere Adipokine wie z.B. Angiopoietin-like protein 8/Betatrophin scheinen nicht renal eliminiert zu werden. Basierend auf diesen Ergebnissen muss nun untersucht werden, ob bestimmte Adipokine eine kausale Rolle in der Entwicklung und Progression einer Niereninsuffizienz spielen. Zusammenfassend wurden somit verschiedene Adipokine in kardiometabolischen Risikoerkrankungen charakterisiert. Es konnten mögliche zukünftige pharmakologische Targets für die Behandlung von Niereninsuffizienz sowie für die bei GDM zugrundeliegende Insulinresistenz identifiziert werden.:1. Einleitung 1.1 Adipokine 1.2 Adipokine sind dysreguliert bei Adipositas 1.3 Adipokine bei kardiovaskulären Erkrankungen, Diabetes mellitus und chronischer Niereninsuffizienz 1.4 Definition der Krankheitsentitäten Niereninsuffizienz und Gestationsdiabetes als kardiometabolische Risikoerkrankungen 1.4.1 Chronische Niereninsuffizienz 1.4.2 Akute Niereninsuffizienz 1.4.3 Gestationsdiabetes 1.5 Hypothese 2. Methoden 2.1 Humane Studien 2.1.1 Patienten mit chronischer Niereninsuffizienz 2.1.2 Patienten mit akuter Niereninsuffizienz 2.1.3 Patientinnen mit Gestationsdiabetes 2.1.4 Humane Querschnittsstudien 2.2 Tierexperimentelle Studien 2.2.1 Tiere mit akuter Niereninsuffizienz: nephrektomierte Sprague Dawley-Ratten 2.2.2 Tiere mit chronischer Niereninsuffizienz: eNOS-/- C57BLKS db/db-Mäuse 2.3 Charakterisierung und Assays 2.4 Statistik 3. Resultate 3.1 Angptl8/Betatrophin 3.2 Irisin 3.3 Progranulin 3.4 AFABP 3.5 FGF21 4. Diskussion und Ausblick 5. Anlagen 5.1 Anlage 1: Erklärungen zur vorgelegten Habilitationsschrift 5.2 Anlage 2: Lebenslauf 5.3 Anlage 3: Publikationsverzeichnis 5.4 Anlage 4: Danksagung 5.5 Anlage 5: Referenze