Open Circulation Research Articles

2053-P: Integrated Blood Flow between Endocrine and Exocrine Pancreas Is Conserved among Multiple Species

Pancreatic islets compose the endocrine pancreas and are considered distinct from the exocrine pancreas in terms of both function and regulation of blood flow. Indeed, enzymatically isolated islets directly respond to glucose and other secretagogues in vitro. The islet has been regarded as an enclosed micro-organ, in which blood flows uni-directionally from an afferent arteriole to an efferent venule. This blood circulation pattern has been termed as “the insulo-acinar portal system.” Historically, the endocrine and exocrine pancreas have been studied separately by different fields of investigators. Using intravital analysis of pancreas blood flow in mice, we have recently reported that islet capillaries are continuously integrated with those in the exocrine pancreas, which makes the islet circulation open, not self-contained. Furthermore, by tracking fluorescently-labeled red blood cells revealed bi-directional blood flow between the endocrine and exocrine pancreas. In the present study, in order to verify whether this integrated vascular network is conserved among different species, we carried out three-dimensional morphological analysis of pancreatic capillary networks using thick pancreatic tissue slices (600-800 µm) in ferrets, rabbits, pigs, dogs and monkeys, besides mice and humans. We have confirmed that the integrated blood flow between endocrine and exocrine pancreas is conserved among multiple species that we studied. Here we propose that the open circulation model physically links both endocrine and exocrine parts of the pancreas as a single organ through the integrated vascular network. This new paradigm may provide revived or contrasting insights into the findings of past studies, as well as a novel approach for prospective research projects. Disclosure J.K. Butterfield: None. M. Hara: None. Funding National Institutes of Health (DK117192, DK020595)

THE SUBSTITUTE FAMILY AS A PSYCHOLOGICAL AND PEDAGOGICAL PHENOMENON: STRUCTURAL AND FUNCTIONAL FEATURES AND TYPICAL DIFFICULTIES

Background. Modern science needs to define the substitute family as a psychological and pedagogical phenomenon. One of the reasons for this scientific interest is the policy of deinstitutionalization – the state policy for the development of family forms of life for orphans and children left without parental care that focuses on potential parents, the values of motherhood, fatherhood and childhood. Aim. The article aims to identify the structural and functional featuresof the substitute family and typical difficulties that arise when communicating with a foster child. Materials and methods: 1) the study involved 100 parents participating in the monitoring support of the substitute family. All parents have higher education, are married, have the average age of 40 years, have no more than two own children, adopted children have own relatives; the study was conducted during a year; 2) the essay “I am a parent” was used; 3) methods of mathematical statistics were used, namely the Statistica 6.0 for Windows for processing the data obtained as a result of text content analysis. Results. The structural and functional features of the substitute family are indicated: open external borders, open circulation of information, lack of polarity in the characteristic of intrafamily emotional ties, a large number of specific (non-normative) tasks that require to be solved in the parent system, the need to take care of the child without mutual relationship, the parents' guilt due to dissatisfaction with the results of their educational activities, the establishment of communication between the child and his/her own relatives, the appearance of a sibling subsystem; a number of typical difficulties in substitute families are identified. Conclusion: based on the severity of typical difficulties in the sample of respondents, the authors reflected paradoxical facts in the functioning of the substitute family.

Architecture and Cellular Composition of the Spleen in the Japanese Quail (Coturnix japonica).

The spleen is considered a key player in birds' immunity. The stroma and the parenchyma of the spleen of the adult quail were demonstrated histologically, histochemically, and ultrastructurally. A thin capsule and the absence of trabeculae were the most characteristics of spleen stroma. The demarcation between white pulp and red pulp was not observed in the quail. White pulp formed from the periarterial lymphatic sheath and the periellipsoidal lymphatic sheath, both of which were surrounded by arteriole and ellipsoid, respectively. Ellipsoids appeared more numerous and were characterized by cuboidal lining of the epithelium and supporting cells. Red pulp consisted of sinuses and cords. White pulp and red pulp of the quail spleen contained various cells, such as red blood cells, macrophages, heterophils with characteristic granules, lymphocytes of different sizes, dendritic cells, plasma cells, and telocytes. In addition, closed circulation and open circulation established the blood flow on the spleen.

Visualization of T Cell Migration in the Spleen Reveals a Network of Perivascular Pathways that Guide Entry into T Zones

SummaryLymphocyte homeostasis and immune surveillance require that T and B cells continuously recirculate between secondary lymphoid organs. Here, we used intravital microscopy to define lymphocyte trafficking routes within the spleen, an environment of open blood circulation and shear forces unlike other lymphoid organs. Upon release from arterioles into the red pulp sinuses, T cells latched onto perivascular stromal cells in a manner that was independent of the chemokine receptor CCR7 but sensitive to Gi protein-coupled receptor inhibitors. This latching sheltered T cells from blood flow and enabled unidirectional migration to the bridging channels and then to T zones, entry into which required CCR7. Inflammatory responses modified the chemotactic cues along the perivascular homing paths, leading to rapid block of entry. Our findings reveal a role for vascular structures in lymphocyte recirculation through the spleen, indicating the existence of separate entry and exit routes and that of a checkpoint located at the gate to the T zone.

Integrated Pancreatic Blood Flow: Bidirectional Microcirculation Between Endocrine and Exocrine Pancreas.

The pancreatic islet is a highly vascularized endocrine micro-organ. The unique architecture of rodent islets, a so-called core-mantle arrangement seen in two-dimensional images, led researchers to seek functional implications for islet hormone secretion. Three models of islet blood flow were previously proposed, all based on the assumption that islet microcirculation occurs in an enclosed structure. Recent electrophysiological and molecular biological studies using isolated islets also presumed unidirectional flow. Using intravital analysis of the islet microcirculation in mice, we found that islet capillaries were continuously integrated to those in the exocrine pancreas, which made the islet circulation rather open, not self-contained. Similarly in human islets, the capillary structure was integrated with pancreatic microvasculature in its entirety. Thus, islet microcirculation has no relation to islet cytoarchitecture, which explains its well-known variability throughout species. Furthermore, tracking fluorescent-labeled red blood cells at the endocrine-exocrine interface revealed bidirectional blood flow, with similar variability in blood flow speed in both the intra- and extra-islet vasculature. To date, the endocrine and exocrine pancreas have been studied separately by different fields of investigators. We propose that the open circulation model physically links both endocrine and exocrine parts of the pancreas as a single organ through the integrated vascular network.

STRATIGRAFIA E SEDIMENTOLOGIA DEI "CALCARI E MARNE A <em>RHAETAVICULA CONTORTA</em> AUCTT. (NORICO-RETICO) DELLA TOSCANA NORD-OCCIDENTALE - NUOVA SUDDIVISIONE FORMAZIONALE

Nine sections from the "Limestones and marls with Rhaetavicula contorta" Auctt. (Norian-Rhaetian) of the Tuscan Nappe in eastern Liguria and northwestern Tuscany, have been examined for their stratigraphic and sedimentological characteristics. The results obtained have been integrated with data pertaining to the previously studied Pania di Corfino section.
 Two formations were identified and studied in detail: that of Pania di Corfino and that of La Spezia.
 Where present, the Pania di Corfino Formation accounts for the lower portion of the sections. It consists mainly of thick beds and massive layers of dolomites, dolomitic limestones and limestones. Thinly-bedded dark limestones appear less frequently, while layers rich in clay are rare. The top of the formation is surely of Rhaetian age, in some sections, as indicated by the presence of Triasina hantkeni Majzon; in the others, it is Norian-Rhaetian. The age of the bottom portion can be regarded as Norian-Rhaetian in all the sections; the presence of considerably thick deposits beneath the established Rhaetian layers in some sections, however, suggests an Early Rhaetian or even Late Norian age.
 The depositional environment of the Pania di Corfino Formation may be envisaged as an epicontinental carbonate platform with predominantly restricted water circulation on which fine carbonate sediments are deposited beneath the wave base; features suggesting a tidal flat are rare. The environment of deposition was, for brief periods only, that of a platform with open circulation in which the effects of wave-motion were prominent; features strictly relatable to a true platform edge have not been found.

Study on flow modes of open natural circulation with low height difference under low power conditions

Open natural circulation systems are widely applied in the field of energy and chemical industries. Under some special conditions, open natural circulation systems with low height difference need to be applied, but research on this type of systems is not sufficient. In this paper, the flow modes of sucha natural circulation system were experimentally studied at low power level by adopting steam heating. In addition, the flow modes and physical phenomena of the natural circulation system were analyzed in detail under different heating power conditions. It is found that there are four flow modes at different power levels in the natural circulation system due to the influence of non-condensable gas and subcooled boiling. The inlet and outlet temperatures of heating section are analyzed in different flow modes. The result shows that the outlet temperature of heating section can be used as a judgment criterion for different flow modes.

Expert consensus on diagnosis and treatment of esophagogastric variceal bleeding in cirrhotic portal hypertension (2019 edition)

Portal hypertension is a clinical syndrome which is a consequence of a pathological increase in portal vein pressure due to various causes, among which, cirrhosis being the most common cause. The most basic pathophysiological features of portal hypertension in cirrhosis are increased portal vein pressure due to blocked portal vein blood flow and open collateral circulation. Among the clinical manifestations of portal hypertension in cirrhosis, esophageal and gastric fundus varicose bleeding is the most urgent and the mortality rate is the highest. In order to standardize the diagnosis and treatment plan of esophagogastric variceal bleeding in cirrhotic portal hypertension, the Chinese Society of Spleen and Portal Hypertension Surgery, Chinese Society of Surgery, have renewed and revised this consensus on diagnosis and treatment of esophagogastric variceal bleeding in cirrhotic portal hypertension (2015 edition) hope to provide references for the clinical practices.

Hybrid Ventricular Tachycardia Ablation after Failed Percutaneous Endocardial and Epicardial Ablation

Introduction: Recurrent ventricular tachycardia (VT) after percutaneous ablation is associated with a high morbidity and mortality. We assessed the feasibility of open chest extracorporeal circulation (ECC)-supported 3D multielectrode mapping and targeted VT substrate ablation in patients with previously failed percutaneous endocardial and epicardial VT ablations. Methods: In patients with previously failed percutaneous endocardial and epicardial VT ablations and a high risk of hemodynamic collapse during the procedure, open chest ECC-supported mapping and ablation were performed in a hybrid EP lab setting. Electro-anatomic maps (3D) were acquired during sinus rhythm and VT using a multielectrode mapping catheter (HD grid; Abbott or Pentaray, Biosense Webster). Irrigated radiofrequency ablations of all inducible VT were performed with a contact force ablation catheter. Results: Hybrid VT ablation was performed in 5 patients with structural heart disease (i.e., 3 with previous old myocardial infarction and 2 with nonischemic cardiomy­opathy) and recurrent VT. Acute procedural success was achieved in all patients. Four patients were successfully weaned off the ECC. In 1 patient with a severely reduced LVEF (16%), damage to the venous graft occurred after sternotomy and that patient died after 1 month. Four patients (80%) remained VT free after a median follow-up of 6 (IQR 4–10) months. Conclusion: In high-risk patients with previously failed percutaneous endocardial and epicardial VT ablations, open chest ECC-supported multielectrode epicardial mapping revealed a VT substrate in all of the patients, and targeted epicardial ablation abolished VT substrate in these patients.

Analysis of natural circulation loop in MTRs using CONVEC code

Natural circulation is an important process in core cooling and decay heat removal of Material Testing Reactors (MTRs). Analysis of an open pool natural circulation loop (NCL) was performed using the CONVEC V3.4 code developed for steady state analysis of MTRs during natural convection. Verification and Validation of code calculations for similar natural circulation loops were provided. The code calculations were carried out to investigate the geometric parameters that enhance the natural loop cooling capacity or increase the margin to Onset of Nucleate Boiling (ONB) as a limiting condition. The results describe the operating envelop in terms of core power without ONB and pool temperature for various dimensions of loop components including the fuel element and pool depth. This paper is useful for the researchers working on the research reactor design.

Effect of throttling on the two-phase flow stability in an open natural circulation system

Low pressure natural circulation systems fit the concept of passive safety systems as useful feature to bring a nuclear power plant to a safe and stable state during a postulated accident without active systems. The operation is characterized by low mass fluxes and passing the known unstable two-phase region from activation to a continuous heat removal in the stable two-phase region. The occurring mass flow oscillations and the condensation induced water hammer phenomenon limited the performance of heat removal. These effects are highly undesirable because they may effect destruction of entire apparatus. The GENEVA test facility as an open natural circulation system represents the containment cooling condenser of the KERENATM reactor concept in the main dimensions. Initiated by the steam supply, the mass flow results from induced heat flux and is limited only by the internal pressure drops: the local, the frictional, the acceleration and the gravitational pressure drop across the flow path. The influence of the flow resistance on its unstable two-phase region and their oscillatory behavior are experimentally studied in detail. Its variation is summarized in stability maps plotted in the parameter plan of the heat flux and the subcooling number at the inlet of the heated section. Thereby, the dynamical evolution of the boiling boundary indicates the initiation of two-phase flow oscillations and the condensation induced water hammer phenomenon. The increasing local pressure drop at the inlet of the heated section reduces the velocity amplitudes but a clear reduction of the pressure surges could not be determined although these should be more pronounced due to decreasing buoyancy and increasing back flow.

El Open Access a debate: entre el pago por publicar y la apertura radical sostenible

Se muestra la evolución del movimiento de acceso abierto, en contraste con la resistencia de empresas editoriales que desean seguir controlando la distribución de la información científica a través del pago por publicar. Se presenta a los actores y el escenario donde se da esta disputa, con base en los antecedentes de la comunicación científica y de las diferentes etapas del proceso de acceso a las publicaciones especializadas. Se discute la relevancia y viabilidad del movimiento Open Access (AO), y se proporcionan algunas claves para su posible sustentabilidad. Se destaca la necesidad de replantear la dictaminación por pares de los artículos, a fin de alcanzar una revisión abierta (Open Review, OR), en un contexto generalizado de cultura libre. Se concluye que se trata de un fenómeno de carácter económico, social, político y epistémico, además de que la esencia del Open Access demanda un modelo de circulación libre, abierta y gratuita del conocimiento científico, en un contexto de prácticas colaborativas entre autores, editores, revisores y bibliotecarios, en el entendido de que el conocimiento es un bien común y que, por ello, es necesario definir nuevos patrones de producción, evaluación, distribución, consumo y propiedad del conocimiento.

Expression of mucosal addressin cell adhesion molecule-1 on the reticular framework between white pulp and the marginal zone in the human spleen.

The antigenic heterogeneity of the reticular framework of the white pulp and marginal zone is well documented in the human adult spleen. Immunostaining of α-smooth muscle actin characterizes the heterogeneity of the reticular framework of the white pulp and marginal zone. In the human spleen, the blood cells flow in an open circulation. T and B lymphocytes flow out from the arterial terminal, and migrate in the reticular framework. Homing of lymphocytes to lymphoid tissues is regulated by selective interactions between cell surface homing receptors and tissue vascular addressins at sites of lymphocyte recruitment from the blood. In the present study, mucosal addressin cell adhesion molecule-1 was selectively expressed on α-smooth muscle actin-positive reticular framework. The reticular framework may function in lymphocyte homing and segregation into the periarteriolar lymphoid sheath, lymph follicle and marginal zone.

Numerical analysis on the effectiveness of warm water supply in water flow window for room heating

Water flow window has been well proven as an efficient way for both solar energy utilization and cooling energy saving for air-conditioned buildings, especially in the cooling-dominant regions. However, investigations on its heating application performance in cold winter season, when the direct solar thermal energy penetration is not sufficient to maintain a comfort room temperature, are quite few. In response, this paper suggests to supply warm water to the window gap and act as heat radiator, in order to help maintaining a suitable indoor thermal environment in winter. In this way, window is no longer the weak point of heat insulation, but a combination of both solar collector and heat radiator. Parametric optimization was completed numerically with a validated FORTRAN program to determine the proper operation parameters. The impacts of water circulation mode, supply water flow rate, warm water temperature and supply period were investigated. With open circulation, the energy saving potential was found to be superior compared to close circulation design with less room heat exchange and improved thermal efficiency. Supply water flow rate of 400 ml/min was recommended for the cases under investigation. The proper temperature of supply warm water varied with the climate, especially the solar intensity. A higher temperature was required for cities with weaker solar radiation and lower ambient temperature. Warm water supply was an effective measure to provide assisted heat source during heating season and the proper supply period was from November to March.

Locating human splenic capillary sheaths in virtual reality

Stromal capillary sheath cells in human spleens strongly express CD271, the low affinity nerve growth factor receptor p75. Serial sections of a representative adult human spleen were double-stained for CD271 versus smooth muscle alpha actin (SMA) plus CD34 to visualise capillary sheaths, the arterial tree and endothelial cells by transmitted light. Preliminary three-dimensional (3D) reconstructions of single regions were inspected in virtual reality (VR). This method showed that a large number of CD271+ sheaths occur in a post-arteriolar position often surrounding capillaries located close to divisions of arterioles. The length and diameter of capillary sheaths are rather heterogeneous. Long sheaths were observed to accompany one or two generations of capillary branches. We hypothesise that human splenic capillary sheaths may attract recirculating B-lymphocytes from the open circulation of the red pulp to start their migration into white pulp follicles along branches of the arterial tree. In addition, they may provide sites of interaction among sheath macrophages and B-lymphocytes. Our innovative approach allows stringent quality control by inserting the original immunostained serial sections into the 3D model for viewing and annotation in VR. Longer series of sections will allow to unequivocally localise most of the capillary sheaths in a given volume.

Drosophila immune cells extravasate from vessels to wounds using Tre1 GPCR and Rho signaling.

Inflammation is pivotal to fight infection, clear debris, and orchestrate repair of injured tissues. Although Drosophila melanogaster have proven invaluable for studying extravascular recruitment of innate immune cells (hemocytes) to wounds, they have been somewhat neglected as viable models to investigate a key rate-limiting component of inflammation-that of immune cell extravasation across vessel walls-due to their open circulation. We have now identified a period during pupal development when wing hearts pulse hemolymph, including circulating hemocytes, through developing wing veins. Wounding near these vessels triggers local immune cell extravasation, enabling live imaging and correlative light-electron microscopy of these events in vivo. We show that RNAi knockdown of immune cell integrin blocks diapedesis, just as in vertebrates, and we uncover a novel role for Rho-like signaling through the GPCR Tre1, a gene previously implicated in the trans-epithelial migration of germ cells. We believe this new Drosophila model complements current murine models and provides new mechanistic insight into immune cell extravasation.

Mangifera indica L. Leaf Extract in Combination With Luteolin or Quercetin Enhances VO2peak and Peak Power Output, and Preserves Skeletal Muscle Function During Ischemia-Reperfusion in Humans.

It remains unknown whether polyphenols such as luteolin (Lut), mangiferin and quercetin (Q) have ergogenic effects during repeated all-out prolonged sprints. Here we tested the effect of Mangifera indica L. leaf extract (MLE) rich in mangiferin (Zynamite®) administered with either quercetin (Q) and tiger nut extract (TNE), or with luteolin (Lut) on sprint performance and recovery from ischemia-reperfusion. Thirty young volunteers were randomly assigned to three treatments 48 h before exercise. Treatment A: placebo (500 mg of maltodextrin/day); B: 140 mg of MLE (60% mangiferin) and 50 mg of Lut/day; and C: 140 mg of MLE, 600 mg of Q and 350 mg of TNE/day. After warm-up, subjects performed two 30 s Wingate tests and a 60 s all-out sprint interspaced by 4 min recovery periods. At the end of the 60 s sprint the circulation of both legs was instantaneously occluded for 20 s. Then, the circulation was re-opened and a 15 s sprint performed, followed by 10 s recovery with open circulation, and another 15 s final sprint. MLE supplements enhanced peak (Wpeak) and mean (Wmean) power output by 5.0–7.0% (P < 0.01). After ischemia, MLE+Q+TNE increased Wpeak by 19.4 and 10.2% compared with the placebo (P < 0.001) and MLE+Lut (P < 0.05), respectively. MLE+Q+TNE increased Wmean post-ischemia by 11.2 and 6.7% compared with the placebo (P < 0.001) and MLE+Lut (P = 0.012). Mean VO2 during the sprints was unchanged, suggesting increased efficiency or recruitment of the anaerobic capacity after MLE ingestion. In women, peak VO2 during the repeated sprints was 5.8% greater after the administration of MLE, coinciding with better brain oxygenation. MLE attenuated the metaboreflex hyperpneic response post-ischemia, may have improved O2 extraction by the Vastus Lateralis (MLE+Q+TNE vs. placebo, P = 0.056), and reduced pain during ischemia (P = 0.068). Blood lactate, acid-base balance, and plasma electrolytes responses were not altered by the supplements. In conclusion, a MLE extract rich in mangiferin combined with either quercetin and tiger nut extract or luteolin exerts a remarkable ergogenic effect, increasing muscle power in fatigued subjects and enhancing peak VO2 and brain oxygenation in women during prolonged sprinting. Importantly, the combination of MLE+Q+TNE improves skeletal muscle contractile function during ischemia/reperfusion.

Citogenotoxic response of juvenile cobia Rachycentron canadum (Linnaeus, 1766) reared in two different systems

Abstract Aquaculture production is continuously growing worldwide, and marine fish farming in Brazil is still in its infancy. Intensive farming conditions may cause physiological stress to the cultured organism, which can be evaluated by citogenotoxic biomarkers. The aim of this study was to assess the genotoxic effect of the rearing conditions in red blood cells of juvenile cobia Rachycentron canadum by using comet assay and micronucleus and other nuclear abnormalities assay. Juvenile cobia were reared for 13 weeks in indoor tank with open water circulation and in near shore cage. The comet assay and the nuclear abnormalities assay detected higher DNA damage and higher nuclear abnormalities frequency in erythrocytes of fish reared in the indoor tank. Results showed that two methods are complementary. Additionally, cobia were injected with ß-naphthoflavone (BNF) at concentrations of 2mgkg-1 and 10mgkg-1 in laboratory controlled conditions, and maintained for 7 days in separate tanks to better understand the response mechanisms of this species to a toxic substance. The comet assay did not detect any significant differences between BNF injected and control fish, whereas nuclear abnormalities assay showed significant differences between BNF injected and the control groups. The damages identified by the comet assay are repairable breaks in the DNA strands, whereas nuclear abnormalities may be permanent. Possibly the period of maintenance after injection was enough to clean BNF from the organisms and to repair the breaks in the DNA strands. As cobia seems to respond very well to genotoxic elements, comet assay and nuclear abnormalities assay would be useful tools to monitor farming conditions.

Experimental Study on the Condensation of Steam With Air Out of the Vertical Tube Bundles

In this paper, experimental study was carried out in an open natural circulation loop,to figure out the condensation heat transfer characteristic on the outside of the vertical pipe tube bundle and single- tube. Condensation heat transfer coefficients have been obtained under the wall subcooling ranging from 5 to 22◦C, total pressure ranging from 0.3 to 0.6MPa and air mass fraction ranging from 0.05 to 0.65. The influence of mixed gas pressure, condensate depression of walls, and content of non-condensable gas on the condensation heat transfer performance is analyzed. Under the condition of the same air mass fraction, the condensation heat transfer coefficient increases with the increase of pressure. Also, as the air mass fraction is more than 30%, the effect of pressure will be weakened. The heat transfer features of pipe bundle and single tube is compared and studied, and an empirical correlation of the pipe bundle for the heattransfer coefficient is developed, covered all data points within 10%. According to the research results, heat transfer coefficient for pipe bundle decreases with the increase in non-condensable gas quality and wall subcooling, but increases with the increase in pressure.

A shallow marine clinoform system in limestones (Paleocene/Eocene Jafnayn Formation, Oman): geometry, microfacies, environment and processes

This is the first report of Cenozoic shallow marine limestone clinoforms from Oman in an outcrop of exceptional exposure. The depositional system displays a few hundred well-developed foreset beds/clinobeds, representing a paleoslope of ~ 15° (post-compaction), occurring in a 3–5 m-thick stratigraphic interval. In the outcrop, foreset beds can be followed along for approximately 20 m. The foreset beds are composed of packstones to floatstones. They pass into very short, minimally developed bottomset beds with a base-discordant relation (downlap). Directly below the bottomset beds is a marly limestone bed (wackestone to floatstone). Bedding of the topset beds is largely obliterated by bioturbation, causing nodular bedding in the topset segment and in an overlying red algae-bearing unit, consisting of floatstones to rudstones. The clinobeds represent cross-beds within an overall aggradational sequence. We use the geometry of the clinoform systems as a “platform level”. Although the foreset process had been repeated several hundred times, neither the steepness of the paleoslope nor the length/height of the foreset beds changed, suggesting a very gentle slope as on a shelf and not as on a ramp. Because of local evidence for synsedimentary extensional faulting, we assume that such deformation caused the creation of the initial intraplatform slope. Dasycladacean algae indicate that deposition ensued in the photic zone. Above the red algae unit, alveolinid wackestones to floatstones accumulated. The observed microfacies change from the marly limestone to the alveolinid limestone indicates that the studied clinoform system developed within a shallowing-up succession. In the same direction, water energy and coastal influences increased. The microfacies types are compatible with a lagoon setting on a shelf with open circulation. Erosion of the red algae may have been due to moving and abrading skeletal grains, driven by tidal and rip currents and/or boring organisms. Tidal and rip currents are suggested to have shed the red algae fragments and other carbonate debris onto the depositional slope. In the absence of early marine cements, slope stability is attributed to the moderate paleoslope angle, different grain shapes and possibly to encrustation and binding of sediment by red algae. The presence of Ranikothalia sp. demonstrates that the succession dates from Paleocene to lowermost Eocene. Similarly, the red algae Distychoplax biserialis indicates a Paleocene to Lower Eocene age.