scholarly journals Biological basis for taphonomic patterns in the trilobite fossil record

1992 ◽  
Vol 6 ◽  
pp. 34-34
Author(s):  
Danita Brandt
Keyword(s):  
Fossil Record ◽  
Shape Function ◽  
Differential Susceptibility ◽  
Late Ordovician ◽  
Biological Factors ◽  
Ventral Plate ◽  
Similar Shape ◽  
The Impact ◽  
Biological Component ◽  
Successful Predation

Appreciating the biological component of taphonomic patterns is necessary for accurately interpreting the mode of formation of fossiliferous assemblages. This study documents taphonomic patterns in three Late Ordovician trilobite genera (Flexicalymene, Isotelus, Ceraurus) and identifies four biological factors that affect incorporation of trilobite exoskeletal elements into the fossil record:1) Exoskeletal architecture. Recurring patterns of displaced tergites and points of disartiuclation indicate differential susceptibility of the exoskeleton during ecdysis, and presumably also during decay of a carcass. Disolcations are most common at articulation points, e.g., between cephalon and thorax, among thoracic segments, and between the thorax and pygidium. There is no evidence that facial sutures were lines of weakness except during ecdysis.2) Exoskeletal thickness. Thickness is a better predictor of preservation potential than the position, shape, function, or size of a tergite. For example, Ceraurus and Flexicalymene have hypostomata of similar shape and size, but the thicker Ceraurus hypostoma is more frequently preserved (or at least identified) than the thin ventral plate of Flexicalymene.3) Ecdysis. Molting potentially releases the greatest number of trilobite tergites to the fossil record. Molt ensembles are recognized by recurring assemblages of tergites (e.g., thoracopygidia, cephalothorax, multiple thoracic segments) although individual elements (e.g., hypostomata and librigenae) are shed as well. Distinguishing individual molt elements from tergites disarticulated via scavenging or post-mortem transport of carcass or exuvia is problematic. Ecdysis often releases intact exoskeletal elements: most breakage probably occurs later. during post-ecdysial transport or scavenging of the exuvia.4) Predation/scavenging. These effects are characterized by broken (vs. disarticulated) exoskeletal elements. The impact of these processes on the trilobite fossil record is difficult to assess: sublethal wounds are easiest to recognize, the product of successful predation/scavenging is most often unidentifiable comminuted trilobite debris. The products of successful predation/scavenging are identified as such indirectly by their association with the remains of possible predators or by their presence in coprolites.

IDENTIFICATION AND ASSESSMENT OF RISK FACTORS ROLE IN MYOCARDIAL INFARCTION DEVELOPMENT

2019 ◽  
Vol 72 (5) ◽  
pp. 779-783
Author(s):  
Victor A. Ognev ◽  
Anna A. Podpriadova ◽  
Anna V. Lisova
Keyword(s):  
Risk Factors ◽  
Myocardial Infarction ◽  
Cardiovascular Disease ◽  
Cardiovascular System ◽  
Control Group ◽  
Biological Factors ◽  
Prevention And Treatment ◽  
High Level ◽  
Social Importance ◽  
The Impact

Introduction:The high level of morbidity and mortality from cardiovascular disease is largely due toinsufficient influence on the main risk factors that contribute to the development of myocardial infarction.Therefore, a detailed study and assessment of risk factors is among the most important problems of medical and social importance. The aim: To study and evaluate the impact of biological, social and hygienic, social and economic, psychological, natural and climatic risk factors on the development of myocardial infarction. Materials and methods: A sociological survey was conducted in 500 people aged 34 to 85. They were divided into two groups. The main group consisted of 310 patients with myocardial infarction. The control group consisted of 190 practically healthy people, identical by age, gender and other parameters, without diseases of the cardiovascular system. Results: It was defined that 30 factors have a significant impact on the development of myocardial infarction.Data analysis revealed that the leading risk factors for myocardial infarction were biological and socio-hygienic. The main biological factors were: hypertension and hypercholesterolemia. The man socio-hygienic factor was smoking. Conclusions: Identification of risk factors provides new opportunities for the development of more effective approaches for the prevention and treatment of myocardial infarction.

Hybrid crinoids in the fossil record (Early Mississippian, Phylum Echinodermata)

Paleobiology ◽  
1994 ◽  
Vol 20 (3) ◽  
pp. 362-367 ◽  
Author(s):  
William I. Ausich ◽  
David L. Meyer
Keyword(s):  
Fossil Record ◽  
Evolutionary Process ◽  
Parent Species ◽  
Probable Explanation ◽  
South Central ◽  
Most Probable Explanation ◽  
The Impact

Potential hybrid fossil crinoids, Eretmocrinus magnificus x Eretmocrinus praegravis, are identified from the Lower Mississippian Fort Payne Formation of south-central Kentucky. These are the first fossil hybrid crinoids identified, and one of very few examples of hybrids recognized in the fossil record. Eretmocrinus magnificus x E. praegravis specimens have shapes and calyx plate sculpturing that are morphologically intermediate between well-defined, distinct parent species. Suspected hybrids occur at localities where parent species co-occur and where the parent species are the most abundant; the hybrids occur at what may have been the distributional margins of the parent species; and the mixture of characters on suspected hybrids seems to be morphogenetically partitioned. Parent species are derived from separate lineages within Eretmocrinus, and hybridization is the most probable explanation for these morphologically intermediate specimens. This example highlights the need to consider hybridization as a potential interpretation of intermediate morphologies among fossils and raises questions concerning the impact of hybridization for our interpretation of the fossil record and the role of hybridization in the evolutionary process.

scholarly journals A meta-analysis reveals the environmental and host factors shaping the structure and function of the shrimp microbiota

PeerJ ◽  
2018 ◽  
Vol 6 ◽  
pp. e5382 ◽  
Author(s):  
Fernanda Cornejo-Granados ◽  
Luigui Gallardo-Becerra ◽  
Miriam Leonardo-Reza ◽  
Juan Pablo Ochoa-Romo ◽  
Adrian Ochoa-Leyva
Keyword(s):  
Developmental Stage ◽  
High Throughput Sequencing ◽  
Meta Analysis ◽  
Biological Factor ◽  
Rrna Gene ◽  
Wild Type ◽  
Biological Factors ◽  
Sequencing Data ◽  
Freshwater Environment ◽  
The Impact

The shrimp or prawn is the most valuable traded marine product in the world market today and its microbiota plays an essential role in its development, physiology, and health. The technological advances and dropping costs of high-throughput sequencing have increased the number of studies characterizing the shrimp microbiota. However, the application of different experimental and bioinformatics protocols makes it difficult to compare different studies to reach general conclusions about shrimp microbiota. To meet this necessity, we report the first meta-analysis of the microbiota from freshwater and marine shrimps using all publically available sequences of the 16S ribosomal gene (16S rRNA gene). We obtained data for 199 samples, in which 63.3% were from marine (Alvinocaris longirostris, Litopenaeus vannamei and Penaeus monodon), and 36.7% were from freshwater (Macrobrachium asperulum, Macrobrachium nipponense, Macrobranchium rosenbergii, Neocaridina denticulata) shrimps. Technical variations among studies, such as selected primers, hypervariable region, and sequencing platform showed a significant impact on the microbiota structure. Additionally, the ANOSIM and PERMANOVA analyses revealed that the most important biological factor in structuring the shrimp microbiota was the marine and freshwater environment (ANOSIM R = 0.54, P = 0.001; PERMANOVA pseudo-F = 21.8, P = 0.001), where freshwater showed higher bacterial diversity than marine shrimps. Then, for marine shrimps, the most relevant biological factors impacting the microbiota composition were lifestyle (ANOSIM R = 0.341, P = 0.001; PERMANOVA pseudo-F = 8.50, P = 0.0001), organ (ANOSIM R = 0.279, P = 0.001; PERMANOVA pseudo-F = 6.68, P = 0.001) and developmental stage (ANOSIM R = 0.240, P = 0.001; PERMANOVA pseudo-F = 5.05, P = 0.001). According to the lifestyle, organ, developmental stage, diet, and health status, the highest diversity were for wild-type, intestine, adult, wild-type diet, and healthy samples, respectively. Additionally, we used PICRUSt to predict the potential functions of the microbiota, and we found that the organ had more differentially enriched functions (93), followed by developmental stage (12) and lifestyle (9). Our analysis demonstrated that despite the impact of technical and bioinformatics factors, the biological factors were also statistically significant in shaping the microbiota. These results show that cross-study comparisons are a valuable resource for the improvement of the shrimp microbiota and microbiome fields. Thus, it is important that future studies make public their sequencing data, allowing other researchers to reach more powerful conclusions about the microbiota in this non-model organism. To our knowledge, this is the first meta-analysis that aims to define the shrimp microbiota.

scholarly journals Obstáculos en la comunicación entre el cerebro y el intestino

2018 ◽  
Vol 27 (1) ◽  
pp. 91-114
Author(s):  
Sanda Pletikosić Tončić ◽  
Mladenka Tkalčić
Keyword(s):  
Protective Factor ◽  
Short Form ◽  
Negative Mood ◽  
Positive Mood ◽  
Serum Cortisol ◽  
Fecal Calprotectin ◽  
Biological Factors ◽  
Irritable Bowel ◽  
The Impact

Irritable bowel syndrome (IBS) is a complex disorder that results from interactions of numerous factors. The biopsychosocial model describes a number of predisposing, precipitating, and perpetuating factors, which contribute to the onset and maintenance of symptoms and consequently to quality of life (QoL) impairment. The aim of this study was to examine the impact of several psychological and biological factors on the physical and mental components of QoL in IBS patients. A total of 46 IBS patients completed a set of questionnaires (Big Five Inventory, State-Trait Anxiety Inventory, Beck Depression Inventory-II, Medical Outcome Study Short-Form 36) and kept a diary of their mood, daily stress, and symptoms over a period of two weeks. Patients' heart rate variability, serum cortisol, and fecal calprotectin levels were also measured. The results of regression analyses showed that depression (β = -.30) and negative mood (β = -.28) predicted physical QoL, while depression (β = -.45) and positive mood (β = .33) significantly predicted mental QoL. The model, which included calprotectin, cortisol, anxiety, depression, and positive and negative mood, explained a total of 47% of variance of physical and 57% of variance of mental QoL. Our results confirm the role of negative affect in IBS QoL impairment. They also indicate that biological factors seem important for physical QoL in IBS patients. The role of positive mood as a protective factor for mental QoL might be significant for psychological interventions with IBS patients.

scholarly journals СЕЗОННА МІНЛИВІСТЬ БІОГЕННИХ РЕЧОВИН У РІЧЦІ ВОРСКЛА

2014 ◽  
pp. 115-120 ◽  
Author(s):  
Н. І. Авраменко
Keyword(s):  
Seasonal Variability ◽  
Direct Relationship ◽  
Nutrient Content ◽  
Water Runoff ◽  
Biological Processes ◽  
Biological Factors ◽  
Cyclical Fluctuations ◽  
Vital Functions ◽  
Main Factors ◽  
The Impact

Розглядаються основні чинники, що найбільшевпливають на сезонну мінливість біогенних речовин урічці Ворскла. Встановлено, що важливу роль віді-грають природні циклічні коливання водного стоку ійого зарегулювання. Зазначено пряму залежністьміж життєдіяльністю гідробіонтів та сезоннимвмістом біогенних речовин у водоймах. Наведено ре-зультати досліджень із вивчення впливу гідробіологі-чних (фотосинтетичних) процесів та біологічногофактора на коливання значень вмісту біогенних ре-човин. Підкреслюється, що рівень вмісту біогеннихречовин лімітує розвиток біологічних процесів у воді.Визначено, що мінливість біогенних елементів у річ-ковій воді має чітко виражений сезонний характер.Встановлено залежність між величиною водногостоку й розвитком гідробіологічних процесів. Охарак-теризовано евтрофікаційні процеси річки Ворскла, зякої проводився збір агроекологічної інформації. Specified is the main factors that have the greatest impact on the seasonal variability of nutrients in the river Vorskla. Found that an important role is played by the natural cyclical fluctuations in water flow and its regulation of . Specified is a direct relationship between the vital functions of aquatic and seasonal content of nutrients in water bodies . The results of research on the impact of hydrobiological ( photosynthetic ) processes and biological factors on fluctuations in the values ​​of nutrient content . Emphasized that the levels of nutrients limiting the development of biological processes in the water. Determined that the variability of nutrients in river water has a distinctly seasonal. The dependence on the magnitude of water runoff and the development of hydrobiological processes.

scholarly journals Influence of Biological Factors on the Strength of Static Rope Used by Firefighters in Rescue Operations

2021 ◽  
Vol 79 ◽  
pp. 7-30
Author(s):  
Michał Cecelski ◽  
Robert Piec ◽  
Barbara Szykuła-Piec
Keyword(s):  
Biological Agents ◽  
The State ◽  
Biological Factors ◽  
Research Focus ◽  
Second Stage ◽  
Lack Of Information ◽  
Chemical Factors ◽  
Physical And Chemical ◽  
Document Review ◽  
The Impact

After conducting a document review, the authors found no reports concerning the influence of biological factors, such as blood, mould, and dirt, on the durability of rescue ropes. This study aims to answer the question of whether and how selected biological factors affect static rope 10.5, which is frequently used by firefighters for rescues. In the first stage of the research, focus studies were conducted among fifteen members of the Specialist High-Rescue Group in Plock (Poland), which aimed to determine the state of knowledge about the impact of biological factors on the strength of rope. The results indicated that the group had knowledge as to the impact of physical and chemical factors on the rope; however, a lack of information on the impact of biological factors was identified. In the second stage, the force necessary to break static rope contaminated with selected biological agents was measured. To achieve this, a 100-m section of a new rope was divided into 63 sections, which were then exposed to impurities. The first endurance measurement was taken after 9 months and the second after 12 months. Findings: contamination with biological agents has an impact on static rope strength, and knowledge about this impact is negligible and not included in any rope-use instructions.

Reefs as the Centralizing Theme in an Undergraduate Invertebrate Paleontology Course

2012 ◽  
Vol 12 ◽  
pp. 21-42
Author(s):  
Constance M. Soja
Keyword(s):  
Fossil Record ◽  
Evolutionary History ◽  
Marine Invertebrate ◽  
Scientific Information ◽  
Field Trip ◽  
Mass Extinctions ◽  
Paleontological Data ◽  
San Salvador ◽  
Invertebrate Paleontology ◽  
The Impact

This course is designed so that topics in invertebrate paleontology are discussed in the context of reefs and their change through time. The goal is to help undergraduate students connect modern conservation issues with an enlightened appreciation of the fossil record. Using reefs as the centralizing theme of the course allows key concepts (invertebrate taxonomy and systematics, form and function, evolution, etc.) to be emphasized while exploring the importance of biogenic buildups—and communities that inhabited ecosystems adjacent to those “engines of evolution”—from the past to the present. Students who satisfactorily complete the course achieve seven main learning objectives: They 1) are intimately familiar with the fossil record of marine invertebrate life; 2) understand the evolutionary history of reefs and the ecological roles played by key reef-building invertebrates through time; 3) are able to engage in discussions about paleontological data published in the primary literature; 4) are knowledgeable about the value of paleontological evidence for shedding insights into the decline of ancient and living reefs; 5) gain experience working collaboratively and thinking outside-of-the-box to explore solutions to societal problems linked with the degradation of modern coral reefs; 6) improve scientific writing; and 7) develop a personal style for communicating scientific information to the general public. During classroom discussions, laboratories, a field trip, and museum visit, students explore the anatomy, ecology, evolutionary history, and life-sustaining ecosystem services of shelly animals and associated marine organisms that coexisted in reefs and adjacent habitats past and present. Evolutionary events, including the Cambrian “explosion,” mass extinctions, and gaps in reef existence, are linked to dramatic physical (tectonic) and climatic changes that occurred in Earth's past. Emphasizing evidence for the impact of global change on ancient reef communities alerts students to the value of paleontological data for predicting how modern reefs—and invertebrates living in interconnected marine ecosystems—will respond as the Sixth Extinction gains traction. That topic is the focus of an optional extended study (nine-day field trip offered in alternate years during spring break) of modern and Pleistocene reefs on San Salvador Island, Bahamas.

An enigmatic blastozoan echinoderm fauna from central kentucky

2009 ◽  
Vol 83 (5) ◽  
pp. 739-749 ◽  
Author(s):  
Colin D. Sumrall ◽  
Carlton E. Brett ◽  
Troy A. Dexter ◽  
Alexander Bartholomew
Keyword(s):  
North America ◽  
Northwest Territories ◽  
Middle Devonian ◽  
Fossil Record ◽  
Foreland Basin ◽  
Late Ordovician ◽  
Upper Devonian ◽  
Range Extension ◽  
First Report ◽  
Appalachian Foreland

A series of small road cuts of lower Boyle Formation (Middle Devonian: Givetian) near Waco, Kentucky, has produced numerous specimens of three blastozoan clades, including both “anachronistic” diploporan and rhombiferan “cystoids” and relatively advanced Granatocrinid blastoids. This unusual assemblage occurs within a basal grainstone unit of the Boyle Limestone, apparently recording a local shoal deposit. Diploporans, the most abundant articulated echinoderms, are represented by a new protocrinitid species, Tristomiocystis globosus n. gen. and sp. Glyptocystitoid rhombiferans are represented by isolated thecal plates assignable to Callocystitidae. Three species of blastoids, all previously undescribed, include numerous thecae of the schizoblastid Hydroblastus hendyi n. gen. and sp., the rare nucleocrinid Nucleocrinus bosei n. sp., and an enigmatic troosticrinid radial. The blastoid Nucleocrinus is typical for the age; however, the callocystitid, schizoblastid, and protocrinitid are not. Hydroblastus is the oldest known schizoblastid. Middle and Upper Devonian callocystitids have been previously reported only from Iowa and Michigan USA with unpublished reports from Missouri USA and the Northwest Territories, Canada. This occurrence is thus the first report of a Middle Devonian rhombiferan from the Appalachian foreland basin. Tristomiocystis is the first known protocrinitid in North America and the only protocrinitid younger than Late Ordovician. This occurrence thus represents a range extension of nearly 50 million years for protocrinids. This extraordinary sample of echinoderms in a Middle Devonian limestone from a well-studied area of North America highlights the incompleteness of the known fossil record, at least in fragile organisms such as echinoderms.

scholarly journals The importance of sampling standardization for comparisons of insect herbivory in deep time: a case study from the late Palaeozoic

2018 ◽  
Vol 5 (3) ◽  
pp. 171991 ◽  
Author(s):  
Sandra R. Schachat ◽  
Conrad C. Labandeira ◽  
S. Augusta Maccracken
Keyword(s):  
Surface Area ◽  
Fossil Record ◽  
Insect Herbivory ◽  
Ecological Factors ◽  
Published Data ◽  
Deep Time ◽  
Leaf Surface Area ◽  
Number Of Leaves ◽  
The Impact

Sampling standardization has not been fully addressed for the study of insect herbivory in the fossil record. The effects of sampling within a single locality were explored almost a decade ago, but the importance of sampling standardization for comparisons of herbivory across space and time has not yet been evaluated. Here, we present a case study from the Permian in which we evaluate the impact of sampling standardization on comparisons of insect herbivory from two localities that are similar in age and floral composition. Comparisons of insect damage type (DT) diversity change dramatically when the number of leaves examined is standardized by surface area. This finding suggests that surface area should always be taken into account for comparisons of DT diversity. In addition, the three most common metrics of herbivory—DT diversity, proportion of leaves herbivorized and proportion of leaf surface area herbivorized—are inherently decoupled from each other. The decoupling of the diversity and intensity of insect herbivory necessitates a reinterpretation of published data because they had been conflated in previous studies. Future studies should examine the divergent ecological factors that underlie these metrics. We conclude with suggestions to guide the sampling and analysis of herbivorized leaves in the fossil record.

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