Differences in the growth, form and life history of Plumularia setacea (Ellis and Solander) (Hydrozoa : Plumulariidae) in two contrasting habitats

1986 ◽  
Vol 228 (1251) ◽  
pp. 113-125 ◽  

P. setacea that grow on the hydroid Nemertesia antennina at a depth of 15m in Torbay, Devon, are mature when about two months old ; early sexual reproduction ensures continued colonization of N. antennina , which lives for only 4-5 months. Growth and reproduction of P. setacea occur throughout the year. The growth of the generally unbranched stolon is oriented toward the tip of the N. antennina hydrocaulus, which always bends downcurrent. The pinnate hydrocauli of P. setacea are held across the current in the most efficient position for feeding. The oldest tissue of P. setacea is continually resorbed towards the younger parts of the hydroid, leaving an empty perisarc, which eventually degenerates. This behaviour, together with the oriented growth of the stolon, means that the hydroids ‘move’ distally along the N. antennina hydrocauli. On concrete substrata at ELWS at Felixstowe, Suffolk, P. setacea reproduces only from June to August. The young hydroids may briefly achieve an exponential growth rate, but this probably occurs infrequently because of mortality and interference by predators and competitors. The initial growth of the stolon is unbranched ; subsequent branched growth produces a complex network of stolons, which covers the available substrata. The oldest tissue of these hydroids is also continually resorbed. In addition, in autumn the coenosarc of all hydrocauli is resorbed into the stolon and P. setacea overwinters as a dormant stolon. Rapid regrowth of large mature hydrocauli occurs in May and June from small sections of the stolon that are not destroyed during dormancy. These hydroids die after reproducing and therefore have a life-span of about one year. The modular construction of P. setacea , contrary to previous assumptions on hydroid biology, does not confer the potential for an infinite growth and life-span, but endows the potential for variable growth and form that enables P. setacea to survive, as opportunists, in these different habitats.

1967 ◽  
Vol 45 (4) ◽  
pp. 397-405 ◽  
Author(s):  
S. Tyrell Smith

The habitat, diet, life history, and reproductive cycle of Retusa obtusa were investigated over a period of [Formula: see text] years in a population found in the Inner Harbour at Barry, Glamorgan, U.K. A technique was devised for extracting Retusa from the mud of this area. R. obtusa occurs in the topmost 3.5 cm of fine mud covering Barry harbor, which is immersed by the sea for only a short time at each high tide. The principal prey was found to be Hydrobia ulvae.The life cycle was found to be annual, the adults dying in spring, following the natural breeding season. Occasionally, a short extra breeding period occurs in the fall. The life span in no case greatly exceeded one year. Retusa is a protandrous hermaphrodite, and copulates in the fall. The eggs mature through the late fall and the winter, a few at a time, until oviposition occurs in the spring. The average number of eggs produced per individual was 33, deposited in 1–4 egg batches. Development is direct.


2020 ◽  
Vol 29 (3) ◽  
pp. 1389-1403
Author(s):  
Jessica Brown ◽  
Kelly Knollman-Porter

Purpose Although guidelines have changed regarding federally mandated concussion practices since their inception, little is known regarding the implementation of such guidelines and the resultant continuum of care for youth athletes participating in recreational or organized sports who incur concussions. Furthermore, data regarding the role of speech-language pathologists in the historic postconcussion care are lacking. Therefore, the purpose of this retrospective study was to investigate the experiences of young adults with history of sports-related concussion as it related to injury reporting and received follow-up care. Method Participants included 13 young adults with history of at least one sports-related concussion across their life span. We implemented a mixed-methods design to collect both quantitative and qualitative information through structured interviews. Participants reported experiencing 42 concussions across the life span—26 subsequent to sports injuries. Results Twenty-three concussions were reported to a parent or medical professional, 14 resulted in a formal diagnosis, and participants received initial medical care for only 10 of the incidents and treatment or services on only two occasions. Participants reported concussions to an athletic trainer least frequently and to parents most frequently. Participants commented that previous experience with concussion reduced the need for seeking treatment or that they were unaware treatments or supports existed postconcussion. Only one concussion incident resulted in the care from a speech-language pathologist. Conclusion The results of the study reported herein shed light on the fidelity of sports-related concussion care management across time. Subsequently, we suggest guidelines related to continuum of care from injury to individualized therapy.


VASA ◽  
2010 ◽  
Vol 39 (2) ◽  
pp. 169-174 ◽  
Author(s):  
Reich-Schupke ◽  
Weyer ◽  
Altmeyer ◽  
Stücker

Background: Although foam sclerotherapy of varicose tributaries is common in daily practice, scientific evidence for the optimal sclerosant-concentration and session-frequency is still low. This study aimed to increase the knowledge on foam sclerotherapy of varicose tributaries and to evaluate the efficacy and safety of foam sclerotherapy with 0.5 % polidocanol in tributaries with 3-6 mm in diameter. Patients and methods: Analysis of 110 legs in 76 patients. Injections were given every second or third day. A maximum of 1 injection / leg and a volume of 2ml / injection were administered per session. Controls were performed approximately 6 months and 12 months after the start of therapy. Results: 110 legs (CEAP C2-C4) were followed up for a period of 14.2 ± 4.2 months. Reflux was eliminated after 3.4 ± 2.7 injections per leg. Insufficient tributaries were detected in 23.2 % after 6.2 ± 0.9 months and in 48.2 % after 14.2 ± 4.2 months, respectively. Only 30.9 % (34 / 110) of the legs required additional therapy. In 6.4 % vein surgery was performed, in 24.5 % similar sclerotherapy was repeated. Significantly fewer sclerotherapy-sessions were required compared to the initial treatment (mean: 2.3 ± 1.4, p = 0.0054). During the whole study period thrombophlebitis (8.2 %), hyperpigmentation (14.5 %), induration in the treated region (9.1 %), pain in the treated leg (7.3 %) and migraine (0.9 %) occurred. One patient with a history of thrombosis developed thrombosis of a muscle vein (0.9 %). After one year there were just hyperpigmentation (8.2 %) and induration (1.8 %) left. No severe adverse effect occurred. Conclusions: Foam sclerotherapy with injections of 0.5 % polidocanol every 2nd or 3rd day, is a safe procedure for varicose tributaries. The evaluation of efficacy is difficult, as it can hardly be said whether the detected tributaries in the controls are recurrent veins or have recently developed in the follow-up period. The low number of retreated legs indicates a high efficacy and satisfaction of the patients.


Author(s):  
Jed Z. Buchwald ◽  
Mordechai Feingold

Isaac Newton’s Chronology of Ancient Kingdoms Amended, published in 1728, one year after the great man’s death, unleashed a storm of controversy. And for good reason. The book presents a drastically revised timeline for ancient civilizations, contracting Greek history by five hundred years and Egypt’s by a millennium. This book tells the story of how one of the most celebrated figures in the history of mathematics, optics, and mechanics came to apply his unique ways of thinking to problems of history, theology, and mythology, and of how his radical ideas produced an uproar that reverberated in Europe’s learned circles throughout the eighteenth century and beyond. The book reveals the manner in which Newton strove for nearly half a century to rectify universal history by reading ancient texts through the lens of astronomy, and to create a tight theoretical system for interpreting the evolution of civilization on the basis of population dynamics. It was during Newton’s earliest years at Cambridge that he developed the core of his singular method for generating and working with trustworthy knowledge, which he applied to his study of the past with the same rigor he brought to his work in physics and mathematics. Drawing extensively on Newton’s unpublished papers and a host of other primary sources, the book reconciles Isaac Newton the rational scientist with Newton the natural philosopher, alchemist, theologian, and chronologist of ancient history.


2019 ◽  
Vol 16 (3) ◽  
pp. 250-257 ◽  
Author(s):  
Jiann-Der Lee ◽  
Ya-Han Hu ◽  
Meng Lee ◽  
Yen-Chu Huang ◽  
Ya-Wen Kuo ◽  
...  

Background and Purpose: Recurrent ischemic strokes increase the risk of disability and mortality. The role of conventional risk factors in recurrent strokes may change due to increased awareness of prevention strategies. The aim of this study was to explore the potential risk factors besides conventional ones which may help to affect the advances in future preventive concepts associated with one-year stroke recurrence (OSR). Methods: We analyzed 6,632 adult patients with ischemic stroke. Differences in clinical characteristics between patients with and without OSR were analyzed using multivariate logistic regression and classification and regression tree (CART) analyses. Results: Among the study population, 525 patients (7.9%) had OSR. Multivariate logistic regression analysis revealed that male sex (OR 1.243, 95% CI 1.025 – 1.506), age (OR 1.015, 95% CI 1.007 - 1.023), and a prior history of ischemic stroke (OR 1.331, 95% CI 1.096 – 1.615) were major factors associated with OSR. CART analysis further identified age and a prior history of ischemic stroke were important factors for OSR when classified the patients into three subgroups (with risks of OSR of 8.8%, 3.8%, and 12.5% for patients aged > 57.5 years, ≤ 57.5 years/with no prior history of ischemic stroke, and ≤ 57.5 years/with a prior history of ischemic stroke, respectively). Conclusions: Male sex, age, and a prior history of ischemic stroke could increase the risk of OSR by multivariate logistic regression analysis, and CART analysis further demonstrated that patients with a younger age (≤ 57.5 years) and a prior history of ischemic stroke had the highest risk of OSR.


Author(s):  
Shinwan Kany ◽  
Johannes Brachmann ◽  
Thorsten Lewalter ◽  
Ibrahim Akin ◽  
Horst Sievert ◽  
...  

Abstract Background Non-paroxysmal (NPAF) forms of atrial fibrillation (AF) have been reported to be associated with an increased risk for systemic embolism or death. Methods Comparison of procedural details and long-term outcomes in patients (pts) with paroxysmal AF (PAF) against controls with NPAF in the prospective, multicentre observational registry of patients undergoing LAAC (LAARGE). Results A total of 638 pts (PAF 274 pts, NPAF 364 pts) were enrolled. In both groups, a history of PVI was rare (4.0% vs 1.6%, p = 0.066). The total CHA2DS2-VASc score was lower in the PAF group (4.4 ± 1.5 vs 4.6 ± 1.5, p = 0.033), while HAS-BLED score (3.8 ± 1.1 vs 3.9 ± 1.1, p = 0.40) was comparable. The rate of successful implantation was equally high (97.4% vs 97.8%, p = 0.77). In the three-month echo follow-up, LA thrombi (2.1% vs 7.3%, p = 0.12) and peridevice leak > 5 mm (0.0% vs 7.1%, p = 0.53) were numerically higher in the NPAF group. Overall, in-hospital complications occurred in 15.0% of the PAF cohort and 10.7% of the NPAF cohort (p = 0.12). In the one-year follow-up, unadjusted mortality (8.4% vs 14.0%, p = 0.039) and combined outcome of death, stroke and systemic embolism (8.8% vs 15.1%, p = 0.022) were significantly higher in the NPAF cohort. After adjusting for CHA2DS2-VASc and previous bleeding, NPAF was associated with increased death/stroke/systemic embolism (HR 1.67, 95% CI 1.02–2.72, p = 0.041). Conclusion Atrial fibrillation type did not impair periprocedural safety or in-hospital MACE patients undergoing LAAC. However, after one year, NPAF was associated with higher mortality. Graphic abstract


2021 ◽  
Vol 182 ◽  
pp. 106396
Author(s):  
David A. Kaminsky ◽  
Donald G. Grosset ◽  
Deena M. Kegler-Ebo ◽  
Salvador Cangiamilla ◽  
Michael Klingler ◽  
...  

1998 ◽  
Vol 507 ◽  
Author(s):  
J.K. Rath ◽  
F.D. Tichelaar ◽  
H. Meiling ◽  
R.E.I. Schropp

ABSTRACTSolar cell using profiled poly-Si:H by HWCVD as i-layer in the configuration SS/n-µSi:H(PECVD)/i-poly-Si:H(HWCVD)/p-µc-Si:H(PECVD)/ITO showed 3.7% efficiency. A current of 23.6 mA/cm2 was generated in only 1.5 µm thick poly-Si:H i-layer grown at ∼5Å/s. TFTs made with the poly-Si:H films (grown at ≥ 9Å/s) exhibited remarkable stability to long duration of 23 hours of gate bias stress of ∼lMV/cm. A saturation mobility of 1.5 cm2/Vs for the TFT has been achieved. Films made at low hydrogen dilution (Poly2) showed device quality (purely intrinsic nature, ambipolar diffusion length of 568 nm, only (220) oriented growth and low ESR defect density of <1017/cm3with complete absence of signal due to conduction electrons) but with an incubation phase of amorphous initial growth, whereas the films made at high hydrogen dilution (Polyl) had a polycrystalline initial growth, though with higher defect density, incorporated oxygen and randomly oriented grains. Poly2 films are compact and hydrogen bonding is at compact Si-H sites manifested as 2000 cm−1IR vibration and high temperature hydrogen evolution peak. Exchange interaction of spins and spin pairing are observed while increasing defects in such a compact structure. A new approach has been used to integrate these two regimes of growth to make profiled poly-Si:H layers. The new layers show good electronic properties as well as complete elimination of incubation phase.


2015 ◽  
Vol 65 (3-4) ◽  
pp. 311-320 ◽  
Author(s):  
João Fabrício Mota Rodrigues ◽  
José Roberto Feitosa Silva

Studies focusing on the natural history of species are essential for developing effective conservation measures and evaluating ecological hypotheses. To this end, we describe natural history data of the Cotinga River toadhead turtle, Phrynops tuberosus, in the Banabuiú River in Ceará, Brazil, and evaluated sexual dimorphism, epibionts, and mutilation effects. We hand-captured 134 individuals by snorkeling, over a period of one year, resulting in the capture of 94 males, 24 females, and 16 juveniles. Females had larger head width and body mass than males, while males had longer tail length. One quarter of the turtles captured had some sort of injury or deformation, most common injuries being missing claws, mutilations, and shell deformations. We found no difference in body condition index between mutilated and non-mutilated animals. Mollusks, insects, and leeches were found as epibionts on P. tuberosus and most of the captured turtles had extensive algal cover. Future studies should focus on understanding the effect of mutilations on animal fitness and reproductive success.


2015 ◽  
Vol 2015 ◽  
pp. 1-5 ◽  
Author(s):  
Abelardo Loya-Solis ◽  
Karla Judith González-Colunga ◽  
Cynthia M. Pérez-Rodríguez ◽  
Natalie Sofía Ramírez-Ochoa ◽  
Luis Ceceñas-Falcón ◽  
...  

Ameloblastic fibrosarcoma is an uncommon odontogenic tumor composed of a benign epithelial component and a malignant ectomesenchymal component most frequently seen in the third and fourth decades of life. It mainly presents as a painful maxillary or mandibular swelling. Radiographs show a radiolucent mass with ill-defined borders. Radical surgical excision and long-term follow-up are the suggested treatment. We report the case of a 22-year-old female with a 2-month history of an asymptomatic swelling in her left mandible. Examination revealed an exophytic growth measuring3×3 cm extending from the mandibular left first premolar to the second molar. The patient underwent a left hemimandibular resection. Histopathological examination revealed a biphasic tumor composed of inconspicuous islands of benign odontogenic epithelium and an abundant malignant mesenchymal component with marked cellularity, nuclear pleomorphism, hyperchromatism, and moderate mitotic figures with clear margins; one year after the surgical procedure, the patient is clinically and radiologically disease-free.


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