scholarly journals The comparative energetics of the turtles and crocodiles

2021 ◽  
Author(s):  
Nina Marn ◽  
Sebastiaan Kooijman
Keyword(s):  
General Rule ◽  
Life Time ◽  
Reserve Capacity ◽  
Scaling Exponent ◽  
Dynamic Energy Budget ◽  
Large Size ◽  
Embryo Stage ◽  
Parameter Values ◽  
Age At Birth

The Add-my-Pet (AmP) collection of data on energetics and Dynamic Energy Budget (DEB) parameters currently contains 92 species of turtles and 23 species of crocodiles. We discuss patterns of eco-physiological traits of turtles and crocodiles, as functions of parameter values, and compare them with other taxa. Turtles and crocodiles accurately match the general rule that the life-time cumulated neonate mass production equals ultimate weight. The weight at birth for reptiles scales with ultimate weight to the power 0.6. The scaling exponent is between that of amphibians and birds, while that for mammals is close to 1. We explain why this points to limitations imposed by embryonic respiration, the role of water stress and the accumulation of nitrogen waste during the embryo stage. Weight at puberty is proportional to ultimate weight, and is the largest for crocodiles, followed by that of turtles. These facts explain why the precociality coefficient – approximated by the ratio of weight at birth and weight at puberty at abundant food – decreases with ultimate weight. It is the smallest for crocodile,s because of their large size, while that lizards and snakes are much larger than for turtles. The maximum reserve capacity in both turtles and crocodiles clearly decreases with the precociality coefficient. This relationship has not be found that clearly in other taxa, not even in other reptiles. Crocodiles have a relatively large assimilation rate and, as consequence, a large reserve capacity. Sea-turtles have a small weight and age at birth, which we link to reducing risks on the beach.

Zeit und gutes Leben

2020 ◽  
Vol 74 (4) ◽  
pp. 493-513
Author(s):  
Holmer Steinfath
Keyword(s):  
Internal Structure ◽  
Good Life ◽  
External Factor ◽  
Life Time ◽  
The Good Life ◽  
Adequate Understanding ◽  
Gutes Leben

Time is a neglected subject in recent, especially analytically minded reflections on the good life. The article highlights the fundamental role of time and temporality for an adequate understanding of the good life. Time functions both as an external factor with which we have to reckon in our practical deliberations and as an internal structure of living our lives. It is argued that striving for a good life also means striving for being in harmony with the time of one's life. The exploration of this idea allows to link analytical with phenomenological approaches to time and good life.

Central ossifying fibroma of mandible

2020 ◽  
Vol 13 (12) ◽  
pp. e239286
Author(s):  
Kumar Nilesh ◽  
Prashant Punde ◽  
Nitin Shivajirao Patil ◽  
Amol Gautam
Keyword(s):  
Fibrous Tissue ◽  
Three Dimensional ◽  
Facial Asymmetry ◽  
Ossifying Fibroma ◽  
Mandible Reconstruction ◽  
Three Dimensional Printing ◽  
Osseous Lesion ◽  
Large Size ◽  
Dimensional Printing

Ossifying fibroma (OF) is a rare, benign, fibro-osseous lesion of the jawbone characterised by replacement of the normal bone with fibrous tissue. The fibrous tissue shows varying amount of calcified structures resembling bone and/or cementum. The central variant of OF is rare, and shows predilection for mandible among the jawbone. Although it is classified as fibro-osseous lesion, it clinically behaves as a benign tumour and can grow to large size, causing bony swelling and facial asymmetry. This paper reports a case of large central OF of mandible in a 40-year-old male patient. The lesion was treated by segmental resection of mandible. Reconstruction of the surgical defect was done using avascular fibula bone graft. Role of three-dimensional printing of jaw and its benefits in surgical planning and reconstruction are also highlighted.

scholarly journals Intracellular pH modulates the availability of vascular L-type Ca2+ channels.

1994 ◽  
Vol 103 (4) ◽  
pp. 647-663 ◽  
Author(s):  
U Klöckner ◽  
G Isenberg
Keyword(s):  
Intracellular Ph ◽  
Single Channel ◽  
Surface Membrane ◽  
Life Time ◽  
Bicarbonate Buffer ◽  
State Changes ◽  
Channel Currents ◽  
Inside Out ◽  
Ca2 Channels

L-type Ca2+ channel currents were recorded from myocytes isolated from bovine pial and porcine coronary arteries to study the influence of changes in intracellular pH (pHi). Whole cell ICa fell when pHi was made more acidic by substituting HEPES/NaOH with CO2/bicarbonate buffer (pHo 7.4, 36 degrees C), and increased when pHi was made more alkaline by addition of 20 mM NH4Cl. Peak ICa was less pHi sensitive than late ICa (170 ms after depolarization to 0 mV). pHi-effects on single Ca2+ channel currents were studied with 110 mM BaCl2 as the charge carrier (22 degrees C, pHo 7.4). In cell-attached patches pHi was changed by extracellular NH4Cl or through the opened cell. In inside-out patches pHi was controlled through the bath. Independent of the method used the following results were obtained: (a) Single channel conductance (24 pS) and life time of the open state were not influenced by pHi (between pHi 6 and 8.4). (b) Alkaline pHi increased and acidic pHi reduced the channel availability (frequency of nonblank sweeps). (c) Alkaline pHi increased and acidic pHi reduced the frequency of late channel re-openings. The effects are discussed in terms of a deprotonation (protonation) of cytosolic binding sites that favor (prevent) the shift of the channels from a sleepy to an available state. Changes of bath pHo mimicked the pHi effects within 20 s, suggesting that protons can rapidly permeate through the surface membrane of vascular smooth muscle cells. The role of pHi in Ca2+ homeostases and vasotonus is discussed.

Second language acquisition: Theoretical and experimental issues in contemporary research

1996 ◽  
Vol 19 (4) ◽  
pp. 677-714 ◽  
Author(s):  
Samuel David Epstein ◽  
Suzanne Flynn ◽  
Gita Martohardjono
Keyword(s):  
Second Language ◽  
Second Language Acquisition ◽  
Universal Grammar ◽  
Functional Categories ◽  
L2 Acquisition ◽  
Psycholinguistic Research ◽  
Explanatory Theory ◽  
Parameter Values ◽  
Theoretical Issues

AbstractTo what extent, if any, does Universal Grammar (UG) constrain second language (L2) acquisition? This is not only an empirical question, but one which is currently investigable. In this context, L2 acquisition is emerging as an important new domain of psycholinguistic research. Three logical possibilities have been articulated regarding the role of UG in L2 acquisition: The first is the “no access” hypothesis that claims that no aspect of UG is available to the L2 learner. The second is the “partial access” hypothesis that claims that only LI instantiated principles and LI instantiated parameter-values of UG are available to the learner. The third, called the “full access” hypothesis, asserts that UG in its entirety constrains L2 acquisition.In this paper we argue that there is no compelling evidence to support either of the first two hypotheses. Moreover, we provide evidence concerning functional categories in L2 acquisition consistent with the claim that UG is fully available to the L2 learner (see also Flynn 1987; Li 1993; Martohardjono 1992; Schwartz & Sprouse 1991; Thomas 1991; White 1989). In addition, we will attempt to clarify some of currently unclear theoretical issues that arise with respect to positing UG as an explanatory theory of L2 acquisition. We will also investigate in some detail certain crucial methodological questions involved in experimentally testing the role of UG in L2 acquisition and finally, we will present a set of experimental results of our own supporting the “Full Access” hypothesis.

An Overview of the Latest Applications of Platelet-Derived Microparticles and Nanoparticles in Medical Technology 2010-2020

2021 ◽  
Vol 21 ◽  
Author(s):  
Tahereh Zadeh Mehrizi
Keyword(s):  
Drug Delivery ◽  
Cell Types ◽  
Current Status ◽  
Target Cells ◽  
Interesting Point ◽  
Large Size ◽  
Review Study ◽  
Cellular Pathways ◽  
Different Cell Types

: Today, Platelets and platelet-derived nanoparticles and microparticles have found many applications in nanomedical technology. The results of our review study show that no article has been published in this field to review the current status of applications of these platelet derivatives so far. Therefore, in present study, our goal is to compare the applications of platelet derivatives and review their latest status between 2010 and 2020 to present the latest findings to researchers. A very interesting point about the role of platelet derivatives is the presence of molecules on their surface which makes them capable of hiding from the immune system, reaching different target cells, and specifically attaching to different cell types. According to the results of this study, most of their applications include drug delivery, diagnosis of various diseases, and tissue engineering. However, their application in drug delivery is limited due to heterogeneity, large size, and the possibility of interference with cellular pathways in microparticles derived from other cells. On the other hand, platelet nanoparticles are more controllable and have been widely used for drug delivery in treatment of cancer, atherosclerosis, thrombosis, infectious diseases, repair of damaged tissue, and photothermal therapy. The results of this study show that platelet nanoparticles are more controllable than platelet microparticles and have a higher potential for use in medicine.

scholarly journals Insights on the mechanisms of Ca2+ regulation of connexin26 hemichannels revealed by human pathogenic mutations (D50N/Y)

2013 ◽  
Vol 142 (1) ◽  
pp. 23-35 ◽  
Author(s):  
William Lopez ◽  
Jorge Gonzalez ◽  
Yu Liu ◽  
Andrew L. Harris ◽  
Jorge E. Contreras
Keyword(s):  
Essential Role ◽  
Negative Charge ◽  
Salt Bridge ◽  
Cysteine Residue ◽  
Wild Type ◽  
Closed State ◽  
Large Size ◽  
Deactivation Kinetics ◽  
Connexin Hemichannel

Because of the large size and modest selectivity of the connexin hemichannel aqueous pore, hemichannel opening must be highly regulated to maintain cell viability. At normal resting potentials, this regulation is achieved predominantly by the physiological extracellular Ca2+ concentration, which drastically reduces hemichannel activity. Here, we characterize the Ca2+ regulation of channels formed by wild-type human connexin26 (hCx26) and its human mutations, D50N/Y, that cause aberrant hemichannel opening and result in deafness and skin disorders. We found that in hCx26 wild-type channels, deactivation kinetics are accelerated as a function of Ca2+ concentration, indicating that Ca2+ facilitates transition to, and stabilizes, the closed state of the hemichannels. The D50N/Y mutant hemichannels show lower apparent affinities for Ca2+-induced closing than wild-type channels and have more rapid deactivation kinetics, which are Ca2+ insensitive. These results suggest that D50 plays a role in (a) stabilizing the open state in the absence of Ca2+, and (b) facilitating closing and stabilization of the closed state in the presence of Ca2+. To explore the role of a negatively charged residue at position 50 in regulation by Ca2+, this position was substituted with a cysteine residue, which was then modified with a negatively charged methanethiosulfonate reagent, sodium (2-sulfanoethyl) methanethiosulfonate (MTSES)−. D50C mutant hemichannels display properties similar to those of D50N/Y mutants. Recovery of the negative charge with chemical modification by MTSES− restores the wild-type Ca2+ regulation of the channels. These results confirm the essential role of a negative charge at position 50 for Ca2+ regulation. Additionally, charge-swapping mutagenesis studies suggest involvement of a salt bridge interaction between D50 and K61 in the adjacent connexin subunit in stabilizing the open state in low extracellular Ca2+. Mutant cycle analysis supports a Ca2+-sensitive interaction between these two residues in the open state of the channel. We propose that disruption of this interaction by extracellular Ca2+ destabilizes the open state and facilitates hemichannel closing. Our data provide a mechanistic understanding of how mutations at position 50 that cause human diseases are linked to dysfunction of hemichannel gating by external Ca2+.

scholarly journals Role of Ashwagandha Taila Matrabasti in the Management of Katigraha

2020 ◽  
Vol 11 (2) ◽  
pp. 310-313
Author(s):  
Snehal Vasant Bhende ◽  
Shweta Parwe
Keyword(s):  
Low Back Pain ◽  
Back Pain ◽  
Psychological Factors ◽  
Life Time ◽  
Low Back ◽  
Test Results ◽  
Relieve Pain ◽  
Paired T Test ◽  
Inpatient Department

Background: Katigraha (lumbago)is the condition which is characterised by Stiffness and Pain. Due to Vitiation of Vata in the Katipradesh. About 80% of the industrial population and 60% of the general population experience low back pain at some point of their life time due to wrong postural habits and psychological factors. Basti chikitsa is mainly useful in disorders related to Vata Doshas. Matrabasti is a type of Sneha Basti which can be given in all seasons without any strict regimen of Diet. It has Brumhana and Vatashamaka in nature. And Madhur Dravya (Ashwagandha Taila) is one such combination to pacify the Vata in Katigraha. Objectives: To evaluate the efficacy of Madhur Dravya (Ashwagandha Taila) Matrabasti in Katigraha for relieving Pain and Stiffness. Settings and design: This was an open-labelled single arm interventional clinical study. Methods: Fifteen diagnosed case of katigraha were registered from the outpatient and inpatient department of Panchakarma and Madhur Dravya (Ashwagandha Taila) Matrabasti administered for 9 days. Statistical Analysis- The data were statistically analysed by using paired t test. Results: Highly significant (P< 0.0001) result was found in all the assessment parameter like Pain, Stiffness Schober’s Test and functional rating Index quaternary. Conclusion: Madhur Dravya (Ashwagandha Taila) Matrabasti is one of the best to relieve Pain and Stiffness in Katigraha.

Abstract 5011: Role of Autonomic Nervous System Dysregulation and Inflammation in the Increased Risk of Depression for Cardiovascular Mortality: The Cardiovascular Health Study

Circulation ◽  
2008 ◽  
Vol 118 (suppl_18) ◽  
Author(s):  
Willem J Kop ◽  
Phyllis K Stein ◽  
Joshua I Barzilay ◽  
Russell P Tracy ◽  
John S Gottdiener
Keyword(s):  
Nervous System ◽  
Autonomic Nervous System ◽  
Cardiovascular Mortality ◽  
Inflammatory Markers ◽  
Cardiovascular Health ◽  
Health Study ◽  
Cardiovascular Health Study ◽  
Scaling Exponent ◽  
Autonomic Nervous

The increased cardiovascular (CV) risk associated with depression is hypothesized to be explained by autonomic nervous system (ANS) dysregulation and inflammatory processes. This study determines the role of ANS dysregulation and inflammation in the predictive value of depression for CV mortality. 908 participants of the Cardiovascular Health Study (age 71±5 yrs) free of CV disease were evaluated for depression (CES-D scale), ANS dysregulation by abnormal non-linear heart rate variability (decreased short-term fractal scaling exponent), and inflammation (IL-6, CRP, fibrinogen and WBC). Predictors of CV mortality were examined using Cox regression analysis, adjusting for age, sex, race, systolic blood pressure, diabetes, subclinical disease, use of beta-blockers, smoking status, BMI, and physical activity (median follow-up=13.3 yrs). Risks were calculated for subgroups based on the presence or absence of depression, and ANS or inflammatory CV risk factors (Figure ). Depression was predictive of CV mortality (RR=1.88, CI=1.23–2.86), ANS dysregulation (p=0.014) and inflammatory markers (IL-6 p=0.072; WBC p=0.033; and fibrinogen p=0.050) were correlated with depression. The association of depression with CV mortality occurred primarily in the presence of ANS dysregulation and/or inflammation (Figure ). Addition of ANS and inflammatory markers to the multivariate model did not substantially reduce the CV mortality risk of depression (adjusted RR=1.65, CI=1.03–2.65). Depression is predictive of cardiovascular mortality, and the elevated risk is additive to autonomic nervous system dysregulation and inflammation

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