Novel non-cellular adhesion and tissue grafting in the mutable collagenous tissue of the sea cucumber Parastichopus parvimensis

1998 ◽  
Vol 201 (21) ◽  
pp. 3003-3013 ◽  
Author(s):  
G. K. Szulgit ◽  
R. E. Shadwick
Keyword(s):  
Wound Healing ◽  
Sea Cucumber ◽  
Wound Closure ◽  
Cellular Adhesion ◽  
Shear Stresses ◽  
Short Term ◽  
Cellular Processes ◽  
Collagenous Tissue ◽  
External Pressures

Previous work on wound healing in holothurians (sea cucumbers) has been concerned with the relatively long-term cellular processes of wound closure and regeneration of new tissue. In this report, we characterize a short-term adhesion that is a very early step in holothurian wound healing. Dissected pieces of dermis from the sea cucumber Parastichopus parvimensis adhered to each other after only 2 h of contact, whether the cells in the tissues were intact or had been lysed. Lapshear tests showed that the breaking stresses of adhered tissues reached approximately 0.5 kPa after 24 h of contact. Furthermore, dermal allografts were incorporated into the live recipient individuals without any external pressures, sutures or artificial gels to keep them in place. Dislodging the grafts after 24 h of contact required shear stresses of approximately 14 kPa. It appears that the adhesive property of the dermis plays a key role in the initiation of this grafting.

The transition of a socio-technical system to a smart grid: illustrated with the Indian electricity network

2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Lakshminarayana Kompella
Keyword(s):  
Technical System ◽  
Transition Theory ◽  
Short Term ◽  
Indian States ◽  
Content Type ◽  
External Pressures ◽  
Policy Systems ◽  
Transition Trajectory ◽  
Practical Implications

Purpose This paper aims to explain transitions in a socio-technical system characterized by non-economic entities that influence economic activity, i.e. embeddedness and coalitions. The selected socio-technical system is an Indian electric network with an interventionist policy. Its embeddedness and coalitions drive the transition. The insights from such analysis expand socio-technical transition theory and provide valuable insights to practitioners in their policymaking. Design/methodology/approach The authors need to observe the effects of non-economic institutions in their setting. Moreover, in India, the regional policies influence decision-making; therefore, selected two Indian states. The two Indian states, along with their non-economic entities, provided diverse analytic and heuristic views. Findings The findings show that coalitions, with their embeddedness in the absence of any mediating policy systems, act as external pressures and influence innovation and the socio-technical system’s transition trajectory. Their coalitions’ embeddedness follows a shaping, not selection logic. Thereby influence innovations in cumulating as stable designs. Such an approach provides benefits in the short-term but not in the long-term. Research limitations/implications The study selected two states and examined two of the four trajectories. By considering other states, the authors can obtain more renewable energy investments and further insights into the transformational trajectory. Practical implications The study highlights the coalition dynamics specific to the Indian electric power network and its transition trajectories. The non-economic entities influenced transition trajectories, innovation and policymaking of the socio-technical system. Originality/value The study expands the socio-technical transition theory by including embeddedness. The embeddedness brings a shaping logic instead of a selection logic.

scholarly journals Spatial-Memory Formation After Spaced Learning Involves ERKs1/2 Activation Through a Behavioral-Tagging Process

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Ramiro Tintorelli ◽  
Pablo Budriesi ◽  
Maria Eugenia Villar ◽  
Paul Marchal ◽  
Pamela Lopes da Cunha ◽  
...  
Keyword(s):  
Protein Synthesis ◽  
Prior Training ◽  
Short Term ◽  
Promoting Effect ◽  
Cellular Processes ◽  
Spaced Learning ◽  
Inter Trial Interval ◽  
Established Fact ◽  
Massed Learning

AbstractThe superiority of spaced over massed learning is an established fact in the formation of long-term memories (LTM). Here we addressed the cellular processes and the temporal demands of this phenomenon using a weak spatial object recognition (wSOR) training, which induces short-term memories (STM) but not LTM. We observed SOR-LTM promotion when two identical wSOR training sessions were spaced by an inter-trial interval (ITI) ranging from 15 min to 7 h, consistently with spaced training. The promoting effect was dependent on neural activity, protein synthesis and ERKs1/2 activity in the hippocampus. Based on the “behavioral tagging” hypothesis, which postulates that learning induces a neural tag that requires proteins to induce LTM formation, we propose that retraining will mainly retag the sites initially labeled by the prior training. Thus, when weak, consecutive training sessions are experienced within an appropriate spacing, the intracellular mechanisms triggered by each session would add, thereby reaching the threshold for protein synthesis required for memory consolidation. Our results suggest in addition that ERKs1/2 kinases play a dual role in SOR-LTM formation after spaced learning, both inducing protein synthesis and setting the SOR learning-tag. Overall, our findings bring new light to the mechanisms underlying the promoting effect of spaced trials on LTM formation.

Effectiveness of two tagging devices in the sea cucumber Holothuria (Halodeima) grisea

2017 ◽  
Vol 68 (3) ◽  
pp. 563
Author(s):  
Ruber Rodríguez-Barreras ◽  
Julián López-Morell ◽  
Alberto M. Sabat
Keyword(s):  
Sea Cucumber ◽  
Body Wall ◽  
The Body ◽  
Short Term ◽  
Pit Tag ◽  
Sea Cucumbers ◽  
Pit Tags ◽  
Significant Difference ◽  
Long Term Studies

A reliable and harmless mark–recapture method provides valuable information for the management of commercial sea cucumber species. Nevertheless, marking and tracking sea cucumbers is notoriously difficult and represents a serious challenge. In this study, we tested one external and one internal tag in the sea cucumber Holothuria grisea. A passive integrated transponder (PIT) tag was inserted into the coelomic cavity in one treatment, whereas a T-bar (external tag) was attached in the upper surface of the body wall in the other treatment; sea cucumbers were then followed for 17 weeks. The tagging procedure caused no evisceration in the experimental groups, nor was a significant difference in growth rate found between treatments. The retention of the PIT tag was low, with 100% lost by Week 9. Retention of T-bars was higher, with 90% still attached by the end of the Week 8, but retention decreased thereafter as T-bar absorption increased. No relationship was found between initial weight and the number of weeks PIT tags (r=–0.173, P=0.781) or T-bars (r=–0.220, P=0.652) were retained. Neither the T-bar nor the PIT tags fulfilled the requirements of high retention required for long-term studies. However, we do recommend the use of T-bars for short-term studies for H. grisea under laboratory conditions or in a habitat with low substrate complexity.

scholarly journals Partial inferior turbinectomy versus submucosal diathermy in hypertrophied inferior turbinates

2020 ◽  
Vol 6 (11) ◽  
pp. 2011
Author(s):  
Smitha S. Gangaraj ◽  
Shilpa Thomas
Keyword(s):  
Wound Healing ◽  
Comparative Study ◽  
Nasal Obstruction ◽  
Short Term ◽  
Mild Pain ◽  
Group A ◽  
Term Evaluation ◽  
Group B ◽  
Operative Assessment

<p><strong>Background:</strong> The study aims to compare the efficacy of submucosal diathermy and partial inferior turbinectomy in terms of improvement in nasal obstruction, pain, haemorrhage, crusting and wound healing.</p><p><strong>Methods: </strong>A prospective sequentially randomized comparative study involving fifty patients, divided into two groups of 25 patients each. Group A consists of patients who underwent SMD and group B consists of patients who underwent PIT. Post-operative assessment was done at day 1, 2 weeks, 1 month, 3 months and 6 months.</p><p><strong>Results: </strong>Post-operative improvement in nasal obstruction was seen in both groups. 80% showed significant improvement in SMD and 32% in PIT group at the end of second week. By sixth month, 40% in SMD group and 80% in PIT group showed significant improvement. Mild pain was observed in 12% of PIT group at 2 weeks. In SMD group, 8% developed reactionary haemorrhage. In PIT group, 24% developed minimal soakage and 12% developed moderate soakage. Severe nasal crusting was seen in 64% of the cases in PIT group and in 40% of the cases in SMD group at second week. By 1 month, 44% in PIT group and 12% in SMD group showed severe crusting.</p><p><strong>Conclusions: </strong>Short term complications like pain, obstruction and haemorrhage was noted to be higher with PIT. On long term evaluation, PIT showed better results in terms of improvement in nasal obstruction scores.</p>

scholarly journals Effects of Different Ambient Temperatures on Caecal Microbial Composition in Broilers

2021 ◽  
Vol 70 (1) ◽  
Author(s):  
YUTING YANG ◽  
XING LI ◽  
ZHENHUI CAO ◽  
YINGING QIAO ◽  
QIUYE LIN ◽  
...  
Keyword(s):  
Temperature Stress ◽  
Short Term ◽  
Microbial Composition ◽  
Ambient Temperatures ◽  
Cellular Processes ◽  
Stress Biomarkers ◽  
Tnf Α ◽  
Shock Proteins ◽  
Environmental Information Processing

Short-term or acute temperature stress affect the immune responses and alters the gut microbiota of broilers, but the influences of long-term temperature stress on stress biomarkers and the intestinal microbiota remains largely unknown. Therefore, we examined the effect of three long-term ambient temperatures (high (HC), medium (MC), and low (LC) temperature groups) on the gene expression of broilers’ heat shock proteins (Hsps) and inflammation – related genes, as well as the caecal microbial composition. The results revealed that Hsp70 and Hsp90 levels in HC group significantly increased, and levels of Hsp70, Hsp90, IL-6, TNF-α, and NFKB1 in LC group were significantly higher than in MC group (p < 0.05). In comparison with the MC group, the proportion of Firmicutes increased in HC and LC groups, while that of Bacteroidetes decreased in LC group at phylum level (p < 0.05). At genus level, the proportion of Escherichia/Shigella, Phascolarctobacterium, Parabacteroides, and Enterococcus increased in HC group; the fraction of Faecalibacterium was higher in LC group; and the percentage of Barnesiella and Alistipes decreased in both HC and LC groups (p < 0.05). Functional analysis based on communities’ phylogenetic investigation revealed that the pathways involved in environmental information processing and metabolism were enriched in the HC group. Those involved in cellular processes and signaling, metabolism, and gene regulation were enriched in LC group. Hence, we conclude that the long-term temperature stress can greatly alter the intestinal microbial communities in broilers and may further affect the host’s immunity and health.

Definitive Wound Closure Techniques in Fournier's Gangrene

2018 ◽  
Vol 84 (1) ◽  
pp. 86-92
Author(s):  
Margaret Lauerman ◽  
Olga Kolesnik ◽  
Habeeba Park ◽  
Laura S. Buchanan ◽  
William Chiu ◽  
...  
Keyword(s):  
Wound Healing ◽  
Confidence Interval ◽  
Odds Ratio ◽  
Primary Closure ◽  
Wound Closure ◽  
Fournier’S Gangrene ◽  
Fournier's Gangrene ◽  
Secondary Intention ◽  
Primary Wound Closure

Necrotizing soft tissue infection of the perineum, or Fournier's gangrene (FG), is a morbid and mortal diagnosis. Despite the severity of FG, the optimal definitive wound closure strategy is unknown, as are long-term wound outcomes. A retrospective review was performed over a 3-year period at a single trauma center. Patients were managed according to our institutional approach focusing on primary wound closure and secondary intention healing in residual wounds. Overall 168 patients were included. Complete primary wound closure was accomplished in 39.9 per cent of patients. Patients undergoing primary wound closure were primarily male (89.6 vs 64.4%, P < 0.001), had lower mean sequential organ failure assessment (SOFA) scores (1.70 ± 2.30 vs 2.98 ± 3.36, P = 0.004), more often had perineum-limited FG (67.2 vs 42.6%, P = 0.003), and required fewer debridements (2.40 vs 2.79, P = 0.02). On logistic regression, predictors of primary closure included gender (odds ratio 4.643, 95% confidence interval 1.885–11.437, P = 0.001) and SOFA score (odds ratio 0.834, 95% confidence interval 0.727–0.957, P = 0.01). Wound healing rates increased over time, to an 82.1 per cent wound healing rate without further intervention at greater than six months of follow-up. Wounds healed with secondary intention ranged from 70 to 9520 cm3 and primary closure ranged from 126 to 6912 cm3, whereas wounds requiring skin grafts ranged from 405 to 16,170 cm3. Complete primary wound closure is often achievable in FG patients. Using this standardized approach to FG wound management, even large wounds and wounds undergoing secondary intention healing will often close with long-term wound care and do not require flap creation or early skin grafting.

scholarly journals Tectonic processes in Svalbard tide-water glacier surges: evidence from structural glaciology

1994 ◽  
Vol 40 (136) ◽  
pp. 553-560 ◽  
Author(s):  
Hodgkins Richard ◽  
Julian A. Dowdeswell
Keyword(s):  
Shear Stresses ◽  
Large Magnitude ◽  
Short Term ◽  
Principal Stresses ◽  
Stress Regime ◽  
Glacier Terminus ◽  
Tectonic Processes ◽  
Glacier Surges ◽  
Glacier Advance

AbstractThe tectonic effects of a glacier surge differ from those of steady state because flow is driven by longitudinal stresses rather than shear stresses. The orientations of recently formed crevasses, indicating the directions of the principal stresses, have been used to investigate tectonic processes in glacier surges recorded by repeat aerial photography. Long-term, large-magnitude shifts in stress regime are demonstrated, as are short-term propagation features. Two types of tide-water glacier advance are identified, depending on the position of the surge front relative to a low effective-pressure zone at the glacier terminus.

Effects of hard clam (Mercenaria mercenaria) density and bottom shear stress on cohesive sediment erodibility and implications for benthic-pelagic coupling

2020 ◽  
Vol 78 (2) ◽  
pp. 91-130
Author(s):  
Elka T. Porter ◽  
Barbara J. Johnson ◽  
Lawrence P. Sanford
Keyword(s):  
Shear Stress ◽  
Mercenaria Mercenaria ◽  
Cohesive Sediment ◽  
Hard Clam ◽  
Shear Stresses ◽  
Bottom Shear Stress ◽  
Short Term ◽  
Benthic Pelagic Coupling ◽  
Hard Clams

The interacting effects of little neck hard clam (Mercenaria mercenaria) density and bottom shear stress on cohesive sediment erodibility were investigated. Short-term stepwise erosion experiments in 30 and 40 cm diameter Gust microcosms over a range of 0.0083 to 0.1932 Pa were performed using sequential 20-minute constant shear stress steps while sampling turbidity regularly. In addition, sediment erodibility was monitored in two one-month long ecosystem experiments with tidal resuspension and 0, 10, and 50 hard clams in 1 m3 shear turbulence resuspension mesocosms (STURM) with an initial stepwise erosion experiment (0.313 to 0.444 Pa). In short-term erosion experiments, a low density of hard clams did not significantly affect sediment erodibility, but a high density of hard clams destabilized muddy sediments through significantly decreased critical shear stresses and higher erosion rates, resulting in higher cumulative suspended mass (CSM). In long-term erosion experiments, the sediment stabilized over time between treatments and decreased to a CSM of approximately 60 g m–2 with different densities of hard clams. This was likely due to development of microphytobenthos, mediated by the filter-feeding clams, bottom shear stress and increased light. Bioturbation by a dense bed of hard clams in interaction with infrequent high bottom shear due to storms may increase CSM in the water column, with subsequent direct and indirect effects on the ecosystem. However, more controlled longer-term erosion studies to determine the interacting effects of long-term exposure to high bottom shear stress, benthos, and microphytobenthos on sediment erodibility and benthic-pelagic coupling are needed.

scholarly journals Tectonic processes in Svalbard tide-water glacier surges: evidence from structural glaciology

1994 ◽  
Vol 40 (136) ◽  
pp. 553-560 ◽  
Author(s):  
Hodgkins Richard ◽  
Julian A. Dowdeswell
Keyword(s):  
Shear Stresses ◽  
Large Magnitude ◽  
Short Term ◽  
Principal Stresses ◽  
Stress Regime ◽  
Glacier Terminus ◽  
Tectonic Processes ◽  
Glacier Surges ◽  
Glacier Advance

AbstractThe tectonic effects of a glacier surge differ from those of steady state because flow is driven by longitudinal stresses rather than shear stresses. The orientations of recently formed crevasses, indicating the directions of the principal stresses, have been used to investigate tectonic processes in glacier surges recorded by repeat aerial photography. Long-term, large-magnitude shifts in stress regime are demonstrated, as are short-term propagation features. Two types of tide-water glacier advance are identified, depending on the position of the surge front relative to a low effective-pressure zone at the glacier terminus.

Osteoblasts respond to pulsatile fluid flow with short-term increases in PGE2 but no change in mineralization

2001 ◽  
Vol 90 (5) ◽  
pp. 1849-1854 ◽  
Author(s):  
E. A. Nauman ◽  
R. L. Satcher ◽  
T. M. Keaveny ◽  
B. P. Halloran ◽  
D. D. Bikle
Keyword(s):  
Shear Stress ◽  
Fluid Flow ◽  
Fluid Shear Stress ◽  
Bone Cells ◽  
Shear Stresses ◽  
Long Term Effects ◽  
Fluid Shear ◽  
Short Term

Although there is no consensus as to the precise nature of the mechanostimulatory signals imparted to the bone cells during remodeling, it has been postulated that deformation-induced fluid flow plays a role in the mechanotransduction pathway. In vitro, osteoblasts respond to fluid shear stress with an increase in PGE2production; however, the long-term effects of fluid shear stress on cell proliferation and differentiation have not been examined. The goal of this study was to apply continuous pulsatile fluid shear stresses to osteoblasts and determine whether the initial production of PGE2 is associated with long-term biochemical changes. The acute response of bone cells to a pulsatile fluid shear stress (0.6 ± 0.5 Pa, 3.0 Hz) was characterized by a transient fourfold increase in PGE2 production. After 7 days of static culture (0 dyn/cm2) or low (0.06 ± 0.05 Pa, 0.3 Hz) or high (0.6 ± 0.5 Pa, 3.0 Hz) levels of pulsatile fluid shear stress, the bone cells responded with an 83% average increase in cell number, but no statistical difference ( P > 0.53) between the groups was observed. Alkaline phosphatase activity per cell decreased in the static cultures but not in the low- or high-flow groups. Mineralization was also unaffected by the different levels of applied shear stress. Our results indicate that short-term changes in PGE2 levels caused by pulsatile fluid flow are not associated with long-term changes in proliferation or mineralization of bone cells.

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