scholarly journals Storm surge and ponding explain mangrove dieback in southwest Florida following Hurricane Irma

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
David Lagomasino ◽  
Temilola Fatoyinbo ◽  
Edward Castañeda-Moya ◽  
Bruce D. Cook ◽  
Paul M. Montesano ◽  
...  
Keyword(s):  
Storm Surge ◽  
Ground Surface ◽  
Tree Height ◽  
Water Levels ◽  
Airborne Lidar ◽  
Southwest Florida ◽  
Before And After ◽  
Wind Exposure ◽  
One Year ◽  
Hurricane Irma

AbstractMangroves buffer inland ecosystems from hurricane winds and storm surge. However, their ability to withstand harsh cyclone conditions depends on plant resilience traits and geomorphology. Using airborne lidar and satellite imagery collected before and after Hurricane Irma, we estimated that 62% of mangroves in southwest Florida suffered canopy damage, with largest impacts in tall forests (>10 m). Mangroves on well-drained sites (83%) resprouted new leaves within one year after the storm. By contrast, in poorly-drained inland sites, we detected one of the largest mangrove diebacks on record (10,760 ha), triggered by Irma. We found evidence that the combination of low elevation (median = 9.4 cm asl), storm surge water levels (>1.4 m above the ground surface), and hydrologic isolation drove coastal forest vulnerability and were independent of tree height or wind exposure. Our results indicated that storm surge and ponding caused dieback, not wind. Tidal restoration and hydrologic management in these vulnerable, low-lying coastal areas can reduce mangrove mortality and improve resilience to future cyclones.

Alteration in tides and flood dynamics caused by channel deepening:  case study of the Saint Johns River, Florida

2021 ◽  
Author(s):  
Stefan Talke ◽  
David Jay ◽  
Ramin Familkhalili
Keyword(s):  
Numerical Modeling ◽  
Storm Surge ◽  
River Estuary ◽  
High Water ◽  
Water Levels ◽  
Tidal Range ◽  
Case Scenario ◽  
Worst Case ◽  
Length Changes ◽  
Hurricane Irma

<p>In this contribution, we show that channel deepening can amplifiy tide and storm surge--while simultaneously decreasing the river slope during both normal conditions and during floods.  We investigate the Saint Johns River Estuary, Florida, an example of a hyposynchronous, strongly frictional estuary with a landward decay in tidal amplitudes. Records since the 1890s and numerical modeling show that tidal range doubled in Jacksonville, Florida (40 km from coast), while tidal discharge approximately doubled everywhere. Overall, an increase in channel depth from 5 to 10m drove the observed changes, with width and length changes comparatively minor factors. Tidal amplitude evolved in a spatially variable way--negligible at the coast and inland, maximal 20-30km from the ocean.  The change in the M2 constituent is approximated by the equation x * exp(mu*x), where x is the distance from the ocean and mu is a damping coefficient that depends on depth, drag coefficient, and other system properties.  The observed tidal evolution is similar to storm surge:  Numerical modeling of hurricane Irma (Sept. 2017) under 1898 and 2017 bathymetric conditions confirms that both tidal and storm surge amplitudes have increased over time, with a maximum change about 20-25km from the inlet. Nonetheless, hurricane Irma produced overall high water levels in the historical bathymetric configuration. The reason is that the mean water level slope required to move water out of the modern estuary has decreased. An analytical model confirms that reduced slope is caused primarily by channel deepening.  However, greater tides and storm surge imply an increased vulnerability to a worst-case scenario hurricane. </p>

scholarly journals Storm surge, not wind, caused mangrove dieback in southwest Florida following Hurricane Irma

2020 ◽  
Author(s):  
David Lagomasino ◽  
Lola Fatoyinbo ◽  
Edward Castaneda ◽  
Bruce Cook ◽  
Paul Montesano ◽  
...  
Keyword(s):  
Storm Surge ◽  
Southwest Florida ◽  
Hurricane Irma

scholarly journals Probabilistic Assessment of Roof Snow Load and the Calibration of Shape Coefficients in the Eurocodes

2021 ◽  
Vol 11 (7) ◽  
pp. 2984
Author(s):  
Pietro Croce ◽  
Paolo Formichi ◽  
Filippo Landi
Keyword(s):  
Conversion Factor ◽  
Reference Value ◽  
Construction Site ◽  
Probability Of Exceedance ◽  
Snow Load ◽  
Shape Coefficient ◽  
Annual Probability ◽  
Wind Exposure ◽  
Design Values ◽  
One Year

In modern structural codes, the reference value of the snow load on roofs is commonly given as the product of the characteristic value of the ground snow load at the construction site multiplied by the shape coefficient. The shape coefficient is a conversion factor which depends on the roof geometry, its wind exposure, and its thermal properties. In the Eurocodes, the characteristic roof snow load is either defined as the value corresponding to an annual probability of exceedance of 0.02 or as a nominal value. In this paper, an improved methodology to evaluate the roof snow load characterized by a given probability of exceedance (e.g., p=0.02 in one year) is presented based on appropriate probability density functions for ground snow loads and shape coefficients, duly taking into account the influence of the roof’s geometry and its exposure to wind. In that context, the curves for the design values of the shape coefficients are provided as a function of the coefficient of variation (COVg) of the yearly maxima of the snow load on the ground expected at a given site, considering three relevant wind exposure conditions: sheltered or non-exposed, semi-sheltered or normal, and windswept or exposed. The design shape coefficients for flat and pitched roofs, obtained considering roof snow load measurements collected in Europe during the European Snow Load Research Project (ESLRP) and in Norway, are finally compared with the roof snow load provisions given in the relevant existing Eurocode EN1991-1-3:2003 and in the new version being developed (prEN1991-1-3:2020) for the “second generation” of the Eurocodes.

scholarly journals Real-World Experience of the One-Year Efficacy of Rifaximin Add-On to Lactulose Is Superior to Lactulose Alone in Patients with Cirrhosis Complicated with Recurrent Hepatic Encephalopathy in Taiwan

2021 ◽  
Vol 11 (6) ◽  
pp. 478
Author(s):  
Ching Chang ◽  
Chien-Hao Huang ◽  
Hsiao-Jung Tseng ◽  
Fang-Chen Yang ◽  
Rong-Nan Chien
Keyword(s):  
Hepatic Encephalopathy ◽  
Real World ◽  
Ammonia Level ◽  
Decompensated Cirrhosis ◽  
Control Group ◽  
Multivariable Logistic Regression Model ◽  
Before And After ◽  
One Year ◽  
The One ◽  
Serum Ammonia

Background: Hepatic encephalopathy (HE), a neuropsychiatric complication of decompensated cirrhosis, is associated with high mortality and high risk of recurrence. Rifaximin add-on to lactulose for 3 to 6 months is recommended for the prevention of recurrent episodes of HE after the second episode. However, whether the combination for more than 6 months is superior to lactulose alone in the maintenance of HE remission is less evident. Therefore, the aim of this study is to evaluate the one-year efficacy of rifaximin add-on to lactulose for the maintenance of HE remission in Taiwan. Methods: We conducted a real-world single-center retrospective cohort study to compare the long-term efficacy of rifaximin add-on to lactulose (group R + L) versus lactulose alone (group L, control group). Furthermore, the treatment efficacy before and after rifaximin add-on to lactulose was also analyzed. The primary endpoint of our study was time to first HE recurrence (Conn score ≥ 2). All patients were followed up every three months until death, and censored at one year if still alive. Results and Conclusions: 12 patients were enrolled in group R + L. Another 31 patients were stratified into group L. Sex, comorbidity, ammonia level, and ascites grade were matched while age, HE grade, and model for end-stage liver disease (MELD) score were adjusted in the multivariable logistic regression model. Compared with group L, significant improvement in the maintenance of HE remission and decreased episodes and days of HE-related hospitalizations were demonstrated in group R + L. The serum ammonia levels were significantly lower at the 3rd and 6th month in group 1. Concerning changes before and after rifaximin add-on in group R + L, mini-mental status examination (MMSE), episodes of hospitalization, and variceal bleeding also improved at 6 and 12 months. Days of hospitalization, serum ammonia levels also improved at 6th month. Except for concern over price, no patients discontinued rifaximin due to adverse events or complications. The above results provide evidence for the one-year use of rifaximin add-on to lactulose in reducing HE recurrence and HE-related hospitalization for patients with decompensated cirrhosis.

scholarly journals Cloth simulation-based construction of pit-free canopy height models from airborne LiDAR data

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Wuming Zhang ◽  
Shangshu Cai ◽  
Xinlian Liang ◽  
Jie Shao ◽  
Ronghai Hu ◽  
...  
Keyword(s):  
Tree Height ◽  
Point Clouds ◽  
Airborne Lidar ◽  
Canopy Height ◽  
Lidar Data ◽  
Cloth Simulation ◽  
Simulation Based ◽  
Maximum Tree Height ◽  
Airborne Lidar Data ◽  
Better Than

Abstract Background The universal occurrence of randomly distributed dark holes (i.e., data pits appearing within the tree crown) in LiDAR-derived canopy height models (CHMs) negatively affects the accuracy of extracted forest inventory parameters. Methods We develop an algorithm based on cloth simulation for constructing a pit-free CHM. Results The proposed algorithm effectively fills data pits of various sizes whilst preserving canopy details. Our pit-free CHMs derived from point clouds at different proportions of data pits are remarkably better than those constructed using other algorithms, as evidenced by the lowest average root mean square error (0.4981 m) between the reference CHMs and the constructed pit-free CHMs. Moreover, our pit-free CHMs show the best performance overall in terms of maximum tree height estimation (average bias = 0.9674 m). Conclusion The proposed algorithm can be adopted when working with different quality LiDAR data and shows high potential in forestry applications.

scholarly journals Evaluating the Implementation of the “Build-Back-Better” Concept for Critical Infrastructure Systems: Lessons from Saint-Martin’s Island Following Hurricane Irma

2021 ◽  
Vol 13 (6) ◽  
pp. 3133
Author(s):  
Rita Der Sarkissian ◽  
Anas Dabaj ◽  
Youssef Diab ◽  
Marc Vuillet
Keyword(s):  
Decision Making ◽  
Conceptual Analysis ◽  
Scientific Literature ◽  
Critical Infrastructure ◽  
Methodological Approach ◽  
Infrastructure Systems ◽  
Before And After ◽  
Study Offer ◽  
Hurricane Irma ◽  
Operational Aspects

A limited number of studies in the scientific literature discuss the “Build-Back-Better” (BBB) critical infrastructure (CI) concept. Investigations of its operational aspects and its efficient implementation are even rarer. The term “Better” in BBB is often confusing to practitioners and leads to unclear and non-uniform objectives for guiding accurate decision-making. In an attempt to fill these gaps, this study offers a conceptual analysis of BBB’s operational aspects by examining the term “Better”. In its methodological approach, this study evaluates the state of Saint-Martin’s CI before and after Hurricane Irma and, accordingly, reveals the indicators to assess during reconstruction projects. The proposed methods offer practitioners a guidance tool for planning efficient BBB CI projects or for evaluating ongoing programs through the established BBB evaluation grid. Key findings of the study offer insights and a new conceptual equation of the BBB CI by revealing the holistic and interdisciplinary connotations behind the term “Better” CI: “Build-Back-resilient”, “Build-Back-sustainable”, and “Build-Back-accessible to all and upgraded CI”. The proposed explanations can facilitate the efficient application of BBB for CI by operators, stakeholders, and practitioners and can help them to contextualize the term “Better” with respect to their area and its CI systems.

Changes In Prothrombin And Activated Partial Thromboplastin Time During Replacement Therapy With Human Recombinant Growth Hormone In Growth Hormone Deficient Adults

2020 ◽  
Vol 154 (Supplement_1) ◽  
pp. S102-S103
Author(s):  
Y S Kamel
Keyword(s):  
Growth Hormone ◽  
Replacement Therapy ◽  
Healthy Subjects ◽  
Recombinant Growth Hormone ◽  
Gh Replacement ◽  
Coagulation Tests ◽  
Before And After ◽  
Human Recombinant Growth Hormone ◽  
Male Patients ◽  
One Year

Abstract Introduction/Objective The aim of this study was to investigate the effects of GH administration on basic coagulation parameters: PT, aPTT and fibrinogen concentrations in adult GHD patients before and during one year of GH replacement. Methods Twenty-one adult patients with severe GHD (mean age +/- SE: 38.6 +/- 2.8 years) were included in this hospital based, prospective, interventional study. All patients were treated with rhGH for 12 months (GH dose: 0.4 mg/day for male and 0.6 mg/day for female patients). IGF-1 concentrations were determined using RIA-INEP kits. Basic coagulation tests, i.e. aPTT and fibrinogen concentrations, were measured before and after 3, 6 and 12 months of treatment with rhGH. Control values were obtained from fourteen “healthy” subjects matched by age, sex and body mass index (BMI). Results At baseline, we observed no significant differences in PT, aPTT and fibrinogen values between GHD and healthy subjects. IGF-1 concentrations increased significantly within 3 months of GH therapy (8.2 +/- 1.5 vs. 24.2 +/- 2.9 nmol/l, p <0.05) and remained stable thereafter. A significant increase in PT values, which was more pronounced in female subjects, was noted after 6 and 12 months of treatment with GH. aPTT values increased significantly after 12 months of treatment only in male patients (28.8 +/- 4.6 vs. 39.7 +/- 2.1 s.; p <0.05). No significant changes in fibrinogen concentrations were found during the study. Conclusion Twelve months of GH replacement therapy led to a significant increase in PT and aPTT values in adult GHD patients, while fibrinogen concentrations did not change. Changes in PT were more pronounced in female GHD patients, while an increase in aPTT values was observed only in male patients with GHD. The clinical significance of these changes needs further evaluation.

scholarly journals 19 Colectomy Rate for Moderate to Severe Ulcerative Colitis with Biologics

2021 ◽  
Vol 108 (Supplement_2) ◽  
Author(s):  
J W H Koh ◽  
C H Ng ◽  
M H Lee ◽  
Y H Chin ◽  
Z H Ong ◽  
...  
Keyword(s):  
Ulcerative Colitis ◽  
Current Literature ◽  
Biologic Therapy ◽  
Meta Analysis ◽  
Severe Ulcerative Colitis ◽  
Before And After ◽  
Arcsine Transformation ◽  
One Year

Abstract Introduction Biologics are recommended by both the ACG and ECCO community for the treatment of ulcerative colitis. Yet, current literature has yet to estimate the rate of colectomies after biologic therapy, and thus a pooled meta-analysis was conducted the rate of colectomies in 1month, 6 months, 1 year, 2years and five years after biologics. Method Medline and Embase were searched for articles examining biologics use in moderate to severe UC or acute severe UC (ASUC) from inception to 21st May 2020. Analysis of proportions were undertaken after a freeman-tukey double arcsine transformation. Results The pooled overall colectomy rates of ASUC and moderate to severe UC were 9% (CI: 4% - 14%) at one month, 18% (CI: 13% - 25%) at six months, 21% (CI:16% - 27%) at one year, 29% (CI:24% - 34%) at two years and 38% (CI:30% - 45%) at five years. Additionally, colectomy rates were consistently lower comparing between articles before and after 2010. At one-year, overall colectomy rate following infliximab use was at 25%, golimumab at 15%, vedolizumab at 14%, and adalimumab at 3%. Conclusions Colectomy rates in the era of biologics ranged from 8% to 38% and lower post-2010 showing significant improvement in management and supporting the utility of biologics in Ulcerative colitis management.

Exercise Training and the Speed of Self-Selected Walking Pace in Men at Retirement

1986 ◽  
Vol 5 (1) ◽  
pp. 19-26 ◽  
Author(s):  
D. A. Cunningham ◽  
P. A. Rechnitzer ◽  
A. P. Donner
Keyword(s):  
Exercise Training ◽  
Training Program ◽  
Walking Speed ◽  
Exercise Group ◽  
Cardiovascular Fitness ◽  
Blue Collar ◽  
Intervention Trial ◽  
Before And After ◽  
Exercise Endurance ◽  
One Year

ABSTRACTAn intervention trial with regular physical activity was carried out to test the hypothesis that walking speed is related to the level of cardiovascular fitness (maximal oxygen uptake). Earlier research has demonstrated that when VO2 max is held constant in a multiple regression analysis the association between walking speed and age (29–65 y) is eliminated. To describe the association between self-selected speeds of walking, and level of cardiovascular fitness, 63 men age 60 to 65 were studied before and after a 1 year program of exercise training. VO2 max was determined on a motor driven treadmill. A test of self-selected walking pace was administered over a 240 m indoor course. The men were asked to walk at 3 paces considered by the subjects to be rather slow, normal, and fast, respectively. They were randomly assigned with stratification for white and blue collar occupation to a program of exercise training (n = 33) or control (n = 27). The training program consisted of walking or jogging for 30 min three times per week for one year. After the training program the exercise group increased their VO2 max (9.5%) and their normal walking speed (1.29 to 1.43 m.s−1) significantly compared to the controls. A program of exercise endurance training will result in an increase in the speed of self-selected pace.

Sign in / Sign up

Export Citation Format

Share Document