Long-term decomposition and nutrient dynamics in Pacific silver fir needles in western Washington

1984 ◽  
Vol 14 (3) ◽  
pp. 395-400 ◽  
Author(s):  
Robert L. Edmonds

Long-term needle decomposition and nutrient dynamics (N, P, K, Ca, Mg, and Mn) were studied over a 6-year period in a Pacific silver fir (Abiesamabilis (Dougl.) Forb.) ecosystem in western Washington, U.S.A. Weight loss of needles was 41.2% after 14 months and 64.3% after 6 years. Decomposition constants (k values) declined with time of decomposition, but tended to stabilize afer4–6years. The mean residence time of needles was estimated to be 9 years. After 4 years decomposition weight loss paralleled lignin loss. Nitrogen was strongly immobilized in needles with 242% of original mass of N remaining after 4 years and 213% after 6 years. Net mineralization occurred when the C:N ratio fell below 20. Phosphorus appeared to be slightly immobilized in the 9- to 48-month period. Only 49% of the original P mass remained after 6 years. None of the other elements was immobilized during the 6-year period. The element mobility series was N < P < Mn < Ca < Mg < K. Two-year litter bag studies in subalpine coniferous ecosystems are not long enough to study litter decomposition rates and nutrient dynamics.

1973 ◽  
Vol 13 (61) ◽  
pp. 117 ◽  
Author(s):  
JE Frisch

The mortality rates, weight changes and associated effects of a. draught in 1969 were observed in a herd of Shorthorn x Hereford (SH), Brahman x SH (BX) and Africander x SH (AX) crossbred cows and small herds of purebred Brahman and Africander cows at 'Belmont', Queensland. About half of the cows calved over a two month period from mid-October 1969. All the cows were weighed in February 1968, February and October 1969 and in January 1970 and the data from the crossbreds analysed by the method of least squares. The weights and weight changes of both the calving and non-calving groups followed a similar pattern though the weight changes of the non-calving group were of greater magnitude. The weights showed that the three crossbreds reached the same mature weight but at different rates. The SH cows reached mature weight least rapidly, had the highest mean weight loss during the drought and had the lowest mean gains after the season broke. Weight changes both during and after the drought were however dependent on lactational status in February 1969. The mean weight loss of cows that weaned a calf in 1969 (wet) was similar for all breeds. However, the mean loss of the dry SH cows was significantly greater than that of the dry BX and AX cows. Previously wet cows exhibited compensatory gains after calving but the gain of the wet SH cows was the lowest of the crossbred means. The mean birth weight of the SH calves was reduced below the long term mean by about 4 kg but birthweights of BX and AX calves were similar to those in other years. During the drought the purebred Brahmans lost the least and the purebred Africanders lost the most weight of all breeds. However, the nature of the data precludes any strict comparisons from being drawn. Mortality rates of breeding cows were recorded from 1960 to 1969. Rates were generally highest for the SH, particularly in the drought years of 1965 and 1969. Some reasons are advanced which may explain the differences in performance of the breed types.


2006 ◽  
Vol 120 (11) ◽  
pp. 932-938 ◽  
Author(s):  
T Iyngkaran ◽  
J Kanagalingam ◽  
R Rajeswaran ◽  
C Georgalas ◽  
B Kotecha

Laser-assisted uvulopalatoplasty (LAUP) is an established treatment for snoring. Our institution has been using a modification of the Kamami technique since 1995. Between January 1995 and December 2001, 469 patients underwent LAUP for snoring. A telephone survey of these patients and their partners was conducted retrospectively. One hundred and sixty-eight patients and their partners were interviewed and the findings analysed.Of the 168 patients, 122 had LAUP alone, 42 had LAUP and tonsillectomy and four had LAUP and septoplasty. The median follow-up time was 59 months (range 19 to 98 months).Seventy-four per cent reported improvement at six weeks, 69 per cent reported improvement at nine months and 55 per cent reported improvement at the time of interview. To assess the degree of improvement, patients and their partners were asked to grade any improvement in percentage terms. The mean subjective improvement scores were 57 per cent at six weeks (95 per cent confidence interval (CI) 50–64 per cent), 45 per cent at nine months (95 per cent CI 38–59 per cent) and 30 per cent at the time of interview (95 per cent CI 23–35 per cent). Patients who reported weight gain since surgery did not have a poorer outcome than those who reported no weight change or weight loss. Neither did weight loss predict a better outcome. The procedure was generally well tolerated, with only 30 patients (18 per cent) reporting complications (mainly minor).The benefits of LAUP wane with time and the results are best in the first 12 months following surgery. Our study suggests that 55 per cent of patients selected after sleep studies and sleep nasendoscopy will enjoy long-term benefit.


1980 ◽  
Vol 10 (3) ◽  
pp. 327-337 ◽  
Author(s):  
Robert L. Edmonds

Decomposition rates and changes in the nutrient content of needle and leaf litter were examined in Douglas-fir (Pseudotsugamenziesii Mirb. Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), Pacific silver fir (Abiesamabilis (Dougl.) Forbes), and red alder (Alnusrubra Bong.) ecosystems in western Washington, U.S.A. Nylon litterbags (1-mm mesh) were placed in the stands in November and December 1974. Bags were collected after 3, 6, 12, and 24 months and weighed, except in the Pacific silver fir stand when bags were collected after 6, 9, 14, and 24 months. Litter was analyzed for C, N, P, K, Ca, Mg, Mn, lignin, and cellulose. Decomposition constants (k values) were determined. Fastest decomposition after 2 years occurred in red alder leaves, followed by Douglas-fir, western hemlock, and Pacific silver fir needles. There were significant differences in weight loss among species after 1 year, but no significant differences were evident after 2 years. Red alder leaves showed rapid weight loss in the 1st year but decomposed little in the 2nd year. Decomposition constants were highly positively correlated with minimum air temperatures and negatively correlated with C:N ratios. Low litter moisture tended to reduce decomposition in summer, particularly in the Pacific silver fir stand. Decomposition proceeded under snow in this ecosystem. The pattern of loss of elements from litterbags after 2 years varied from ecosystem to ecosystem, particularly for N. The following element mobility series resulted for the four ecosystems: red alder (K > Mg > Ca > P > N > Mn), Douglas-fir (K > P > Ca > Mg > Mn > N), western hemlock (K > Ca > Mg > N > Mn > P), and Pacific silver fir (K > Mg > Ca > Mn > P > N).


1982 ◽  
Vol 60 (8) ◽  
pp. 1561-1568 ◽  
Author(s):  
Håkan Staaf ◽  
Björn Berg

Plant nutrient dynamics in decomposing needle litter were measured during a 5-year period in a Scots pine forest in central Sweden. As seen over the whole 5-year period, the nutrients were retained (to a litter weight loss of about 75%) in the order Mn < Ca < K < Mg < S < N < P. During the first 1.5 years there was a net increase of N and P whereafter a net release took place. A similar but less pronounced development could be seen for S, whereas Ca, K, Mn, and Mg were released from the start of the incubation. It is suggested that P was the most limiting element for microbial activity during this first phase. There appeared to be only little initial leaching from the litter and the different behaviours of the elements could largely be explained by their concentration in litter in relation to the needs of microorganisms and to their solubility. K and Mg were the elements that were released at rates most similar to organic matter weight loss.


2009 ◽  
Vol 2009 ◽  
pp. 1-4 ◽  
Author(s):  
Ryan C. Case ◽  
John Schweinfurth

Objective. Obesity is a significant contributor to oxygen demand and dynamic airway obstruction. The objective of the current study is to determine the long-term success of conservative measures directed toward weight reduction on airway management without respect to specific airway disease etiology.Methods. Patients with chronic airway obstruction secondary anatomic lesions or obstructive sleep apnea were recruited and followed prospectively. Demographics, initial and final weights, diagnosis, and followup information were recorded. Patients were referred to a registered dietician, provided counseling, and started on a weight-loss regimen. Outcome measures were change in body mass index (BMI) and rate of decannulation from weight loss alone.Results. Of fourteen patients, ten remained tracheostomy-dependent and four had high-grade lesions with the potential for improvement in oxygen demand and dynamic airway collapse with weight loss. The mean follow up period was 25 months. The mean change in BMI was an increase of 1.4 kg/m2per patient.Conclusions. Conservative measures alone were not effective in achieving weight reduction in the population studied. This may be due to comorbid disease and poor compliance. The promise of decannulation was an insufficient independent motivator for weight loss in this study. Although the theoretical benefits of weight loss support its continued recommendation, the long-term success rate of conservative measures is low. More aggressive facilitated interventions including pharmacotherapy or bariatric surgery should be considered early in the course of treating airway disease complicated by obesity.


2021 ◽  
Author(s):  
Niccolò Petrucciani ◽  
Francesco Martini ◽  
Marine Benois ◽  
Radwan Kassir ◽  
Hubert Boudrie ◽  
...  

Abstract Purpose Laparoscopic adjustable gastric banding (LAGB) was a common procedure worldwide but associated with a high rate of long-term failure. This study aims to evaluate the safety and effectiveness of conversion to one anastomosis gastric bypass (OAGB) after failed LAGB. Materials and Methods We undertook a retrospective analysis of a prospectively maintained database in a tertiary referral center for bariatric surgery. All cases of revisional OAGB with a biliopancreatic limb (BPL) of 150 cm after failed LAGB performed between 2010 and 2016 were analyzed. Results Overall, 215 patients underwent conversion from LAGB to OAGB. Indication for surgery was primary weight loss (WL) failure in 30.7% of cases and long-term complications in the remaining patients, with or without associated weight regain. At the time of OAGB, the mean age was 43.2 ± 10.5 years and the mean BMI was 42 ± 6.9. Overall postoperative morbidity was 13.5%. The postoperative abscess ± leak rate was 5.9% in the overall population. Two years after OAGB, 9.7% of patients were lost to follow-up, % excess weight loss (EWL) was 88.2 ± 23.9, and % total weight loss (TWL) was 38.7 ± 9.3. At 5 years, 16.6% of patients were lost to follow-up, %EWL was 82.4 ± 25, and %TWL was 36.1 ± 10. There was no statistical difference in complication rates or WL results between the one-stage and two-stage approaches. Conclusion OAGB with a 150-cm BPL represents a safe and effective option after failed LAGB. Both synchronous OAGB and two-step revisional OAGB guarantee satisfying results in terms of postoperative morbidity and WL outcomes. Graphical abstract (PLEASE CORRECT THE GRAPHICAL ABSTRACT !!! 215 PATIENTS INSTEAD OF 250


2021 ◽  
Vol 2021 ◽  
pp. 1-6
Author(s):  
Saqib Saeed ◽  
Leaque Ahmed ◽  
Khuram Khan ◽  
Sanjiv Gray ◽  
Kashif Saeed ◽  
...  

Background. Laparoscopic Roux-en-Y gastric bypass (LRYGB) and laparoscopic sleeve gastrectomy (LSG) have comparable weight loss outcomes in a general bariatric population. Objectives. This study aimed to investigate whether similar outcomes can be observed in Hispanic and African American population. Settings. Community Hospital in New York, New York, United States. Methods. The 5-year prospective data of patients who underwent LRYGB and LSG at a single center were retrospectively reviewed. The long-term weight loss outcomes between patients who had LRYGB and LSG were compared after adjusting for age, sex, race, diabetes mellitus, and hypertension with the linear mixed-effects or logistic regression model. Results. Most patients were Hispanic (59.2%) and African American (22.7%). The mean% total weight loss (%TWL) values of patients with BMI <45 kg/m2 who underwent LRYGB and LSG were 73% and 62% after 1 year, 69% and 56% after 2 years, and 71% and 54% after 5 years, respectively. In patients with a BMI of 45–50 kg/m2 who underwent LRYGB and LSG, the mean %TWL values were 69% and 56% after 1 year, 75% and 58% after 2 years, and 57% and 45% after 5 years, respectively. Meanwhile, the %TWL values of patients with BMI >50 kg/m2 who had LRYGB and LSG were 53% and 42% after 1 year, 53% and 45% after 2 years, and 49% and 36% after 5 years, respectively. All results were statistically significant p < 0.0001 and remained valid after adjusting for cofactors. Conclusion. Thus, LRYGB had consistent and sustained long-term weight loss outcomes compared with LSG in a predominantly ethnically diverse patient population with different BMI. Our study had several limitations in that it is retrospective in nature and some patients were lost to follow-up during the study period.


1987 ◽  
Vol 17 (6) ◽  
pp. 499-509 ◽  
Author(s):  
Robert L. Edmonds

Decomposition rates and nutrient dynamics in small-diameter woody litter (twigs, cones, and branches) were studied in four ecosystems in western Washington: high elevation Pacific silver fir (Abiesamabilis (Dougl.) Forbes) and low elevation Douglas-fir (Pseudotsugamenziesii (Mirb.) Franco), western hemlock (Tsugaheterophylla (Raf.) Sarg.), and red alder (Alnusrubra Bong.). Conifer twigs decomposed faster (k = 0.14–0.24 year−1) than cones (k = 0.09–0.12 year−1) and branches (k = 0.03–0.11 year−1). Decomposition constants were related better to initial lignin/initial N ratios (r = −0.64) than initial lignin concentrations. N was generally the least mobile nutrient while K was the most mobile. Many nutrients were strongly immobilized in conifer fine woody litter, including N, Mg, Mn, and Ca. There was little immobilization of N in red alder branches. N release from decomposing woody litter appears to be controlled by a critical C/N ratio. This critical C/N ratio, however, was not constant and increased as the substrate decomposition rate increased.


2019 ◽  
Vol 85 (12) ◽  
pp. 1386-1390
Author(s):  
Tristan Greilsamer ◽  
David Jacobi ◽  
Michel Krempf ◽  
Guillaume Boulanger ◽  
Marie Guillouche ◽  
...  

Vertical banded gastroplasty (VBG), introduced by Mason in 1982, is now discarded because of important long-term complications and technical difficulties to do revisional surgery. We investigated the long-term complications of VBG in our center and compared it with the literature data. Patients who underwent an open VBG at the University Hospital of Nantes between October 1991 and May 2006 were included. We reviewed preoperative clinical data, long-term outcome in weight loss, complications, and revisional surgeries with a long follow-up. Sixty-three patients (52 women and 11 men) were included, with a mean age of 43 ± 10 years and a body mass index of 46.7 ± 8.3 kg/m. The mean follow-up was 8.2 ± 4.2 years. At the end of follow-up, the mean excess weight loss (EWL) was 29.8%. Long-term success (excess weight loss > 50%) of the procedure was observed in 25 patients (39.7%). A second intervention was performed in 15 patients (23.8%), and three needed a third redo procedure. Six patients (40%) had this new intervention for late complications, and nine (60%) for weight regain. Weight loss is satisfying in the long term although the rate of reintervention is high. Long-term complication can be severe, especially with gastric stenosis that could lead to esophageal cancer. A second reintervention could be technically demanding, especially by laparoscopy, and the patients should be referred to a specialized center.


2021 ◽  
Author(s):  
Alper Ozturk ◽  
Yusuf Celik

Abstract Background: To investigate the effect of Sleeve Gastrectomy (SG) in patient with a Body Mass Index (BMI)≥50 kg/m² groups on weight loss and comorbidities as the first and alone option. Methods: The prospectively maintained data obtained from patients with a BMI ≥ 50 who underwent SG between February, 2016 - February, 2020 were evaluated. Results: 138 patient with a BMI≥50 kg/m² underwent surgery. Average BMI: 56.36±7.661, age 37.41±12.33. Forty eight patients underwent cholecystectomy and/or hiatal hernia repair (HHR), as well. The percentage of excess weight loss (%EWL) values of patients in months 3, 6, 12 and 24 were 36.70%, 54.34%, 67.58%, 72.45%, 74.14% and the percentage of total weight loss (TWL%) values were 20.17%, 29.59%, 36.93%, 39.62%, 40.65%, respectively. The mean BMI values in month 0 and in the 3rd, 6th, 12th, 18th, 24th months were 56.36, 45.10, 39.76, 35.48, 33.96 and 33.42 respectively. The values measured in the month 0 and in the 3rd, 6th, 12th, 18th, 24th months were significantly different for EWL%, TWL% and BMI variables (p<0.001), but EWL% (p = 0.527), TWL% (p = 0.396) and BMI (p=0.657) were not found significantly different between the 18th and 24th months. When EWL% was accepted as ≥50, the success rate was found to be 93.55%(n=93) and 92%(n=50) in months 12 and 24, respectively. Conclusion: SG appears to be an effective and safe treatment method as the first option for weight loss and for treatment of concomitant disorders in patient with a BMI ≥ 50 kg/m² groups. Further long-term studies are needed to confirm these results.


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