Ecosystem Services of Tropical Dry Forests Maass, J. Manuel; Balvanera, Patricia; Castillo, Alicia ...
Ecology and society,
06/2005, Letnik:
10, Številka:
1
Journal Article
Recenzirano
Odprti dostop
In the search for an integrated understanding of the relationships among productive activities, human well-being, and ecosystem functioning, we evaluated the services delivered by a tropical dry ...forest (TDF) ecosystem in the Chamela Region, on the Pacific Coast of Mexico. We synthesized information gathered for the past two decades as part of a long-term ecosystem research study and included social data collected in the past four years using the Millennium Ecosystem Assessment (MA) conceptual framework as a guide. Here we identify the four nested spatial scales at which information has been obtained and emphasize one of them through a basin conceptual model. We then articulate the biophysical and socioeconomic constraints and drivers determining the delivery of ecosystem services in the Region. We describe the nine most important services, the stakeholders who benefit from those services, and their degree of awareness of such services. We characterize spatial and temporal patterns of the services’ delivery as well as trade-offs among services and stakeholders. Finally, we contrast three alternative future scenarios on the delivery of ecosystem services and human well-being. Biophysical and socioeconomic features of the study site strongly influence human–ecosystem interactions, the ecosystem services delivered, the possible future trajectories of the ecosystem, and the effect on human well-being. We discuss future research approaches that will set the basis for an integrated understanding of human–ecosystem interactions and for constructing sustainable management strategies for the TDF.
A prospective analysis evaluating neurologic outcome after early versus late surgery for cervical spinal cord trauma.
The study was conducted to determine whether neurologic and functional outcome is ...improved in traumatic cervical spinal cord-injured patients (C3-T1, American Spinal Injury Association grades A-D) who had early surgery (<72 hours after spinal cord injury) compared with those patients who had late surgery (>5 days after spinal cord injury).
There is considerable controversy as to the appropriate timing of surgical decompression and stabilization for cervical spinal cord trauma. There have been numerous retrospective studies, but no prospective studies, to determine whether neurologic outcome is best after early versus late surgical treatment for cervical spinal cord injury.
Patients meeting appropriate inclusion criteria were randomized to an early (<72 hours after spinal cord injury) or late (>5 days after spinal cord injury) surgical treatment protocol. The neurologic and functional outcomes were recorded from the acute hospital admission to the most recent follow-up.
Comparison of the two groups showed no significant difference in length of acute postoperative intensive care stay, length of inpatient rehabilitation, or improvement in American Spinal Injury Association grade or motor score between early (mean, 1.8 days) versus late (mean, 16.8 days) surgery.
The results of this study reveal no significant neurologic benefit when cervical spinal cord decompression after trauma is performed less than 72 hours after injury (mean, 1.8 days) as opposed to waiting longer than 5 days (mean, 16.8 days).
Background Post-discharge surgical care fragmentation is defined as readmission to any hospital other than the hospital at which the surgery was performed. The objective of this study was to assess ...the impact of fragmented readmissions within the first year following orthotopic liver transplant (OLT). Study Design The Healthcare Cost and Utilization Project State Inpatient Databases (HCUP SID) for Florida and California from 2006-2011 were used to identify OLT patients. Post-discharge fragmentation was defined as any readmission to a non-index hospital, including readmitted patients transferred to the index hospital after 24 hours. Outcomes included adverse events defined as 30-day mortality and 30-day readmission following a fragmented readmission. All statistical analyses considered a hierarchical data structure and were performed with multilevel, mixed-effects models. Results 2,996 patients with 7,485 readmission encounters at 299 hospitals were analyzed. 1,236 (16.5%) readmissions were fragmented. Following adjustment for age, sex, readmission reason, index liver transplant cost, readmission length of stay, number of previous readmissions, and time from transplant, post-discharge fragmentation increased the odds of both 30-day mortality (OR 1.75, 1.16 - 2.65) and 30-day readmission (OR 2.14, 1.83 - 2.49). Predictors of adverse events following a fragmented readmission included: increased number of previous readmissions (OR 1.07, 1.01 - 1.14) and readmission within 90 days of OLT (OR 2.19, 1.61 - 2.98). Conclusion Post-discharge fragmentation significantly increases the risk of both 30-day mortality and subsequent readmission after a readmission in the first year after OLT. More inpatient visits prior to a readmission and less time elapsed from index surgery increases the odds of an adverse event following discharge from a fragmented readmission. These parameters could guide transfer decisions for patients with post-discharge fragmentation.
To compare the performance of various liver disease scoring systems in predicting early mortality after transjugular intrahepatic portosystemic shunt (TIPS) creation.
In this single-institution ...retrospective study, eight scoring systems were used to grade liver disease in 211 patients (male-to-female ratio = 131:80; mean age, 54 y) before TIPS creation from 1999-2011. Scoring systems included bilirubin level, Child-Pugh (CP) score, Model for End-Stage Liver Disease (MELD) and Model for End-Stage Liver Disease sodium (MELD-Na) score, Emory score, prognostic index (PI), Acute Physiology and Chronic Health Evaluation (APACHE) 2 score, and Bonn TIPS early mortality (BOTEM) score. Medical record review was used to identify 30-day and 90-day clinical outcomes. The relationship of scoring parameters with mortality outcomes was assessed with multivariate analysis, and the relative ability of systems to predict mortality after TIPS creation was evaluated by comparing area under receiver operating characteristic (AUROC) curves.
TIPS were successfully created for variceal hemorrhage (n = 121), ascites (n = 72), hepatic hydrothorax (n = 15), and portal vein thrombosis (n = 3). All scoring systems had a significant association with 30-day and 90-day mortality (P<.050 in each case) on multivariate analysis. Based on 30-day and 90-day AUROC, MELD (0.878, 0.816) and MELD-Na (0.863, 0.823) scores had the best capability to predict early mortality compared with bilirubin (0.786, 0.749), CP (0.822, 0.771), Emory (0.786, 0.681), PI (0.854, 0.760), APACHE 2 (0.836, 0.735), and BOTEM (0.798, 0.698), with statistical superiority over bilirubin, Emory, and BOTEM scores.
Several liver disease scoring systems have prognostic value for early mortality after TIPS creation. MELD and MELD-Na scores most effectively predict survival after TIPS creation.
Both donor and recipient race impact outcomes after liver transplantation (LT), especially for hepatitis C virus (HCV). The interaction and simultaneous impact of both on patient survival is not ...clearly defined. The purpose of this study was to examine the impact of donor and recipient race on recipient and graft survival after HCV-related LT using the United Network for Organ Sharing database.
A total of 16,053 recipients (75.5% white, 9.3% black, and 15.2% Hispanic) who underwent primary LT for HCV between 1998 and 2008 were included. Cox regression models were used to assess the association between recipient/donor race and patient survival.
A significant interaction between donor and recipient race was noted (P=0.01). Black recipients with white donors had a higher risk of patient mortality (adjusted hazard ratio, 1.66; 95% confidence interval, 1.47-1.87) compared with that of white recipients with white donors. In contrast, the pairing of Hispanic recipients with black donors was associated with a lower risk of recipient mortality compared with that of white recipients with white donors (adjusted hazard ratio, 0.64; 95% confidence interval, 0.46-0.87). Similar results were noted for graft failure.
In conclusion, the impact of donor and recipient race on patient survival varies substantially by the matching of recipient/donor race.
To assess clinical outcomes of transjugular intrahepatic portosystemic shunt (TIPS) treatment of variceal hemorrhage.
A total of 128 patients (82 men and 46 women; mean age, 52 y) with liver ...cirrhosis and refractory variceal hemorrhage underwent TIPS creation from 1998 to 2010. Mean Child-Pugh and Model for End-stage Liver Disease (MELD) scores were 9 and 18, respectively. From 1998 to 2004, 12-mm Wallstents (n = 58) were used, whereas from 2004 to 2010, 10-mm VIATORR covered stent-grafts (n = 70) were used. Technical success, hemodynamic success, complications, shunt dysfunction, recurrent bleeding, and overall survival were assessed.
Technical and hemodynamic success rates were 100% and 94%, respectively. Mean portosystemic gradient reduction was 13 mm Hg. Complications at 30 days included encephalopathy (14%), renal failure (5.5%), infection (1.6%), and liver failure (0.8%). Shunt patency rates were 93%, 82%, and 60% at 30 days, 1 year, and 2 years, respectively. Dysfunction, or loss of TIPS primary patency, occurred more with Wallstent versus VIATORR TIPSs (29% vs 11%; P = .009). Recurrent bleeding incidences were 9%, 22%, and 29% at 30 days, 1 year, and 2 years, respectively, and were similar between Wallstent and VIATORR TIPSs (19% vs 19%; P = .924). Variceal embolization significantly reduced recurrent bleeding rates (5% vs 25%; P = .013). Overall survival rates were 80%, 69%, and 65% at 30 days, 1 year, and 2 years, respectively, and were similar between Wallstent and VIATORR TIPSs (35% vs 26% mortality rate; P = .312). Advanced MELD score was associated with increased mortality on multivariate analysis.
Wallstent and VIATORR TIPSs effectively treat variceal hemorrhage, particularly when accompanied by variceal embolization. Although TIPS with a VIATORR device showed improved shunt patency, patient survival is similar to that with Wallstent TIPS. These results further validate TIPS creation for refractory variceal bleeding.
Background & Aims: Mild to moderate hepatic iron loading is common in patients with chronic hepatitis C. We sought to determine whether mutations in the hemochromatosis gene,
HFE, are associated with ...iron overload and acceleration of disease progression in hepatitis C patients.
Methods: A total of 316 patients with chronic hepatitis C were studied: 198 consecutive patients undergoing liver biopsy for compensated liver disease and 118 who underwent liver transplantation for end-stage liver disease. Serum iron studies, quantitative hepatic iron concentration, histologic activity index, and
HFE genotype were determined.
Results: Among patients with compensated liver disease, the presence of
HFE mutations was independently associated with elevations in serum iron level, serum transferrin-iron saturation, serum ferritin level, and hepatic iron index (
P < 0.05). After adjustment for duration of infection with hepatitis C virus,
HFE mutations were also independently associated with the presence of bridging fibrosis or cirrhosis (odds ratio, 18; 95% confidence interval, 1.7–193).
HFE mutations were not independently associated with iron loading in patients with end-stage liver disease. There was no significant difference in the prevalence of
HFE mutations between patients with compensated and end-stage liver disease (42% vs. 33%, respectively;
P = 0.67).
Conclusions: The presence of
HFE mutations is independently associated with iron loading and advanced fibrosis in patients with compensated liver disease from chronic hepatitis C, especially after controlling for duration of disease. These results suggest that
HFE mutations accelerate hepatic fibrosis in hepatitis C but may not be responsible for progression to end-stage liver disease.
A prospective clinical study using magnetic resonance imaging of the cervical spine in a consecutive series of patients with cervical spine dislocations.
To determine the incidence of intervertebral ...disc herniations and injury to the spinal ligaments before and after awake closed traction reduction of cervical spine dislocations.
Prior series in which the prereduction imaging of disc herniations in the dislocated cervical spine are described have been anecdotal and have involved small numbers of patients. In addition, no uniform clinical criteria to define the presence of an intervertebral disc herniation in the dislocated cervical spine has been described. The incidence of disc herniations in the unreduced dislocated cervical spine is unknown.
Eleven consecutive patients with cervical spine dislocations who met the clinical criteria for an awake closed traction reduction had prereduction and postreduction magnetic resonance imaging. Using strict clinical criteria for the definition of an intervertebral disc herniation, the presence or absence of disc herniation, spinal ligament injury, and cord injury was determined. Neurologic status before, during, and after the closed reduction maneuver was documented.
Disc herniations were identified in 2 of 11 patients before reduction. Awake closed traction reduction was successful in 9 of the 11 patients. Of the nine patients with a successful closed reduction, two had disc herniations before reduction, and five had disc herniations after reduction. No patient had neurologic worsening after attempted awake closed traction reduction.
The process of closed traction reduction appears to increase the incidence of intervertebral disc herniations. The relation of these findings, however, to the neurologic safety of awake closed traction reduction remain unclear.
This study reviewed 36 retrospective patients who underwent surgeries for rare cervico-thoracic junctional problems.
The authors review cervico-thoracic junctional disorders and study diagnostic ...methods, surgical approaches, surgical outcomes, and associated complications.
The literature is sparse on cervico-thoracic junctional problems. This paper is the largest series to date on this subject.
Thirty-six patients who underwent surgeries for spinal problems at the cervico-thoracic region (C7-T3) were reviewed. These included 18 patients with trauma, 15 patients with tumors, 2 patients with herniated discs, and one patient with postlaminectomy instability. There were 20 males and 16 females. The age ranged from 17 to 83 years with a mean of 43.5 years. Surgically, 21 patients had only posterior procedures, that included 12 wiring, 5 Luque rodding, 1 plate-screw fixation for postlaminectomy instability, 1 transpedicular biopsy, 1 foraminotomy for herniated C7-T1 disc, and 1 costotransversectomy for T2-T3 herniated disc. Neurologically, the majority of traumatic patients presented with neurologic deficits (10 complete and 4 incomplete, and 1 root injuries), and nontraumatic disorders were associated with 10 incomplete cord syndromes and 5 root dysfunctions.
Follow-up average was 38 months based on 33 of 36 patients. There were three postoperative deaths (two sternotomies, one anterior C7 corpectomy). Neurologically, patients with complete cord injuries remained complete, whereas patients with incomplete or root deficits improved significantly. Complications included C6-C7 subluxation after C7-T2 fusion, pseudomeningocele, vocal cord paralysis, dysphagia, and Horner's syndrome. Other complications included wound infections, urinary tract infections, decubiti, deep vein thrombosis, pneumonia, and tumor recurrence.
In treating patients with cervico-thoracic problems, one should do careful clinical and radiologic survey to avoid missed or delayed diagnoses, and the surgeon must be thoroughly familiar with anterior and posterior landmarks and associated vital structures and remember that the cervico-thoracic junction is an area of potential instability particularly after trauma or laminectomy. Complications of surgery at the cervico-thoracic junction are frequent, and meticulous surgical techniques and postoperative care are important in the prevention of these complications.
We studied the morphology of the thoracic vertebrae in the spines of seventeen human cadavera in order to define parameters that could be used as guidelines for the placement of hooks and screws in ...the pedicles to obtain internal fixation. We also reviewed computerized tomographic scans of nineteen thoracic spines in living patients who had no evidence of any vertebral deformity. The transverse diameter of the pedicle, which helps to determine the size of the screw, ranged from a mean (and standard deviation) of 4.5 +/- 1.2 millimeters in the fourth thoracic vertebra to a mean of 7.8 +/- 2.0 millimeters in the twelfth thoracic vertebra. The pedicles were inclined anteromedially throughout the thoracic spine, and the angle ranged from 0.3 degree toward the midline in the twelfth thoracic vertebra to 13.9 degrees in the fourth thoracic vertebra. The morphometric data revealed wide variations in the dimensions of the pedicles, demonstrating the importance of accurate preoperative imaging with transaxial computerized tomographic scans to visualize the precise osseous margins and angles of insertion of the thoracic pedicles.
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