Temporal coherence among tropical coastal lagoons: a search for patterns and mechanisms.

Temporal coherence (i.e., the degree of synchronicity of a given variable among ecological units within a predefined space) has been shown for several limnological features among temperate lakes, allowing predictions about the structure and function of ecosystems. However, there is little evidence of temporal coherence among tropical aquatic systems, where the climatic variability among seasons is less pronounced. Here, we used data from long-term monitoring of physical, chemical and biological variables to test the degree of temporal coherence among 18 tropical coastal lagoons. The water temperature and chlorophyll-a concentration had the highest and lowest temporal coherence among the lagoons, respectively, whereas the salinity and water colour had intermediate temporal coherence. The regional climactic factors were the main factors responsible for the coherence patterns in the water temperature and water colour, whereas the landscape position and morphometric characteristics explained much of the variation of the salinity and water colour among the lagoons. These results indicate that both local (lagoon morphometry) and regional (precipitation, air temperature) factors regulate the physical and chemical conditions of coastal lagoons by adjusting the terrestrial and marine subsidies at a landscape-scale. On the other hand, the chlorophyll-a concentration appears to be primarily regulated by specific local conditions resulting in a weak temporal coherence among the ecosystems. We concluded that temporal coherence in tropical ecosystems is possible, at least for some environmental features, and should be evaluated for other tropical ecosystems. Our results also reinforce that aquatic ecosystems should be studied more broadly to accomplish a full understanding of their structure and function.

Continuous versus interrupted suture for hepatic artery anastomosis in liver transplantation: differences in the incidence of hepatic artery thrombosis.

BACKGROUND: Hepatic artery thrombosis (HAT) is a serious complication after orthotopic liver transplantation (OLT) and remains a significant cause of graft loss. HAT following OLT has been reported in 3% to 9% of patients. Among the surgical factors considered to be associated with HAT, arterial reconstruction might be the most important. The goal of this study was to compare the incidence of HAT between interrupted suture (IS) and continuous suture (CS) techniques during hepatic artery reconstruction in liver transplantation. METHODS: We performed a retrospective analysis of 200 consecutive liver transplantations occurring between May 2002 and December 2006, including medical records for: age, gender, cold ischemic time, warm ischemic time, type and number of arterial anastomosis. Hepatic artery anastomoses were performed using a 7-0 prolene with a running CS in the first 105 patients (CS group), and with an IS in the last 95 patients (IS group). RESULTS: Statistical analysis of age, gender, cold and warm ischemia time, and number of hepatic artery anastomoses was not different between the CS and IS groups. Eleven episodes of HAT were identified in the CS group (10%) and two episodes (2%) in the IS cohort, a significant difference (P = .0173). CONCLUSIONS: Our results suggested that IS might be a better choice for hepatic artery anastomosis with a lower incidence of HAT.

A new biliodigestive anastomosis technique after hepatic artery thrombosis as bridge to liver retransplantation: a case presentation.

Arterial complications after liver transplantation are frequent. Hepatic artery thrombosis (HAT) is usually associated with biliary complications. Herein we have reported a case of a patient who was admitted for jaundice, itch, and elevated aspartate aminotransferase and alanine aminotransferase levels at 6 weeks after liver transplantation. HAT associated with a biloma was diagnosed and an urgent operation performed requiring a new biliodigestive anastomosis technique. Fourteen months after the first transplant, the patient was retransplanted. The operation performed may be an alternative to treat biliary complications due to late HAT.

Validity of single- and multislice CT for assessment of mandibular condyle lesions.

OBJECTIVES: The purpose of this study was to evaluate and to compare the validity of the different CT image protocols (single- and multislice CT) in the analysis of simulated mandibular condyle lesions. METHODS: Simulated lesions were created in 15 dry mandibles using a dental round burr. The mandibles were then submitted to a single slice CT, and the same specimens were subsequently submitted to a multislice CT. The analysis was performed by two previously calibrated examiners in four protocols: (1) single slice-axial, (2) multislice-axial, (3) single slice-axial/multiplanar reconstructed (MPR) and (4) multislice-axial/MPR. The examiners evaluated the absence or presence of bony destruction and their localization in each protocol, considering also some bony erosion caused by its reabsorption. Statistical analysis was carried out using validity and chi(2) tests to compare the protocols. RESULTS: Protocol 1 presented the lowest validity values (62.7%). The validity of Protocols 2 and 3 was 66.2% and 72.7%, respectively. The highest value of validity was 93.1% and corresponded to Protocol 4. CONCLUSIONS: All CT-imaging protocols were considered accurate for mandibular condyle lesions assessment. The association of axial with MPR images using multislice CT demonstrated highest accuracy. A new imaging protocol was established for diagnosis of these lesions.

Community financed and operated health services: the case of the Ajo-Lukeville Health Service District.

The concept of a health service district, as a variation of the special tax district, is described and discussed. Tax districts have traditionally been used to support both capital construction (revenue bonds) and operational expenses of single-purpose governmental entities. The health service district, where authorized by state laws, may be used by local areas to subsidize the delivery of ambulatory health care. A particular case, the Ajo-Lukeville Health Service District in Arizona, illustrates what can be accomplished by this mechanism with the cooperation of local residents and outside agencies. Both the process of establishing such a district and the outcome of the Ajo-Lukeville experience is described. Reasons why health service districts may prove potentially attractive at this time are reviewed. Impediments to the development of more health service districts are also explored, including the lack of technical assistance, an inadequate awareness of the potential of health service districts, and the absence of a widespread orientation toward community financed and controlled health care. Movement in this direction should facilitate the development of additional health service districts.