Effect of risk aversion on prioritizing conservation projects

Conservation outcomes are uncertain. Agencies making decisions about what threat mitigation actions to take to save which species frequently face the dilemma of whether to invest in actions with high probability of success and guaranteed benefits or to choose projects with a greater risk of failure that might provide higher benefits if they succeed. The answer to this dilemma lies in the decision maker's aversion to risk—their unwillingness to accept uncertain outcomes. Little guidance exists on how risk preferences affect conservation investment priorities. Using a prioritization approach based on cost effectiveness, we compared 2 approaches: a conservative probability threshold approach that excludes investment in projects with a risk of management failure greater than a fixed level, and a variance‐discounting heuristic used in economics that explicitly accounts for risk tolerance and the probabilities of management success and failure. We applied both approaches to prioritizing projects for 700 of New Zealand's threatened species across 8303 management actions. Both decision makers’ risk tolerance and our choice of approach to dealing with risk preferences drove the prioritization solution (i.e., the species selected for management). Use of a probability threshold minimized uncertainty, but more expensive projects were selected than with variance discounting, which maximized expected benefits by selecting the management of species with higher extinction risk and higher conservation value. Explicitly incorporating risk preferences within the decision making process reduced the number of species expected to be safe from extinction because lower risk tolerance resulted in more species being excluded from management, but the approach allowed decision makers to choose a level of acceptable risk that fit with their ability to accommodate failure. We argue for transparency in risk tolerance and recommend that decision makers accept risk in an adaptive management framework to maximize benefits and avoid potential extinctions due to inefficient allocation of limited resources. El Efecto de la Aversión de Riesgo sobre la Priorización de Proyectos de Conservación     

Visions and strategies for growth management: Teller County/Woodland Park example

This article is the third in a series prepared to explain the Teller County growth management planning process. Once it was determined by local decision-makers that Teller County, Colorado, would pursue a policy of directed growth, concepts based on this policy were developed. These concepts presented visions and options for the future. Landscape plans then were developed for Teller County and the City of Woodland Park planning area so that these options could be visualized by local leaders and the public. The landscape plans were used as part of the ongoing citizen involvement process to inform the public about the options for growth management. To provide even more information, detailed designs were developed for specific areas in the county. From the landscape plan, public involvement effort, and detailed designs, specific implementation measures were identified, discussed, and adopted. These measures included guidelines for administration, so that county and city goals could be linked to the actual day-to-day management of development proposals. Paper 3 in a series of 3.     

Influences on the quality of supervisor–subordinate relations: The role of time-pressure,organizational commitment,and locus of control

Despite a growing literature devoted to the study of differences in the quality of leader–member exchange, little empirical evidence is available concerning factors that influence the degree of differentiation among leader–member dyads on the dimension of quality of working relationships. As time-pressure has been suggested as one potential influence, the impact of time-based stress on leader–member exchange was examined with a sample of 138 loan officers representing 24 bank branches. Results indicated that unit-level variability on leader–member exchange was inversely related with time-based stress, while unit-level mean on leader–member exchange was positively related with time-based stress. Additionally, leader–member exchange acted as a mediator of the relation between employee locus of control (a suspected antecedent of dyadic quality) and organizational commitment (a suspected outcome), while employee locus of control correlated with leader–member exchange, and leader–member exchange correlated with employee organizational commitment. The results suggest the usefulness of considering time-based stress in conjunction with current models of leadership.     

A comparison of the particle track and α-spectrometric techniques in excess thorium-230 dating of Eastern Atlantic pelagic sediments

The particle track analysis and α-spectrometric techniques have been applied to a comparative study of excess ²³⁰Th dating of three deep-sea cores from the Eastern Atlantic. Both methods yield similar sediment accumulation rates. Limitations of the α-track phase of the particle track detection process, arising from the non-specific determination of ²³⁰Th and from the mobility of some alpha-emitting daughters, suggest that details of the sedimentation record may fail to be identified. The conventional radiochemical technique, on the other hand, specifically isolates all the radionuclides of interest but at the expense of a more complex experimental procedure and a longer sample processing time. The combined particle track technique (i.e. α and fission track analyses) therefore seems excellently suited to a complementary role in tandem with the α-spectrometric method of ²³⁰Th dating. Uranium determination by the fission track technique is accurate and rapid, showing good agreement with the α-spectrometric method.     

Biodegradation of Polyaromatics Synthesized by Peroxidase-Catalyzed Free-Radical Polymerization

Polymers formed from peroxidase-based free-radical polymerization reactions were characterized for rates of mineralization against lignin and humic acid controls. Degradation studies were carried out in soil systems over 202 days and cumulative net CO₂ was determined. Whereas mineralization of the humic acid and alkali lignin controls totaled ca. 20% at the end of the test exposure, there was essentially no net mineralization of the hydrolytic lignin control. Mineralization of the test samples totaled 5% for poly(p-ethylphenol) and 11% for poly(m-cresol). At the same time, mineralization of the poly(p-phenyl phenol) totaled 64%. Conversely, the readily biodegradable polymers cellulose and PHB reached values of 91 to 97% in less than 60 days. Our data suggest that the mineralization kinetics of the enzymatically derived polyaromatics mimic those of the naturally occurring heteropolymers.     

Prenatal evaluation and in utero platelet transfusion for thrombocytopenia absent radii syndrome

A fetus with absent radii in both forearms was discovered on routine ultrasound examination performed at 18 weeks of pregnancy. No other significant abnormalities were found, and no signs of haemorrhage were detected. Serial ultrasound examinations revealed no evidence of fetal internal bleeding. At 37 weeks of pregnancy, a CBC obtained by cordocentesis under ultrasound guidance confirmed the diagnosis of thrombocytopenia absent radii (TAR) syndrome. Apheresis platelets were transfused into the umbilical vein to correct the thrombocytopenia and was followed by an uncomplicated delivery. No bleeding was encountered during the remainder of the baby's neonatal course. We conclude that TAR syndrome can be readily identified prenatally on sonogram, and if severe thrombocytopenia is confirmed by cordocentesis, platelets should be transfused to diminish the risk of serious internal bleeding during and immediately after delivery.     

Third trimester ultrasound diagnosis of intestinal atresia following clinical evidence of polyhydramnios

Five cases of intestinal atresia were diagnosed using real-time ultrasonography following clinical evidence of polyhydramnios. No correlation was noted between ultrasound findings and the severity of the lesions. Two of the five babies died at 35 and 77 days respectively. Prematurity and presence of other abnormalities were factors in the deaths.     

Risk factors associated with transcervical CVS losses

Factors found to be associated with pregnancy loss after transcervical CVS were race (higher for non-white), history of spontaneous abortion, unplanned pregnancy, history of spotting or bleeding during the pregnancy prior to CVS, and placental position (higher for fundal or lateral locations). Whether the increase in loss risk is due to the factor, per se, or the factor plus the CVS cannot be determined due to the lack of appropriate control data.