Fecundity and reproductive strategies in deep-sea incirrate octopuses (Cephalopoda: Octopoda)

Coleoid cephalopods show flexibility in their reproductive strategies or mode of spawning, which can range from simultaneous terminal spawning over a short period at the end of the animal’s life to continuous spawning over a long period of the animal’s life. Although a simultaneous terminal spawning strategy is typical of shallow water temperate octopuses, it is not known whether deep-sea octopods would have the same reproductive strategy. The reproductive strategies and fecundity were investigated in nine species of deep-sea incirrate octopuses: Bathypolypus arcticus, Bathypolypus bairdii, Bathypolypus ergasticus, Bathypolypus sponsalis, Bathypolypus valdiviae, Benthoctopus levis, Benthoctopus normani, Benthoctopus sp., and Graneledone verrucosa (total n = 85). Egg-length frequency graphs and multivariate analysis (principal components analysis) suggest that B. sponsalis has a synchronous ovulation pattern and therefore a simultaneous terminal spawning strategy. Although a simultaneous terminal spawning strategy is most likely for B. levis and B. normani, the egg-length frequency graphs and multivariate analysis also suggest a greater variation in egg-lengths which could lead to spawning over an extended period.     

USABILITY ASSESSMENTS FOR HYDROLOGIC FORECASTING DSS1

ABSTRACT: Usability assessments were used to obtain feedback on the development of a flood forecasting decision support system. The feedback was used to guide design of system functionality, interface, training, implementation, and operations. The usability process was user focused and was dependent upon implementation of a prototype system in an operational setting. This paper describes concepts and methods applied to collect reflective and objective data on DSS components and information outputs. The general structure of the usability assessments is discussed and results of assessments are summarized.     

International Society for Prenatal Diagnosis 2022 DEBATE: There should be formal accreditation and ongoing quality assurance/review for units offering fetal therapy that includes public reporting of outcomes

The field of fetal therapy has so far escaped from formal accreditation and quality control. Despite that, current published evidence shows that outcomes of interventions in younger fetal therapy centers are similar to what is achieved in more experienced centers and outcomes of interventions have improved over time. The question however remains what is not being published and what should be the standard of care, given the lack of level 1 evidence from randomized controlled trials for many interventions. Formal collaborative networks such as NAFTnet and others allow for anonymized benchmarking of center outcomes, without publicly shaming (and financially punishing) underperforming centers. Large registries also allow for tracking of rare complications and may result in improved patient outcomes over time. Core outcome sets, which could serve as a basis for outcome reporting, are available for some conditions, but certainly not for all, resulting in communication difficulties between centers. Formal accreditation, quality control, and outcome reporting are hard to implement, expensive, and may result in decreasing access to care by pushing smaller centers out of the market. Despite the existing difficulties, international societies have committed to quality improvement, and fetal therapy programs are strongly recommended to participate in voluntary outcome tracking.     

Support services for lift irrigation in Bangladesh

The impacts of changing support systems for lift irrigation in Bangladesh from the public to the private sector are examined. Data are presented from an extensive study undertaken by IIMI and the Bangladesh Agricultural University. The results of the study clearly demonstrate that farmers, small dealers and input sellers all feel that transfer to the private sector has improved the quality of support services. As a result of the privatization of support services, more fuel is available, it is closer to the farms and there is less adulteration. A similar case holds for agricultural chemicals. In addition to improving the situation for small farmers, privatization has created thousands of jobs for small traders and repair shops. Data are presented that document the improvements in services and the expansion of small traders. The one issue that still must be solved is the future of deep tubewells, as the article documents that they are not economically vaiable without Government subsidies.     

Life-history trade-offs influence disease in changing climates: strategies of an amphibian pathogen

Life-history trade-offs allow many animals to maintain reproductive fitness across a range of climatic conditions. When used by parasites and pathogens, these strategies may influence patterns of disease in changing climates. The chytrid fungus, Batrachochytrium dendrobatidis, is linked to global declines of amphibian populations. Short-term growth in culture is maximal at 17 degrees-25 degrees C. This has been used in an argument that global warming, which increases the time that amphibians spend at these temperatures in cloud-covered montane environments, has led to extinctions. Here we show that the amphibian chytrid responds to decreasing temperatures with trade-offs that increase fecundity as maturation rate slows and increase infectivity as growth decreases. At 17 degrees-25 degrees C, infectious zoospores encyst (settle and develop a cell wall) and develop into the zoospore-producing stage (zoosporangium) faster, while at 7 degrees-10 degrees C, greater numbers of zoospores are produced per zoosporangium; these remain infectious for a longer period of time. We modeled the population growth of B. dendrobatidis through time at various temperatures using delayed differential equations and observational data for four parameters: developmental rate of thalli, fecundity, rate of zoospore encystment, and rate of zoospore survival. From the models, it is clear that life-history trade-offs allow B. dendrobatidis to maintain a relatively high long-term growth rate at low temperatures, so that it maintains high fitness across a range of temperatures. When a seven-day cold shock is simulated, the outcome is intermediate between the two constant temperature regimes, and in culture, a sudden drop in temperature induces zoospore release. These trade-offs can be ecologically important for a variety of organisms with complex life histories, including pathogenic microorganisms. The effect of temperature on amphibian mortality will depend on the interaction between fungal growth and host immune function and will be modified by host ecology, behavior, and life history. These results demonstrate that B. dendrobatidis populations can grow at high rates across a broad range of environmental temperatures and help to explain why it is so successful in cold montane environments.     

PREDICTABILITY OF SURFACE WATER POLLUTION LOADING IN PENNSYLVANIA USING WATERSHED‐BASED LANDSCAPE MEASUREMENTS1

ABSTRACT: We formally evaluated the relationship between landscape characteristics and surface water quality in the state of Pennsylvania (USA) by regressing two different types of pollutant responses on landscape variables that were measured for whole watersheds. One response was the monthly exported mass of nitrogen estimated from field measurements, while the other response was a GIS‐modeled pollution potential index. Regression models were built by the stepwise selection protocol, choosing an optimal set of landscape predictors. After factoring out the effect of physiography, the dominant predictors were the proportion of “annual herbaceous” land and “total herbaceous” land for the nitrogen loading and pollution potential index, respectively. The strength of these single predictors is encouraging because the marginal land cover proportions are the simplest landscape measurements to obtain once a land cover map is in hand; however, the optimal set of predictors also included several measurements of spatial pattern. Thus, for watersheds at this general hierarchical scale, gross landscape pattern may be an important influence on instream pollution loading. Overall, there is strong evidence that using landscape measurements alone, obtained solely from remotely sensed data, can explain most of the water quality variability (R²= approx. 0.75) within these watersheds.     

Allowable levels of take for the trade in Nearctic songbirds

The take of Nearctic songbirds for the caged-bird trade is an important cultural and economic activity in Mexico, but its sustainability has been questioned. We relied on the theta-logistic population model to explore options for setting allowable levels of take for 11 species of passerines that were subject to legal take in Mexico in 2010. Because estimates of population size necessary for making-periodic adjustments to levels of take are not routinely available, we examined the conditions under which a constant level of take might contribute to population depletion (i.e., a population below its level of maximum net productivity). The chance of depleting a population is highest when levels of take are based on population sizes that happen to be much lower or higher than the level of maximum net productivity, when environmental variation is relatively high and serially correlated, and when the interval between estimation of population size is relatively long (> or = 5 years). To estimate demographic rates of songbirds involved in the Mexican trade we relied on published information and allometric relationships to develop probability distributions for key rates, and then sampled from those distributions to characterize the uncertainty in potential levels of take. Estimates of the intrinsic rate of growth (r) were highly variable, but median estimates were consistent with those expected for relatively short-lived, highly fecund species. Allowing for the possibility of nonlinear density dependence generally resulted in allowable levels of take that were lower than would have been the case under an assumption of linearity. Levels of take authorized by the Mexican government in 2010 for the 11 species we examined were small in comparison to relatively conservative allowable levels of take (i.e., those intended to achieve 50% of maximum sustainable yield). However, the actual levels of take in Mexico are unknown and almost certainly exceed the authorized take. Also, the take of Nearctic songbirds in other Latin American and Caribbean countries ultimately must be considered in assessing population-level impacts.