Effects of experimentally added salmon subsidies on resident fishes via direct and indirect pathways

Artificial additions of nutrients of differing forms such as salmon carcasses and analog pellets (i.e. pasteurized fishmeal) have been proposed as a means of stimulating aquatic productivity and enhancing populations of anadromous and resident fishes. Nutrient mitigation to enhance fish production in stream ecosystems assumes that the central pathway by which effects occur is bottom-up, through aquatic primary and secondary production, with little consideration of reciprocal aquatic-terrestrial pathways. The net outcome (i.e. bottom-up vs. top-down) of adding salmon-derived materials to streams depend on whether or not these subsidies indirectly intensify predation on in situ prey via increases in a shared predator or alleviate such predation pressure. We conducted a 3-year experiment across nine tributaries of the N. Fork Boise River, Idaho, USA, consisting of 500-m stream reaches treated with salmon carcasses (n = 3), salmon carcass analog (n = 3), and untreated control reaches (n = 3). We observed 2–8 fold increases in streambed biofilms in the 2–6 weeks following additions of both salmon subsidy treatments in years 1 and 2 and a 1.5-fold increase in standing crop biomass of aquatic invertebrates to carcass additions in the second year of our experiment. The consumption of benthic invertebrates by stream fishes increased 110–140% and 44–66% in carcass and analog streams in the same time frame, which may have masked invertebrate standing crop responses in years 3 and 4. Resident trout directly consumed 10.0–24.0 g·m-2·yr-1 of salmon carcass and \u3c1–11.0 g·m-2·yr-1 of analog material, which resulted in 1.2–2.9 g·m-2·yr-1 and 0.03–1.4 g·m-2·yr-1 of tissue produced. In addition, a feedback flux of terrestrial maggots to streams contributed 0.0–2.0 g·m-2·yr-1 to trout production. Overall, treatments increased annual trout production by 2–3 fold, though density and biomass were unaffected. Our results indicate the strength of bottom-up and top-down responses to subsidy additions was asymmetrical, with top-down forces masking bottom-up effects that required multiple years to manifest. The findings also highlight the need for nutrient mitigation programs to consider multiple pathways of energy and nutrient flow to account for the complex effects of salmon subsidies in stream-riparian ecosystems

The Early Evolution of Biting–Chewing Performance in Hexapoda

Insects show a plethora of different mandible shapes. It was advocated that these mandible shapes are mainly a function of different feeding habits. This hypothesis was tested on a larger sampling of non-holometabolan biting–chewing insects with additional tests to understand the interplay of mandible function, feeding guild, and phylogeny. The results show that at the studied systematic level, variation in mandible biting–chewing effectivity is regulated to a large extent by phylogenetic history and the configuration of the mandible joints rather than the food preference of a given taxon. Additionally, lineages with multiple mandibular joints such as primary wingless hexapods show a wider functional space occupation of mandibular effectivity than dicondylic insects (= silverfish + winged insects) at significantly different evolutionary rates. The evolution and occupation of a comparably narrow functional performance space of dicondylic insects is surprising given the low effectivity values of this food uptake solution. Possible reasons for this relative evolutionary “stasis” are discussed

The architecture and effect of participation: a systematic review of community participation for communicable disease control and elimination. Implications for malaria elimination

Community engagement and participation has played a critical role in successful disease control and elimination campaigns in many countries. Despite this, its benefits for malaria control and elimination are yet to be fully realized. This may be due to a limited understanding of the influences on participation in developing countries as well as inadequate investment in infrastructure and resources to support sustainable community participation. This paper reports the findings of an atypical systematic review of 60 years of literature in order to arrive at a more comprehensive awareness of the constructs of participation for communicable disease control and elimination and provide guidance for the current malaria elimination campaign.Evidence derived from quantitative research was considered both independently and collectively with qualitative research papers and case reports. All papers included in the review were systematically coded using a pre-determined qualitative coding matrix that identified influences on community participation at the individual, household, community and government/civil society levels. Colour coding was also carried out to reflect the key primary health care period in which community participation programmes originated. These processes allowed exhaustive content analysis and synthesis of data in an attempt to realize conceptual development beyond that able to be achieved by individual empirical studies or case reports.Of the 60 papers meeting the selection criteria, only four studies attempted to determine the effect of community participation on disease transmission. Due to inherent differences in their design, interventions and outcome measures, results could not be compared. However, these studies showed statistically significant reductions in disease incidence or prevalence using various forms of community participation. The use of locally selected volunteers provided with adequate training, supervision and resources are common and important elements of the success of the interventions in these studies. In addition, qualitative synthesis of all 60 papers elucidates the complex architecture of community participation for communicable disease control and elimination which is presented herein.The current global malaria elimination campaign calls for a health systems strengthening approach to provide an enabling environment for programmes in developing countries. In order to realize the benefits of this approach it is vital to provide adequate investment in the 'people' component of health systems and understand the multi-level factors that influence their participation. The challenges of strengthening this component of health systems are discussed, as is the importance of ensuring that current global malaria elimination efforts do not derail renewed momentum towards the comprehensive primary health care approach. It is recommended that the application of the results of this systematic review be considered for other diseases of poverty in order to harmonize efforts at building 'competent communities' for communicable disease control and optimising health system effectiveness

NACA Research Memorandums

A heat-transfer investigation was conducted with water flowing in an electrically heated Inconel tube with an inside diameter of 0.204 inch and a length-diameter ratio of 50 for ranges of Reynolds number up to 100,000 and of entrance pressure up to 200 inches of mercury gage. Correlation of average heat-transfer coefficients was obtained by use of the familiar Nusselt relation, wherein the physical properties of water were evaluated at an average bulk temperature. For conditions in which no boiling occurred, the data gave a good correlation. Runs made in the nucleate-boiling region, however, gave higher values of heat-transfer coefficient than would be predicted by the Nusselt relation

Research Notes: Iowa State University and United States Department of Agriculture

In 1968 Walter R. Fehr, Department of Agronomy, Iowa State University, observed sterile plants in a single plant progeny row of the cultivar 'Hark'. Further analyses by Fehr indicated that sterility existed in both sexes and that it was a recessive genetic trait (Fehr, personal communication, 1970). The current research effort began in 1970.</p