Tests of a Rotenone-Impregnated Bait for Controlling Common Carp

An experimental rotenone-impregnated pelleted (approximately 10 mg/pellet) bait was tested in force-feeding and field-feeding experiments as a method of control for common carp (Cyprinus carpio). Mortality rates of force-fed fish ranged from less than 40% when fed one pellet to 100% when fed more than 10 pellets. Mortality occurred within 48 h. Mortality rates of control fish did not exceed 10%. In reservoir feeding trials in 1994 and 1995, carp were fed for 2-3 weeks on a non-toxic, vegetable-based bait dispensed by automatic feeders, followed by one feeding of the bait with rotenone added. Carp ceased feeding on the rotenone bait within minutes. Only three dead common carp were observed in 1994 and no dead carp were observed in 1995. The common carp would not consume enough rotenone pellets for a fatal dosage. Their selectiveness is attributed to their ability to detect the rotenone in the pellets. More palatable rotenone baits are needed for common carp

The influence of depth and velocity on age‐0 Scaphirhynchus sturgeon prey consumption: Implications for aquatic habitat restoration

After the pallid sturgeon (Scaphirhynchus albus) was listed as endangered in 1990, a variety of management actions focusing on early life history needs have been implemented to aid species recovery. Given the scarcity of age‐0 pallid sturgeon, managers and scientists have relied on sympatric congeners to evaluate the effectiveness of management actions in the short term; however, increased understanding of habitat requirements for age‐0 Scaphirhynchus sturgeon is still needed to appropriately focus management efforts. Recently, a lack of food‐producing and foraging habitats were proposed as potential limiting factors for pallid sturgeon, and the purpose of this study was to evaluate the current definition of these habitats at multiple spatial scales using data from age‐0 Scaphirhynchus sturgeon (shovelnose sturgeon [Scaphirhynchus platyrhynchus] or hybrid [shovelnose sturgeon x pallid sturgeon]). Results showed the water depths and velocities that currently define age‐0 pallid sturgeon foraging habitat had little effect on age‐0 Scaphirhynchus sturgeon prey consumption. Similar results occurred when evaluating the relationship between prey consumption and food‐producing habitat present 10, 20, and 30 days before capture. Assuming that individuals captured during this study were a valid surrogate, these results suggest that increasing foraging and food‐producing habitat as defined by the current depth and velocity criteria is unlikely to result in the desired benefits of increased growth and survival of age‐0 pallid sturgeon

Network deconvolution as a general method to distinguish direct dependencies in networks

Recognizing direct relationships between variables connected in a network is a pervasive problem in biological, social and information sciences as correlation-based networks contain numerous indirect relationships. Here we present a general method for inferring direct effects from an observed correlation matrix containing both direct and indirect effects. We formulate the problem as the inverse of network convolution, and introduce an algorithm that removes the combined effect of all indirect paths of arbitrary length in a closed-form solution by exploiting eigen-decomposition and infinite-series sums. We demonstrate the effectiveness of our approach in several network applications: distinguishing direct targets in gene expression regulatory networks; recognizing directly interacting amino-acid residues for protein structure prediction from sequence alignments; and distinguishing strong collaborations in co-authorship social networks using connectivity information alone. In addition to its theoretical impact as a foundational graph theoretic tool, our results suggest network deconvolution is widely applicable for computing direct dependencies in network science across diverse disciplines.National Institutes of Health (U.S.) (grant R01 HG004037)National Institutes of Health (U.S.) (grant HG005639)Swiss National Science Foundation (Fellowship)National Science Foundation (U.S.) (NSF CAREER Award 0644282

Study of downward Terrestrial Gamma-ray Flashes with the surface detector of the Pierre Auger Observatory

The surface detector (SD) of the Pierre Auger Observatory, consisting of 1660 water-Cherenkov detectors (WCDs), covers 3000 km2 in the Argentinian pampa. Thanks to the high efficiency of WCDs in detecting gamma rays, it represents a unique instrument for studying downward Terrestrial Gamma-ray Flashes (TGFs) over a large area. Peculiar events, likely related to downward TGFs, were detected at the Auger Observatory. Their experimental signature and time evolution are very different from those of a shower produced by an ultrahigh-energy cosmic ray. They happen in coincidence with low thunderclouds and lightning, and their large deposited energy at the ground is compatible with that of a standard downward TGF with the source a few kilometers above the ground. A new trigger algorithm to increase the TGF-like event statistics was installed in the whole array. The study of the performance of the new trigger system during the lightning season is ongoing and will provide a handle to develop improved algorithms to implement in the Auger upgraded electronic boards. The available data sample, even if small, can give important clues about the TGF production models, in particular, the shape of WCD signals. Moreover, the SD allows us to observe more than one point in the TGF beam, providing information on the emission angle

Age-0 Sturgeon Accessibility to Constructed and Modified Chutes in the Lower Missouri River

Shallow-water habitat is hypothesized to provide nursery habitat for young fish. The construction of side-channel chutes to restore shallow-water habitat is common in the lower Missouri River; however, a recent adaptive management strategy document (developed by a multiagency, multidiscipline team), as well as previous research, has suggested that the accessibility of chutes to age-0 Scaphirhynchus spp. (sturgeon hereafter) may be limited. Access is a critical prerequisite for young fish utilizing chute habitat; thus, we investigated chute-specific accessibility for age-0 sturgeon at seven chutes (constructed and natural). Age-0 sturgeon were capable of accessing most chutes; however, accessibility appeared limited at sites with highly restrictive inlet structures. Our results suggest that future consideration of chute inlet designs that meet authorized Missouri River purposes while providing improved fish access is warranted. Additionally, capture sites for exogenously feeding age-0 sturgeon were usually deeper (\u3e1.5 m) and faster (\u3e0.5 m/s) than sites without sturgeon in chute and adjacent main-stem habitats. This finding is consistent with previous research that suggests that slow and shallow habitats may not be used by age-0 sturgeon as frequently as other habitat types in the lower Missouri River

Using Age-0 Stocking to Assess Growth and Recruitment of Endangered Pallid Sturgeon Scaphirhynchus albus

(1) Assessing growth and recruitment can be difficult during early life history, especially for rare species such as the pallid sturgeon Scaphirhynchus albus (federally endangered in the United States). One potential tool to address this knowledge gap is the stocking of age-0 individuals. (2) During July 2018, two stocking events of marked age-0 pallid sturgeon (53–56 or 41–42 days old) occurred in the lower Missouri River resulting in the release of 8495 individuals. Over the following three years, pallid sturgeon were sampled with baited trotlines and benthic trawls during routine monitoring. (3) During this period, we captured 77 individuals that recruited to age 1 or older. Only 9% of captured individuals yielded length-at-age values falling below the 95% prediction interval for pallid sturgeon raised entirely in an energetically favorable hatchery environment with abundant food resources. (4) These results suggest that the lower Missouri River is capable of supporting hatchery-level growth for young pallid sturgeon. This study also provided a unique opportunity to document recruitment to age-1 of age-0 pallid sturgeon stocked at relatively small sizes, which highlights the potential benefits of utilizing stocking to address endangered species knowledge gaps

Using Age-0 Stocking to Assess Growth and Recruitment of Endangered Pallid Sturgeon <i>Scaphirhynchus albus</i>

(1) Assessing growth and recruitment can be difficult during early life history, especially for rare species such as the pallid sturgeon Scaphirhynchus albus (federally endangered in the United States). One potential tool to address this knowledge gap is the stocking of age-0 individuals. (2) During July 2018, two stocking events of marked age-0 pallid sturgeon (53–56 or 41–42 days old) occurred in the lower Missouri River resulting in the release of 8495 individuals. Over the following three years, pallid sturgeon were sampled with baited trotlines and benthic trawls during routine monitoring. (3) During this period, we captured 77 individuals that recruited to age 1 or older. Only 9% of captured individuals yielded length-at-age values falling below the 95% prediction interval for pallid sturgeon raised entirely in an energetically favorable hatchery environment with abundant food resources. (4) These results suggest that the lower Missouri River is capable of supporting hatchery-level growth for young pallid sturgeon. This study also provided a unique opportunity to document recruitment to age-1 of age-0 pallid sturgeon stocked at relatively small sizes, which highlights the potential benefits of utilizing stocking to address endangered species knowledge gaps

Protecting Mobile Food Diaries from Getting too Personal

Smartphone applications that use passive sensing to support human health and well-being primarily rely on: (a) generating low-dimensional representations from high-dimensional data streams; (b) making inferences regarding user behavior; and (c) using those inferences to benefit application users. Meanwhile, sometimes these datasets are shared with third parties as well. Human-centered ubiquitous systems need to ensure that sensitive attributes of users are protected when applications provide utility to people based on such behavioral inferences. In this paper, we demonstrate that inferences of sensitive attributes of users (gender, body mass index category) are possible using low-dimensional and sparse data coming from mobile food diaries (a combination of sensor data and self-reports). After exposing this potential risk, we demonstrate how deep learning techniques can be used for feature transformation to preserve sensitive user information while achieving high accuracies for application-related inferences (e.g. inferring the type of consumed food). Our work is based on two datasets of daily eating behavior of 160 young adults from Switzerland (NCH=122) and Mexico (NMX=38). Results show that using the proposed approach, accuracies in the order of 75%-90% can be achieved for application related inferences, while reducing the sensitive inference to almost random performance