University of Maine at Machias

If a user is presented an AI system that portends to explain how it works, how do we know whether the explanation works and the user has achieved a pragmatic understanding of the AI? This question entails some key concepts of measurement such as explanation goodness and trust. We present methods for enabling developers and researchers to: (1) Assess the a priori goodness of explanations, (2) Assess users' satisfaction with explanations, (3) Reveal user's mental model of an AI system, (4) Assess user's curiosity or need for explanations, (5) Assess whether the user's trust and reliance on the AI are appropriate, and finally, (6) Assess how the human-XAI work system performs. The methods we present derive from our integration of extensive research literatures and our own psychometric evaluations. We point to the previous research that led to the measurement scales which we aggregated and tailored specifically for the XAI context. Scales are presented in sufficient detail to enable their use by XAI researchers. For Mental Model assessment and Work System Performance, XAI researchers have choices. We point to a number of methods, expressed in terms of methods' strengths and weaknesses, and pertinent measurement issues.

This paper focuses on the emergent importance of curiosity at work for individuals and organizations by reviewing management research on curiosity at work. We start by leveraging prior reviews on e...

The present study investigated whether (a) siblings of children with (LD) and without learning disabilities (NLD) differed in terms of psychological adjustment and perceived impact of their target brother or sister, and (b) whether parents of LD and NLD children differed in terms of perceived stress and burden. Based on Child Behavior Checklist (CBCL) scores of target child behavior, families were divided into four groups: (a) No LD and no behavior problems (BP), (b) LD only, (c) BP only, and (d) LD and BP. Siblings ( n=71) and their parents ( n=67) were interviewed in their homes. Regardless of whether the target child was LD or NLD, parent reports of the internalizing and externalizing behavior scores from the CBCL differentially reflected the presence of behavior problems. The results indicated that (a) LD and NLD siblings differed in their perception of the quality of their sibling relationships and self-reports of their own behavior, and (b) the parents of children reported to have a behavior problem with or without LD reported higher levels of perceived burden. A substantial indicator of the impact of a child with LD on siblings and parents was related to whether children with LD also had behavior problems.

Abstract Climate change is one of the biggest challenges facing development and continuation of sustainable aquaculture in temperate regions. We primarily consider the ecological and physical resilience of aquaculture in the Gulf of Maine (GoM), where a thriving industry includes marine algae, extensive and intensive shellfish aquaculture, and a well‐established Atlantic salmon industry, as well as the infrastructure required to support these economically important ventures. The historical record of sea surface temperature in the GoM, estimated from gridded, interpolated in situ measurements, shows considerable interannual and decade‐scale variability superimposed on an overall warming trend. Climate model projections of sea surface temperature indicate that the surface waters in the GoM could warm 0.5–3.5°C beyond recent values by the year 2100. This suggests that, while variability will continue, anomalous warmth of marine heatwaves that have been observed in the past decade could become the norm in the GoM ca . 2050, but with the most significant impacts to existing aquaculture along the southernmost region of the coast. We consider adaptations leading to aquacultural resilience despite the effects of warming, larger numbers of harmful nonindigenous species (including pathogens and parasites), acidification, sea‐level rise, and more frequent storms and storm surges. Some new species will be needed, but immediate attention to adapt existing species (e.g. preserve/define wild biodiversity, breed for temperature tolerance and incorporate greater husbandry) and aquaculture infrastructure can be successful. We predict that these measures and continued collaboration between industry, stakeholders, government and researchers will lead to sustaining a vibrant working waterfront in the GoM.

Following a brief introduction to the acculturation process and Mexican American culture, the authors propose that people of Mexican heritage in the United States tend to assimilate rather than integrate with regard to their sex-role attitudes. The authors also propose that the degree of assimilation will be affected by several factors, including generational status and age. Using longitudinal data, the results of the study indicated that the degree of sex-role assimilation among Mexican Americans was affected by the aforementioned variables.

Recent advances in high-throughput DNA sequencing technologies have equipped biologists with a powerful new set of tools for advancing research goals. The resulting flood of sequence data has made it critically important to train the next generation of scientists to handle the inherent bioinformatic challenges. The North East Bioinformatics Collaborative (NEBC) is undertaking the genome sequencing and annotation of the little skate (Leucoraja erinacea) to promote advancement of bioinformatics infrastructure in our region, with an emphasis on practical education to create a critical mass of informatically savvy life scientists. In support of the Little Skate Genome Project, the NEBC members have developed several annotation workshops and jamborees to provide training in genome sequencing, annotation and analysis. Acting as a nexus for both curation activities and dissemination of project data, a project web portal, SkateBase (http://skatebase.org) has been developed. As a case study to illustrate effective coupling of community annotation with workforce development, we report the results of the Mitochondrial Genome Annotation Jamborees organized to annotate the first completely assembled element of the Little Skate Genome Project, as a culminating experience for participants from our three prior annotation workshops. We are applying the physical/virtual infrastructure and lessons learned from these activities to enhance and streamline the genome annotation workflow, as we look toward our continuing efforts for larger-scale functional and structural community annotation of the L. erinacea genome.

We tested the usefulness of 15 N values in the organic matrix of whole shells from Mercenaria mercenaria as tracers of anthropogenic nitrogen inputs to coastal ecosystems. Low and high stringency acidification methods were used to define parameters for reliable 15 N determination in shell material for comparison with 15 N values in soft tissues. 15 N values in shell from transplanted and native clams reflected %-wastewater contribution to estuaries, but were 2.3 to 2.5% lighter than 15 N values in soft tissues. Accuracy of 15 N values in shell material depended on recovering a sufficient quantity of organic N from shell (~70 g) and was not altered by acidification method. Reliable 15 N values were obtained with as little as 80 mg of shell and using 100 l of acid, but higher stringency methods (treating more shell with more acid for longer duration) typically yielded more N for subsequent stable isotope analysis. Conversely, higher concentrations of acid reduced N recovery. These results suggest that the content of N recovered was of greater concern to obtaining reliable 15 N values from shell material than acidification effects. Differences between 15 N values in shell material and soft tissues likely reflected differences in N assimilation among tissues. In combination with other analyses, this method may be applied to refine modern and historical trophic assessments and discern natural from anthropogenic influences on coastal ecosystems

Water velocity and depth preferences of spawning Atlantic salmon (Salmo salar) in four rivers in Maine were measured during October in 1975-1977. Female Atlantic salmon constructed redds in water with a mean depth of 38 ± 0.8 cm. Mean water velocity measured 12 cm above the substrate was 53 ± 1.3 cm/sec. Management implications of water depth and velocity requirements of spawning salmonids are discussed.

A series of intertidal field experiments was conducted from 1986–2003 in eastern Maine to examine biotic and abiotic factors influencing the growth and survival of wild and cultured individuals of the softshell clam, Mya arenaria L. Separate experiments examined: (1) the efficacy of transferring sublegal wild clams (<50.8 mm SL) from areas near the high intertidal zone where shell growth was slow to areas where growth was predicted to be faster; (2) effects of tidal height on wild and cultured clam growth; (3) effects of spatial variation on cultured clam growth; (4) dispersion and growth of cultured juveniles in small experimental units; (5) effects of the naticid gastropod, Euspira heros Say, predation on survival of wild and cultured clams and (6) the species composition of large, crustacean predators that forage intertidally during periods of tidal inundation. Protective netting (4.2 mm aperture) increased recovery rate of transferred clams by 120% and resulted in a 3-fold enhancement of wild recruits. Effects of tidal height on wild clam growth revealed complex behaviors in >0 y-class individuals. Clams growing near the upper intertidal take >8 y to attain a legal size of 50.8 mm SL, whereas animals near the mid intertidal generally take 4.5–6.5 y. Unexpectedly, clams initially 38–54 mm SL and growing near the extreme low tide mark at a mud flat in Eastport, Maine, added, on average, <2 mm of new shell in a year, which was 8–10 mm SL less than animals at higher shore levels. It is hypothesized that biological disturbance by moon snails, that consumed >90% of clams at the low shore levels, contributed to this slow growth. In another field trial from 1986–1987, moon snails and other consumers were allowed access to clams ranging in size from 15–51 mm. E. heros preyed on clams over the entire size range and attacked clams between 31–40 mm at a rate that was nearly double what had been expected. Mean snail size was estimated to range from 10–52 mm shell height (SH), based on a laboratory study that yielded information about the linear relationship between snail size and its borehole diameter. In an experiment from June to September 1993, moon snails consumed >70% of juvenile clams (ca. 10 mm SL) within a month after planting at each of three tidal heights. Snail sizes ranged from 15–20 mm SD with larger individuals occurring near the upper intertidal zone. Green crabs, Carcinus maenas (L.) also prey heavily on softshell clam populations, but most studies that use shell damage to assign a predator have assumed that all crushing and chipping predation is because of this invasive species. An intertidal trapping study demonstrated that both green crabs and rock crabs, Cancer irroratus Say, are present during periods of tidal inundation, with the latter species accounting for ca. 40% of large crustacean numbers.

UNLABELLED: Genomic analysis of a large set of phages infecting the common host Mycobacterium smegmatis mc(2)155 shows that they span considerable genetic diversity. There are more than 20 distinct types that lack nucleotide similarity with each other, and there is considerable diversity within most of the groups. Three newly isolated temperate mycobacteriophages, Bongo, PegLeg, and Rey, constitute a new group (cluster M), with the closely related phages Bongo and PegLeg forming subcluster M1 and the more distantly related Rey forming subcluster M2. The cluster M mycobacteriophages have siphoviral morphologies with unusually long tails, are homoimmune, and have larger than average genomes (80.2 to 83.7 kbp). They exhibit a variety of features not previously described in other mycobacteriophages, including noncanonical genome architectures and several unusual sets of conserved repeated sequences suggesting novel regulatory systems for both transcription and translation. In addition to containing transfer-messenger RNA and RtcB-like RNA ligase genes, their genomes encode 21 to 24 tRNA genes encompassing complete or nearly complete sets of isotypes. We predict that these tRNAs are used in late lytic growth, likely compensating for the degradation or inadequacy of host tRNAs. They may represent a complete set of tRNAs necessary for late lytic growth, especially when taken together with the apparent lack of codons in the same late genes that correspond to tRNAs that the genomes of the phages do not obviously encode. IMPORTANCE: The bacteriophage population is vast, dynamic, and old and plays a central role in bacterial pathogenicity. We know surprisingly little about the genetic diversity of the phage population, although metagenomic and phage genome sequencing indicates that it is great. Probing the depth of genetic diversity of phages of a common host, Mycobacterium smegmatis, provides a higher resolution of the phage population and how it has evolved. Three new phages constituting a new cluster M further expand the diversity of the mycobacteriophages and introduce novel features. As such, they provide insights into phage genome architecture, virion structure, and gene regulation at the transcriptional and translational levels.

Green sea urchins (Strongylocentrotus droebachiensis) have been a dominant structuring force in boreal, hard-bottom communities and recently have become an important fishery. Despite these roles, relatively little is known about the age, growth, and demographics of field populations. To begin to address these issues, we systematically sampled urchins during 1997 and 1998 at two sites (Allen Island [AI] and Schoodic Peninsula [SP]) in the Gulf of Maine, USA. Basic demographic information (density and size structure) was obtained and a subset of urchins aged by counting annual bands on the interambulacral plates. Size-at-age analyses showed that the population at AI consisted of two sympatric growth morphs, fast growing (fg) and slow growing (sg), each described by its own von Bertalanffy growth parameters for mean size and size variance. The two morphs also differed in maximum observed ages (sg, 6–11 yr, vs. fg, 16–18 yr) and in maximum test diameter sizes (sg, 30–35 mm, vs. fg, 50–70 mm). At SP, a single (fg) morph was identified which had growth characteristics similar to the fg morph at AI. An obviously bimodal size-frequency distribution at AI reflects the accumulation of urchins of each morph at asymptotic size. We advanced several hypotheses; including intrinsic factors, e.g., sex ratios, morphology, and genetics; and extrinsic factors, e.g., density, spatial distribution, settlement history, growth history, and migration; to explain the origin and coexistence of the two growth forms. Using primary and post hoc data analyses, we rejected sex ratio, density, spatial relations, and morphology. Analysis of annual growth and age structure indicated that the two morphs had different settlement histories, suggesting the mixing of two genetically distinct populations. Our post hoc analyses could not reject the genetics or growth history and migration hypotheses. Genetically different larvae, or else a phased process of differential settlement, migration, and growth (threshold migration hypothesis) are the most likely cause(s) for the two morphs. Our data indicate that field growth rates in green urchins are intrinsically highly variable, but also vary interannually probably in relation to their environment. Intrinsic variability provides a novel explanation for bimodality of size-frequency distributions in urchin populations. Interestingly, the sublegal size (<50 mm) and short life span of the sg morph preempts its recruitment into the fishery. Moreover, if the sg morph is widespread and genetically based, intensive harvesting may enhance selection for the sg morph. These findings may have serious implications for understanding the population structure and managing the green urchin fishery, and for assessing the grazing impact of these urchins in nearshore communities.

PREMISE OF THE STUDY: Subtribe Hakeinae (526 spp.) represents a large Australian plant radiation central to our understanding of that flora's evolution and ecology. It contains Grevillea-the third largest plant genus in Australia and a group inferred to have among the highest diversification rates in the angiosperms. However, we lack a robust phylogenetic framework for understanding subtribe Hakeinae and recognize that Grevillea lacks an unambiguous synapomorphy supporting its monophyly. METHODS: We used four plastid and one nuclear DNA region from a taxonomically even sampling of a third of the species to infer a time-calibrated phylogeny of Hakeinae and absolute diversification rates of major clades. We developed the R package addTaxa to add unsampled taxa to the tree for diversification rate inference. KEY RESULTS: Grevillea is paraphyletic with respect to Hakea and Finschia. Under most parameter combinations, Hakea contains the major clade with the highest diversification rate in Hakeinae, rather than Grevillea. The crown age of the Grevillea+Hakea+Finschia crown group is about double that of prior estimates. CONCLUSIONS: We demonstrate that the paraphyly of Grevillea considerably enlarges the number of Australian descendants from its most recent common ancestor but has also misled investigators who considered a single operational taxonomic unit as adequate to represent the genus for inferences of diversification rate and timing. Our time-calibrated phylogeny can form the basis of future evolutionary, comparative ecology, and biogeography studies involving this large Australian plant radiation, as well as nomenclatural changes.

Temporary closures of polluted coastal waters to shellfish harvesting protect human health but also generate broad socioeconomic impacts on rural, fishing-dependent communities. Improved understanding of these impacts could help coastal managers prioritize investments to protect water quality and mitigate the effects of coastal pollution. Using a regression model of monthly landings, we explore the impact of temporary closures on the commercial harvest of soft-shell clams (Mya arenaria) in the Machias Bay region of Maine (USA). We find that economic losses are significant and depend heavily on tidal activity, and the size, frequency and timing of closures. Over the nine-year sample period (2001–2009), temporary pollution closures contributed to the loss of $3.6 million in forgone revenue (2014 dollars), approximately 27.4% of total revenue. Closures linked to combined sewer overflows from the Machias wastewater system produce the majority of these losses ($2.0 million) with the largest occurring during the peak clamming season (May–August). Our results highlight the variability of the impacts of closures and the information burden for efficient management of shellfish areas and coastal waters. By strategically reducing pollution, managers could limit public health risks, avoid destabilizing harvesting and revenue, and bolster the resilience of fishing communities.

The infaunal, suspension-feeding softshell clam (Mya arenaria L.) is a conspicuous member of the intertidal macrofauna in numerous northern temperate and boreal soft-bottom communities. Recruitment variability can affect the magnitude and scope of various ecosystem services provided by M. arenaria, including its role as a source of food and energy for organisms at higher trophic levels. Manipulative field experiments were conducted in the intertidal zone in 2014 and 2015 at three tidal estuaries in southern Maine, to investigate the importance of post-settlement processes in determining the strength of the annual 0-y class cohort across predator-exclusion treatments within and between tidal heights. Four short-term (4–5 mo), small-scale studies over both years in the Webhannet River (Wells, ME) and Fore River (Portland, ME), the two southernmost estuaries, demonstrated that clam recruits were up to 118× more abundant when predators were deterred versus controls. In a 7-mo study conducted in the Harraseeket River (HR; Freeport, ME) during 2014, recruits of Mya attained densities 899× greater in large-scale plots designed to exclude large (>6 mm) predators than in ambient, adjacent sediments where predators were undeterred. A novel, epibenthic settlement trap (0.15 m2), initially containing no sediments and designed to deter both infaunal and epibenthic predators larger than 1.9 mm, was used to examine spatial variability in clam recruitment over a 6-mo period in 2015 in the HR. Traps showed a 60-fold difference in mean number of clam recruits between sides of the river only 600 m apart. Collectively, results suggest that post-settlement mortality rates of 0-y class individuals of Mya exceed 99% at these locations, severely limiting ecosystem services they would otherwise provide, and that these early losses are primarily responsible for explaining distribution and abundance patterns of ≥1-y class individuals.

:There is an interest to develop sugar kelp (Saccharina latissima) cultivation in the rural, eastern Maine region of the United States. Future farming efforts would benefit from an understanding of the genetic diversity and population structure of kelp to inform management and conservation, and to identify genetic resources. The purpose of the present study was to characterize the fine-scale population genetic structure of kelp in eastern Maine using 12 microsatellite loci. A total of 188 samples were genotyped from five sampling locations. Overall, kelp exhibited relatively low genetic diversity and small but significant differentiation among populations (FST = 0.0157). The greatest genetic difference was detected between two geographically close populations in Penobscot and Frenchman Bays, which is likely due to patterns in the Eastern Maine Coastal Current that may limit meiospore recruitment. The population structure could not be fully explained by an isolation-by-distance model. Fine-scale structuring was also detected among populations along the more continuous eastern Maine coastline. These differences highlight that sugar kelp populations are finely structured across small spatial scales, and that future management and farming efforts should aim to maintain genetic diversity and assess the culture potential of local populations.

This paper examines the similarities and differences in the art of boys and girls aged six, seven, and eight. It is primarily concerned with the ways in which the subject matter of the children's art reflects sex differences in interests, introspective thought, and symbolic organization of the world. The methodology, based on the spontaneous art experience, seeks to establish that artistic activity is a viable medium through which information on the non-discursive aspects of children's thought can be obtained. Over 1800 drawings, done by 26 children, were collected. The content of the drawings was examined for its range of subject matter and for thematic trends over time. It was found that girls and boys consistently portray very different subjects. The children's art did not present stereotypic images of sex roles nor could the contrasts be specifically attributed to genetic, social, or psychological differences between the sexes, although there was some correlation with the research findings in those areas. It was concluded that girls and boys have very different expressive interests and needs which are not fully incorporated into their educational environment and which affect all areas of school adjustment.

Haliotis iris is a species of abalone common on rocky reefs in southern and central New Zealand. This study examined the poorly understood feeding habits and preferences of H. iris in a series of laboratory experiments. Generally, H. iris consumed the blades of brown algae over red and green algae. However, when upright whole plants were given to H. iris, the highly preferred kelp Lessonia variegata was consumed in lower proportions than the less preferred but more accessible red alga Gigartina circumcincta. H. iris were less capable of reaching the blades or consuming the stipe of L. variegata, which has a stipe of ∼100–350 mm high. H. iris consumed greater amounts of drift over benthic L. vareigata. Water movement appeared to inhibit the active grazing of H. iris, but not the drift-trapping behavior, resulting in lower overall feeding rates for abalone under conditions of higher water movement. Abalone consumed fresh and aged algae equally. We conclude that H. iris feeds primarily on drift algae because preferred food sources are more accessible as drift than as attached macroalgae, and because this may be a more successful foraging strategy in the high flow environment this species commonly inhabits.

Transmissible cancers are infectious parasitic clones that metastasize to new hosts, living past the death of the founder animal in which the cancer initiated. We investigated the evolutionary history of a cancer lineage that has spread though the soft-shell clam (Mya arenaria) population by assembling a chromosome-scale soft-shell clam reference genome and characterizing somatic mutations in transmissible cancer. We observe high mutation density, widespread copy-number gain, structural rearrangement, loss of heterozygosity, variable telomere lengths, mitochondrial genome expansion and transposable element activity, all indicative of an unstable cancer genome. We also discover a previously unreported mutational signature associated with overexpression of an error-prone polymerase and use this to estimate the lineage to be >200 years old. Our study reveals the ability for an invertebrate cancer lineage to survive for centuries while its genome continues to structurally mutate, likely contributing to the evolution of this lineage as a parasitic cancer.

Supporting worldwide Healthy Parks, Healthy People (HPHP) research expansion, this study investigated how wellness motivations interplay with auditory experiences by examining relationships between protected area visitors’ wellness motivations, and their perceptions of particular sounds and overall soundscape appeal. Visitor surveys (N = 899), implemented in the Coyhaique National Reserve in Chilean Patagonia, included participant demographics, wellness motivations, a listening exercise, and overall soundscape ratings. Wellness motivations were reduced into emotional, intellectual, physical, sensory, and social dimensions. All dimensions were significantly correlated with participants’ ratings of the soundscape’s appeal and their desire to visit more (based on the soundscape). Cluster analysis grouped participants into low, moderate, and high wellness motives groups. Groups with high-wellness motives were found to rate specific natural sounds and the overall soundscape higher than groups with lower wellness motives. This study suggests incorporating visitors’ wellness motivations into soundscape and other perception-based research may assist with HPHP objectives.

Protected areas (PAs) worldwide are facing increasing visitation and complexity. Mounting pressures from the private sector are intensifying the risks associated with overtourism. The increasing strategic importance of PAs for the communities and regions in which they are situated requires improved management effectiveness; yet, recent studies indicate significant and growing systemic risk. Worldview analysis can be a valuable tool for building consciousness and informing the evolution of PA planning and management. Directed content analysis was used to examine two Visitor Use Plans developed for the Coyhaique National Reserve, located in the iconic Patagonia cultural area of southern Chile. The plans were developed using distinct planning frameworks, with different underlying assumptions. Research questions focused on how modernist, postmodernist and integral worldviews were expressed within the two plans. Worldviews were explored in both manifest and latent manners, considering plan text, models and overall context revealing patterns and links between the plans and planning frameworks that guided their development. Rich context and a thorough discussion of methods assists with the incorporation of worldview evaluation within PA management theory, informing the continuing development of knowledge and capacities that can better prepare PAs for future challenges.