Visceral Leishmaniasis in Traveler to Guyana Caused by Leishmania siamensis, London, UK.

The parasite Leishmania siamensis is a zoonotic agent of leishmaniasis; infection in animals has been documented in Europe and the United States. Reported authochthonous human infections have been limited to Thailand. We report a case of human visceral Leishmania siamensis infection acquired in Guyana, suggesting colonization in South America

Neural Substrates of Attentive Listening Assessed with a Novel Auditory Stroop Task

A common explanation for the interference effect in the classic visual Stroop test is that reading a word (the more automatic semantic response) must be suppressed in favor of naming the text color (the slower sensory response). Neuroimaging studies also consistently report anterior cingulate/medial frontal, lateral prefrontal, and anterior insular structures as key components of a network for Stroop-conflict processing. It remains unclear, however, whether automatic processing of semantic information can explain the interference effect in other variants of the Stroop test. It also is not known if these frontal regions serve a specific role in visual Stroop conflict, or instead play a more universal role as components of a more generalized, supramodal executive-control network for conflict processing. To address these questions, we developed a novel auditory Stroop test in which the relative dominance of semantic and sensory feature processing is reversed. Listeners were asked to focus either on voice gender (a more automatic sensory discrimination task) or on the gender meaning of the word (a less automatic semantic task) while ignoring the conflicting stimulus feature. An auditory Stroop effect was observed when voice features replaced semantic content as the “to-be-ignored” component of the incongruent stimulus. Also, in sharp contrast to previous Stroop studies, neural responses to incongruent stimuli studied with functional magnetic resonance imaging revealed greater recruitment of conflict loci when selective attention was focused on gender meaning (semantic task) over voice gender (sensory task). Furthermore, in contrast to earlier Stroop studies that implicated dorsomedial cortex in visual conflict processing, interference-related activation in both of our auditory tasks was localized ventrally in medial frontal areas, suggesting a dorsal-to-ventral separation of function in medial frontal cortex that is sensitive to stimulus context

Evaluation of sample collection and storage protocols for surface eDNA surveys of an invasive terrestrial insect

Environmental DNA surveys have revolutionized monitoring of rare or cryptic species and species inhabiting areas where conventional sampling is difficult or dangerous. Recent advancements within terrestrial environments include the capture of eDNA deposited by animals on surfaces such as tree bark and foliage, hereafter “surface eDNA.” Notably, a technique which uses commercial paint rollers to aggregate surface eDNA has been deployed with success to detect the presence of forest insect pests providing a potentially powerful new management tool. However, before widespread adoption is feasible, the efficiency and logistics of roller sample collection and study design, especially relative to realistic survey conditions, must be evaluated. We compared the performance of two DNA preservation treatments—cold and ethanol—on their ability to reduce the loss of captured eDNA on rollers over time. Additionally, we evaluated how the detection probability of our target species, the spotted lanternfly (Lycorma delicatula), varied with sampling effort (time spent rolling per sample) and the initial quantity of eDNA present. Finally, we evaluated how the number of trees sampled per roller influenced the final concentrations of lanternfly eDNA remaining on the roller. We found storing rollers with ethanol or cold temperatures resulted in 3–10-fold greater concentrations of experimentally controlled eDNA relative to no treatment after 24 h. Detection probability declined as the amount of lanternfly eDNA decreased, but did not change in response to sampling effort over sample time (10–80 s/tree). Finally, recovered lanternfly eDNA decreased as more trees were sampled by a single roller—a 91% reduction after 7 trees—potentially due to captured DNA being transferred back from the roller onto the bark. Our results provide improved guidance for deploying roller surface eDNA methods for spotted lanternfly surveys, and for invasive insect pest surveillance and monitoring programs generally

Epidemiology of imported cutaneous leishmaniasis at the Hospital for Tropical Diseases, London, United Kingdom: use of polymerase chain reaction to identify the species.

This study reviewed all patients diagnosed with imported cutaneous leishmaniasis (CL) at the Hospital for Tropical Diseases in London, United Kingdom, over an 11-year period. Diagnostic and epidemiologic information was collected prospectively for all patients with imported CL to this hospital during 1998-2009. A total of 223 patients were given a diagnosis of CL. Ninety patients were diagnosed with Old World CL, which was caused most commonly by Leishmania donovani complex (n = 20). A total of 71% were tourists to the Mediterranean region, 36% were migrants or visiting friends and relatives, and 17% were soldiers. One hundred thirty-three patients were given a diagnosis of New World CL. The Leishmania subgenus Viannia caused 97 of these cases; 44% of these were in backpackers and 29% were in soldiers. Polymerase chain reaction was more sensitive and faster for detecting Leishmania DNA (86% for Old World CL and 96% for New World CL) than culture. This is the largest study of imported leishmaniasis, and demonstrates that tourists to the Mediterranean and backpackers in Central and South America are at risk for this disease

A perfect storm: two ecosystem engineers interact to degrade deciduous forests of New Jersey

Abstract Ecosystem engineers play a large role in physically structuring the ecosystem in which they are embedded

Critical Perspective: Named Reactions Discovered and Developed by Women

Named organic reactions. As chemists, we’re all familiar with them: who can forget the Diels−Alder reaction? But how much do we know about the people behind the names? For example, can you identify a reaction named for a woman? How about a reaction discovered or developed by a woman but named for her male adviser? Our attempts to answer these simple questions started us on the journey that led to this Account. We introduce you to four reactions named for women and nine reactions discovered or developed by women. Using information obtained from the literature and, whenever possible, through interviews with the chemists themselves, their associates, and their advisers, we paint a more detailed picture of these remarkable women and their outstanding accomplishments. Some of the women you meet in this Account include Irma Goldberg, the only woman unambiguously recognized with her own named reaction. Gertrude Maud Robinson, the wife of Robert Robinson, who collaborated with him on several projects including the Piloty−Robinson pyrrole synthesis. Elizabeth Hardy, the Bryn Mawr graduate student who discovered the Cope rearrangement. Dorothee Felix, a critical member of Albert Eschenmoser’s research lab for over forty years who helped develop both the Eschenmoser−Claisen rearrangement and the Eschenmoser−Tanabe fragmentation. Jennifer Loebach, the University of Illinois undergraduate who was part of the team in Eric Jacobsen’s lab that discovered the Jacobsen−Katsuki epoxidation. Keiko Noda, a graduate student in Tsutomu Katsuki’s lab who also played a key role in the development of the Jacobsen−Katsuki epoxidation. Lydia McKinstry, a postdoc in Andrew Myers’s lab who helped develop the Myers asymmetric alkylation. Rosa Lockwood, a graduate student at Boston College whose sole publication is the discovery of the Nicholas reaction. Kaori Ando, a successful professor in Japan who helped develop the Roush asymmetric alkylation as a postdoc at MIT. Bianka Tchoubar, a critically important member of the organic chemistry community in France who developed the Tiffeneau−Demjanov rearrangement. The accomplishments of the women in this Account illustrate the key roles women have played in the discovery and development of reactions used daily by organic chemists around the world. These pioneering chemists represent the vanguard of women in the field, and we are confident that many more of the growing number of current and future female organic chemists will be recognized with their own named reactions

Identifying invasive species threats, pathways, and impacts to improve biosecurity

Managing invasive species with prevention and early-detection strategies can avert severe ecological and economic impacts. Horizon scanning, an evidence-based process combining risk screening and consensus building to identify threats, has become a valuable tool for prioritizing invasive species management and prevention. We assembled a working group of experts from academic, government, and nonprofit agencies and organizations, and conducted a multi-taxa horizon scan for Florida, USA, the first of its kind in North America. Our primary objectives were to identify high-risk species and their introduction pathways, to detail the magnitude and mechanism of potential impacts, and, more broadly, to demonstrate the utility of horizon scanning. As a means to facilitate future horizon scans, we document the process used to generate the list of taxa for screening. We evaluated 460 taxa for their potential to arrive, establish, and cause negative ecological and socioeconomic impacts, and identified 40 potential invaders, including alewife, zebra mussel, crab-eating macaque, and red swamp crayfish. Vertebrates and aquatic invertebrates posed the greatest invasion threat, over half of the high-risk taxa were omnivores, and there was high confidence in the scoring of high-risk taxa. Common arrival pathways were ballast water, biofouling of vessels, and escape from the pet/aquarium/horticulture trade. Competition, predation, and damage to agriculture/forestry/aquaculture were common impact mechanisms. We recommend full risk analysis for the high-risk taxa; increased surveillance at Florida's ports, state borders, and high-risk pathways; and periodic review and revision of the list. Few horizon scans detail the comprehensive methodology (including list-building), certainty estimates for all scoring categories and the final score, detailed pathways, and the magnitude and mechanism of impact. Providing this information can further inform prevention efforts and can be efficiently replicated in other regions. Moreover, harmonizing methodology can facilitate data sharing and enhance interpretation of results for stakeholders and the general public.</p

Mate-Finding as an Overlooked Critical Determinant of Dispersal Variation in Sexually-Reproducing Animals

Dispersal is a critically important process in ecology, but robust predictive models of animal dispersal remain elusive. We identify a potentially ubiquitous component of variation in animal dispersal that has been largely overlooked until now: the influence of mate encounters on settlement probability. We use an individual-based model to simulate dispersal in sexually-reproducing organisms that follow a simple set of movement rules based on conspecific encounters, within an environment lacking spatial habitat heterogeneity. We show that dispersal distances vary dramatically with fluctuations in population density in such a model, even in the absence of variation in dispersive traits between individuals. In a simple random-walk model with promiscuous mating, dispersal distributions become increasingly ‘fat-tailed’ at low population densities due to the increasing scarcity of mates. Similar variation arises in models incorporating territoriality. In a model with polygynous mating, we show that patterns of sex-biased dispersal can even be reversed across a gradient of population density, despite underlying dispersal mechanisms remaining unchanged. We show that some widespread dispersal patterns found in nature (e.g. fat tailed distributions) can arise as a result of demographic variability in the absence of heterogeneity in dispersive traits across the population. This implies that models in which individual dispersal distances are considered to be fixed traits might be unrealistic, as dispersal distances vary widely under a single dispersal mechanism when settlement is influenced by mate encounters. Mechanistic models offer a promising means of advancing our understanding of dispersal in sexually-reproducing organisms

Morphology, Competition, and the Structure of Some Introduced Passerine Communities

Several morphological analyses have been conducted on the introduced passerines of the Hawaiian islands that have implicated interspecific competition as having played a role in the assembly of that community. In this thesis, I extended these morphological analyses to another tropical island, Tahiti. I chose to center my analyses to the search for one particular morphological pattern, overdispersion. Morphological overdispersion here means that the set of surviving species in a community are more different from one another than what would be expected by chance alone. There have been at least 41 passerine species introduced to Tahiti and of those only seven still exist in the community. Using multiversity statistics and Monte Carlo simulations, these seven species were shown to be morphologically overdispersed. This result is consistent with the hypothesis that interspecific competition played a role in the assembly of this community. Although these analyses are a unique and revealing way to observe corranunities through an extended length of time, they are not without their potential problems. The second part of this thesis is focused around three potential biases outlined by Colwell and Winkler (1984). In particular, I illustrate the Narcissus effect among the introduced finches of Oahu, Hawaii. At least 25 species of finches have been introduced to Oahu and of these 15 are currently surviving. When the dispersion of these 15 are compared to a series of random communities they appear morphologically overdispersed. Of these 15 surviving species, seven are found in sugarcane field habitat. When these seven are compared to all 25 species introduced to Oahu, they too appear morphologically overdispersed. According to Colwell and Winkler this is the appropriate pool of species for comparison. When these seven species present in sugarcane are compared only the 15 surviving species, though, they do not appear morphologically overdispersed. Unfortunately, this is the pool of comparison that most morphological analyses on natural communities are forced to use. The discrepancy in the results among the introduced finches of Oahu is apparently due to a Narcissus effect