What Amphibians Can Teach Us About the Evolution of Parental Care.

Parenting is considered a key evolutionary innovation that contributed to the diversification and expansion of vertebrates. However, we know little about how such diversity evolved. Amphibians are an ideal group in which to identify the ecological factors that have facilitated or constrained the evolution of different forms of parental care. Among, but also within, the three amphibian orders-Anura, Caudata, and Gymnophiona-there is a high level of variation in habitat use, fertilization mode, mating systems, and parental sex roles. Recent work using broad phylogenetic, experimental, and physiological approaches has helped to uncover the factors that have selected for the evolution of care and transitions between different forms of parenting. Here, we highlight the exceptional diversity of amphibian parental care, emphasize the unique opportunities this group offers for addressing key questions about the evolution of parenting, and give insights into promising novel directions of research.

Sexy fingers: Pheromones in the glands of male dendrobatid frogs.

Many animals exchange chemicals during courtship and mating. In some amphibians, sexual chemical communication is mediated by pheromones produced in male breeding glands that are transferred to the female's nostrils during mating. This has been mostly studied in salamanders, despite frogs having similar glands and courtship behaviours suggestive of chemical communication. In Neotropical poison frogs (Dendrobatidae and Aromobatidae), males of many species develop breeding glands in their fingers, causing certain fingers to visibly swell. Many also engage in cephalic amplexus, whereby the male's swollen fingers are placed in close contact with the female's nares during courtship. Here, we investigate the possible roles of swollen fingers in pheromone production using whole-transcriptome sequencing (RNAseq). We examined differential gene expression in the swollen versus non-swollen fingers and toes of two dendrobatid species, Leucostethus brachistriatus and Epipedobates anthonyi, both of which have specialised mucous glands in finger IV, the latter of which has cephalic amplexus. The overwhelming pattern of gene expression in both species was strong upregulation of sodefrin precursor-like factors (SPFs) in swollen fingers, a well-known pheromone system in salamanders. The differentially expressed SPF transcripts in each species were very high (>40), suggesting a high abundance of putative protein pheromones in both species. Overall, the high expression of SPFs in the swollen fingers in both species, combined with cephalic amplexus, supports the hypothesis that these traits, widespread across members of the subfamilies Colostethinae and Hyloxalinae (ca. 141 species), are involved in chemical signalling during courtship.

Muchos animales intercambian sustancias químicas durante el cortejo y el apareamiento. En algunos anfibios, la comunicación química sexual está mediada por feromonas producidas en las glándulas reproductoras de los machos que se transfieren a las hembras durante el apareamiento. Esto se ha estudiado sobre todo en salamandras, a pesar de que las ranas tienen glándulas similares y comportamientos de cortejo que sugieren una comunicación química. En las ranas venenosas neotropicales (Dendrobatidae y Aromobatidae), los machos de muchas especies desarrollan glándulas en los dedos, lo que hace que algunos dedos se vean hinchados. Asimismo, varias especies presentan amplexo cefálico, comportamiento de cortejo en el cual los dedos hinchados entran en estrecho contacto con las narinas y boca de la hembra. En este estudio investigamos las posibles funciones de los dedos hinchados en la producción de feromonas mediante la secuenciación del transcriptoma completo (RNAseq). Examinamos la expresión génica diferencial en los dedos hinchados y no hinchados de dos especies de dendrobátidos, Leucostethus brachistriatus y Epipedobates anthonyi, ambos con glándulas mucosas especializadas en el dedo IV, y esta última especie, con amplexo cefálico. El patrón abrumador de expresión génica en ambas especies fue la alta expression de Sodefrin Precursor­Like Factor (SPF) en los dedos hinchados, un sistema de feromonas ampliamente conocido en las salamandras. El número de transcritos SPF expresados diferencialmente en cada especie fue muy elevado (>40), lo que sugiere una gran abundancia de feromonas proteicas putativas en ambas especies. En general, la elevada expresión de SPF en los dedos hinchados en ambas especies, combinada con el amplexo cefálico, apoya la hipótesis de que estos rasgos, muy extendidos entre los miembros de las subfamilias Colostethinae e Hyloxalinae (aprox 141 especies), están implicados en la señalización química durante el cortejo.

Multiple Routes to Color Convergence in a Radiation of Neotropical Poison Frogs.

Convergent evolution is defined as the independent evolution of similar phenotypes in different lineages. Its existence underscores the importance of external selection pressures in evolutionary history, revealing how functionally similar adaptations can evolve in response to persistent ecological challenges through a diversity of evolutionary routes. However, many examples of convergence, particularly among closely related species, involve parallel changes in the same genes or developmental pathways, raising the possibility that homology at deeper mechanistic levels is an important facilitator of phenotypic convergence. Using the genus Ranitomeya, a young, color-diverse radiation of Neotropical poison frogs, we set out to 1) provide a phylogenetic framework for this group, 2) leverage this framework to determine if color phenotypes are convergent, and 3) to characterize the underlying coloration mechanisms to test whether color convergence occurred through the same or different physical mechanisms. We generated a phylogeny for Ranitomeya using ultraconserved elements and investigated the physical mechanisms underlying bright coloration, focusing on skin pigments. Using phylogenetic comparative methods, we identified several instances of color convergence, involving several gains and losses of carotenoid and pterin pigments. We also found a compelling example of nonparallel convergence, where, in one lineage, red coloration evolved through the red pterin pigment drosopterin, and in another lineage through red ketocarotenoids. Additionally, in another lineage, "reddish" coloration evolved predominantly through structural color mechanisms. Our study demonstrates that, even within a radiation of closely related species, convergent evolution can occur through both parallel and nonparallel mechanisms, challenging the assumption that similar phenotypes among close relatives evolve through the same mechanisms.

Welfare, Work and the Conditions of Social Solidarity: British Campaigns to Defend Healthcare and Social Security.

When the welfare state is under attack from neoliberal reformers, how can trade unionists and other campaigners build solidarity to defend it? Based on 45 qualitative interviews, this article compares campaigns to defend British health services and social security benefits between 2007 and 2016. Building on the macro-insights of comparative welfare-state literature and the more micro-level insights of studies on mobilisation, community unionism and union strategy, it examines the factors that help or hinder the construction of solidarity. This research finds that building solidarity is more difficult when defending targeted benefits than universal ones, not only because of differences in public opinion and political support for services, but also because the labour process associated with targeting benefits, namely the assessing and sanctioning of clients, can generate conflicts among campaigners.

Maternal Provisioning of Alkaloid Defenses are Present in Obligate but not Facultative Egg Feeding Dendrobatids.

Poison frogs sequester alkaloid defenses from a diet of largely mites and ants. As a result, frogs are defended against certain predators and microbial infections. Frogs in the genus Oophaga exhibit complex maternal care, wherein mothers transport recently hatched tadpoles to nursery pools and return regularly to supply developing tadpoles with unfertilized (nutritive) eggs. Developing tadpoles are obligate egg feeders. Further, female O. pumilio and O. sylvatica maternally provision their nutritive eggs with alkaloid defenses, providing protection to their developing tadpoles at a vulnerable life-stage. In another genus of poison frog, Ranitomeya, tadpoles only receive and consume eggs facultatively, and it is currently unknown if mothers also provision these eggs (and thus their tadpoles) with alkaloid defenses. Here, we provide evidence that mother frogs of another species in the genus Oophaga (Oophaga granulifera) also provision alkaloid defenses to their tadpoles. We also provide evidence that Ranitomeya imitator and R. variabilis eggs and tadpoles do not contain alkaloids, suggesting that mother frogs in this genus do not provision alkaloid defenses to their offspring. Our findings suggest that among dendrobatid poison frogs, maternal provisioning of alkaloids may be restricted to the obligate egg-feeding members of Oophaga.

Effects of Resistance Training as a Behavioural Preventive Measure on Musculoskeletal Complaints, Maximum Strength and Ergonomic Risk in Dentists and Dental Assistants.

INTRODUCTION: For dental professionals, musculoskeletal disorders (MSD) are common health hazards and resistance training programmes have been promising approaches in the quest for a reduction in the pain intensity of these professionals. Therefore, the aim of the current study was to investigate the effect of a trunk-oriented 10-week resistance training programme. METHOD: In total, the study was conducted with 17 dentists and dental assistants (3 m/14 f) over a course of 10 weeks, with workouts being performed 2 times a week using a 60 min intervention programme consisting of 11 resistance training exercises. The outcome values that were collected were the pain intensity (visual analogue scale (VAS) combined with a modified version of the Nordic Questionnaire), the MVIC and the rapid upper limb assessment (RULA) score (based on data from inertial motion units) during a standardised dental treatment protocol. RESULTS: A significant reduction in pain intensity was found for each queried body region: the neck, upper back, lower back and the right and left shoulders. The maximum voluntary isometric contraction (MVIC) improved significantly in all outcome measures: flexion, extension, right and left lateral flexion and right and left rotation. CONCLUSIONS: A 10-week resistance training programme for dentists and dental assistants had significant effects on pain intensity reduction and the MVIC of the musculature of the trunk and is, therefore, suitable as a behavioural preventive measure against MSD in dental professionals.

Love bites: male frogs (Plectrohyla, Hylidae) use teeth scratching to deliver sodefrin precursor-like factors to females during amplexus.

BACKGROUND: Efficient transfer of chemical signals is important for successful mating in many animal species. Multiple evolutionary lineages of animals evolved direct sex pheromone transmission during traumatic mating-the wounding of the partner with specialized devices-which helps to avoid signal loss to the environment. Although such direct transmission modes of so-called allohormone pheromones are well-documented in invertebrates, they are considered rare in vertebrates. Males of several species of the frog genus Plectrohyla (Hylidae, Anura) have elongated teeth and develop swollen lips during the breeding season. Here we investigated the possibility that these structures are used to scratch the females' skin and apply allohormone pheromones during traumatic mating in several Plectrohyla species. RESULTS: Our behavioural observations revealed that males press their upper jaw onto the females' dorsum during amplexus, leaving small skin scratches with their teeth. Histological examinations of the males' lips identified specialized mucus glands, resembling known amphibian pheromone glands. Whole-transcriptome sequencing of these breeding glands showed high expression of sodefrin precursor-like factor (SPF) proteins, which are known to have a pheromone function in multiple amphibian species. CONCLUSIONS: Our study suggests SPF delivery via traumatic mating in several anuran species: the males have specialized breeding glands in the lips for production and secretion and use their elongated teeth as wounding devices for application. We hypothesize that these SPF proteins end up in the females' circulatory system, where understanding their exact function will require further molecular, physiological and behavioural testing.

Multiple Independent Recruitment of Sodefrin Precursor-Like Factors in Anuran Sexually Dimorphic Glands.

Chemical signaling in animals often plays a central role in eliciting a variety of responses during reproductive interactions between males and females. One of the best-known vertebrate courtship pheromone systems is sodefrin precursor-like factors (SPFs), a family of two-domain three-finger proteins with a female-receptivity enhancing function, currently only known from salamanders. The oldest divergence between active components in a single salamander species dates back to the Late Paleozoic, indicating that these proteins potentially gained a pheromone function earlier in amphibian evolution. Here, we combined whole transcriptome sequencing, proteomics, histology, and molecular phylogenetics in a comparative approach to investigate SPF occurrence in male breeding glands across the evolutionary tree of anurans (frogs and toads). Our study shows that multiple families of both terrestrially and aquatically reproducing frogs have substantially increased expression levels of SPFs in male breeding glands. This suggests that multiple anuran lineages make use of SPFs to complement acoustic and visual sexual signaling during courtship. Comparative analyses show that anurans independently recruited these proteins each time the gland location on the male's body allowed efficient transmission of the secretion to the female's nares.

Prairie strips improve biodiversity and the delivery of multiple ecosystem services from corn-soybean croplands.

Loss of biodiversity and degradation of ecosystem services from agricultural lands remain important challenges in the United States despite decades of spending on natural resource management. To date, conservation investment has emphasized engineering practices or vegetative strategies centered on monocultural plantings of nonnative plants, largely excluding native species from cropland. In a catchment-scale experiment, we quantified the multiple effects of integrating strips of native prairie species amid corn and soybean crops, with prairie strips arranged to arrest run-off on slopes. Replacing 10% of cropland with prairie strips increased biodiversity and ecosystem services with minimal impacts on crop production. Compared with catchments containing only crops, integrating prairie strips into cropland led to greater catchment-level insect taxa richness (2.6-fold), pollinator abundance (3.5-fold), native bird species richness (2.1-fold), and abundance of bird species of greatest conservation need (2.1-fold). Use of prairie strips also reduced total water runoff from catchments by 37%, resulting in retention of 20 times more soil and 4.3 times more phosphorus. Corn and soybean yields for catchments with prairie strips decreased only by the amount of the area taken out of crop production. Social survey results indicated demand among both farming and nonfarming populations for the environmental outcomes produced by prairie strips. If federal and state policies were aligned to promote prairie strips, the practice would be applicable to 3.9 million ha of cropland in Iowa alone.

Developments in Amphibian Parental Care Research: History, Present Advances, and Future Perspectives.

Despite rising interest among scientists for over two centuries, parental care behavior has not been as thoroughly studied in amphibians as it has in other taxa. The first reports of amphibian parental care date from the early 18th century, when Maria Sibylla Merian went on a field expedition in Suriname and reported frog metamorphs emerging from their mother's dorsal skin. Reports of this and other parental behaviors in amphibians remained descriptive for decades, often as side notes during expeditions with another purpose. However, since the 1980s, experimental approaches have proliferated, providing detailed knowledge about the adaptive value of observed behaviors. Today, we recognize more than 30 types of parental care in amphibians, but most studies focus on just a few families and have favored anurans over urodeles and caecilians. Here, we provide a synthesis of the last three centuries of parental care research in the three orders comprising the amphibians. We draw attention to the progress from the very first descriptions to the most recent experimental studies, and highlight the importance of natural history observations as a source of new hypotheses and necessary context to interpret experimental findings. We encourage amphibian parental care researchers to diversify their study systems to allow for a more comprehensive perspective of the behaviors that amphibians exhibit. Finally, we uncover knowledge gaps and suggest new avenues of research using a variety of disciplines and approaches that will allow us to better understand the function and evolution of parental care behaviors in this diverse group of animals.

Using Spatially Targeted Conservation to Evaluate Nitrogen Reduction and Economic Opportunities for Best Management Practice Placement in Agricultural Landscapes.

The US Cornbelt leads North American production of intensively managed, row-crop corn and soybeans. While highly productive, agricultural management in the region is often linked with nonpoint source nutrient pollution that negatively impacts water quality. Presently, conservation programs designed to install best management practices (BMPs) to mitigate agricultural nonpoint source pollution have not been targeted to those areas of the landscape that contribute disproportionately to surface water quality concerns. We used an innovative spatially targeted conservation protocol coupled with a GIS-based landscape planning tool to evaluate the cost and effect on water quality from nitrate-nitrogen loss under alternative landscape scenarios in an Iowa watershed. Outputs indicate large reductions in watershed-level nitrate-nitrogen loss could be achieved through coordinated placement of BMPs on high-contributing parcels with limited reduction of cultivated land, resulting in improved surface water quality at relatively low economic costs. For example, one scenario, which added wetlands, cover crops, and saturated buffers in the watershed, required the removal of <5% of cultivated area to reduce nitrate-nitrogen loss by an estimated 49%, exceeding the Iowa Nutrient Reduction Strategy goal for enhancing water quality. Annualized establishment and management costs of landscape scenarios that met the nonpoint source nitrogen reduction goal varied from $3.16 to $3.19 million (2017 US dollars). These results support our hypothesis that water quality can be improved by targeting high-contributing parcels, and highlights the potential to minimize tradeoffs by coupling targeted conservation and planning tools to help stakeholders achieve water quality outcomes within agricultural landscapes.

Extracellular ATP Induces Vascular Inflammation and Atherosclerosis via Purinergic Receptor Y2 in Mice.

OBJECTIVE: A solid body of evidence supports a role of extracellular ATP and its P2 receptors in innate and adaptive immunity. It promotes inflammation as a danger signal in various chronic inflammatory diseases. Thus, we hypothesize contribution of extracellular ATP and its receptor P2Y2 in vascular inflammation and atherosclerosis. APPROACH AND RESULTS: Extracellular ATP induced leukocyte rolling, adhesion, and migration in vivo as assessed by intravital microscopy and in sterile peritonitis. To test the role of extracellular ATP in atherosclerosis, ATP or saline as control was injected intraperitoneally 3× a week in low-density lipoprotein receptor(-/-) mice consuming high cholesterol diet. Atherosclerosis significantly increased after 16 weeks in ATP-treated mice (n=13; control group, 0.26 mm2; ATP group, 0.33 mm2; P=0.01). To gain into the role of ATP-receptor P2Y2 in ATP-induced leukocyte recruitment, ATP was administered systemically in P2Y2-deficient or P2Y2-competent mice. In P2Y2-deficient mice, the ATP-induced leukocyte adhesion was significantly reduced as assessed by intravital microscopy. P2Y2 expression in atherosclerosis was measured by real-time polymerase chain reaction and immunohistochemistry and demonstrates an increased expression mainly caused by influx of P2Y2-expressing macrophages. To investigate the functional role of P2Y2 in atherogenesis, P2Y2-deficient low-density lipoprotein receptor(-/-) mice consumed high cholesterol diet. After 16 weeks, P2Y2-deficient mice showed significantly reduced atherosclerotic lesions with decreased macrophages compared with P2Y2-competent mice (n=11; aortic arch: control group, 0.25 mm(2); P2Y2-deficient, 0.14 mm2; P=0.04). Mechanistically, atherosclerotic lesions from P2Y2-deficient mice expressed less vascular cell adhesion molecule-1 and intercellular adhesion molecule-1 RNA. CONCLUSIONS: We show that extracellular ATP induces vascular inflammation and atherosclerosis via activation of P2Y2.

Public-Private Partnerships Working Beyond Scale Challenges toward Water Quality Improvements from Private Lands.

In recognition that Iowa agriculture must maintain long-term production of food, fiber, clean water, healthy soil, and robust rural economies, Iowa recently devised a nutrient reduction strategy to set objectives for water quality improvements. To demonstrate how watershed programs and farmers can reduce nutrient and sediment pollution in Iowa waters, the Iowa Water Quality Initiative selected the Boone River Watershed Nutrient Management Initiative as one of eight demonstration projects. For over a decade, diverse public, private, and non-profit partner organizations have worked in the Boone River Watershed to engage farmers in water quality management efforts. To evaluate social dynamics in the Boone River Watershed and provide partners with actionable recommendations, we conducted and analyzed semi-structured interviews with 33 program leaders, farmers, and local agronomists. We triangulated primary interview data with formal analysis of Boone River Watershed documents such as grant applications, progress reports, and outreach materials. Our evaluation suggests that while multi-stakeholder collaboration has enabled partners to overcome many of the traditional barriers to watershed programming, scale mismatches caused by external socio-economic and ecological forces still present substantial obstacles to programmatic resilience. Public funding restrictions and timeframes, for example, often cause interruptions to adaptive management of water quality monitoring and farmer engagement. We present our findings within a resilience framework to demonstrate how multi-stakeholder collaboration can help sustain adaptive watershed programs to improve socio-ecological function in agricultural watersheds such as the Boone River Watershed.

Coinhibitory suppression of T cell activation by CD40 protects against obesity and adipose tissue inflammation in mice.

BACKGROUND: Costimulatory cascades such as the CD40L-CD40 dyad enhance immune cell activation and inflammation during atherosclerosis. Here, we tested the hypothesis that CD40 directly modulates traits of the metabolic syndrome in diet-induced obesity in mice. METHODS AND RESULTS: To induce the metabolic syndrome, wild-type or CD40(-/-) mice consumed a high-fat diet for 20 weeks. Unexpectedly, CD40(-/-) mice exhibited increased weight gain, impaired insulin secretion, augmented accumulation of inflammatory cells in adipose tissue, and enhanced proinflammatory gene expression. This proinflammatory and adverse metabolic phenotype could be transplanted into wild-type mice by reconstitution with CD40-deficient lymphocytes, indicating a major role for CD40 in T or B cells in this context. Conversely, therapeutic activation of CD40 signaling by the stimulating antibody FGK45 abolished further weight gain during the study, lowered glucose levels, improved insulin sensitivity, and suppressed adipose tissue inflammation. Mechanistically, CD40 activation decreased the expression of proinflammatory cytokines in T cells but not in B cells or macrophages. Finally, repopulation of lymphocyte-free Rag1(-/-) mice with CD40(-/-) T cells provoked dysmetabolism and inflammation, corroborating a protective role of CD40 on T cells in the metabolic syndrome. Finally, levels of soluble CD40 showed a positive association with obesity in humans, suggesting clinical relevance of our findings. CONCLUSIONS: We present the surprising finding that CD40 deficiency on T cells aggravates whereas activation of CD40 signaling improves adipose tissue inflammation and its metabolic complications. Therefore, positive modulation of the CD40 pathway might describe a novel therapeutic concept against cardiometabolic disease.

P2Y6 deficiency limits vascular inflammation and atherosclerosis in mice.

OBJECTIVE: Nucleotides such as ATP, ADP, UTP, and UDP serve as proinflammatory danger signals via purinergic receptors on their release to the extracellular space by activated or dying cells. UDP binds to the purinergic receptor Y6 (P2Y6) and propagates vascular inflammation by inducing the expression of chemokines such as monocyte chemoattractant protein 1, interleukin-8, or its mouse homologsCCL1 (chemokine [C-C motif] ligand 1)/keratinocyte chemokine, CXCL2 (chemokine [C-X-C motif] ligand 2)/macrophage inflammatory protein 2, and CXCL5 (chemokine [C-X-C motif] ligand 5)/LIX, and adhesion molecules such as vascular cell adhesion molecule 1 and intercellular cell adhesion molecule 1. Thus, P2Y6 contributes to leukocyte recruitment and inflammation in conditions such as allergic asthma or sepsis. Because atherosclerosis is a chronic inflammatory disease driven by leukocyte recruitment to the vessel wall, we hypothesized a role of P2Y6 in atherogenesis. APPROACH AND RESULTS: Intraperitoneal stimulation of wild-type mice with UDP induced rolling and adhesion of leukocytes to the vessel wall as assessed by intravital microscopy. This effect was not present in P2Y6-deficient mice. Atherosclerotic aortas of low-density lipoprotein receptor-deficient mice consuming high-cholesterol diet for 16 weeks expressed significantly more transcripts and protein of P2Y6 than respective controls. Finally, P2Y6 (-/-)/low-density lipoprotein receptor-deficient mice consuming high-cholesterol diet for 16 weeks developed significantly smaller atherosclerotic lesions compared with P2Y6 (+/+)/low-density lipoprotein receptor-deficient mice. Bone marrow transplantation identified a crucial role of P2Y6 on vascular resident cells, most likely endothelial cells, on leukocyte recruitment and atherogenesis. Atherosclerotic lesions of P2Y6-deficient mice contained fewer macrophages and fewer lipids as determined by immunohistochemistry. Mechanistically, RNA expression of vascular cell adhesion molecule 1 and interleukin-6 was decreased in these lesions and P2Y6-deficient macrophages took up less modified low-density lipoprotein cholesterol. CONCLUSIONS: We show for the first time that P2Y6 deficiency limits atherosclerosis and plaque inflammation in mice.

A danger foreseen is a danger avoided: how chemical cues of different tadpoles influence parental decisions of a Neotropical poison frog.

The protection of offspring against predators and competitors is especially important in organisms using spatially separated breeding resources, impeding the offspring's chances to escape. One example of such isolated reproductive resources are phytotelmata (small water bodies in plant axils), exploited by the Neotropical poison frog Ranitomeya variabilis (Dendrobatidae) for both clutch and tadpole deposition. Because poison frog tadpoles are often cannibalistic, parents tend to avoid deposition with conspecifics. Previous studies have shown that this avoidance is based on chemical cues produced by conspecific tadpoles. Further, cues produced by phylogenetically less-related tadpoles (Bufonidae) were avoided for clutch but not tadpole depositions. We analyzed how the different responses to tadpole cues are triggered. We tested the reactions of parental R. variabilis to tadpole cues of species differing in two aspects: whether or not they are dendrobatids, and whether or not they reproduce in phytotelmata. We found that for clutch deposition, tadpole cues were always avoided, i.e., all tadpoles were treated by the frogs as if they pose a danger to the eggs. However, responses varied for tadpole depositions: while dendrobatid larvae living in phytotelmata were avoided, those breeding in streams were not. Non-poison frog tadpoles were ignored when associated with habitat other than phytotelmata, but they were preferred when living in phytotelmata. This suggests that both phylogeny and tadpole habitat are important triggers for the decisions made by R. variabilis. Only tadpoles using the same breeding resources are considered as relevant for the frog's own larvae (i.e., as a potential danger or food resource), while further decisions are related to evolutionary relationship.

Prognostic factors of recurrence and disease-free survival in radically resected pulmonary carcinoids: a real-world analysis.

Background: Pulmonary carcinoids (PCs) are rare neuroendocrine lung tumors which may recur, thus worsening their otherwise favorable overall prognosis. Aiming to identify patients at risk for recurrence, we examined parameters affecting disease-free survival (DFS). Methods: A retrospective single-center analysis of 82 consecutive patients undergoing curative intent resection for primary PC tumors between 2010 and 2019 was carried out. Kaplan-Meier method was utilized for survival analysis. Independent prognostic factors were determined using multivariable Cox and logistic regression. Results: During the observation period 82 patients, 48 females (58.5%) and 34 males (41.5%) were operated, representing 84 cases of PCs, 56 typical (TCs) (66.7%) and 28 atypical (ACs) (33.3%) carcinoids. Five-year overall survival was 87.5% and 84.7%, 5-year DFS 97.5% and 74.9% (P=0.012) for TCs and ACs, respectively. Recurrences occurred in one patient (1.8%) with TCs and five patients (17.9%) with ACs (P=0.014). Using multivariable Cox regression, tumor size (cm) remained as an independent prognostic factor for reduced DFS (P=0.018). In logistic regression, nodal involvement (P=0.043) and tumor size (cm) (P=0.023) were independently associated with higher risk of recurrence. Age, sex, smoking, location, and Ki-67 index were not independently associated with recurrence or DFS. Conclusions: Recurrence in PCs after complete resection is relatively rare. However, DFS is reduced in ACs compared to TCs. Tumor size (cm) and nodal involvement appear as the most important prognostic factors associated with recurrence in PCs, independent of histologic type.

A US perspective on closing the carbon cycle to defossilize difficult-to-electrify segments of our economy.

Electrification to reduce or eliminate greenhouse gas emissions is essential to mitigate climate change. However, a substantial portion of our manufacturing and transportation infrastructure will be difficult to electrify and/or will continue to use carbon as a key component, including areas in aviation, heavy-duty and marine transportation, and the chemical industry. In this Roadmap, we explore how multidisciplinary approaches will enable us to close the carbon cycle and create a circular economy by defossilizing these difficult-to-electrify areas and those that will continue to need carbon. We discuss two approaches for this: developing carbon alternatives and improving our ability to reuse carbon, enabled by separations. Furthermore, we posit that co-design and use-driven fundamental science are essential to reach aggressive greenhouse gas reduction targets.

Topographic and soil influences on root productivity of three bioenergy cropping systems.

Successful modeling of the carbon (C) cycle requires empirical data regarding species-specific root responses to edaphic characteristics. We address this need by quantifying annual root production of three bioenergy systems (continuous corn, triticale/sorghum, switchgrass) in response to variation in soil properties across a toposequence within a Midwestern agroecosystem. Using ingrowth cores to measure annual root production, we tested for the effects of topography and 11 soil characteristics on root productivity. Root production significantly differed among cropping systems. Switchgrass root productivity was lowest on the floodplain position, but root productivity of annual crops was not influenced by topography or soil properties. Greater switchgrass root production was associated with high percent sand, which explained 45% of the variation. Percent sand was correlated negatively with soil C and nitrogen and positively with bulk density, indicating this variable is a proxy for multiple important soil properties. Our results suggest that easily measured soil parameters can be used to improve model predictions of root productivity in bioenergy switchgrass, but the edaphic factors we measured were not useful for predicting root productivity in annual crops. These results can improve C cycling modeling efforts by revealing the influence of cropping system and soil properties on root productivity.

Field-level financial assessment of contour prairie strips for enhancement of environmental quality.

The impacts of strategically located contour prairie strips on sediment and nutrient runoff export from watersheds maintained under an annual row crop production system have been studied at a long-term research site in central Iowa. Data from 2007 to 2011 indicate that the contour prairie strips utilized within row crop-dominated landscapes have greater than proportionate and positive effects on the functioning of biophysical systems. Crop producers and land management agencies require comprehensive information about the Best Management Practices with regard to performance efficacy, operational/management parameters, and the full range of financial parameters. Here, a farm-level financial model assesses the establishment, management, and opportunity costs of contour prairie strips within cropped fields. Annualized, depending on variable opportunity costs the 15-year present value cost of utilizing contour prairie strips ranges from $590 to $865 ha(-1) year(-1) ($240-$350 ac(-1) year(-1)). Expressed in the context of "treatment area" (e.g., in this study 1 ha of prairie treats 10 ha of crops), the costs of contour prairie strips can also be viewed as $59 to about $87 per treated hectare ($24-$35 ac(-1)). If prairie strips were under a 15-year CRP contract, total per acre cost to farmers would be reduced by over 85 %. Based on sediment, phosphorus, and nitrogen export data from the related field studies and across low, medium, and high land rent scenarios, a megagram (Mg) of soil retained within the watershed costs between $7.79 and $11.46 mg(-1), phosphorus retained costs between $6.97 and $10.25 kg(-1), and nitrogen retained costs between $1.59 and $2.34 kg(-1). Based on overall project results, contour prairie strips may well become one of the key conservation practices used to sustain US Corn Belt agriculture in the decades to come.