Ixodes ticks maintain a large and diverse array of human pathogens in the enzootic cycle, including Borrelia burgdorferi and Babesia microti . Despite the poor ecological fitness of B. microti , ...babesiosis has recently emerged in areas endemic for Lyme disease. Studies in ticks, reservoir hosts, and humans indicate that coinfection with B. burgdorferi and B. microti is common, promotes transmission and emergence of B. microti in the enzootic cycle, and causes greater disease severity and duration in humans. These interdisciplinary studies may serve as a paradigm for the study of other vector-borne coinfections. Identifying ecological drivers of pathogen emergence and host factors that fuel disease severity in coinfected individuals will help guide the design of effective preventative and therapeutic strategies.
Humans rely on the ability of budding yeasts to grow without oxygen in industrial scale fermentations that produce beverages, foods, and biofuels. Oxygen is deeply woven into the energy metabolism ...and biosynthetic capabilities of budding yeasts. While diverse ecological habitats may provide wide varieties of different carbon and nitrogen sources for yeasts to utilize, there is no direct substitute for molecular oxygen, only a range of availability. Understanding how a small subset of budding yeasts evolved the ability to grow without oxygen could expand the set of useful species in industrial scale fermentations as well as provide insight into the cryptic field of yeast ecology. However, we still do not yet appreciate the full breadth of species that can growth without oxygen, what genes underlie this adaptation, and how these genes have evolved.
Oxygen is essential for animal life, and while geochemical proxies have been instrumental in determining the broad evolutionary history of oxygen on Earth, much of our insight into Phanerozoic oxygen ...comes from biogeochemical modelling. The GEOCARBSULF model utilizes carbon and sulphur isotope records to produce the most detailed history of Phanerozoic atmospheric O
currently available. However, its predictions for the Paleozoic disagree with geochemical proxies, and with non-isotope modelling. Here we show that GEOCARBSULF oversimplifies the geochemistry of sulphur isotope fractionation, returning unrealistic values for the O
sourced from pyrite burial when oxygen is low. We rebuild the model from first principles, utilizing an improved numerical scheme, the latest carbon isotope data, and we replace the sulphur cycle equations in line with forwards modelling approaches. Our new model, GEOCARBSULFOR, produces a revised, highly-detailed prediction for Phanerozoic O
that is consistent with available proxy data, and independently supports a Paleozoic Oxygenation Event, which likely contributed to the observed radiation of complex, diverse fauna at this time.
Measurements of body size and mass are fundamental to pinniped population management and research. Manual measurements tend to be accurate but are invasive and logistically challenging to obtain. ...Ground-based photogrammetric techniques are less invasive, but inherent limitations make them impractical for many field applications. The recent proliferation of unmanned aerial systems (UAS) in wildlife monitoring has provided a promising new platform for the photogrammetry of free-ranging pinnipeds. Leopard seals (Hydrurga leptonyx) are an apex predator in coastal Antarctica whose body condition could be a valuable indicator of ecosystem health. We aerially surveyed leopard seals of known body size and mass to test the precision and accuracy of photogrammetry from a small UAS. Flights were conducted in January and February of 2013 and 2014 and 50 photogrammetric samples were obtained from 15 unrestrained seals. UAS-derived measurements of standard length were accurate to within 2.01 ± 1.06%, and paired comparisons with ground measurements were statistically indistinguishable. An allometric linear mixed effects model predicted leopard seal mass within 19.40 kg (4.4% error for a 440 kg seal). Photogrammetric measurements from a single, vertical image obtained using UAS provide a noninvasive approach for estimating the mass and body condition of pinnipeds that may be widely applicable.
The term autophagy encompasses different pathways that route cytoplasmic material to lysosomes for degradation and includes macroautophagy, chaperone-mediated autophagy, and microautophagy. Since ...these pathways are crucial for degradation of aggregate-prone proteins and dysfunctional organelles such as mitochondria, they help to maintain cellular homeostasis. As post-mitotic neurons cannot dilute unwanted protein and organelle accumulation by cell division, the nervous system is particularly dependent on autophagic pathways. This dependence may be a vulnerability as people age and these processes become less effective in the brain. Here, we will review how the different autophagic pathways may protect against neurodegeneration, giving examples of both polygenic and monogenic diseases. We have considered how autophagy may have roles in normal CNS functions and the relationships between these degradative pathways and different types of programmed cell death. Finally, we will provide an overview of recently described strategies for upregulating autophagic pathways for therapeutic purposes.
The term autophagy encompasses different pathways enabling lysosomal degradation of cytoplasmic material, such as macroautophagy, chaperone-mediated autophagy, and microautophagy. Fleming et al. review how different autophagic pathways protect against neurodegeneration and consider recently described therapeutic strategies exploiting autophagic upregulation.
, the leading cause of Legionnaires' disease in the United States, is found in lakes, ponds, and streams but poses a health risk when it grows in building water systems. The growth of
in hot water ...systems of healthcare facilities poses a significant risk to patients, staff, and visitors. Hospitals and long-term care facilities account for 76% of reported Legionnaires' disease cases with mortality rates of 25%. Controlling
growth in hot water systems serving healthcare and hospitality buildings is currently achieved primarily by adding oxidizing chemical disinfectants. Chemical oxidants generate disinfection byproducts and can accelerate corrosion of premise plumbing materials and equipment. Alternative control methods that do not generate hazardous disinfection byproducts or accelerate corrosion are needed.
is an obligate aerobe that cannot sustain cellular respiration, amplify, or remain culturable when dissolved oxygen (DO) concentrations are too low (< 0.3 mg/L). An alternative method of controlling
growth by reducing DO levels in a hot water model system using a gas transfer membrane contactor was evaluated. A hot water model system was constructed and inoculated with
at DO concentrations above 0.5 mg/L. Once the model system was colonized, DO levels were incrementally reduced. Water samples were collected each week to evaluate the effect of reducing dissolved oxygen levels when all other conditions favored
amplification. At DO concentrations below 0.3 mg/L,
concentrations were reduced by 1-log over 7 days. Under conditions in the hot water model system, at favorable temperatures and with no residual chlorine disinfectant,
concentrations were reduced by 1-log, indicating growth inhibition by reducing DO levels as the sole control measure. In sections of the model system where DO levels were not lowered
continued to grow. Reducing dissolved oxygen levels in hot water systems of healthcare and other large buildings to control
could also lower the risk of supplemental chemical treatment methods currently in use.
Evidence-based guidelines for the management of patients with Lyme disease, human granulocytic anaplasmosis (formerly known as human granulocytic ehrlichiosis), and babesiosis were prepared by an ...expert panel of the Infectious Diseases Society of America. These updated guidelines replace the previous treatment guidelines published in 2000 (Clin Infect Dis 2000; 31Suppl 1:1–14). The guidelines are intended for use by health care providers who care for patients who either have these infections or may be at risk for them. For each of these Ixodes tickborne infections, information is provided about prevention, epidemiology, clinical manifestations, diagnosis, and treatment. Tables list the doses and durations of antimicrobial therapy recommended for treatment and prevention of Lyme disease and provide a partial list of therapies to be avoided. A definition of post–Lyme disease syndrome is proposed.
The aim of this guideline is to provide standards for the recommendation, performance, interpretation and reporting of
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Ga-PSMA PET/CT for prostate cancer imaging. These recommendations will help ...to improve accuracy, precision, and repeatability of
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Ga-PSMA PET/CT for prostate cancer essentially needed for implementation of this modality in science and routine clinical practice.
Precipitation, evapotranspiration (ET), waste tonnage, landfill gas (LFG), and leachate data were aggregated from public sources to perform a 5–10 year water balance and estimate the contributions of ...three water sources (precipitation, incoming waste, and leachate recycling) for 36 active municipal solid waste (MSW) landfills in Ohio, USA. Uniquely, the water balance incorporated waste decomposition, using gas collection data to inform mass loss from biodegradation. Moisture contents of 20–30% for incoming waste indicate that entrained water is the largest source of landfill moisture. Infiltration of precipitation into the landfill after ET was the second largest source. Even at facilities where a majority of the leachate generated was recirculated, it did not significantly affect the moisture content in that year. Using the water balance approach, it appears leachate recirculation is unlikely to increase moisture content above 40% by mass, a regulatory threshold in the US, which would impose stricter air pollution control requirements. However, poor stormwater management could easily allow for “bioreactor” conditions to develop. The calculated landfill moisture content was significantly affected by the assumed runoff coefficient (CRO) parameter. CRO values below 20% and above 50% produced unrealistically high or low moisture contents, respectively. This approach can assist operators and regulators in understanding the contribution of different sources to a landfill's moisture profile and avoid future operational problems.
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•Weather, waste, landfill gas, and leachate data were used to perform a 5–10 year water balance.•Collected LFG was used to inform mass loss from biodegradation.•Entrained water in incoming waste is likely the largest source of landfill moisture.•Leachate recirculation alone is unlikely to increase moisture content above 40% by mass.•Poor stormwater management could allow for “bioreactor” conditions to develop.
Despite a growing appreciation of their vast diversity in nature, mechanisms of speciation are poorly understood in Bacteria and Archaea. Here we use high-throughput genome sequencing to identify ...ongoing speciation in the thermoacidophilic Archaeon Sulfolobus islandicus. Patterns of homologous gene flow among genomes of 12 strains from a single hot spring in Kamchatka, Russia, demonstrate higher levels of gene flow within than between two persistent, coexisting groups, demonstrating that these microorganisms fit the biological species concept. Furthermore, rates of gene flow between two species are decreasing over time in a manner consistent with incipient speciation. Unlike other microorganisms investigated, we do not observe a relationship between genetic divergence and frequency of recombination along a chromosome, or other physical mechanisms that would reduce gene flow between lineages. Each species has its own genetic island encoding unique physiological functions and a unique growth phenotype that may be indicative of ecological specialization. Genetic differentiation between these coexisting groups occurs in large genomic "continents," indicating the topology of genomic divergence during speciation is not uniform and is not associated with a single locus under strong diversifying selection. These data support a model where species do not require physical barriers to gene flow but are maintained by ecological differentiation.
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