Publications by authors named "Robert Dunn"

We develop a fluid mechanical model of the arterial tree in order to address the key question of what determines heart rate in mammals. We propose that the frequency of the pulsatile pressure gradient, which minimizes resistance to flow and facilitates fluid movement, coincides with the physiological heart rate. Using data from the literature on heart rate in 95 mammals as a function of body mass, and the radius of the aorta as a function of body mass, we construct a target curve of cardiac frequency versus aortic radius.

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Although variation in effect sizes and predicted values among studies of similar phenomena is inevitable, such variation far exceeds what might be produced by sampling error alone. One possible explanation for variation among results is differences among researchers in the decisions they make regarding statistical analyses. A growing array of studies has explored this analytical variability in different fields and has found substantial variability among results despite analysts having the same data and research question.

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  • Habitat partitioning allows brown and white shrimp to coexist by using estuarine habitats at different times, although they do overlap, particularly towards the end of their nursery residency.
  • Laboratory experiments tested how the density and presence of each shrimp species impacted their growth and mortality rates.
  • The study found that species identity influenced growth and survival, with smaller shrimp having higher mortality, indicating environmental changes could affect their populations in varying ways.
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Study Design: Retrospective cohort study.

Objectives: To identify predictors for early mortality following traumatic spinal cord injury (TSCI), as recognition of factors associated with early mortality is essential for public resource allocation and optimized acute care.

Methods: Retrospective Analysis of SCI patients admitted to the acute SCI ward from 2003 to 2022 was performed.

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Background Context: There are no current guidelines for the management of civilian gunshot wound injuries (GSW) to the spine and patient management often relies on algorithms derived from blunt trauma (BT). However, spinal cord injury due to GSW or blunt trauma mechanism may have significantly different clinical presentation, management, and outcomes. To ensure improved and evidence-based treatment, we need to understand the outcome determining characteristics of civilian GSW to the spine and identify the differences to the well-studied BT.

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  • Tidal wetlands can absorb greenhouse gases, but methane emissions can vary due to environmental factors and human activities.
  • Land managers require detailed maps of methane properties in these wetlands for effective restoration and greenhouse gas inventories, yet current sampling methods don't align well with broader mapping products.
  • Research involved sampling 27 tidal wetlands, revealing that sulfate concentration is the strongest predictor of methane levels, while salinity also plays a significant role; future studies should focus on understanding local environmental influences on methane variation.
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The understanding of recent climate extremes and the characterization of climate risk require examining these extremes within a historical context. However, the existing datasets of observed extremes generally exhibit spatial gaps and inaccuracies due to inadequate spatial extrapolation. This problem arises from traditional statistical methods used to account for the lack of measurements, particularly prevalent before the mid-20th century.

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Climate warming disproportionately impacts countries in the Global South by increasing extreme heat exposure. However, geographic disparities in adaptation capacity are unclear. Here, we assess global inequality in green spaces, which urban residents critically rely on to mitigate outdoor heat stress.

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Refractive index (RI) detection using backscatter interferometry (BSI) enables universal detection in capillary electrophoresis (CE). BSI detection is a versatile on-capillary approach that is easily integrated with capillary or microfluidic channels, straightforward to miniaturize, and inexpensive. The focused BSI light source can also double as the excitation source for fluorescence, enabling simultaneous universal (BSI) and specific (fluorescence) signals from the same detection volume.

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Electroosmotic flow (EOF) is the bulk flow of solution in a capillary or microchannel induced by an applied electric potential. For capillary and microchip electrophoresis, the EOF enables analysis of both cations and anions in one separation and can be varied to modify separation speed and resolution. The EOF arises from an electrical double layer at the capillary wall and is normally controlled through the pH and ionic strength of the background buffer or with the use of additives.

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Objectives: spp. are one of the leading foodborne pathogens in the world, and chickens are a known reservoir. This is significant considering broiler chicken is the top consumed meat worldwide.

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Background: Tuberculosis (TB) is one of the top ten causes of death worldwide, with approximately 10 million cases annually. Focus has been on pulmonary TB, while extrapulmonary TB (EPTB) has received little attention. Diagnosis of EPTB remains challenging due to the invasive procedures required for sample collection.

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Background: Tuberculosis (TB) is caused by Mycobacterium tuberculosis (Mtb) and typically infects the lungs. However, extrapulmonary forms of TB can be found in approximately 20% of cases. It is suggested, that up to 10% of extrapulmonary TB affects the musculoskeletal system, in which spinal elements (spinal tuberculosis, STB) are involved in approximately 50% of the cases.

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The architecture of magma plumbing systems plays a fundamental role in volcano eruption and evolution. However, the precise configuration of crustal magma reservoirs and conduits responsible for supplying eruptions are difficult to explore across most active volcanic systems. Consequently, our understanding of their correlation with eruption dynamics is limited.

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Extended-spectrum beta-lactamase (ESBL) Escherichia coli (E. coli) is an emerging pathogen of high concern given its resistance to extended-spectrum cephalosporins. Broiler chicken, which is the number one consumed meat in the United States and worldwide, can be a reservoir of ESBL E.

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Globally, human house types are diverse, varying in shape, size, roof type, building materials, arrangement, decoration and many other features. Here we offer the first rigorous, global evaluation of the factors that influence the construction of traditional (vernacular) houses. We apply macroecological approaches to analyse data describing house features from 1900 to 1950 across 1000 societies.

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  • Salt marshes are crucial coastal ecosystems that filter nutrients and pollutants, with the mid-Atlantic U.S. marshes exhibiting unique geochemical behaviors compared to other global estuaries.
  • Research on the southeastern U.S. salt marsh revealed that metal concentrations and bioaccumulation varied significantly based on marsh location and species, with high marsh zones showing lower sediment concentrations but higher biotic accumulation factors.
  • The study found specific patterns in metal accumulation among different species, particularly in bivalves, providing insights for biomonitoring and potential remediation strategies like phytoremediation, highlighting the need for targeted environmental management.
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Backscatter interferometry (BSI) is a refractive index (RI) detection method that is easily integrated with capillary electrophoresis (CE) and is capable of detecting species ranging from inorganic ions to proteins without additional labels or contrast agents. The BSI signal changes linearly with the square of the separation voltage which has been used to quantify sample injection, but has not been explored as a potential signal enhancement mechanism in CE. Here we develop a mathematical model that predicts a signal enhancement at high field strengths, where the BSI signal is dominated by the voltage dependent mechanism.

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Background: Diagnostic specimens for spinal tuberculosis (STB) are mostly collected via open surgery. Percutaneous computed tomography (CT)-guided biopsies are used in times of limited surgical availability. However, poor diagnostic accuracy of () culture has been reported with this method, due to limited sample volume and the paucibacillary nature of STB.

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Animal ecology and evolution have long been known to shape host physiology, but more recently, the gut microbiome has been identified as a mediator between animal ecology and evolution and health. The gut microbiome has been shown to differ between wild and domestic animals, but the role of these differences for domestic animal evolution remains unknown. Gut microbiome responses to new animal genotypes and local environmental change during domestication may promote specific host phenotypes that are adaptive (or not) to the domestic environment.

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is a dimorphic fungus found in certain parts of North, Central, and South America. Transmission is primarily through airborne inoculation from inhaled fungal microconidia. Histoplasmosis is typically a self-limited mycosis; however, in patients with immunodeficiency, disseminated disease can occur and may lead to high disease burden.

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The microbial fermentation behind sourdough bread is among our oldest technologies, yet there are many opportunities for sourdough science to learn from traditional bakers. We analyzed 16S rRNA sequences in R to assess the bacterial community structure and performance of 40 starters grown from 10 types of flour over 14 days, and identified six distinct stages of succession. At each stage, bacterial taxa correlate with determinants of bread quality including pH, rise, and aromatic profile.

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  • * A new study using phylogenomic analysis has clarified the phylogeny of mosquitoes, revealing their origins date back to the early Triassic period, which is significantly older than earlier estimates.
  • * The research indicates that mosquitoes have repeatedly shifted to feeding on mammals throughout their evolution, with these changes often aligning with major continental drift and vertebrate diversification events.
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Shotgun metagenomics is an increasingly cost-effective approach for profiling environmental and host-associated microbial communities. However, due to the complexity of both microbiomes and the molecular techniques required to analyze them, the reliability and representativeness of the results are contingent upon the field, laboratory, and bioinformatic procedures employed. Here, we consider 15 field and laboratory issues that critically impact downstream bioinformatic and statistical data processing, as well as result interpretation, in bacterial shotgun metagenomic studies.

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