Publications by authors named "McLachlan D"

Long-distance wound signalling in plants involves systemic propagation of calcium waves, but the exact process of initiation and transmission of these waves remains elusive. A new study proposes a mechanism whereby pressure changes are the trigger for this response.

View Article and Find Full Text PDF

Diatoms represent one of the most successful groups of marine phytoplankton and are major contributors to ocean biogeochemical cycling. They have colonized marine, freshwater and ice environments and inhabit all regions of the World's oceans, from poles to tropics. Their success is underpinned by a remarkable ability to regulate their growth and metabolism during nutrient limitation and to respond rapidly when nutrients are available.

View Article and Find Full Text PDF

Importance: Evidence regarding corticosteroid use for severe coronavirus disease 2019 (COVID-19) is limited.

Objective: To determine whether hydrocortisone improves outcome for patients with severe COVID-19.

Design, Setting, And Participants: An ongoing adaptive platform trial testing multiple interventions within multiple therapeutic domains, for example, antiviral agents, corticosteroids, or immunoglobulin.

View Article and Find Full Text PDF

Objectives: Pediatric appendicitis remains a challenging diagnosis in the emergency department (ED). Available risk prediction algorithms may contribute to excessive ED imaging studies. Incorporation of physician gestalt assessment could help refine predictive tools and improve diagnostic imaging decisions.

View Article and Find Full Text PDF

The Editor-in Chief of Molecular Neurobiology has retracted this article [1] at the request of the corresponding author. This is because it significantly overlaps with their previous publication [2]. Both articles report the same results and as such this article is redundant.

View Article and Find Full Text PDF

High temperature promotes guard cell expansion, which opens stomatal pores to facilitate leaf cooling. How the high-temperature signal is perceived and transmitted to regulate stomatal aperture is, however, unknown. Here, we used a reverse-genetics approach to understand high temperature-mediated stomatal opening in Arabidopsis ().

View Article and Find Full Text PDF

Aluminum is a ubiquitous neurotoxin highly enriched in our biosphere, and has been implicated in the etiology and pathology of multiple neurological diseases that involve inflammatory neural degeneration, behavioral impairment and cognitive decline. Over the last 36 years our group has analyzed the aluminum content of the temporal lobe neocortex of 511 high quality coded human brain samples from 18 diverse neurological and neurodegenerative disorders, including 2 groups of age-matched controls. Brodmann anatomical areas including the inferior, medial and superior temporal gyrus (A20-A22) were selected for analysis: (i) because of their essential functions in massive neural information processing operations including cognition and memory formation; and (ii) because subareas of these anatomical regions are unique to humans and are amongst the earliest areas affected by progressive neurodegenerative disorders such as Alzheimer's disease (AD).

View Article and Find Full Text PDF

With continuing cooperation from 18 domestic and international brain banks over the last 36 years, we have analyzed the aluminum content of the temporal lobe neocortex of 511 high-quality human female brain samples from 16 diverse neurological and neurodegenerative disorders, including 2 groups of age-matched controls. Temporal lobes (Brodmann areas A20-A22) were selected for analysis because of their availability and their central role in massive information-processing operations including efferent-signal integration, cognition, and memory formation. We used the analytical technique of (i) Zeeman-type electrothermal atomic absorption spectrophotometry (ETAAS) combined with (ii) preliminary analysis from the advanced photon source (APS) hard X-ray beam (7 GeV) fluorescence raster-scanning (XRFR) spectroscopy device (undulator beam line 2-ID-E) at the Argonne National Laboratory, US Department of Energy, University of Chicago IL, USA.

View Article and Find Full Text PDF

Expansion of gene families facilitates robustness and evolvability of biological processes but impedes functional genetic dissection of signalling pathways. To address this, quantitative analysis of single cell responses can help characterize the redundancy within gene families. We developed high-throughput quantitative imaging of stomatal closure, a response of plant guard cells, and performed a reverse genetic screen in a group of Arabidopsis mutants to five stimuli.

View Article and Find Full Text PDF

Experimental results of the complex magnetic permeability (μ) and the electrical conductivity (σ) of a granular paramagnetic Gadolinium Gallium Garnet (GGG: 0.3 to 26 Vol. %) and Teflon (PTFE) system are presented, and discussed in relation to previously published (conductivity) and unpublished (permeability) studies on granular FeO - talc and Ni - talc wax systems.

View Article and Find Full Text PDF

Takahashi et al. (2018) report that the peptide CLE25 together with the BAM1, BAM3 LRR receptor-like kinases are involved in root-to-shoot communication during dehydration stress in Arabidopsis.

View Article and Find Full Text PDF

Study Objective: Outpatient management of emergency department (ED) patients with acute pulmonary embolism is uncommon. We seek to evaluate the facility-level variation of outpatient pulmonary embolism management and to describe patient characteristics and outcomes associated with home discharge.

Methods: The Management of Acute Pulmonary Embolism (MAPLE) study is a retrospective cohort study of patients with acute pulmonary embolism undertaken in 21 community EDs from January 2013 to April 2015.

View Article and Find Full Text PDF

Introduction: The Pulmonary Embolism Severity Index (PESI) is a validated prognostic score to estimate the 30-day mortality of emergency department (ED) patients with acute pulmonary embolism (PE). A simplified version (sPESI) was derived but has not been as well studied in the U.S.

View Article and Find Full Text PDF

Stomata regulate the uptake of CO2 and the loss of water vapor [1] and contribute to the control of water-use efficiency [2] in plants. Although the guard-cell-signaling pathway coupling blue light perception to ion channel activity is relatively well understood [3], we know less about the sources of ATP required to drive K(+) uptake [3-6]. Here, we show that triacylglycerols (TAGs), present in Arabidopsis guard cells as lipid droplets (LDs), are involved in light-induced stomatal opening.

View Article and Find Full Text PDF
Article Synopsis
  • Increased atmospheric CO2 levels lead to reduced stomatal openings and density in plants, impacting water loss and nutrient uptake.
  • The study identifies that the closure of stomata and reduction in their density due to high CO2 requires the production of reactive oxygen species (ROS) and involves the PYR/RCAR family of ABA receptors.
  • The findings suggest that the signaling pathways for stomatal responses to elevated CO2 are mediated by the hormone ABA, indicating an evolutionary significance of the ABA pathway in plant responses to environmental changes.
View Article and Find Full Text PDF

Terrestrial plants rely on stomata, small pores in the leaf surface, for photosynthetic gas exchange and transpiration of water. The stomata, formed by a pair of guard cells, dynamically increase and decrease their volume to control the pore size in response to environmental cues. Stresses can trigger similar or opposing movements: for example, drought induces closure of stomata, whereas many pathogens exploit stomata and cause them to open to facilitate entry into plant tissues.

View Article and Find Full Text PDF

Stomatal movements rely on alterations in guard cell turgor. This requires massive K(+) bidirectional fluxes across the plasma and tonoplast membranes. Surprisingly, given their physiological importance, the transporters mediating the energetically uphill transport of K(+) into the vacuole remain to be identified.

View Article and Find Full Text PDF

Plant water loss and CO2 uptake are controlled by valve-like structures on the leaf surface known as stomata. Stomatal aperture is regulated by hormonal and environmental signals. We show here that stomatal sensitivity to the drought hormone abscisic acid (ABA) is acquired during leaf development by exposure to an increasingly dryer atmosphere in the rosette plant Arabidopsis.

View Article and Find Full Text PDF
Article Synopsis
  • Red seaweeds like Chondrus crispus (Irish moss) are important for coastal ecosystems and the economy but have been understudied genetically; researchers have sequenced its 105-Mbp genome, identifying 9,606 genes.
  • The genome has a unique structure with densely packed genes but also regions rich in repetitive DNA, and it reveals characteristics typical of compact genomes, including few introns and limited gene families.
  • The study also highlights important metabolic adaptations in marine red algae, including specialized carbohydrate metabolism, and suggests an evolutionary history of gene loss followed by increased genome size due to transposable elements.
View Article and Find Full Text PDF

Complex photoreceptor pathways exist in algae to exploit light as a sensory stimulus. Previous studies have implicated calcium in blue-light signaling in plants and algae. A photophobic response to high-intensity blue light was characterized in the marine benthic diatom Navicula perminuta (Grunow) in van Heurck.

View Article and Find Full Text PDF

Emotion recognition is a critical life skill children need for mental health promotion to meet the complexities and challenges of growing up in the world today. Five nursing students and their instructor designed Emotion Locomotion, a program for children ages 6-8 during a public health nursing practicum for an inner-city parochial school. Emotion Locomotion used an analogy that the "engine" of a train represents the "individual" and the train "cars" represent various emotions, such as happiness, sadness, calmness, and anger.

View Article and Find Full Text PDF

Motility of estuarine epipelic (mud-inhabiting) diatoms is an important adaptation to living in biofilms present within fine sediments. Motility allows cells to migrate within the photic zone in response to a wide range of environmental stimuli. The motile responses of two species of benthic diatoms to photon fluence rates and spectral quality were investigated.

View Article and Find Full Text PDF