High sugar diet alters immune function and the gut microbiome in juvenile green iguanas (Iguana iguana).

The present work aimed to study whether a high sugar diet can alter immune responses and the gut microbiome in green iguanas. Thirty-six iguanas were split into four treatment groups using a 2×2 design. Iguanas received either a sugar-supplemented diet or a control diet, and either a lipopolysaccharide (LPS) injection or a phosphate-buffered saline (PBS) injection. Iguanas were given their respective diet treatment through the entire study (∼3 months) and received a primary immune challenge 1 and 2 months into the experiment. Blood samples and cloacal swabs were taken at various points in the experiment and used to measure changes in the immune system (bacterial killing ability, lysis and agglutination scores, LPS-specific IgY concentrations), and alterations in the gut microbiome. We found that a sugar diet reduces bacterial killing ability following an LPS challenge, and sugar and the immune challenge temporarily alters gut microbiome composition while reducing alpha diversity. Although sugar did not directly reduce lysis and agglutination following the immune challenge, the change in these scores over a 24-h period following an immune challenge was more drastic (it decreased) relative to the control diet group. Moreover, sugar increased constitutive agglutination outside of the immune challenges (i.e. pre-challenge levels). In this study, we provide evidence that a high sugar diet affects the immune system of green iguanas (in a disruptive manner) and alters the gut microbiome.

The effects of anthropogenic noise on frogs housed on exhibit at a public aquarium.

Anuran behavior and reproduction are dominated by vocalizations, rendering them vulnerable to the effects of signal masking. For anurans on display in zoos and aquaria, a major source of ambient noise is visitors, which pose a unique source of potential anthropogenic signal masking. Call characteristics (total call duration, and minimum and maximum call frequencies) of three populations of dendrobatids (Dendrobates leucomelas, Epipedobates tricolor, and Ranitomeya imitator) on public display were investigated at time periods of increasing visitor-related noise (closed, off-peak, and peak aquarium visiting hours) to determine if there were changes in call characteristics that correlated with changes in visitor noise levels. The data revealed that call length increased with more visitor noise for D. leucomelas and E. tricolor, with their longest calls during peak hours, and all three species had their shortest calls during closed hours. Both minimum and maximum call frequencies increased with more visitor noise for E. tricolor and R. imitator, with their highest frequencies during peak hours, and lowest frequencies during closed hours. This study found evidence that anurans on public display adjust their vocalizations in the presence of visitor noise. These findings support expanded monitoring of ambient noise for animals on public display to determine if noise poses significant effects that might influence well-being or reproduction.

Environment and shipping drive environmental DNA beta-diversity among commercial ports.

The spread of nonindigenous species by shipping is a large and growing global problem that harms coastal ecosystems and economies and may blur coastal biogeographical patterns. This study coupled eukaryotic environmental DNA (eDNA) metabarcoding with dissimilarity regression to test the hypothesis that ship-borne species spread homogenizes port communities. We first collected and metabarcoded water samples from ports in Europe, Asia, Australia and the Americas. We then calculated community dissimilarities between port pairs and tested for effects of environmental dissimilarity, biogeographical region and four alternative measures of ship-borne species transport risk. We predicted that higher shipping between ports would decrease community dissimilarity, that the effect of shipping would be small compared to that of environment dissimilarity and shared biogeography, and that more complex shipping risk metrics (which account for ballast water and stepping-stone spread) would perform better. Consistent with our hypotheses, community dissimilarities increased significantly with environmental dissimilarity and, to a lesser extent, decreased with ship-borne species transport risks, particularly if the ports had similar environments and stepping-stone risks were considered. Unexpectedly, we found no clear effect of shared biogeography, and that risk metrics incorporating estimates of ballast discharge did not offer more explanatory power than simpler traffic-based risks. Overall, we found that shipping homogenizes eukaryotic communities between ports in predictable ways, which could inform improvements in invasive species policy and management. We demonstrated the usefulness of eDNA metabarcoding and dissimilarity regression for disentangling the drivers of large-scale biodiversity patterns. We conclude by outlining logistical considerations and recommendations for future studies using this approach.

Changes in resistome profile of potential probiotic Lactiplantibacillus pentosus in response to edible oil adaptation.

Despite increasing interest to investigate horizontal gene transfer as a leading cause of antibiotic resistance spread, the resistome is not only influenced by the influx and efflux of genes in different environments. Rather, the expression of existing genes under different stress conditions requires special attention. This study determined whether pre-adapting Lactiplantibacillus pentosus strains, isolated from Aloreña green table olives, to vegetable-based edible oils influence their phenotypic and genotypic responses to antibiotics. This has significant diet, food matrix, gut health, and food safety concerns. Pre-adapting L. pentosus strains to oils significantly changed their susceptibility profile to antibiotics. However, results generally differed among the three strains; although changes in the Minimum Inhibitory Concentration (MIC) of antibiotics occurred, it depended on the L. pentosus strain and the oil used for adaptation. The pre-adaptation of L. pentosus strains with olive, sunflower, argan and linseed oils induced gene expressions (e.g., rpsL, recA and uvrB) in several stress responses. Thus, to analyze this fact in-depth, transcriptional changes were reported in the selected potential probiotic L. pentosus CF2-10 adapted with olive or sunflower, rerouting its metabolic pathways to export toxic molecules through efflux pumps and ABC transporters. Pre-adaptation of some lactobacilli with olive or sunflower oils may represent a novel approach for manufacturing probiotic products with improved stability, functionality and robustness.

Phylogenomics and historical biogeography of West Indian Rock Iguanas (genus Cyclura).

The genus Cyclura includes nine extant species and six subspecies of West Indian Rock Iguanas and is one of the most imperiled genera of squamate reptiles globally. An understanding of species diversity, evolutionary relationships, diversification, and historical biogeography in this group is crucial for implementing sound long-term conservation strategies. We collected DNA samples from 1 to 10 individuals per taxon from all Cyclura taxa (n = 70 ingroup individuals), focusing where possible on incorporating individuals from different populations of each species. We also collected 1-2 individuals from each of seven outgroup species of iguanas (Iguana delicatissima; five Ctenosaura species) and Anolis sagrei (n = 12 total outgroup individuals). We used targeted genomic sequence capture to isolate and to sequence 1,872 loci comprising of 687,308 base pairs (bp) from each of the 82 individuals from across the nuclear genome. We extracted mitochondrial reads and assembled and annotated mitogenomes for all Cyclura taxa plus outgroup species. We present well-supported phylogenomic gene tree/species tree analyses for all extant species of Cyclura using ASTRAL-III, SVDQuartets, and StarBEAST2 methods, and discuss the taxonomic, biogeographic, and conservation implications of these data. We find a most recent common ancestor of the genus 9.91 million years ago. The earliest divergence within Cyclura separates C. pinguis from a clade comprising all other Cyclura. Within the latter group, a clade comprising C. carinata from the southern Lucayan Islands and C. ricordii from Hispaniola is the sister taxon to a clade comprising the other Cyclura. Among the other Cyclura, the species C. cornuta and C. stejnegeri (from Hispaniola and Isla Mona) form the sister taxon to a clade of species from Jamaica (C. collei), Cuba and Cayman Islands (C. nubila and C. lewisi), and the eastern (C. rileyi) and western (C. cychlura) Lucayan Islands. Cyclura cychlura and C. rileyi form a clade whose sister taxa are C. nubila and C. lewisi. Cyclura collei is the sister taxon to these four species combined.

Glucose tolerance of iguanas is affected by high-sugar diets in the lab and supplemental feeding by ecotourists in the wild.

There is great interspecific variation in the nutritional composition of natural diets, and the varied nutritional content is physiologically tolerated because of evolutionarily based balances between diet composition and processing ability. However, as a result of landscape change and human exposure, unnatural diets are becoming widespread among wildlife without the necessary time for evolutionary matching between the diet and its processing. We tested how a controlled, unnatural high glucose diet affects glucose tolerance using captive green iguanas, and we performed similar glucose tolerance tests on wild Northern Bahamian rock iguanas that are either frequently fed grapes by tourists or experience no such supplementation. We evaluated both short and longer-term blood glucose responses and corticosterone (CORT) concentrations as changes have been associated with altered diets. Experimental glucose supplementation in the laboratory and tourist feeding in the wild both significantly affected glucose metabolism. When iguanas received a glucose-rich diet, we found greater acute increases in blood glucose following a glucose challenge. Relative to unfed iguanas, tourist-fed iguanas had significantly lower baseline CORT, higher baseline blood glucose, and slower returns to baseline glucose levels following a glucose challenge. Therefore, unnatural consumption of high amounts of glucose alters glucose metabolism in laboratory iguanas with short-term glucose treatment and free-living iguanas exposed to long-term feeding by tourists. Based on these results and the increasing prevalence of anthropogenically altered wildlife diets, the consequences of dietary changes on glucose metabolism should be further investigated across species, as such changes in glucose metabolism have health consequences in humans (e.g. diabetes).

Correlated Population Genetic Structure in a Three-Tiered Host-Parasite System: The Potential for Coevolution and Adaptive Divergence.

Three subspecies of Northern Bahamian Rock Iguanas, Cyclura cychlura, are currently recognized: C. c. cychlura, restricted to Andros Island, and C. c. figginsi and C. c. inornata, native to the Exuma Island chain. Populations on Andros are genetically distinct from Exuma Island populations, yet genetic divergence among populations in the Exumas is inconsistent with the 2 currently recognized subspecies from those islands. The potential consequences of this discrepancy might include the recognition of a single subspecies throughout the Exumas rather than 2. That inference also ignores evidence that populations of C. cychlura are potentially adaptively divergent. We compared patterns of population relatedness in a three-tiered host-parasite system: C. cychlura iguanas, their ticks (genus Amblyomma, preferentially parasitizing these reptiles), and Rickettsia spp. endosymbionts (within tick ectoparasites). Our results indicate that while C. c. cychlura on Andros is consistently supported as a separate clade, patterns of relatedness among populations of C. c. figginsi and C. c. inornata within the Exuma Island chain are more complex. The distribution of the hosts, different tick species, and Rickettsia spp., supports the evolutionary independence of C. c. inornata. Further, these patterns are also consistent with two independent evolutionarily significant units within C. c. figginsi. Our findings suggest coevolutionary relationships between the reptile hosts, their ectoparasites, and rickettsial organisms, suggesting local adaptation. This work also speaks to the limitations of using neutral molecular markers from a single focal taxon as the sole currency for recognizing evolutionary novelty in populations of endangered species.

The Safe Resumption of Elective Plastic Surgery in Accredited Ambulatory Surgery Facilities During the COVID-19 Pandemic.

BACKGROUND: On March 11, 2020, the World Health Organization declared the novel Coronavirus-19 (COVID-19) a worldwide pandemic, resulting in an unprecedented shift in the Canadian healthcare system, where protection of an already overloaded system became a priority; all elective surgeries and non-essential activities were ceased. With the impact being less than predicted, on May 26, 2020, elective surgeries and non-essential activities were permitted to resume. OBJECTIVES: The authors sought to examine outcomes following elective aesthetic surgery and the impact on the Canadian healthcare system with the resumption of these services during the COVID-19 worldwide pandemic. METHODS: Data were collected in a prospective manner on consecutive patients who underwent elective plastic surgery procedures in 6 accredited ambulatory surgery facilities. Data included patient demographics, procedural characteristics, COVID-19 polymerase chain reaction (PCR) test status, airway management, and postoperative outcomes. RESULTS: A total of 368 patients underwent elective surgical procedures requiring a general anesthetic. All 368 patients who underwent surgery were negative on pre-visit screening. A COVID-19 PCR test was completed by 352 patients (95.7%) and all were negative. In the postoperative period, 7 patients (1.9%) had complications, 3 patients (0.8%) required a hospital visit, and 1 patient (0.3%) required hospital admission. No patients or healthcare providers developed COVID-19 symptoms or had a positive test for COVID-19 within 30 days of surgery. CONCLUSIONS: With appropriate screening and safety precautions, elective aesthetic plastic surgery can be performed in a manner that is safe for patients and healthcare providers and with a very low risk for accelerating virus transmission within the community.

The legacy of industrial pollution in estuarine sediments: spatial and temporal variability implications for ecosystem stress.

The direct impacts of anthropogenic pollution are widely known public and environmental health concerns, and details on the indirect impact of these are starting to emerge, for example affecting the environmental microbiome. Anthropogenic activities throughout history with associated pollution burdens are notable contributors. Focusing on the historically heavily industrialised River Clyde, Scotland, we investigate spatial and temporal contributions to stressful/hostile environments using a geochemical framework, e.g. pH, EC, total organic carbon and potentially toxic elements: As, Co, Cr, Cu, Ni, Pb and Zn and enrichment indicators. With regular breaches of the sediment quality standards in the estuarine system we focused on PTE correlations instead. Multivariate statistical analysis (principle component analysis) identifies two dominant components, PC1: As, Cr, Cu, Pb and Zn, as well as PC2: Ni, Co and total organic carbon. Our assessment confirms hot spots in the Clyde Estuary indicative of localised inputs. In addition, there are sites with high variability indicative of excessive mixing. We demonstrate that industrialised areas are dynamic environmental sites dependant on historical anthropogenic activity with short-scale variation. This work supports the development of 'contamination' mapping to enable an assessment of the impact of historical anthropogenic pollution, identifying specific 'stressors' that can impact the microbiome, neglecting in estuarine recovery dynamics and potentially supporting the emergence of antimicrobial resistance in the environment.

Energetic investment associated with vitellogenesis induces an oxidative cost of reproduction.

Oxidative stress is a potential cost of reproduction, but conclusive evidence for this relationship is lacking. The goal of this study was to serially assess across a seasonal gradient the relationship between reproduction, circulating plasma energy metabolites and oxidative state. Here, we examine a study animal ideally suited to test for the oxidative costs of reproduction: the Allen Cays Rock Iguana. Female rock iguanas reproduce at varying frequencies, often skipping years, allowing for a comparison between reproductive and non-reproductive females during the same narrow, annual breeding season. This feature of iguana life history enabled us to address not just sex and seasonal differences in physiology, but also potential oxidative costs of reproduction in females. Male and female iguanas were sampled during the early (vitellogenic), late (gravid) and post-reproductive seasons. Ultrasound examinations were performed on females to quantify reproductive investment, and blood samples were collected for physiology assays, which included reactive oxygen metabolites (d-ROMs), antioxidants, triglycerides, free glycerol and glucose. The early reproductive season was characterized by significant increases in reproductive female's triglycerides, free glycerol and oxidative stress compared to late and post-reproductive periods and non-reproductive females and males during all sampling periods. Antioxidants were significantly elevated during the early reproductive season for reproductive females, non-reproductive females and males when compared to late and post-season. Follicle number in early reproductive females was positively related to d-ROMs, triglycerides and free glycerol, negatively related to antioxidants and showed no relationship with glucose. Measures of oxidative stress, d-ROMs and oxidative index were positively correlated with circulating levels of the lipid metabolite free glycerol during the early reproductive period, but this relationship weakened in the late season and disappeared in the post-season. Broadly, this study supports the hypothesis that the relationship between reproduction and oxidative stress is driven by energy investment, being greatest during early reproduction when vitellogenesis is occurring.

Efficacy of "HLE"-a multidrug efflux-pump inhibitor-as a disinfectant against surface bacteria.

We evaluated the efficacy of a new disinfectant product, HLE, to inhibit multiple species of planktonic and biofilm bacterial cultures. The HLE disinfectant comprised of EDTA, lactic acid and hydrogen peroxide, and our data indicated that the disinfectant had effective antimicrobial and anti-biofilm activity even at low concentrations (0.15% to 0.4% HLE, v/v). Furthermore, the HLE disinfectant destabilized biofilm structures eradicated them due to the synergistic effect of EDTA and both antimicrobials (lactic acid and hydrogen peroxide), as revealed by confocal laser scanning microscopy. Additionally, sub-inhibitory concentrations of HLE disinfectant, with EDTA as an efflux pump inhibitor, inhibited the expression of multidrug EfrAB, NorE and MexCD efflux pumps in both planktonic and biofilm cultures. This could provide an alternative way to disinfect surfaces to avoid spreading multi-drug resistant strains in the food chain and the environment by decreasing efflux pump expression and consequently reducing the antibiotic selective pressure caused by systemic antibiotics and disinfectant use.

Proteomic analysis of Lactobacillus pentosus for the identification of potential markers involved in acid resistance and their influence on other probiotic features.

Acidity often prevents the undesirable microbial colonization both in fermented foods and under gastric conditions. Thus, the acid resistance of Lactobacillus pentosus strains used as starter cultures and/or probiotics requires further understanding. This was investigated by means of comparative proteomic approach using three strains representing the phenotypes: resistant (AP2-15), intermediate (AP2-18) and sensitive (LP-1) to acidic conditions. Proteomic analysis of constitutive phenotypes revealed that the intrinsic resistance of L. pentosus is associated with the over-production of three principal proteins: 2,3-bisphosphoglycerate-dependent phosphoglycerate mutase 2 (PGAM-d), elongation factor G and 50S ribosomal protein L10, and additionally on ATP synthase subunit beta and chaperone protein DnaK; they are associated with metabolic pathways of proteins and carbohydrates, energy production and stress responses. Suggested protein biomarkers for acid resistance in L. pentosus include elongation factor G and PGAM-d, both being abundantly found in the constitutive proteome of the resistant phenotype under standard and acidic conditions. Furthermore, L. pentosus strains pre-exposed to acids displayed enhanced probiotic function such as auto-aggregation ability via surface proteins. We conclude that pre-exposure of probiotic L. pentosus strains to acid may strategically enhance their performance as starter cultures and probiotics.

The use of minimum selectable concentrations (MSCs) for determining the selection of antimicrobial resistant bacteria.

The use of antimicrobial compounds is indispensable in many industries, especially drinking water production, to eradicate microorganisms. However, bacterial growth is not unusual in the presence of disinfectant concentrations that would be typically lethal, as bacterial populations can develop resistance. The common metric of population resistance has been based on the Minimum Inhibitory Concentration (MIC), which is based on bacteria lethality. However, sub-lethal concentrations may also select for resistant bacteria due to the differences in bacterial growth rates. This study determined the Minimal Selective Concentrations (MSCs) of bacterial populations exposed to free chlorine and monochloramine, representing a metric that possibly better reflects the selective pressures occurring at lower disinfectant levels than MIC. Pairs of phylogenetically similar bacteria were challenged to a range of concentrations of disinfectants. The MSCs of free chlorine and monochloramine were found to range between 0.021 and 0.39 mg L-1, which were concentrations 1/250 to 1/5 than the MICs of susceptible bacteria (MIC susc ). This study indicates that sub-lethal concentrations of disinfectants could result in the selection of resistant bacterial populations, and MSCs would be a more sensitive indicator of selective pressure, especially in environmental systems.

A Histological Snapshot of Hypothetical Multistep Progression From Nevus Sebaceus to Invasive Syringocystadenocarcinoma Papilliferum.

Syringocystadenocarcinoma papilliferum (SCACP) is an extremely rare adnexal neoplasm, believed to arise in a preexisting nevus sebaceus of Jadassohn (NSJ) through a multistep progression process. This hypothetical process involves an NSJ giving rise to syringocystadenoma papilliferum, which then presumably undergoes malignant transformation in rare circumstances to give rise to SCACP in situ, which finally progresses to an invasive SCACP. Of the 30 SCACP cases reported so far, none have documented the process from a birthmark to the final invasive lesion, with histological evidence of each step, in a single tumor. Here, the authors report just such a case. A 74-year-old man presented with a recently enlarging birthmark on the scalp. Excisional biopsy showed an invasive SCACP, in the background of SCACP in situ, syringocystadenoma papilliferum, and NSJ. Furthermore, this tumor showed a concurrent pigmented trichoblastoma and histological evidence of lymphovascular invasion, events that have not been documented with SCACP. Interestingly, all these component lesions were present on a single histological section of this solitary tumor. Regional lymph node metastasis, a rare occurrence in SCACP, was also present in this remarkable case. The authors discuss the implications of these findings in light of the review of relevant literature.

Primary Cutaneous T-cell Lymphoma With Coexpression of T-Cell Receptors αß and γδ.

T lymphocytes belong to 2 distinct sublineages that express either αß or γδ T-cell receptor (TCR) complex. Although malignancy is a great instigator of lineage infidelity, as exemplified by aberrant expression of numerous lineage markers in lymphoma cells, malignant T cells rarely coexpress αß and γδ TCR complexes. Similarly, only rare cases of CD4/CD8 double-positive primary cutaneous T-cell lymphoma have been reported. In this report, we describe a remarkable case of primary cutaneous T-cell lymphoma coexpressing αß and γδ TCR complexes, strong diffuse CD8, and a very restricted coexpression of CD4 and CD8. A 66-year-old man was referred to our center for treatment of a persistent eczematoid eruption of 6 years of duration. An initial biopsy demonstrated not only marked spongiosis, but also an epidermotropic population of CD4 small mature T cells with partial expression of CD8. The process remained indolent for another year, followed by an abrupt progression with development of plaques and tumors. Repeat biopsies of these lesions demonstrated a superimposed population of large anaplastic T cells extensively involving the dermis and epidermis. The large cells showed a strong uniform expression of CD3, CD8, CD45RA, CD5, granzyme, TIA1, perforin, TCR-ß, and TCR-γ and a weaker but unambiguous expression of CD4, CD25, CD2, and CD56. TCR gene rearrangement studies showed clonal rearrangements for TCR-ß and TCR-γ with identical peaks to those seen in the biopsy from a year earlier. The patient developed lymphadenopathy, with a biopsy showing nodal involvement by a morphologically and phenotypically identical neoplastic T-cell population. The disease showed partial response to systemic chemotherapy with development of new plaques, but these new lesions have regressed with radiation therapy.

Biocide tolerance, phenotypic and molecular response of lactic acid bacteria isolated from naturally-fermented Aloreña table to different physico-chemical stresses.

Lactic acid bacteria (LAB) isolated throughout the fermentation process of Aloreña table olives were found to be resistant at least to three antibiotics (Casado Muñoz et al., 2014); however, most were sensitive to the biocides tested in this study (with minimum inhibitory concentrations [MIC] below the epidemiological cut-off values). 2-15% of the isolates were found to be biocide resistant: Leuconostoc Pseudomesenteroides, which were resistant to hexachlorophene, and Lactobacillus pentosus to cetrimide and hexadecylpiridinium. We analyzed the effect of different physico-chemical stresses, including antimicrobials, on the phenotypic and genotypic responses of LAB, providing new insights on how they become resistant in a changing environment. Results indicated that similar phenotypic responses were obtained under three stress conditions: antimicrobials, chemicals and UV light. Susceptibility patterns to antibiotics changed: increasing MICs for ampicillin, chloramphenicol, ciprofloxacin, teicoplanin and tetracycline, and decreasing the MICs for clindamycin, erythromycin, streptomycin and trimethoprim in most strains. Statistically, cross resistance between different antibiotics was detected in all stress conditions. However, expression profiles of selected genes involved in stress/resistance response (rpsL, recA, uvrB and srtA) differed depending on the stress parameter, LAB species and strain, and the target gene. We conclude that, despite the uniform phenotypic response to stresses, the repertoire of induced and repressed genes differs. So, a search for a target to improve stress tolerance of LAB, especially those of importance as starter/protective cultures or probiotics, may depend on the individual screening of each strain, even though we could predict the antibiotic phenotypic response to all stresses.

Dermatological clues to the diagnosis of atypical complete DiGeorge syndrome.

Atypical complete DiGeorge syndrome (DGS) is an extremely rare congenital disease characterized by an eczematous dermatitis, lymphadenopathy, and an oligoclonal T-cell proliferation. Because its initial presentation may be confused with other types of eczematous dermatitis, diagnosis and treatment are usually delayed. We describe herein a case of an infant with atypical complete DGS to draw attention to the clinical and histopathological findings that lead us to the diagnosis.

Phylogeography of the endangered Lesser Antillean iguana, Iguana delicatissima: a recent diaspora in an archipelago known for ancient herpetological endemism.

Iguana delicatissima is an endangered endemic of the Lesser Antilles in the Caribbean. Phylogeographic analyses for many terrestrial vertebrate species in the Caribbean, particularly lizards, suggest ancient divergence times. Often, the closest relatives of species are found on the same island, indicating that colonization rates are so low that speciation on islands is often more likely to generate biodiversity than subsequent colonization events. Mitochondrial sequence analysis of the region spanning ND4 was performed on I. delicatissima individuals from islands across the species' range to estimate genetic divergence among geographically isolated populations. Five unique haplotypes were recovered from 46 individuals. The majority of animals carry a single common haplotype. Two of the haplotypes were only present in individuals classified as hybrids from Îles des Saintes. The final 2 haplotypes, single nucleotide substitutions, were present in animals from Îlet Chancel of Martinique and Saint Barthélemy, respectively. Despite the great distances between islands and habitat heterogeneity within islands, this species is characterized by low haplotype diversity. The low mtDNA variation of I. delicatissima suggests a single colonization coupled with rapid range expansion, potentially hastened by human-mediated dispersal.

Cardiovascular and cardiorespiratory phase synchronization in normovolemic and hypovolemic humans.

We investigated whether and how cardiovascular and cardiorespiratory phase synchronization would respond to changes in hydration status and orthostatic stress. Four men and six women were tested during graded head-up tilt (HUT) in both euhydration and dehydration (DEH) conditions. Continuous R-R intervals (RRI), systolic blood pressure (SBP) and respiration were investigated in low (LF 0.04-0.15 Hz) and high (HF 0.15-0.4 Hz) frequency ranges using a phase synchronization index (λ) ranging from 0 (complete lack of interaction) to 1 (perfect interaction) and a directionality index (d), where a positive value of d reflects oscillator 1 driving oscillator 2, and a negative value reflects the opposite driving direction. Surrogate data analysis was used to exclude relationships that occurred by chance. In the LF range, respiration was not synchronized with RRI or SBP, whereas RRI and SBP were phase synchronized. In the HF range, phases among all variables were synchronized. DEH reduced λ among all variables in the HF and did not affect λ between RRI and SBP in the LF region. DEH reduced d between RRI and SBP in the LF and did not affect d among all variables in the HF region. Increasing λ and decreasing d between SBP and RRI were observed in the LF range during HUT. Decreasing λ between SBP and RRI, respiration and RRI, and decreasing d between respiration and SBP were observed in the HF range during HUT. These results show that orthostatic stress disassociated interactions among RRI, SBP and respiration, and that DEH exacerbated the disconnection.

Acute cardiovascular autonomic responses to inhaled particulates.

PURPOSE: Harmful effects of inhaled particulates have been established in epidemiologic studies of ambient air pollution. In particular, heart rate variability responses to high levels of environmental tobacco smoke (ETS), similar to responses observed during direct smoking, have been reported. We sought to determine whether such responses could be observed at lower particulate concentrations. METHODS: We monitored cardiovascular responses of non-smoking 21 women and 19 men to work-place-relevant levels of: ETS, cooking oil fumes (Coil), wood smoke (WS), and water vapor as sham control. Responses, tested on three consecutive days (random order of aerosol presentation), were averaged for each subject. RESULTS: Low frequency spectral powers of heart rate and blood pressure rose during recovery from exposure to particulate, but not to sham exposures. At breathing frequencies, spectral power of men's systolic pressure doubled, and baroreflex effectiveness increased, following ETS exposure. An index of sympathetic control of heart rate was more pronounced in men than women, in response to ETS and Coil, compared to WS and sham. CONCLUSIONS: When measured under controlled conditions, autonomic activities in non-smoking men and women exposed to low level, short term, particulate concentrations were similar to those observed during longer term, higher level exposures to ETS and to direct smoking. These increased indexes of sympathetic control of heart rate and peripheral vasomotion followed introduction of particulates by about 15 min. Finally, coupling of heart rate and systolic pressure indicated an increase in baroreflex activity in the response to breathing ETS that was less effective in men than women.