How do lizard niches conserve, diverge or converge? Further exploration of saurian evolutionary ecology

Background: Environmental conditions on Earth are repeated in non-random patterns that often coincide with species from different regions and time periods having consistent combinations of morphological, physiological and behavioral traits. Observation of repeated trait combinations among species confronting similar environmental conditions suggest that adaptive trait combinations are constrained by functional tradeoffs within or across niche dimensions. In an earlier study, we assembled a high-resolution database of functional traits for 134 lizard species to explore ecological diversification in relation to five fundamental niche dimensions. Here we expand and further examine multivariate relationships in that dataset to assess the relative influence of niche dimensions on the distribution of species in 6-dimensional niche space and how these may deviate from distributions generated from null models. We then analyzed a dataset with lower functional-trait resolution for 1023 lizard species that was compiled from our dataset and a published database, representing most of the extant families and environmental conditions occupied by lizards globally. Ordinations from multivariate analysis were compared with null models to assess how ecological and historical factors have resulted in the conservation, divergence or convergence of lizard niches. Results: Lizard species clustered within a functional niche volume influenced mostly by functional traits associated with diet, activity, and habitat/substrate. Consistent patterns of trait combinations within and among niche dimensions yielded 24 functional groups that occupied a total niche space significantly smaller than plausible spaces projected by null models. Null model tests indicated that several functional groups are strongly constrained by phylogeny, such as nocturnality in the Gekkota and the secondarily acquired sit-and-wait foraging strategy in Iguania. Most of the widely distributed and species-rich families contained multiple functional groups thereby contributing to high incidence of niche convergence. Conclusions: Comparison of empirical patterns with those generated by null models suggests that ecological filters promote limited sets of trait combinations, especially where similar conditions occur, reflecting both niche convergence and conservatism. Widespread patterns of niche convergence following ancestral niche diversification support the idea that lizard niches are defined by trait-function relationships and interactions with environment that are, to some degree, predictable and independent of phylogeny.Fil: Pelegrin, Nicolas. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Córdoba. Instituto de Diversidad y Ecología Animal. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas Físicas y Naturales. Instituto de Diversidad y Ecología Animal; Argentina. Universidad Nacional de Córdoba. Facultad de Ciencias Exactas, Físicas y Naturales; ArgentinaFil: Winemiller, Kirk Owen. Texas A&M University; Estados UnidosFil: Vitt, Laurie J.. University Of Oklahoma; Estados UnidosFil: Fitzgerald, Daniel B.. United States Geological Survey; Estados UnidosFil: Pianka, Eric R. University of Texas at Austin; Estados Unido

Hypertension, kidney disease, HIV and antiretroviral therapy among Tanzanian adults: a cross-sectional study.

BACKGROUND: The epidemics of HIV and hypertension are converging in sub-Saharan Africa. Due to antiretroviral therapy (ART), more HIV-infected adults are living longer and gaining weight, putting them at greater risk for hypertension and kidney disease. The relationship between hypertension, kidney disease and long-term ART among African adults, though, remains poorly defined. Therefore, we determined the prevalences of hypertension and kidney disease in HIV-infected adults (ART-naive and on ART >2 years) compared to HIV-negative adults. We hypothesized that there would be a higher hypertension prevalence among HIV-infected adults on ART, even after adjusting for age and adiposity. METHODS: In this cross-sectional study conducted between October 2012 and April 2013, consecutive adults (>18 years old) attending an HIV clinic in Tanzania were enrolled in three groups: 1) HIV-negative controls, 2) HIV-infected, ART-naive, and 3) HIV-infected on ART for >2 years. The main study outcomes were hypertension and kidney disease (both defined by international guidelines). We compared hypertension prevalence between each HIV group versus the control group by Fisher's exact test. Logistic regression was used to determine if differences in hypertension prevalence were fully explained by confounding. RESULTS: Among HIV-negative adults, 25/153 (16.3%) had hypertension (similar to recent community survey data). HIV-infected adults on ART had a higher prevalence of hypertension (43/150 (28.7%), P = 0.01) and a higher odds of hypertension even after adjustment (odds ratio (OR) = 2.19 (1.18 to 4.05), P = 0.01 in the best model). HIV-infected, ART-naive adults had a lower prevalence of hypertension (8/151 (5.3%), P = 0.003) and a lower odds of hypertension after adjustment (OR= 0.35 (0.15 to 0.84), P = 0.02 in the best model). Awareness of hypertension was ≤ 25% among hypertensive adults in all three groups. Kidney disease was common in all three groups (25.6% to 41.3%) and strongly associated with hypertension (P 2 years had two-fold greater odds of hypertension than HIV-negative controls. HIV-infected adults with hypertension were rarely aware of their diagnosis but often have evidence of kidney disease. Intensive hypertension screening and education are needed in HIV-clinics in sub-Saharan Africa. Further studies should determine if chronic, dysregulated inflammation may accelerate hypertension in this population

Post-traumatic stress disorder: A biopsychosocial case-control study investigating peripheral blood protein biomarkers

Experiencing traumatic events is unfortunately commonplace and, in some cases, may lead to the onset of debilitating mental health disorders, such as post-traumatic stress disorder (PTSD). Current diagnostic criteria for PTSD results in high depression and anxiety comorbidity. Better understanding of biological mechanisms and pathways underlying PTSD could aid in more accurate case identification and stratification of treatments. Recent meta-analysis has identified chronic PTSD to be associated with increased expression of pro-inflammatory cytokines and alterations in neuronal structures which contribute to an overall reduction in brain volume. Despite this, there are currently no biological markers in clinical use to identify PTSD or monitor treatment. This case-control study (n = 40) aimed to identify differences in peripheral blood biomarkers, and biomarker combinations, able to distinguish PTSD participants from controls, and examine in a biopsychosocial framework. The levels of 5/37 biomarkers investigated were significantly altered in the serum of PTSD participants: HDL and LDL cholesterol, tPA, IL-8 and EGF. Biomarkers could be used in combination with psychological criteria, in a biopsychosocial model, to support clinical management decisions and ensure appropriate individual treatment pathways

Energy gap in superconducting fullerides: optical and tunneling studies

Tunneling and optical transmission studies have been performed on superconducting samples of Rb3C60. At temperatures much below the superconducting transition temperature Tc the energy gap is 2 Delta=5.2 +- 0.2meV, corresponding to 2 Delta/kB Tc = 4.2. The low temperature density of states, and the temperature dependence of the optical conductivity resembles the BCS behavior, although there is an enhanced ``normal state" contribution. The results indicate that this fulleride material is an s-wave superconductor, but the superconductivity cannot be described in the weak coupling limit.Comment: RevTex file with four .EPS figures. Prints to four pages. Also available at http://buckminster.physics.sunysb.edu/papers/pubrece.htm

The long term effects of sports concussion on retired Australian football players: a study using Transranial Magnetic Stimulation

This study investigated corticomotor excitability and inhibition, cognitive functioning, and fine motor dexterity in retired elite and amateur Australian football (AF) players who had sustained concussions during their playing careers. Forty male AF players who played at the elite level (n=20; mean age 49.7±5.7 years) or amateur level (n=20; mean age 48.4±6.9 years), and had sustained on average 3.2 concussions 21.9 years previously, were compared with 20 healthy age-matched male controls (mean age 47.56±6.85 years). All participants completed assessments of fine dexterity, visuomotor reaction time, spatial working memory (SWM), and associative learning (AL). Transcranial magnetic stimulation (TMS) was used to measure corticospinal excitability: stimulus-response (SR) curves and motor evoked potential (MEP) 125% of active motor threshold (aMT); and intracortical inhibition: cortical silent period (cSP), short-interval intracortical inhibition (SICI), and long-interval intracortical inhibition (LICI). Healthy participants performed better in dexterity (p=0.003), reaction (p=0.003), and movement time (p=0.037) than did both AF groups. Differences between AF groups were found in AL (p=0.027) and SWM (p=0.024). TMS measures revealed that both AF groups showed reduced cSP duration at 125% aMT (p>0.001) and differences in SR curves (p>0.001) than did healthy controls. Similarly, SICI (p=0.012) and LICI (p=0.009) were reduced in both AF groups compared with controls. Regression analyses revealed a significant contribution to differences in motor outcomes with the three measures of intracortical inhibition. The measures of inhibition differed, however, in terms of which performance measure they had a significant and unique predictive relationship with, reflecting the variety of participant concussion injuries. This study is the first to demonstrate differences in motor control and intracortical inhibition in AF players who had sustained concussions during their playing career two decades previously

Combining genomics and epidemiology to track mumps virus transmission in the United States.

Unusually large outbreaks of mumps across the United States in 2016 and 2017 raised questions about the extent of mumps circulation and the relationship between these and prior outbreaks. We paired epidemiological data from public health investigations with analysis of mumps virus whole genome sequences from 201 infected individuals, focusing on Massachusetts university communities. Our analysis suggests continuous, undetected circulation of mumps locally and nationally, including multiple independent introductions into Massachusetts and into individual communities. Despite the presence of these multiple mumps virus lineages, the genomic data show that one lineage has dominated in the US since at least 2006. Widespread transmission was surprising given high vaccination rates, but we found no genetic evidence that variants arising during this outbreak contributed to vaccine escape. Viral genomic data allowed us to reconstruct mumps transmission links not evident from epidemiological data or standard single-gene surveillance efforts and also revealed connections between apparently unrelated mumps outbreaks

Polymeric Nanoparticle PET/MR Imaging Allows Macrophage Detection in Atherosclerotic Plaques

Author Manuscript 2013 March 02.Rationale: Myeloid cell content in atherosclerotic plaques associates with rupture and thrombosis. Thus, imaging of lesional monocytes and macrophages could serve as a biomarker of disease progression and therapeutic intervention. Objective: To noninvasively assess plaque inflammation with dextran nanoparticle (DNP)-facilitated hybrid positron emission tomography/magnetic resonance imaging (PET/MRI). Methods and Results: Using clinically approved building blocks, we systematically developed 13-nm polymeric nanoparticles consisting of cross-linked short chain dextrans, which were modified with desferoxamine for zirconium-89 radiolabeling ([superscript 89]Zr-DNP) and a near-infrared fluorochrome (VT680) for microscopic and cellular validation. Flow cytometry of cells isolated from excised aortas showed DNP uptake predominantly in monocytes and macrophages (76.7%) and lower signal originating from other leukocytes, such as neutrophils and lymphocytes (11.8% and 0.7%, P<0.05 versus monocytes and macrophages). DNP colocalized with the myeloid cell marker CD11b on immunohistochemistry. PET/MRI revealed high uptake of [superscript 89]Zr-DNP in the aortic root of apolipoprotein E knock out (ApoE[superscript −/−]) mice (standard uptake value, ApoE[superscript −/−] mice versus wild-type controls, 1.9±0.28 versus 1.3±0.03; P<0.05), corroborated by ex vivo scintillation counting and autoradiography. Therapeutic silencing of the monocyte-recruiting receptor C-C chemokine receptor type 2 with short-interfering RNA decreased [superscript 89]Zr-DNP plaque signal (P<0.05) and inflammatory gene expression (P<0.05). Conclusions: Hybrid PET/MRI with a 13-nm DNP enables noninvasive assessment of inflammation in experimental atherosclerotic plaques and reports on therapeutic efficacy of anti-inflammatory therapy.National Heart, Lung, and Blood InstituteNational Institutes of Health (U.S.). Dept. of Health and Human Services (HHSN268201000044C)National Institutes of Health (U.S.). Dept. of Health and Human Services (R01-HL096576)National Institutes of Health (U.S.). Dept. of Health and Human Services (R01-HL095629)National Institutes of Health (U.S.). Dept. of Health and Human Services (T32-HL094301

Improving the sensitivity of the hop index in patients with an ACL deficient knee by transforming the hop distance scores

BACKGROUND: The one leg hop for distance is one of the most commonly employed functional tests utilized in the evaluation of the ACL deficient and reconstructed patient. While the reliability of the hop test scores has been well established, validity studies have revealed low sensitivity rates in detecting functional limitations using the hop index (the ratio or percentage of limb performance). However, the impact of the inherent limitations associated with the hop index have not been investigated to date. One specific limitation relates to the impact of the differences in the underlying hop distance scores. Therefore, this pilot study set out to determine: 1) the impact that between limb differences in hop distance has on the sensitivity of the hop index in detecting functional limitations and; 2) whether a logarithmic transformation of the underlying hop distance scores improves the sensitivity of the hop index. METHODS: A cross sectional design involving the evaluation of one leg hop for distance performance in a consecutive sample of 10 ACL deficient males with an isolated ACL tear awaiting reconstructive surgery and nine gender, age-matched controls. RESULTS: In the ACL deficient, the hop index was associated with the distance hopped on the non-injured limb (r = -0.66, p = 0.04) but not on the injured limb. Transformation (logarithmic) of the hop distance scores and re-calculation of the hop index using the transformed scores increased the sensitivity of the hop index in the detection of functional limitations from 20 to 60% and 50 to 70% using the normal limb symmetry reference norms of ≥ 85% and 90% respectively. CONCLUSION: The distance hopped on the non-injured limb is a critical factor in detecting functional limitations using the hop index in patients with an ACL deficient knee. Logarithmic transformation of the hop distance scores minimizes the effect of the arithmetic differences between limbs however; the sensitivity of the hop index in detecting abnormal limb symmetry remains low