361 research outputs found

    Ontogeny and intervals of development in five reef-associated species of blenny from the northern Gulf of Mexico (Teleostei: Blenniidae)

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    I examined patterns and timing of ontogeny and relative growth in five species of blenny (Teleostei: Blenniidae) from the northern Gulf of Mexico by assigning a suite of discrete character state scores to ontogenetic events (10 external traits; 218 total specimens). This is the first study to evaluate developmental patterns in reef-associated fishes relative to the timing of metamorphosis and settlement by applying scaling techniques and statistical methods to quantify, differentiate, and select criteria for defining intervals of development across taxa. Blennies settle at a common state of ontogeny and share a common pattern of body and fin/cirrus growth. Three \u27natural\u27 intervals of development (labeled \u27larvae\u27, \u27metamorphs\u27, and \u27settlers\u27) were consistently identified based on scoring and summing character states, and cluster analysis. Shape differences separate larvae from metamorphs, but not metamorphs from recent settlers. The common growth pattern consists of a general deepening of the head and abdomen, a narrowing of the interorbital region, and elongation of the pectoral and pelvic fins. These changes during metamorphosis produce the common shape and basic adult body form at settlement. Differences in shape show little relationship to phylogenetic distance. Estuarine blennies settle at a smaller size but similar state of ontogeny as coastal/shelf species, which suggests the timing, rate, and state of ontogeny at important periods of ecological transition, may influence survival. The smaller size at settlement in estuarine blennies is consistent with natural selection emphasizing rapid ontogeny in species or areas where competition for available habitat or resources is great. Differences in fin and body pigmentation patterns and in the number of teeth between estuarine and coastal/shelf blennies suggest that development reflects adaptive convergence to similar ecological niches and habitats, rather than revealing any evolutionary relationship. In blennies, ontogeny progresses gradually and continuously rather than in a stepwise fashion, as postulated by saltatory theory. Differential growth rates of individual body parts provide a similar conclusion. Variability in the timing and magnitude of ontogeny make recognizing proposed thresholds between \u27steps\u27 difficult, if not impossible. Blennies are not juveniles at settlement as commonly accepted for many other demersal and reef-associated species

    Draft genome sequence of the caffeine-degrading methylotroph \u3cem\u3eMethylorubrum populi\u3c/em\u3e Pinkel

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    A pink-pigmented facultative methylotroph, Methylorubrum populi Pinkel, was isolated from compost by selective enrichment with caffeine (3,5,7-trimethylxanthine) as the sole carbon, nitrogen, and energy source. We report here its high-quality draft genome sequence, assembled in 35 contigs totaling 5,630,907 bp. We identified 5,681 protein-coding sequences, including those putatively involved in caffeine degradation. ABSTRACT A pink-pigmented facultative methylotroph, Methylorubrum populi Pinkel, was isolated from compost by selective enrichment with caffeine (3,5,7-trimethylxanthine) as the sole carbon, nitrogen, and energy source. We report here its high-quality draft genome sequence, assembled in 35 contigs totaling 5,630,907 bp. We identified 5,681 protein-coding sequences, including those putatively involved in caffeine degradation

    Practice Settings and Dialectical Behavior Therapy Implementation: A mixed method analysis

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    Background and Significance: Implementation science is the study of transferring innovation into practice. Guided by The Consolidated Framework for Implementation Research (CFIR), this study analyzes Dialectical Behavior Therapy (DBT) utilization in the real world. Such an inquiry informs DBT-uptake in settings, whereby increasing employment of the current gold standard treatment for suicide, non-suicidal self-injury, and behavioral dysregulation. Methods: Seventy-nine intensively trained DBT clinicians completed an online survey that quantified implementation outcomes and practice-setting variables. Practice setting variables were compared to DBT implementation using bivariate analyses. Twenty sequential semi-structured interviews bolstered quantitative findings while exploring the field of inquiry that could not be quantified. Findings and Limitations: Supervision, team cohesion, team communication, and team climate were significantly correlated with DBT implementation and bolstered by qualitative themes. Four other practice-setting variables were related with moderate significance and little qualitative support, and additional hypotheses were generated. Limitations require consideration of the current research as exploratory. Conclusions: The four variables with the clearest connection to DBT implementation can be characterized as interpersonal variables within practice settings. These findings contribute to the identification of key drivers of successful DBT implementation within settings. Future researchers are advised to develop and test implementation strategies incorporating these findings. Practitioners should be mindful of these variables when implementing DBT

    Do Anxiety, Depression, and Mental Health Treatment Impact Christian College Student Religiosity/Spirituality?

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    The majority of Americans report religious affiliation and participate in religious practices. Several studies have sought to analyze the protective factors of religiosity, especially as it relates to mental and physical health issues. However, little research has been conducted which explores the relationship between religiosity/spirituality (R/S), mental health, and its treatment status. This study sought to determine whether participants’ mental health problems (anxiety and depression) and treatment status (treatment versus no treatment) were related to their religiosity/spirituality and if severity of pathology and treatment engagement significantly affected R/S. Results suggest subjects can be aggregated into two meaningful groups: one that endorsed higher symptoms of anxiety and depression, higher rates of treatment, and lower religiosity/spirituality scores and one with fewer symptoms of anxiety and depression, less engagement with treatment, and higher religiosity/spirituality scores. Although subsequent analysis indicated that severity of depression, depression treatment, and religiosity/spirituality were key variables, neither treatment nor symptom severity were significantly related to total religiosity/spirituality scores

    The cytosine chemoreceptor McpC in \u3cem\u3ePseudomonas putida\u3c/em\u3e F1 also detects nicotinic acid

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    Soil bacteria are generally capable of growth on a wide range of organic chemicals, and pseudomonads are particularly adept at utilizing aromatic compounds. Pseudomonads are motile bacteria that are capable of sensing a wide range of chemicals, using both energy taxis and chemotaxis. Whilst the identification of specific chemicals detected by the ≥26 chemoreceptors encoded in Pseudomonas genomes is ongoing, the functions of only a limited number of Pseudomonas chemoreceptors have been revealed to date. We report here that McpC, a methyl-accepting chemotaxis protein in Pseudomonas putida F1 that was previously shown to function as a receptor for cytosine, was also responsible for the chemotactic response to the carboxylated pyridine nicotinic acid

    FINDING MARS PALEOPOLES FROM MAGNETIZATION EDGE EFFECTS TO DETERMINE THE HISTORY OF MARS’ CORE DYNAMO

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    This is a new method of determining magnetization strength, direction, and paleopole location from magnetic anomalies across edges of the equatorial band of magnetic sources on Mars. Different assumed locations of paleopoles result in different inducing field directions in the vicinity of an edge. Thus, with different paleopoles, the resulting magnetic fields from the edges of magnetic sources are different, and correlate differently with the observed fields. Best correlating observed and computed magnetic edge effect fields yield the potential paleopoles. The total gradient (TG) of the z-component magnetic field was used to identify the edges of magnetization boundaries. Three edge segments yielded meaningful paleopoles. They are: (15°S, 285°E)/(0°, 292.5°E) across the northeast trending edge east of Tharsis; (15°N, 195°E) across the southern boundary located in the Terra Cimmeria and Terra Sirenum area; and (15°S, 165°E)/(45°S, 180°E) across the northeast edge of Hellas Planitia. The effective magnetization in these regions (assuming 40km magnetic layer thickness) is 7.02, 42.13-94.79, and 2.63-3.51 A/m, respectively. Evidence from the overlap of regions of TG and chronostratigraphy suggests that the dynamo was active during the Noachian and may have been active in the early Hesperian

    Hybrid two-component sensors for identification of bacterial chemoreceptor function. \u3cem\u3eApplied and Environmental Microbiology\u3c/em\u3e

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    Soil bacteria adapt to diverse and rapidly changing environmental conditions by sensing and responding to environmental cues using a variety of sensory systems. Two-component systems are a widespread type of signal transduction system present in all three domains of life and typically are comprised of a sensor kinase and a response regulator. Many two-component systems function by regulating gene expression in response to environmental stimuli. The bacterial chemotaxis system is a modified two-component system with additional protein components and a response that, rather than regulating gene expression, involves behavioral adaptation and results in net movement toward or away from a chemical stimulus. Soil bacteria generally have 20 to 40 or more chemoreceptors encoded in their genomes. To simplify the identification of chemoeffectors (ligands) sensed by bacterial chemoreceptors, we constructed hybrid sensor proteins by fusing the sensor domains of chemoreceptors to the signaling domains of the NarX/NarQ nitrate sensors. Responses to potential attractants were monitored by β-galactosidase assays using an reporter strain in which the nitrate-responsive promoter was fused to Hybrid receptors constructed from PcaY, McfR, and NahY, which are chemoreceptors for aromatic acids, tricarboxylic acid cycle intermediates, and naphthalene, respectively, were sensitive and specific for detecting known attractants, and the β-galactosidase activities measured in correlated well with results of chemotaxis assays in the native strain. In addition, a screen of the hybrid receptors successfully identified new ligands for chemoreceptor proteins and resulted in the identification of six receptors that detect propionate. Relatively few of the thousands of chemoreceptors encoded in bacterial genomes have been functionally characterized. More importantly, although methyl-accepting chemotaxis proteins, the major type of chemoreceptors present in bacteria, are easily identified bioinformatically, it is not currently possible to predict what chemicals will bind to a particular chemoreceptor. Chemotaxis is known to play roles in biodegradation as well as in host-pathogen and host-symbiont interactions, but many studies are currently limited by the inability to identify relevant chemoreceptor ligands. The use of hybrid receptors and this simple reporter system allowed rapid and sensitive screening for potential chemoeffectors. The fusion site chosen for this study resulted in a high percentage of functional hybrids, indicating that it could be used to broadly test chemoreceptor responses from phylogenetically diverse samples. Considering the wide range of chemical attractants detected by soil bacteria, hybrid receptors may also be useful as sensitive biosensors

    Life History and Ecology of Sand Seatrout Cynoscion arenarius Ginsburg, in the Northern Gulf of Mexico: A Review

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    Sand seatrout usually represent from 5-7% of trawl catches by weight, 8-10% by number, and consistently rank among the top 5 most abundant species in demersal surveys. Sand seatrout mature at 140-180 mm TL, begin to enter the late developing, gravid, or ripe stages around 180 mm TL, and first spawn at 12 months. Spawning occurs primarily from March through September with distinct peaks in both March-April and August-September. Spawning initially takes place in midshelf to offshore waters and moves shoreward as the season progresses, with most occuring in the lower estuary and shallow GOMEX (7-15 m water depth). Larvae are primarily collected in water depths of \u3c25m, more are collected at night than during the day, and they are somewhat surface-oriented but become increasingly demersal with size. In pass studies, larval sand seatrout are also more abundant on night flood tides than at other times. Larvae migrate into shallow areas of the estuary where they remain until at least 50-60 mm TL after which they move to deeper water. Mean size predicted by regression was 250, 425, and 573 mm TL at ages I, II, and Ill, with a typical lifespan of 1-2 years and possibly up to 3 years. Total annual mortality approaches 100% based on trawl data if the lifespan is one year and 90% if two years. Distribution of sand seatrout appears restricted more by water temperature than salinity. Electrophoretic evidence is unclear whether sand seatrout should be recognized as distinct from weakfish. Evidence provided by otolith aging of larvae and differences in larval pigmentation, however, supports the separation of two co-occurring morphological types and suggests separate populations of sand seatrout in the northern Gulf of Mexico

    Direct Observation of Reductive Coupling Mechanism between Oxygen and Iron/Nickel in Cobalt-Free Li-Rich Cathode Material: An in Operando X-Ray Absorption Spectroscopy Study

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    Li-rich cathodes possess high capacity and are promising candidates in next-generation high-energy density Li-ion batteries. This high capacity is partly attributed to its poorly understood oxygen-redox activity. The present Li-rich cathodes contain expensive and environmentally-incompatible cobalt as a main transition metal. In this work, cobalt-free, iron-containing Li-rich cathode material (nominal composition Li1.2_{1.2}Mn0.56_{0.56}Ni0.16_{0.16}Fe0.08_{0.08}O2_{2}) is synthesized, which exhibits excellent discharge capacity (≈250 mAh g−1^{-1} and cycling stability. In operando, X-ray absorption spectroscopy at Mn, Fe, and Ni K edges reveals its electrochemical mechanism. X-ray absorption near edge structure (XANES) features of Fe and Ni K edges show unusual behavior: when an electrode is charged to 4.5 V, Fe and Ni K edges’ XANES features shift to higher energies, evidence for Fe3+^{3+}→Fe4+^{4+} and Ni2+^{2+}→Ni4+^{4+} oxidation. However, when charged above 4.5 V, XANES features of Fe and Ni K edges shift back to lower energies, indicating Fe4+^{4+}→Fe3+^{3+} and Ni4+^{4+}→Ni3+^{3+} reduction. This behavior can be linked to a reductive coupling mechanism between oxygen and Fe/Ni. Though this mechanism is observed in Fe-containing Li-rich materials, the only electrochemically active metal in such cases is Fe. Li1.2_{1.2}Mn0.56_{0.56}Ni0.16_{0.16}Fe0.08_{0.08}O2_{2} has multiple electrochemically active metal ions; Fe and Ni, which are investigated simultaneously and the obtained results will assist tailoring of cost-effective Li-rich materials
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