8,569 research outputs found

    Locating the critical end point using the linear sigma model coupled to quarks

    Full text link
    We use the linear sigma model coupled to quarks to compute the effective potential beyond the mean field approximation, including the contribution of the ring diagrams at finite temperature and baryon density. We determine the model couplings and use them to study the phase diagram in the baryon chemical potential-temperature plane and to locate the Critical End Point.Comment: 8 pages, 2 figures, conference paper from ISMD 201

    Globally enhanced calcification across the coccolithophore Gephyrocapsa complex during the mid-Brunhes interval

    Get PDF
    Evolutionary or adaptative changes in Noelaerhabdaceae coccolithophores occurred in parallel with major changes in carbonate export and burial during scenarios of low orbital eccentricity, with a ∼400 kyr recurrence, during the Pleistocene. Coeval with these conditions of enhanced proliferation, here we report that the calcification of specimens was enhanced at a global scale and across multiple species or morphotypes within the Gephyrocapsa complex during the Mid-Brunhes (MB) interval. This acme of increased production of organic and inorganic carbon by Gephyrocapsa, suggests that such global changes may originate from a common driver. Increased seawater alkalinity, with an appropriately long residence time, is proposed as environmental trigger on the selection of a wide variety of highly calcified and prolific Gephyrocapsa taxa. This new perspective highlights the role of orbital forcing in phytoplankton evolution or adaptation, via a global environmental driver in the form of seawater carbon chemistry. Our results fit with earlier proposals appealing for an intensified biological pump and respiration dissolution during this interval. We hypothesize that the Gephyrocapsa acme may play a double-edged role, by increasing shallow respiration dissolution rates, limiting the removal of alkalinity by burial, which may help to recycle alkalinity and maintain constant levels at the ∼400 kyr scale. This idea suggests the potential capacity of the Noelaerhabdaceae coccolithophore acmes to modify the typical behaviour of carbonate compensation in the ocean and that the changes in coccolithophore calcification may be indicative of changes in ocean carbonate chemistry and the operation of the global carbon cycle in the past

    Ethnomycological knowledge among Kaqchikel, indigenous Maya people of Guatemalan Highlands

    Get PDF
    Background: The Guatemalan Highlands is a region of great but so far poorly known mycological diversity. People living in this area have long used wild fungi as a source of food and income. However, our knowledge of the ethnomycological practices of the Mayan peoples of Guatemala is still rudimental, especially if compared with information reported for the neighboring region of Mexico. Among the main indigenous groups of the Maya people inhabiting the highlands of Central Guatemala, stand the Kaqchikel, accounting for nearly 8% of the entire Guatemalan population. The main aim of this study was to record the traditional knowledge and use of edible wild mushrooms by inhabitants of the municipality of San Juan Sacatepéquez that lies at the heart of the Kaqchikel area in the central highlands of Guatemala, also describing the relevant selling practices and dynamics. A secondary aim was to compare the diversity and composition of the mushroom assemblage offered at the market with the macrofungal diversity of woods in the area. Methodology: This study is the result of 4 years of ethnomycological research, conducted through continuous visits to the municipal market and focused interviews with collectors and vendors. Field sampling in pine-oak forested areas surrounding San Juan Sacatepéquez, from where the mushrooms sold at the market are foraged, were also conducted, in the presence of local collectors. Results: The results show a significant richness of species sold in the market, a network of commerce of purchase, sale, and resale of several species, with relatively stable prices, and knowledge about edible and inedible species that is transmitted mainly within the family nucleus. The business of selling mushrooms in the market is an exclusive activity of women, who are supplied by collectors or by other vendors. Fungi are sold and bought only as food, while no consumption of hallucinogenic mushrooms or medicinal mushrooms was recorded. Several species of Amanita, Cantharellus, Boletus, Lactarius, and Russula were those most commercialized in the 4 years of the study, but we also spotted fungi never reported before as consumed in the country, including Gastropila aff. fumosa (= Calvatia fumosa) and several species of Cortinarius. Field sampling in nearby pine-oak forests confirmed an elevated local macrofungal diversity. Conclusion: Our study unveiled the contemporary wealth of Kaqchikel culture for what concerns mushrooms, demonstrating that mushrooms continue to be culturally and economically important for these communities despite the erosion of traditional knowledge. Our results also confirmed the need to investigate in greater detail the Guatemalan mycodiversity that is vast and poorly known

    Improvements to the X-ray Spectrometer at the Aerosol Laboratory, Instituto de Física, UNAM

    Get PDF
    Due to the demands of better (accurate and precise) analytical results using X-ray Fluorescence (XRF) at the Aerosol Laboratory, Instituto de Física, UNAM, it was necessary to carry out improvements in instrumentation and analytical procedures in the x-ray spectrometer located in this facility. A new turbomolecular vacuum system was installed, which allows reaching the working pressure in a shorter time. Characteristic x-rays are registered with a Silicon Drift Detector, or SDD, (8 mm thick Be window, 140 eV at 5.9 keV resolution), working directly in a high-vacuum, permitting the detection of x-rays with energies as low as 1 keV (Na Ka) and higher counting rates than in the past. Due to the interference produced by the Rh L x-rays emitted by the tube normally used for atmospheric and food analysis with Cl K x-rays, another tube with a W anode was mounted in the spectrometer to avoid this interference, with the possibility to select operation with any of these tubes. Examples of applications in atmospheric aerosols and other samples are presented, to demonstrate the enhanced function of the spectrometer. Other future modifications are also explained

    Dopamine D 4 Receptor-Deficient Mice Display Cortical Hyperexcitability

    Get PDF
    The dopamine D(4) receptor (D(4)R) is predominantly expressed in the frontal cortex (FC), a brain region that receives dense input from midbrain dopamine (DA) neurons and is associated with cognitive and emotional processes. However, the physiological significance of this dopamine receptor subtype has been difficult to explore because of the slow development of D(4)R agonists and antagonists the selectivity and efficacy of which have been rigorously demonstrated in vivo. We have attempted to overcome this limitation by taking a multidimensional approach to the characterization of mice completely deficient in this receptor subtype. Electrophysiological current and voltage-clamp recordings were performed in cortical pyramidal neurons from wild-type and D(4)R-deficient mice. The frequency of spontaneous synaptic activity and the frequency and duration of paroxysmal discharges induced by epileptogenic agents were increased in mutant mice. Enhanced synaptic activity was also observed in brain slices of wild-type mice incubated in the presence of the selective D(4)R antagonist PNU-101387G. Consistent with greater electrophysiological activity, nerve terminal glutamate density associated with asymmetrical synaptic contacts within layer VI of the motor cortex was reduced in mutant neurons. Taken together, these results suggest that the D(4)R can function as an inhibitory modulator of glutamate activity in the FC.Fil: Rubinstein, Marcelo. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; Argentina. Universidad de Buenos Aires. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Cepeda, Carlos. University of California at Los Angeles; Estados UnidosFil: Hurst, Raymond S.. University of California at Los Angeles; Estados UnidosFil: Flores Hernandez, Jorge. University of California at Los Angeles; Estados UnidosFil: Ariano, Marjorie A.. The Chicago Medical School; Estados UnidosFil: Falzone, Tomas Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Investigaciones en Ingeniería Genética y Biología Molecular "Dr. Héctor N. Torres"; ArgentinaFil: Kozell, Laura B.. Oregon Health Sciences University; Estados UnidosFil: Meshul, Charles K.. Oregon Health Sciences University; Estados UnidosFil: Bunzow, James R.. Oregon Health Sciences University; Estados UnidosFil: Low, Malcolm J.. Oregon Health Sciences University; Estados UnidosFil: Levine, Michael S.. University of California at Los Angeles; Estados UnidosFil: Grandy, David K.. Oregon Health Sciences University; Estados Unido

    Intermediary Role of Lung Alveolar Type 1 Cells in Epithelial Repair upon Sendai Virus Infection

    Get PDF
    The lung epithelium forms the first barrier against respiratory pathogens and noxious chemicals; however, little is known about how more than 90% of this barrier, made of AT1 (alveolar type 1) cells, responds to injury. Using the Sendai virus to model natural infection in mice, we find evidence that AT1 cells have an intermediary role by persisting in areas depleted of AT2 cells, upregulating IFN responsive genes, and receding from invading airway cells. Sendai virus infection mobilizes airway cells to form alveolar SOX2+ (Sry-box 2+) clusters without differentiating into AT1 or AT2 cells. Large AT2 cell-depleted areas remain covered by AT1 cells, which we name AT2-less regions , and are replaced by SOX2+ clusters spreading both basally and luminally. AT2 cell proliferation and differentiation are largely confined to topologically distal regions and form de novo alveolar surface, with limited contribution to in situ repairs of AT2-less regions. Time-course single-cell RNA sequencing profiling and RNAscope validation suggest enhanced immune responses and altered growth signals in AT1 cells. Our comprehensive spatiotemporal and genomewide study highlights the hitherto unappreciated role of AT1 cells in lung injury-repair

    Decentralized Discrete-Time Formation Control for Multirobot Systems

    Get PDF
    Inspired from the collective behavior of biological entities for the group motion coordination, this paper analyzes the formation control of mobile robots in discrete time where each robot can sense only the position of certain team members and the group behavior is achieved through the local interactions of robots. The main contribution is an original formal proof about the global convergence to the formation pattern represented by an arbitrary Formation Graph using attractive potential functions. The analysis is addressed for the case of omnidirectional robots with numerical simulations

    Inpatient Massage Therapy Versus Music Therapy Versus Usual Care: A Mixed-methods Feasibility Randomized Controlled Trial.

    Full text link
    BACKGROUND: Little is known about the feasibility of providing massage or music therapy to medical inpatients at urban safety-net hospitals or the impact these treatments may have on patient experience. OBJECTIVE: To determine the feasibility of providing massage and music therapy to medical inpatients and to assess the impact of these interventions on patient experience. DESIGN: Single-center 3-arm feasibility randomized controlled trial. SETTING: Urban academic safety-net hospital. PATIENTS: Adult inpatients on the Family Medicine ward. INTERVENTIONS: Massage therapy consisted of a standardized protocol adapted from a previous perioperative study. Music therapy involved a preference assessment, personalized compact disc, music-facilitated coping, singing/playing music, and/or songwriting. Credentialed therapists provided the interventions. MEASUREMENTS: Patient experience was measured with the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) within 7 days of discharge. We compared the proportion of patients in each study arm reporting "top box" scores for the following a priori HCAHPS domains: pain management, recommendation of hospital, and overall hospital rating. Responses to additional open-ended postdischarge questions were transcribed, coded independently, and analyzed for common themes. RESULTS: From July to December 2014, 90 medical inpatients were enrolled; postdischarge data were collected on 68 (76%) medical inpatients. Participants were 70% females, 43% non-Hispanic black, and 23% Hispanic. No differences between groups were observed on HCAHPS. The qualitative analysis found that massage and music therapy were associated with improved overall hospital experience, pain management, and connectedness to the massage or music therapist. CONCLUSIONS: Providing music and massage therapy in an urban safety-net inpatient setting was feasible. There was no quantitative impact on HCAHPS. Qualitative findings suggest benefits related to an improved hospital experience, pain management, and connectedness to the massage or music therapist
    corecore