Novel physiological data needed for progress in global change ecology

Studies examining the underlying causes of the distributions of species and their future trajectories under climate change have benefitted from the accumulation of measurements of thermal tolerance across the tree of life. However, gaps in the global coverage of heat-tolerance data for ectotherms persist on four critical fronts. First, most large-scale analyses treat heat tolerance as a fixed species trait despite that population-level variation can equal or exceed cross-species variation. Second, terrestrial non-arthropod invertebrates and aquatic ectotherms other than bony fish have been poorly sampled, particularly in boreal and tropical regions, the Indian Ocean and the mesopelagic-deep ocean. Third, the study of climate impacts on the heat tolerance of terrestrial ectotherms has often neglected the interaction of environmental temperatures with water availability. And fourth, the mechanisms driving the dependence of heat tolerance on oxygen supply-demand remain largely unknown. We contend that filling those data and knowledge gaps requires novel strategies for the ecophysiological sampling of the range of understudied populations and species that occupy the length of climatic gradients globally. Such developments are essential for comprehensively predicting species responses to climate change across aquatic and terrestrial biomes

Predictive Model of Student Dropout Based on Logistic Regression

Student desertion is a phenomenon that has spread significantly in many higher education institutions in Ecuador. The objective of the research was to develop a predictive model of student dropout based on multiple binary logistic regression, with the purpose of detecting possible dropouts. The methodology used consists of three phases: Phase 1: Analysis of variables; Phase 2: Formulation of the mathematical model; and Phase 3: Evaluation. For the estimation of the coefficients of the model, the SPSS tool was obtained. After the creation of the predictive model, it was concluded that the most significant variables that contribute to the diagnosis of dropout are marital status, age, gender, Note2s, and Note1s. It is also evident that students have a higher risk of dropping out if they are married and lower risk if they are single or divorced. Finally it was concluded that gender is a factor that directly influences dropout; male students are more likely to drop out than females. Keywords: logistic regression, predictive model, desertion. Resumen La deserción estudiantil es un fenómeno que se ha extendido significativamente en gran cantidad de instituciones educativas de nivel superior en el Ecuador. El objetivo de la investigación fue desarrollar un modelo predictivo de deserción estudiantil basado en la regresión logística binaria múltiple, con el propósito de detectar a posibles desertores. La metodología utilizada consta de tres fases: Fase1: Análisis de variables. Fase2: Formulación del modelo matemático. Fase3: Evaluación. Para la estimación de los coeficientes del modelo se utilizó la herramienta SPSS. Posterior a la creación del modelo predictivo se llegó a concluir que las variables más significativas que aportan al diagnóstico de la deserción son estado civil, edad, género Nota2s y Nota1s, además se evidencia que los estudiantes tienen mayor riesgo de deserción si están casados y menor riesgo si están solteros o divorciados, finalmente se concluye, que el género es un factor que influye directamente en la deserción, los estudiantes masculinos son más propensos a desertar que los femeninos. Palabras Clave: regresión logística, modelo predictivo, deserción

Faraday effect : a field theoretical point of view

We analyze the structure of the vacuum polarization tensor in the presence of a background electromagnetic field in a medium. We use various discrete symmetries and crossing symmetry to constrain the form factors obtained for the most general case. From these symmetry arguments, we show why the vacuum polarization tensor has to be even in the background field when there is no background medium. Taking then the background field to be purely magnetic, we evaluate the vacuum polarization to linear order in it. The result shows the phenomenon of Faraday rotation, i.e., the rotation of the plane of polarization of a plane polarized light passing through this background. We find that the usual expression for Faraday rotation, which is derived for a non-degenerate plasma in the non-relativistic approximation, undergoes substantial modification if the background is degenerate and/or relativistic. We give explicit expressions for Faraday rotation in completely degenerate and ultra-relativistic media.Comment: 20 pages, Latex, uses axodraw.st

Primeros datos polínicos de la secuencia "fuentillejo-1" de la laguna del Maar de Fuentillejo (Campo de Calatrava, Ciudad Real)

XV lnternational A.P.L.E. Symposium of Palynolog

A Case Study for the Recovery of Authentic Microbial Ancient DNA from Soil Samples

High Throughput DNA Sequencing (HTS) revolutionized the field of paleomicrobiology, leading to an explosive growth of microbial ancient DNA (aDNA) studies, especially from environmental samples. However, aDNA studies that examine environmental microbes routinely fail to authenticate aDNA, examine laboratory and environmental contamination, and control for biases introduced during sample processing. Here, we surveyed the available literature for environmental aDNA projects—from sample collection to data analysis—and assessed previous methodologies and approaches used in the published microbial aDNA studies. We then integrated these concepts into a case study, using shotgun metagenomics to examine methodological, technical, and analytical biases during an environmental aDNA study of soil microbes. Specifically, we compared the impact of five DNA extraction methods and eight bioinformatic pipelines on the recovery of microbial aDNA information in soil cores from extreme environments. Our results show that silica-based methods optimized for aDNA research recovered significantly more damaged and shorter reads (<100 bp) than a commercial kit or a phenol–chloroform method. Additionally, we described a stringent pipeline for data preprocessing, efficiently decreasing the representation of low-complexity and duplicated reads in our datasets and downstream analyses, reducing analytical biases in taxonomic classification.Vilma Pérez, Yichen Liu, Martha B. Hengst, and Laura S. Weyric

Risk factors for premature aging of placenta: comparative study of perinatal outcomes between grannum grade III placentas and grannum grade I-II placentas

Introduction: The placenta aging has been related with intrauterine fetal growth, low maternal age, Caucasian, multiparity, hypertensive states and smoking habit. Grannum P. classification is the most used for its assessment. The association between grade III placenta (G3P) and ex-smoking or smokeexposed pregnants has not been studied Main outcome: To asses if smoking, being an ex-smoker or a passive-smoker is a risk factor for developing grade III placenta, as well as if there is a smoking-free period of time to avoid the effect of smoking over placenta Material and methods: A retrospective case-control study of single pregnancies followed-up at the Obstetric Ultrasound Unit between January 2013 and January 2014. Placental grading according to Grannum classification was stablished through abdominal approach between 34-36 weeks of gestation and two groups were established: grade III placenta and grade I-II placenta (G1-2P) Maternal and paternal characteristics, type of delivery and perinatal outcomes were collected Results: Baseline characteristics were similar between the two groups. In G3P the incidence of hypertensive disease of pregnancy was higher(p=0,0107). The percentage was similar for premature birth, 1st and 5th minute Apgar, type of delivery and cesarean due to risk of loss of fetal wellbeing. A lower neonatal weight was found in G3P, at the same median days at delivery, with a mean difference of 148,156(p=0,008313. Regarding weight percentile, it was found a p35 in G3P and a p47,5 in G1- 2P(p=0,08235) 15% of the total pregnant were smokers. In G3P group it was found a higher frequency of smokers and ex-smokers since 1st trimester of pregnancy (p=0.0001), as well as pregnant non-smokers with an smoking partner(p=0,0001). There was an strong evidence for association between pregnant smokers and smoking partners(p=0,0001). No difference was found regarding to neonatal weight comparing smokers, ex-smokers and ex-smokers since 1st trimester of pregnancy. The length of pregnancy was lower between G3P pregnant smokers compared to G1-2P pregnant smokers, with a mean difference of 8 days (p=0,00091) Conclusions: There is a strong evidence for association between smoking during pregnancy, quitting smoking at the beginning of the pregnancy or being a passive smoker with development of G3P Some pregnant smokers don`t develop premature aging of placenta, it could be due to either other parameters or a later aging (data were collected between 34-36 weeks). The association between quitting smoking at the beginning of the pregnancy and not having a smoking partner reduces the risk of developing G3

Evaluating food additives as antifungal agents against Monilinia fructicola in vitro and in hydroxypropyl methylcellulose-lipid composite edible coatings for plums

Common food preservative agents were evaluated in in vitro tests for their antifungal activity against Monilinia fructicola, the most economically important pathogen causing postharvest disease of stone fruits. Radial mycelial growth was measured in Petri dishes of PDA amended with three different concentrations of the agents (0.01-0.2%, v/v) after 7. days of incubation at 25. °C. Thirteen out of fifteen agents tested completely inhibited the radial growth of the fungus at various concentrations. Among them, ammonium carbonate, ammonium bicarbonate and sodium bicarbonate were the most effective while sodium acetate and sodium formate were the least effective. The effective agents and concentrations were tested as ingredients of hydroxypropyl methylcellulose (HPMC)-lipid edible coatings against brown rot disease on plums previously inoculated with M. fructicola (curative activity). 'Friar' and 'Larry Ann' plums were inoculated with the pathogen, coated with stable edible coatings about 24. h later, and incubated at 20. °C and 90% RH. Disease incidence (%) and severity (lesion diameter) were determined after 4, 6, and 8. days of incubation and the 'area under the disease progress stairs' (AUDPS) was calculated. Coatings containing bicarbonates and parabens significantly reduced brown rot incidence in plums, but potassium sorbate, used at 1.0% in the coating formulation, was the most effective agent with a reduction rate of 28.6%. All the tested coatings reduced disease severity to some extent, but coatings containing 0.1% sodium methylparaben or sodium ethylparaben or 0.2% ammonium carbonate or ammonium bicarbonate were superior to the rest, with reduction rates of 45-50%. Overall, the results showed that most of the agents tested in this study had significant antimicrobial activity against M. fructicola and the application of selected antifungal edible coatings is a promising alternative for the control of postharvest brown rot in plums. © 2014 Elsevier B.V

A Geometric Approach to Massive p-form Duality

Massive theories of abelian p-forms are quantized in a generalized path-representation that leads to a description of the phase space in terms of a pair of dual non-local operators analogous to the Wilson Loop and the 't Hooft disorder operators. Special atention is devoted to the study of the duality between the Topologically Massive and the Self-Dual models in 2+1 dimensions. It is shown that these models share a geometric representation in which just one non local operator suffices to describe the observables.Comment: 26 pages, LaTeX. The discussion about the equivalence between the Proca model and two seldual models, with opposite spins, was eliminated. Typos correcte

Two-body Z′Z' decays in the minimal 331 model

The two-body decays of the extra neutral boson Z_2 predicted by the minimal 331 model are analyzed. At the three-level it can decay into standard model particles as well as exotic quarks and the new gauge bosons predicted by the model. The decays into a lepton pair are strongly suppressed, with $Br(Z_2 --> l^+l^-) ~ 10^{-2}$ and $Br(Z_2 --> \bar{\nu}_l \nu) ~ 10^{-3}$. In the bosonic sector, Z_2 would decay mainly into a pair of bilepton gauge bosons, with a branching ratio below the 0.1 level. The Z_2 boson has thus a leptophobic and bileptophobic nature and it would decay dominantly into quark pairs. The anomaly-induced decays $Z_2 --> Z_1\gamma$ and $Z_2 --> Z_1Z_1$, which occurs at the one-loop level are studied. It is found that $Br(Z_2 --> Z_1\gamma) ~ 10^{-9}$ and $Br(Z_2 --> Z_1Z_1) ~ 10^{-6}$ at most. As for the $Z_2 --> W^+W^-$ and $Z_2 --> Z_1H$ decays, with H a relatively light Higgs boson, they are induced via Z'-Z mixing. It is obtained that $Br(Z_2 --> W^+W^-) ~ 10^{-2}$ and $Br (Z_2 --> Z_1H) ~ 10^{-5}$. We also examine the flavor changing neutral current decays $Z_2 --> tc$ and $Z_2 --> tu$, which may have branching fractions as large as $10^{-3}$ and $10^{-5}$, respectively, and thus may be of phenomenological interest.Comment: 14 pages, 3 figures, submitted to Physical Review

Modelling the Dynamics of an Aedes albopictus Population

We present a methodology for modelling population dynamics with formal means of computer science. This allows unambiguous description of systems and application of analysis tools such as simulators and model checkers. In particular, the dynamics of a population of Aedes albopictus (a species of mosquito) and its modelling with the Stochastic Calculus of Looping Sequences (Stochastic CLS) are considered. The use of Stochastic CLS to model population dynamics requires an extension which allows environmental events (such as changes in the temperature and rainfalls) to be taken into account. A simulator for the constructed model is developed via translation into the specification language Maude, and used to compare the dynamics obtained from the model with real data.Comment: In Proceedings AMCA-POP 2010, arXiv:1008.314