A simple method for counting bacteria with active electron transport system in water and sediment samples [Translation from: Kiel. Meeresforsch. 31(2) 83-86, 1975]

Description of a simple method for counting bacteria with active electron transport systems in water and sediment samples. Sodium succinate, NADH and NADPH served as electron donors. It is possible to see several sites of electron transport in the larger cells. Especially impressive are the plankton-algae, protozoa, and small metazoa. This is a partial translation of the ”method” section only

The rate of convergence of new Lax-Oleinik type operators for time-periodic positive definite Lagrangian systems

Assume that the Aubry set of the time-periodic positive definite Lagrangian $L$ consists of one hyperbolic 1-periodic orbit. We provide an upper bound estimate of the rate of convergence of the family of new Lax-Oleinik type operators associated with $L$ introduced by the authors in \cite{W-Y}. In addition, we construct an example where the Aubry set of a time-independent positive definite Lagrangian system consists of one hyperbolic periodic orbit and the rate of convergence of the Lax-Oleinik semigroup cannot be better than $O(\frac{1}{t})$

A new kind of Lax-Oleinik type operator with parameters for time-periodic positive definite Lagrangian systems

In this paper we introduce a new kind of Lax-Oleinik type operator with parameters associated with positive definite Lagrangian systems for both the time-periodic case and the time-independent case. On one hand, the new family of Lax-Oleinik type operators with an arbitrary $u\in C(M,\mathbb{R}^1)$ as initial condition converges to a backward weak KAM solution in the time-periodic case, while it was shown by Fathi and Mather that there is no such convergence of the Lax-Oleinik semigroup. On the other hand, the new family of Lax-Oleinik type operators with an arbitrary $u\in C(M,\mathbb{R}^1)$ as initial condition converges to a backward weak KAM solution faster than the Lax-Oleinik semigroup in the time-independent case.Comment: We give a new definition of Lax-Oleinik type operator; add some reference

Room temperature ferromagnetism in intercalated Fe3-xGeTe2 van der Waals magnet

Among several well-known transition metal-based compounds, the van der Waals (vdW) Fe3-xGeTe2 (FGT) magnet is a strong candidate for use in two-dimensional (2D) magnetic devices due to its strong perpendicular magnetic anisotropy, sizeable Curie temperature (TC ~ 154 K), and versatile magnetic character that is retained in the low-dimensional limit. While the TC remains far too low for practical applications, there has been a successful push toward improving it via external driving forces such as pressure, irradiation, and doping. Here we present experimental evidence of a novel room-temperature (RT) ferromagnetic phase induced by the electrochemical intercalation of common tetrabutylammonium cations (TBA+) into FGT bulk crystals. We obtained Curie temperatures as high as 350 K with chemical and physical stability of the intercalated compound. The temperature-dependent Raman measurements in combination with vdW-corrected ab initio calculations suggest that charge transfer (electron doping) upon intercalation could lead to the observation of RT ferromagnetism. This work demonstrates that molecular intercalation is a viable route in realizing high-temperature vdW magnets in an inexpensive and reliable manner

Uso de de almidón de papa andina nativa y deshidratada (chuño) como estabilizantes en la elaboración de yogur firme reducido en grasa

El yogur es el alimento lácteo fermentado de mayor consumo a nivel internacional, debido tanto a sus propiedades nutricionales y sensoriales distintivas como por su impacto positivo en la salud del consumidor. Así, el mercado de yogur es uno de los más dinámicos del sector lácteo, con propuestas novedosas, entre las cuales se destaca las variedades con contenido reducido en grasas. Sin embargo, la omisión de la grasa introduce problemas de calidad que conducen al rechazo por el consumidor. La principal estrategia empleada para superar estas limitaciones es el agregado de hidrocoloides (HC) como estabilizantes. El objetivo del presente trabajo fue evaluar la influencia del agregado de almidón de papa andina nativa y de "chuño" (papa andina congelada y deshidratada) como estabilizantes en la elaboración de yogur firme bajo en grasas. Se prepararon tres formulaciones de yogures a partir de leche descremada reconstituida (10%, p/v) añadida con almidón de papa nativo (AN) o "chuño" (ACH) [2,5% (p/v) final en producto]. Los HC previamente disueltos en leche (en proporción 1:10) se agregaron previo al tratamiento térmico (90°C, 5 min con agitación). La fermentación de la leche se llevo a cabo a 45ºC en baño de agua hasta pH 4,5. El grado de sinéresis, propiedades de flujo y viscoelásticas de los yogures fueron evaluados y comparados con los de un yogur control preparado sin almidón, en los días 1, 7, 14 y 28 de almacenamiento. Para la obtención de las curvas de flujo y las medidas oscilatorias se utilizó un reómetro (AR 2000; TA Instruments, New Castle, DE, EE. UU.) geometría plato-plato de 40 mm. El agregado de almidones de AN y ACH modificó significativamente los parámetros evaluados en relación al yogur control. En relación a la sinéresis, los mayores valores se observaron en el YC, efecto que incrementó significativamente con el tiempo de almacenamiento. Se observa que las formulaciones con almidones no mostraron diferencias significativas entre ellas hasta el día 7. Sin embargo, el YCH incrementó paulatinamente los valores de sinéresis luego del día 14, mientras que en la formulación YN no se observaron diferencias hasta el final del ensayo. Además, las muestras mostraron claras diferencias en cuanto a sus propiedades reológicas. En términos generales, los yogures que contienen almidones exhibieron valores de viscosidad aparente más altos que los observados en el YC después de 1 día de almacenamiento, tendencia que se mantuvo hasta el final del ensayo. Por otra parte, los valores de los módulos viscoso (G'), elástico (G'') y complejo (G*) incrementaron proporcionalmente a la frecuencia angular, siendo G' superior a G'' en todos los casos. G* también mostró diferencias entre las muestras, siendo significativamente mayores en las muestras con AN, seguida de ACH, en relación al control para todos los tiempos evaluados. Nuestros resultados demostraron que la incorporación de almidones de papa andina y chuño en la formulación de yogur firme reducido en grasas permitió reducir el grado de sinéresis proporcionando mejores características reológicas al producto final.Centro de Investigación y Desarrollo en Criotecnología de Alimento

Functional Analysis of the Phycomyces carRA Gene Encoding the Enzymes Phytoene Synthase and Lycopene Cyclase

Phycomyces carRA gene encodes a protein with two domains. Domain R is characterized by red carR mutants that accumulate lycopene. Domain A is characterized by white carA mutants that do not accumulate significant amounts of carotenoids. The carRA-encoded protein was identified as the lycopene cyclase and phytoene synthase enzyme by sequence homology with other proteins. However, no direct data showing the function of this protein have been reported so far. Different Mucor circinelloides mutants altered at the phytoene synthase, the lycopene cyclase or both activities were transformed with the Phycomyces carRA gene. Fully transcribed carRA mRNA molecules were detected by Northern assays in the transformants and the correct processing of the carRA messenger was verified by RT-PCR. These results showed that Phycomyces carRA gene was correctly expressed in Mucor. Carotenoids analysis in these transformants showed the presence of ß-carotene, absent in the untransformed strains, providing functional evidence that the Phycomyces carRA gene complements the M. circinelloides mutations. Co-transformation of the carRA cDNA in E. coli with different combinations of the carotenoid structural genes from Erwinia uredovora was also performed. Newly formed carotenoids were accumulated showing that the Phycomyces CarRA protein does contain lycopene cyclase and phytoene synthase activities. The heterologous expression of the carRA gene and the functional complementation of the mentioned activities are not very efficient in E. coli. However, the simultaneous presence of both carRA and carB gene products from Phycomyces increases the efficiency of these enzymes, presumably due to an interaction mechanism

Ammonium regeneration: Its contribution to phytoplankton nitrogen requirements in a eutrophic environment

Ammonium regeneration, nutrient uptake, bacterial activity and primary production were measured from March to August 1980 in Bedford Basin, Nova Scotia, Canada, a eutrophic environment. Rates of regeneration and nutrient uptake were determined using 15N isotope dilution and tracer methodology. Although primary production, nutrient uptake and ammonium regeneration were significantly intercorrelated, no relationship was detected between these parameters and heterotrophic activity. The average contribution of ammonium to total nitrogen (ammonium+nitrate) uptake was similar in the spring and in the summer (approximately 60%). On a seasonal average basis, 36% of the phytoplankton ammonium uptake could be supplied by rapid remineralization processes. In spite of the high average contribution of NH4 regeneration to phytoplankton ammonia uptake, there is indirect evidence suggesting that other NH4 sources may occasionally be important

The Effect of Volitional Preemptive Abdominal Contraction on Biomechanical Measures During A Front Versus Back Loaded Barbell Squat

# Background Weightlifting is growing in popularity among recreational and competitive athletes. The barbell back squat (BackS) is commonly included in these training programs, while the barbell front squat (FrontS) is commonly performed as a component of other lifts such as the power clean or clean and jerk, it is less commonly practiced in isolation. # Hypothesis/Purpose The purpose of this study was to examine the effects of VPAC performance on trunk muscle and LE biomechanical responses during loaded BackS versus FrontS in healthy subjects. # Study Design Controlled Laboratory Study # Methods Healthy male subjects with the ability to perform a sub-maximal loaded barbell squat lift were recruited. Subjects completed informed consent, demographic/medical history questionnaires and an instructional video. Subjects practiced VPAC and received feedback. Surface electromyography (sEMG) electrodes and kinematic markers were applied. Muscles included were the internal oblique (IO), external oblique (EO), rectus abdominis, iliocostalis lumborum (ICL), superficial multifidi, rectus femoris, vastus lateralis, biceps femoris, and gluteus maximus. Maximal voluntary isometric contractions established reference sEMG values. A squat one-rep-max (1RM) was predicted by researchers using a three to five repetition maximum (3RM, 5RM) load protocol. Subjects performed BackS trials at 75% 1RM while FrontS trials were performed at 75% BackS weight, both with and without VPAC. Subjects performed three repetitions of each condition with feet positioned on two adjacent force plates. Significant interactions and main effects were tested using a 2(VPAC strategy) x 2(squat variation) and 2(VPAC strategy) x 2(direction) within-subject repeated measures ANOVAs. Tukey's Post-Hoc tests identified the location of significant differences. # Results Trunk muscle activity was significantly higher during FrontS versus BackS regardless of VPAC condition. (IO: p=0.018, EO: p\<0.001, ICL: p\<0.001) VPAC increased performance time for both squat variations (p=.0011), which may be associated with decreased detrimental force potential on the lumbar spine and knees. VPAC led to improved ability to maintain a neutral lumbar spine during both squat variations. This finding is associated with decreased detrimental force potential on the lumbar spine. # Conclusions Findings could help guide practitioners and coaches to choose squat variations and incorporate VPAC strategies during their treatments and/or training programs. # Level of Evidence Level 3 ©The Author(s