3,424 research outputs found
Yellowtail Flounder Length at Maturity in the Grand Bank (1995-98)
In this paper yellowtail length at maturity estimates based data collected in the spring Spanish surveys in the
Regulatory Area of Divisions 3NO are presented. Female length at 50 % maturity decreased from 35 cm in 1995 to
23 cm in 1998. In males, this parameter decreased from 23 cm in 1995 to 19 cm in 1998. The differences in L50
estimates in females were significant between 1997 and the previous years , and between 1998 and both 1996 and 1995,
and were not significant between 1997 and 1998. In males, differences were significant between all the years, except
between 1997 and 1998. The covariance analysis between the linearized maturity curves were highly significant in both
sexes
Data on sharks in NAFO Divisions 3LMNO: 1991-1998
A review of the species composition, distribution and abundance of sharks in both the Spanish commercial
catches (1991-98) and research surveys (1988-98) are carried out. Shark species are by-catches of Greenland halibut
fishery. The proportion of shark species in the total catch is small and the main retained species is the black dogfish,
whereas the main discard is the boreal shark. Since 1996 the retained proportion of black dogfish increase notably,
as well as the proportion of total sharks. In the surveys this shark is the species with the highest biomass index.
Black dogfish is found in the deepest waters. The length range of black dogfish is mainly between 50 and 80 cm,
with a mode about 62-63 cm. No evident geographic pattern in the length distribution is observed during the studied
period
N-Benzoyl-NâČ,NâČ-dimethylÂthioÂurea
In the title compound, C10H12N2OS, the amide NCO group is twisted relative to the thioÂureido SCN2 group, forming a dihedral angle of 55.3â
(2)°. The crystal packing shows interÂmolecular NâHâŻS and weak CâHâŻO interÂactions, the former giving rise to the formation of centrosymmetric R
2
2(8) dimers
Impact of the resistance responses to stress conditions encountered in food and food processing environments on the virulence and growth fitness of non-typhoidal salmonellae
The success of Salmonella as a foodborne pathogen can probably be attributed to two major features: its remarkable genetic diversity and its extraordinary ability to adapt. Salmonella cells can survive in harsh environments, successfully compete for nutrients, and cause disease once inside the host. Furthermore, they are capable of rapidly reprogramming their metabolism, evolving in a short time from a stress-resistance mode to a growth or virulent mode, or even to express stress resistance and virulence factors at the same time if needed, thanks to a complex and fine-tuned regulatory network. It is nevertheless generally acknowledged that the development of stress resistance usually has a fitness cost for bacterial cells and that induction of stress resistance responses to certain agents can trigger changes in Salmonella virulence. In this review, we summarize and discuss current knowledge concerning the effects that the development of resistance responses to stress conditions encountered in food and food processing environments (including acid, osmotic and oxidative stress, starvation, modified atmospheres, detergents and disinfectants, chilling, heat, and non-thermal technologies) exerts on different aspects of the physiology of non-typhoidal Salmonellae, with special emphasis on virulence and growth fitness. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
HF spectrum activity prediction model based on HMM for cognitive radio applications
Although most of the research on Cognitive Radio is focused on communication bands above the HF upper limit (30 MHz), Cognitive Radio principles can also be applied to HF communications to make use of the extremely scarce spectrum more efficiently. In this work we consider legacy users as primary users since these users transmit without resorting to any smart procedure, and our stations using the HFDVL (HF Data+Voice Link) architecture as secondary users. Our goal is to enhance an efficient use of the HF band by detecting the presence of uncoordinated primary users and avoiding collisions with them while transmitting in different HF channels using our broad-band HF transceiver. A model of the primary user activity dynamics in the HF band is developed in this work to make short-term predictions of the sojourn time of a primary user in the band and avoid collisions. It is based on Hidden Markov Models (HMM) which are a powerful tool for modelling stochastic random processes and are trained with real measurements of the 14 MHz band. By using the proposed HMM based model, the prediction model achieves an average 10.3% prediction error rate with one minute-long channel knowledge but it can be reduced when this knowledge is extended: with the previous 8 min knowledge, an average 5.8% prediction error rate is achieved. These results suggest that the resulting activity model for the HF band could actually be used to predict primary users activity and included in a future HF cognitive radio based station
Influence of the initial cell number on the growth fitness of salmonella enteritidis in raw and pasteurized liquid whole egg, egg white, and egg yolk
Salmonella growth in egg and egg products has been widely studied, but there are still some aspects that are not fully known. The objective of this work was to study the influence of the initial cell number on the growth fitness of Salmonella Enteritidis in raw and pasteurized egg products. Growth curves of five Salmonella Enteritidis strains in raw and pasteurized egg products, starting from different initial numbers, were obtained and fitted to the Baranyi and Roberts model. The results revealed that lower initial numbers led to longer lag phases (¿) and lower maximum specific growth rates (”max) in raw liquid whole egg. Similar results were observed in raw egg white (except for one strain). Conversely, no influence (p > 0.05) of the initial concentration on Salmonella growth parameters in raw egg yolk was observed. On the other hand, no influence of the initial number of cells on Salmonella growth fitness in commercial pasteurized liquid whole egg was observed. The results obtained demonstrate that the disappearance of this initial-dose dependency phenomenon was dependent on the intensity of the thermal treatment applied. Finally, the influence of the initial number was, in general, lower in pasteurized than in raw egg white, but large differences among strains were observed. © 2021 by the authors. Licensee MDPI, Basel, Switzerland
Zinc: What Is Its Role in Lung Cancer?
Recently, zinc emerged as an important signaling molecule, activating intracellular pathways and regulating cell fate, although our knowledge remains incomplete. Zinc is required in many enzymatic and metabolic pathways, playing roles as enzyme cofactors. In normal cell physiology, optimal zinc availability is essential for regular growth and proliferation. Zinc accumulation has varied effects: from stimulation to inhibition of cell growth, depending on type. There is evidence that zinc is capable of inducing apoptosis in some cancers, while others proved that zinc may act as apoptosis activator depending on the dose and cell type. Upregulation of telomerase in most cancer tissues is considered to be responsible for unlimited proliferation of cancer cells, and in some cell lines, it was induced by Zn. These suggest that Zn is highly involved in cell cycle and metabolism; whether it goes to the survival or the cancer pathway depends on the concentration and the cell type involved. Nevertheless, the conclusion is that Zn is not just another trace element; but a vital one and further studies are needed to elucidate the mechanisms involved in cancer and metastatic spread in order to identify potential therapies
Recent Overview of Solar Photocatalysis and Solar Photo-Fenton Processes for Wastewater Treatment
This literature research, although not exhaustive, gives perspective to solar-driven photocatalysis, such as solar photo-Fenton and TiO2 solar photocatalysis, reported in the literature for the degradation of aqueous organic pollutants. Parameters that influence the degradation and mineralization of organics like catalyst preparation, type and load of catalyst, catalyst phase, pH, applied potential, and type of organic pollutant are addressed. Such parameters may also affect the photoactivity of the catalysts used in the studied solar processes. Solar irradiation is a renewable, abundant, and pollution-free energy source for low-cost commercial applications. Therefore, these solar processes represent an environmentally friendly alternative mainly because the use of electricity can be decreased/avoided
Anatomical dissection of the mimic facial musculature: iconographic review as a support to the complementary treatments in facial rejuvenation
A la hora de valorar las mĂșltiples tĂ©cnicas empleadas
en el rejuvenecimiento facial y centrĂĄndonos de manera
particular en aquellos procedimientos mĂnimamente invasivos
complementarios a las intervenciones habituales
en CirugĂa PlĂĄstica-EstĂ©tica, cobra especial relevancia el
conocimiento exhaustivo de las estructuras musculares
implicadas en la mĂmica facial. A tal efecto, se ha realizado
un estudio anatĂłmico en cadĂĄveres frescos, en los
que se han disecado las principales estructuras referidas.
Se presenta un resumen iconogrĂĄfico de los mĂșsculos faciales
implicados, haciendo hincapiĂ© en su anatomĂa descriptiva
y funcional, asĂ como un recuerdo de las
principales ĂĄreas problemĂĄticas por alguna circunstancia
especial (presencia de un nervio sensitivo o motor).To value the multiple technologies involved in facial
rejuvenation and focusing in those minimally invasive
complementary procedures to the usual Plastic and Aesthetic
Surgeries, itÂŽs very important the exhaustive knowledge
of the muscular structures involved in the facial
movements. To such an effect, an anatomical study has
been realized in fresh corpses, dissecting the principal
above-mentioned structures. We present an iconographic
summary of the facial implied muscles, emphasizing in
his descriptive and functional anatomy, as well as a recollection
of the principal problematic areas for some
special circumstance (presence of a sensory or motor
nerv
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