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IntroductionThis study investigated the impact of rumen-protected amino acids on beef cattle's growth, fattening performance, and meat quality.MethodsTwo groups of 40 Montbeliard steers (237.8 ± 30 kg body weight) were housed separately and fed, with mono-tunnel feeders, either a control diet (CON) or a diet containing rumen-protected lysine and methionine with 3% less crude protein (APR). Feed consumption and weight were tracked in all animals, and meat quality analysis focused on the longissimus muscle, with 10 steers randomly selected from each treatment.Results and discussionResults for overall performance revealed no significant differences in body weight, average daily gain (ADG), and concentrate conversion ratio between the CON and APR diets (p > 0.05). However, during the final 90 days of the trial, the APR group showed significantly higher ADG (p < 0.05) than the CON group, while the concentrate conversion ratio was significantly higher (p < 0.05) in the CON group compared to the APR group. The hot carcass weight, dressing percentage, and carcass conformation did not differ significantly between the CON and APR diets (p > 0.05). There was a slight tendency (p = 0.06) for higher fatness score in the CON group. Regarding meat composition, the diet did not significantly affect proximate composition, but a tendency (p = 0.059) for higher crude protein content in APR cattle's meat compared to the CON group was observed. The APR meat showed slightly lower levels of C17:1 (0.56% vs. 0.72%) and C18:1n9 (31.7% vs. 34%). There was a tendency for C14:0 to be lower (P = 0.07), and for C16:0, C18:2 and polyunsaturated fatty acids (PUFA) to be greater in meat from cattle fed APR compared to CON. However, meat quality attributes like pH, water-holding capacity, color, and texture were similar in both CON and APR groups (p > 0.05). The findings indicate that utilizing rumen-protected amino acids enables formulating diets with reduced crude protein levels while enhancing nitrogen utilization efficiency for protein synthesis in intensively reared steers. Importantly, these dietary improvements do not adversely affect meat quality.

Academic dropout among university students represents one of the problems faced by educational systems. This preliminary study presents an approach to the phenomenon of academic failure at the Pablo de Olavide University in Spain through the determination of the factors linked to students continuing with their studies, and the subsequent establishment of risk groups. The study consisted of applying an instrument to diagnose the risk of academic dropout among a sample of 70 students from the Pablo de Olavide University (from now on, UPO). The instrument was applied at the beginning of the second semester. Unlike the objective posed by the aforementioned authors (the search for factors linked to students continuing their university studies), the use that we made of the survey was to predict non-persistence (dropout). The average overall score achieved for all of the items allows us to confirm that the student population surveyed seems to be more oriented to continuing with their studies than dropping out, although 15.71% of them show a high risk of dropping out, and most notably more than half of those taking a degree in Business Studies present this high level of risk. In the case of the UPO students the direct associations between the independent variables regarding the dependent variable were present in all of the factors (attitude and behavior, commitment, socio-economic background, and motivation) with a value of p lower than 0.05. Comparing these data to those obtained with students from different universities in Andalusia, it was found that the risk groups of UPO students are less inclined to dropping out than those from other universities, and their level of commitment is lower, although their attitude and behavior are somewhat better. Finally, socio-economic background is a less significant factor for UPO students.

CRISPR/Cas technology is a simple, fast and extremely efficient method for gene editing. In order to describe the principles and medical application of this technology, a bibliographic review was carried out in Pubmed, SciELO, academic Google and the Cochrane Library, with the descriptors “gene editing”, “genome editing”, “CRISPR-Cas systems”, and “CRISPR-associated protein 9”. The CRISPR/Cas9 system comprises a Cas endonuclease and two types of RNA. Cas cuts the invading phage DNA into segments, which are integrated into the CRISPR sequence as spacers. Subsequently, the CRISPR sequence is transcribed to generate crRNA and tracrRNA, which form a double-stranded RNA structure that recruits Cas for cleavage. The introduction of the system into the cell interior occurs with plasmids, RNA or ribonucleoproteins. A nuclear localization sequence allows CRISPR / Cas9 to enter the nucleus. CRISPR/Cas9 technology is an efficient tool for precise gene editing with great impact on scientific research.

Fundamento: La COVID-19 es una pandemia causada por el virus SARS-CoV-2 cuya asociación con el cáncer puede tener efectos adversos. Objetivo: Describir los principales vínculos entre el cáncer y la COVID-19. Metodología: Se realizó una búsqueda bibliográfica en Google Académico, SciELO y PubMed Central con los descriptores SARS-CoV-2, COVID-19 y cáncer, consultados en el DeCS. Se seleccionaron artículos a texto completo en español e inglés, principalmente de revistas arbitradas por pares. Resultados: La COVID-19 produce resultados más desfavorables en los pacientes con cáncer. Estos resultados se relacionan con altas tasas de hospitalización, complicaciones y mortalidad. La frecuente asociación de comorbilidades en pacientes con cáncer parece contribuir a este vínculo peligroso. Las vías de señalización comunes al cáncer y a la infección por el SARS-CoV-2 son citocinas proinflamatorias, interferón tipo I, receptor de andrógenos y puntos de control inmune. Este conocimiento tiene aplicación práctica en el empleo de medicamentos para combatir la COVID-19 en pacientes con cáncer. Conclusiones: El cáncer se relaciona con la COVID-19 grave, por lo que esos pacientes son más vulnerables a la infección viral.

Fundamento: La variabilidad clínica de la infección por el SARS-CoV-2 se debe, en parte, a factores genéticos. Objetivo: Describir los principales genes de susceptibilidad a la Covid-19. Metodología: Se realizó una revisión bibliográfica en Google Académico, SciELO, Annual Reviews y PubMed Central. Los descriptores que se utilizaron para la búsqueda de los documentos fueron consultados en el DeCS, estos fueron: SARS-CoV-2, Covid-19, genética y predisposición genética a la enfermedad. Se seleccionaron artículos disponibles a texto completo en inglés y en español, preferentemente de revistas arbitradas por pares. Resultados: Entre los genes implicados en la infección por el SARS-CoV-2 se encuentran DDX1 que promueve la replicación viral, IFITM1, IFITM2, IFITM3, IFNAR2 que codifican proteínas inducidas por el interferón, los genes de receptores (ACE2, ANPEP, DPP4), los genes de proteasas (TMPRSS2, furin, TMPRSS11D, CTSL, CTSB) que contribuyen a la entrada viral, genes de la respuesta inmune como ABO y metalopeptidasas como la familia ADAM. Se han detectado polimorfismos genéticos de riesgo. Conclusiones: En la infección por el SARS-CoV-2 se produce una compleja interrelación entre factores ambientales y genéticos que determinan la susceptibilidad de las personas a la Covid y su gravedad. El papel de los genes en la susceptibilidad a la Covid-19 deberá continuar investigándose.

Fish can go through periods of feed deprivation, either due to natural causes influenced by temperature or management techniques in animal production, affecting their energy metabolism differently, depending on the duration of fasting in days and water temperature. This study showed the effect of different days of fasting before slaughter in rainbow trout by analyzing the intermediary metabolic enzymes in the muscle and liver. For this purpose, a non-fasting group was compared with trout that fasted for 5, 10, and 20 days (55, 107, and 200 degree days (°C d), respectively). A first phase of increased activity of enzymes involved in glycolysis was observed, increasing hexokinase enzyme activity in muscle and pyruvate kinase enzyme activity in muscle and liver. As the fasting days progressed, enzymes involved in the gluconeogenic and glycogenolytic pathways in the liver such as lactate dehydrogenase and glycogen phosphorylase increased their activity regarding the no fasted group. After 20 days of fasting (200 °C d), lipogenic and protein related enzyme activity depletion was observed, leading to significant changes in energy metabolism. Therefore, prolonged fasting with high degree days duration may compromise the energy supply for the vital development of rainbow trout.