Effects of mass media on opinion spreading in the Sznajd sociophysics model

In this work we consider the influence of mass media in the dynamics of the two-dimensional Sznajd model. This influence acts as an external field, and it is introduced in the model by means of a probability $p$ of the agents to follow the media opinion. We performed Monte Carlo simulations on square lattices with different sizes, and our numerical results suggest a change on the critical behavior of the model, with the absence of the usual phase transition for $p>\sim 0.18$. Another effect of the probability $p$ is to decrease the average relaxation times $\tau$, that are log-normally distributed, as in the standard model. In addition, the $\tau$ values depend on the lattice size $L$ in a power-law form, $\tau\sim L^{\alpha}$, where the power-law exponent depends on the probability $p$.Comment: 11 pages, 8 figures, to appear in Physica

The biodiversity - N cycle relationship: a 15^{15}N tracer experiment with soil from plant mixtures of varying diversity to model N pool sizes and transformation rates

We conducted a $^{15}$N tracer experiment in laboratory microcosms with field-fresh soil samples from a biodiversity xperiment to evaluate the relationship between grassland biodiversity and N cycling. To embrace the complexity of the N cycle, we determined N exchange between five soil N pools (labile and recalcitrant organic N, dissolved NH$_{4}$$^{+}$ and NO3$^{-}$ in soil solution, and exchangeable NH$_{4}$$^{+}$) and eight N transformations (gross N mineralization from labile and recalcitrant organic N, NH$_{4}$$^{+}$ immobilization into labile and recalcitrant organic N, autotrophic nitrification, heterotrophic nitrification, NO$_{3}$$^{-}$ immobilization, adsorption of NH$_{4}$$^{+}$) expected in aerobic soils with the help of the N-cycle model Ntrace. We used grassland soil of the Jena Experiment, which includes plant mixtures with 1 to 60 species and 1 to 4 functional groups (legumes, grasses, tall herbs, small herbs). The 19 soil samples of one block of the Jena Experiment were labeled with either 15NH$_{4}$$^{+}$ or 15NO3- or both. In the presence of legumes, gross N mineralization and autotrophic nitrification increased significantly because of higher soil N concentrations in legume-containing plots and high microbial activity. Similarly, the presence of grasses significantly increased the soil NH$_{4}$$^{+}$ pool, gross N mineralization, and NH$_{4}$$^{+}$immobilization, likely because of enhanced microbial biomass and activity by providing large amounts of rhizodeposits through their dense root systems. In our experiment, previously reported plant species richness effects on the N cycle, observed in a larger-scale field experiment within the Jena Experiment, were not seen. However, specific plant functional groups had a significant positive impact on the N cycling in the incubated soil samples

Sociodemographic and clinical profile of long COVID-19 patients, and its correlation with medical leave: a comprehensive descriptive and multicenter study

The persistent condition of COVID-19 is characterized by a wide range of symptoms that have had a significant impact on both the health status and occupational life of the population. In this observational and multicenter study, the relationship between the sociodemographic and clinical profile of Spanish patients diagnosed with long COVID, and the work-related disability resulting from this pathology was analyzed. The analysis included 689 responses. A descriptive analysis of the variables recorded was performed, together with a bivariate analysis to determine associations between work-related disability and variables such as gender, age, health status, disabling symptoms or comorbidities. The results obtained highlight fatigue and lack of concentration (brain fog) as the most incapacitating symptoms among patients diagnosed with long COVID. Multivariate analysis revealed that time since diagnosis (OR: 0.57, CI95%: 0.36–0.89, p: 0.013), concomitant renal insufficiency (OR: 4.04, CI95%: 1.42–11.4, p: 0.008), and symptoms like fatigue (OR: 0.56, CI95%: 0.33–0.99) and tremors (OR: 2.0, CI95%: 1.06–3.69, p: 0.029), were associated with work-related disability. These findings highlight the need to improve the health and work-related management of this condition in the healthcare system. Besides risk factor control, it is suggested to pay special attention to determining the appropriate timing of medical leave work reintegration, along with coordination between primary care and occupational health services to ensure the gradual and tailored return of patients with long COVID to the workforce

Research training needs in Peruvian national TB/HIV programs

<p>Abstract</p> <p>Background</p> <p>There are few published reports of <it>research training </it>needs assessments and research training programs. In an effort to expand this nascent field of study and to bridge the gap between research and practice, we sought to systematically assess the research training needs of health care professionals working at Peruvian governmental institutions leading HIV and tuberculosis (TB) control and among senior stakeholders in the field.</p> <p>Methods</p> <p>Six institutional workshops were conducted with the participation of 161 mid-level health professionals from agencies involved in national HIV and TB control. At each workshop informants completed a structured questionnaire and participated in small and large group discussions. Additional data and institutional commitment was obtained through in-depth interviews from 32 senior managers and researchers from the Ministry of Health, academia and NGOs.</p> <p>Results</p> <p>Participants exhibited an overwhelming receptivity for additional research training, observing a gap between current levels of research training and their perceived importance. Specialized skills in obtaining funding, developing research protocols, particularly in operational, behavioral and prevention research were considered in greatest need. Beyond research training, participants identified broader social, economic and political factors as influential in infectious disease control.</p> <p>Conclusions</p> <p>The needs assessment suggests that future training should focus on operational research techniques, rather than on clinical skill building or program implementation only. Strengthening health systems not only requires additional research training, but also adequate financial resources to implement research findings.</p

Rotavirus Disrupts Calcium Homeostasis by NSP4 Viroporin Activity

Many viruses alter intracellular calcium homeostasis. The rotavirus nonstructural protein 4 (NSP4), an endoplasmic reticulum (ER) transmembrane glycoprotein, increases intracellular levels of cytoplasmic Ca2+ ([Ca2+]cyto) through a phospholipase C-independent pathway, which is required for virus replication and morphogenesis. However, the NSP4 domain and mechanism that increases [Ca2+]cyto are unknown. We identified an NSP4 domain (amino acids [aa] 47 to 90) that inserts into membranes and has structural characteristics of viroporins, a class of small hydrophobic viral proteins that disrupt membrane integrity and ion homeostasis to facilitate virus entry, assembly, or release. Mutational analysis showed that NSP4 viroporin activity was mediated by an amphipathic α-helical domain downstream of a conserved lysine cluster. The lysine cluster directed integral membrane insertion of the viroporin domain and was critical for viroporin activity. In epithelial cells, expression of wild-type NSP4 increased the levels of free cytoplasmic Ca2+ by 3.7-fold, but NSP4 viroporin mutants maintained low levels of [Ca2+]cyto, were retained in the ER, and failed to form cytoplasmic vesicular structures, called puncta, which surround viral replication and assembly sites in rotavirus-infected cells. When [Ca2+]cyto was increased pharmacologically with thapsigargin, viroporin mutants formed puncta, showing that elevation of calcium levels and puncta formation are distinct functions of NSP4 and indicating that NSP4 directly or indirectly responds to elevated cytoplasmic calcium levels. NSP4 viroporin activity establishes the mechanism for NSP4-mediated elevation of [Ca2+]cyto, a critical event that regulates rotavirus replication and virion assembly

Nutrient utilization and feeding behavior of creole goats in response to the manipulation of early dietary experiences with forage in the Central Monte desert, Argentina

La cría de cabras Criollas bajo sistemas de producción extensivos con pastoreo continuo es una de las principales actividades productivas del NE de Lavalle (Men-doza). Trabajos previos realizados por nuestro equipo de investigación en dicha región dan evidencia del dinamismo y plasticidad del comportamiento alimentario de las cabras frente a variaciones tanto de su medio interno como exter-no. Más recientemente, nuestros resultados indican que las cabras se benefician nutricionalmente a partir de la ingesta de una dieta compuesta por diversas partes y especies de plantas, aún cuando algunos ítems alimentarios presentan elevados contenidos de compuestos secundarios poten-cialmente tóxicos como los taninos. No existen dudas en cuanto a que los procesos adaptativos que moldean el comportamiento alimentario de los herbívoros en pastoreo son afectados por las experiencias dietarias tempranas y el contexto nutricional en el cual los alimentos son ingeridos. Trabajos previos realizados con cabras y ovejas en ambien-tes de pastoreo similares al NE de Lavalle han aportado evi-dencia experimental acerca de cómo las prácticas de ma-nejo que se realizan durante el desarrollo in utero y posnatal temprano afectan de forma permanente el comportamiento alimentario, respuesta al estrés y performance productiva de los animales. Sin embargo, aún se desconoce cómo dichas experiencias afectan el comportamiento alimentario de las cabras Criollas en el NE de Lavalle, y cuál es el rol de los taninos en instancias tempranas del aprendizaje. Objetivo: estudiar la utilización de nutrientes y el compor-tamiento alimentario de cabras Criollas en respuesta a la manipulación de las experiencias dietarias tempranas con forrajeras nativas del NE de Lavalle

Inhibition of the CXCL12/CXCR4-axis as preventive therapy for radiation-induced pulmonary fibrosis

Background: A devastating late injury caused by radiation is pulmonary fibrosis. This risk may limit the volume of irradiation and compromise potentially curative therapy. Therefore, development of a therapy to prevent this toxicity can be of great benefit for this patient population. Activation of the chemokine receptor CXCR4 by its ligand stromal cell-derived factor 1 (SDF-1/CXCL12) may be important in the development of radiation-induced pulmonary fibrosis. Here, we tested whether MSX-122, a novel small molecule and partial CXCR4 antagonist, can block development of this fibrotic process. Methodology/Principal Findings: The radiation-induced lung fibrosis model used was C57BL/6 mice irradiated to the entire thorax or right hemithorax to 20 Gy. Our parabiotic model involved joining a transgenic C57BL/6 mouse expressing GFP with a wild-type mouse that was subsequently irradiated to assess for migration of GFP+ bone marrow-derived progenitor cells to the irradiated lung. CXCL12 levels in the bronchoalveolar lavage fluid (BALF) and serum after irradiation were determined by ELISA. CXCR4 and CXCL12 mRNA in the irradiated lung was determined by RNase protection assay. Irradiated mice were treated daily with AMD3100, an established CXCR4 antagonist; MSX-122; and their corresponding vehicles to determine impact of drug treatment on fibrosis development. Fibrosis was assessed by serial CTs and histology. After irradiation, CXCL12 levels increased in BALF and serum with a corresponding rise in CXCR4 mRNA within irradiated lungs consistent with recruitment of a CXCR4+ cell population. Using our parabiotic model, we demonstrated recruitment of CXCR4+ bone marrow-derived mesenchymal stem cells, identified based on marker expression, to irradiated lungs. Finally, irradiated mice that received MSX-122 had significant reductions in development of pulmonary fibrosis while AMD3100 did not significantly suppress this fibrotic process. Conclusions/Significance: CXCR4 inhibition by drugs such as MSX-122 may alleviate potential radiation-induced lung injury, presenting future therapeutic opportunities for patients requiring chest irradiation. © 2013 Shu et al

Two Brothers with Skewed Thiopurine Metabolism in Ulcerative Colitis Treated Successfully with Allopurinol and Mercaptopurine Dose Reduction

Thiopurine therapy effectively maintains remission in inflammatory bowel disease. However, many patients are unable to achieve optimum benefits from azathioprine or 6-mercaptopurine because of undesirable metabolism related to high thiopurine methyltransferase (TPMT) activity characterized by hepatic transaminitis secondary to increased 6-methylmercaptopurine (6-MMP) production and reduced levels of therapeutic 6-thioguanine nucleotide (6-TGN). Allopurinol can optimize this skewed metabolism. We discuss two brothers who were both diagnosed with ulcerative colitis (UC). Their disease remained active despite oral and topical mesalamines. Steroids followed by 6-mercaptopurine (MP) were unsuccessfully introduced for both patients and both were found to have high 6-MMP and low 6-TGN levels, despite normal TMPT enzyme activity, accompanied by transaminitis. Allopurinol was introduced in combination with MP dose reduction. For both brothers addition of allopurinol was associated with successful remission and optimized MP metabolites. These siblings with active UC illustrate that skewed thiopurine metabolism may occur despite normal TPMT enzyme activity and can lead to adverse events in the absence of disease control. We confirm previous data showing that addition of allopurinol can reverse this skewed metabolism, and reduce both hepatotoxicity and disease activity, but we now also introduce the concept of a family history of preferential MP metabolism as a clue to effective management for other family members

Viroporins

Viroporins are a group of proteins that participate in several viral functions, including the promotion of release of viral particles from cells. These proteins also affect cellular functions, including the cell vesicle system, glycoprotein trafficking and membrane permeability. Viroporins are not essential for the replication of viruses, but their presence enhances virus growth. Comprising some 60-120 amino acids, viroporins have a hydrophobic transmembrane domain that interacts with and expands the lipid bilayer. Some viroporins also contain other motifs, such as basic amino acid residues or a domain rich in aromatic amino acids that confers on the protein the ability to interact with the interfacial lipid bilayer. Viroporin oligomerization gives rise to hydrophilic pores at the membranes of virus-infected cells. As the list of known viroporins steadily grows, recent research efforts focus on deciphering the actions of the viroporins poliovirus 2B, alphavirus 6K, HIV-1 Vpu and influenza virus M2. All these proteins can enhance the passage of ions and small molecules through membranes depending on their concentration gradient. Future work will lengthen the list of viroporins and will provide a deeper understanding of their mechanisms of action.This work was supported by the Comunidad Autonoma de Madrid (082‐0024/2000), Instituto de Salud Carlos III (01/0042) and the DGICYT (PM99‐0002). The authors also acknowledge the institutional grant awarded to the Centro de Biologı́a Molecular ‘Severo Ochoa’ by the Fundación Ramón Areces.S

Gene Expression Variability within and between Human Populations and Implications toward Disease Susceptibility

Variations in gene expression level might lead to phenotypic diversity across individuals or populations. Although many human genes are found to have differential mRNA levels between populations, the extent of gene expression that could vary within and between populations largely remains elusive. To investigate the dynamic range of gene expression, we analyzed the expression variability of ∼18, 000 human genes across individuals within HapMap populations. Although ∼20% of human genes show differentiated mRNA levels between populations, our results show that expression variability of most human genes in one population is not significantly deviant from another population, except for a small fraction that do show substantially higher expression variability in a particular population. By associating expression variability with sequence polymorphism, intriguingly, we found SNPs in the untranslated regions (5′ and 3′UTRs) of these variable genes show consistently elevated population heterozygosity. We performed differential expression analysis on a genome-wide scale, and found substantially reduced expression variability for a large number of genes, prohibiting them from being differentially expressed between populations. Functional analysis revealed that genes with the greatest within-population expression variability are significantly enriched for chemokine signaling in HIV-1 infection, and for HIV-interacting proteins that control viral entry, replication, and propagation. This observation combined with the finding that known human HIV host factors show substantially elevated expression variability, collectively suggest that gene expression variability might explain differential HIV susceptibility across individuals