Formation and availability of methylmercury in mercury-contaminated sediment: effects of activated carbon and biochar amendments

Purpose As the formation of toxic and bioaccumulative methylmercury (MeHg) in Hg-contaminated sediments is of great concern worldwide, suitable remediation options are needed. Activated carbon (AC) amendment is a contested alternative due to uncertainties surrounding sorption efficiency and its potential role in aiding MeHg formation. The purpose of this study was therefore to demonstrate AC performance under favourable conditions for Hg-methylation and to further understand the role AC plays in the methylation process. Materials and methods Mercury-contaminated sediment (57.1 mg kg−1) was sampled from the Gunneklev fjord, a site known as the most heavily contaminated fjord in Norway. In a laboratory experiment, lignite AC (A-AC, 5%) or activated biochar (A-BC, 5%) along with dried algae biomass, serving as an excess source of easily degradable organic matter (OM) and sulphate, were added to sediment samples that were kept anoxic and dark over a period of 12 months. Results and discussion The amount of MeHg in sediment and porewater of the amended samples were measured at 0, 1, 3, 6, and 12 months and compared to an unamended control. A net increase of MeHg in the sediment was observed in both control and amended samples, but contrary to expectations, sediment MeHg was 5 and 3 times higher in the A-AC and A-BC treatments, respectively, relative to the control after 12 months. As the stimulation of Hg-methylation could not be attributed to the sorbents supplying more available OM or sulphate for dissimilatory sulphate reduction, it is speculated that the sorbents rather aid this process through shuttling of electrons between the substrates involved. Meanwhile, the A-AC and A-BC amendments strongly reduced the available MeHg-concentration in porewater (by 87% for A-AC and by 93% for A-BC after 12 months), confirming that AC sorbents can be used to effectively limit the transport of MeHg from sediments. Conclusion When considering remediation of OM-rich Hg-contaminated sediments with AC, caution is thus warranted, as the overall effect of reducing MeHg-transport out of the sediment could partly be offset by an increased fraction of MeHg in the sediment. Thin-layer capping with AC might therefore be preferable to complete mixing of AC and sediment.

JOGANDO FUTEBOL COM A REALIDADE

Resumo: Este estudo objetiva examinar um futebol fora dos holofotes do espetáculo, a partir da configuração dos chamados “trabalhadores da bola”. Entendendo que a simples observação contemplativa de tal fenômeno é insuficiente para compreendê-lo; procurou-se fazer uma mediação com categorias norteadoras, a saber: trabalho e capitalismo. A investigação foi caracterizada como exploratória, quantitativo-qualitativa, bibliográfica e de cunho documental. Os dados foram coletados nas seguintes fontes: a) Site salario.com.br; b) Novo CAGED; c) eSocial; d) empregador web; e) dados de relatórios da Confederação Brasileira de Futebol. Como principais achados, percebeu-se uma desigualdade profunda em relação a salários, altos índices de desemprego e uma permanente precarização.

Application of RtcB ligase to monitor self-cleaving ribozyme activity by RNA-seq

Self-cleaving ribozymes are catalytic RNAs and can be found in all domains of life. They catalyze a site-specific cleavage that results in a 5′ fragment with a 2′,3′ cyclic phosphate (2′,3′ cP) and a 3′ fragment with a 5′ hydroxyl (5′ OH) end. Recently, several strategies to enrich self-cleaving ribozymes by targeted biochemical methods have been introduced by us and others. Here, we develop an alternative strategy in which 5ʹ OH RNAs are specifically ligated by RtcB ligase, which first guanylates the 3′ phosphate of the adapter and then ligates it directly to RNAs with 5′ OH ends. Our results demonstrate that adapter ligation to highly structured ribozyme fragments is much more efficient using the thermostable RtcB ligase from Pyrococcus horikoshii than the broadly applied Escherichia coli enzyme. Moreover, we investigated DNA, RNA and modified RNA adapters for their suitability in RtcB ligation reactions. We used the optimized RtcB-mediated ligation to produce RNA-seq libraries and captured a spiked 3ʹ twister ribozyme fragment from E. coli total RNA. This RNA-seq-based method is applicable to detect ribozyme fragments as well as other cellular RNAs with 5ʹ OH termini from total RNA.

RESPON IMUN HOSPES TERHADAP INFEKSI Vibrio cholerae

The immune sistem is a way of the body’s defense sistem to save the host from the invasion of outside pathogen. Based on how respon to disease, that differentiated into two immune system are innate and adaptive system. Because it an cant throgh the stomach, these pathogenic bacteria go to the small intestin as a site infection. In the intestine, V. cholerae bactesia adhere and colonize and invasion to intestinal epihelial cells. Protection mechanism to V. cholerae are the natural defense presence of tick mucosa on the surface of epithelial cells can inhibit pathogene to adhere tointestinal epithelial cells. One anothet defense namely innate immune system did by phagocytic cells to attac pathogen agent and adaptive immune system involves IgA to opsonization so that can increase intestinal mucosal immune system

An antibody targeting the N-terminal domain of SARS-CoV-2 disrupts the spike trimer

The protective human antibody response to the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus focuses on the spike (S) protein which decorates the virion surface and mediates cell binding and entry. Most SARS-CoV-2 protective antibodies target the receptor-binding domain or a single dominant epitope (supersite) on the N terminal domain (NTD). Here, using the single B cell technology LIBRA-seq, we isolated a large panel of NTD-reactive and SARS-CoV-2 neutralizing antibodies from an individual who had recovered from COVID-19. We found that neutralizing antibodies to the NTD supersite commonly are encoded by the IGHV1-24 gene, forming a genetic cluster that represents a public B cell clonotype. However, we also discovered a rare human antibody, COV2-3434, that recognizes a site of vulnerability on the SARS-CoV-2 S protein in the trimer interface and possesses a distinct class of functional activity. COV2-3434 disrupted the integrity of S protein trimers, inhibited cell-to-cell spread of virus in culture, and conferred protection in human ACE2 transgenic mice against SARS-CoV-2 challenge. This study provides insight about antibody targeting of the S protein trimer interface region, suggesting this region may be a site of virus vulnerability.

Kangaroo Court: The Black Power Movement and the Courtroom as a Space of Resistance

Scholars in many disciplines have examined how social movements use the law to create social change. While the study of the law and social movements has largely relied on studies of the US civil rights movement to develop theoretical tools for understanding how movements target the state to create legal changes, none of these studies have examined the legal strategy of the Black Power movement. This article draws on data from a larger project on Black Power law and the National Conference of Black Lawyers to develop the idea of the courtroom as contested space and construct a concept of courtroom resistance. I argue that the courtroom, operating as hegemonic white space, was viewed as a site of contestation by Black Power activists who found creative ways to challenge the legal, ideological, and physical “space” of the courtroom. These conceptual tools open an important avenue for researchers interested in examining the relationship between social movements and the law and how race operates in the courts.

Protecting Whiteness: Counter-Terrorism, and British Identity in the BBC’s Bodyguard

This article uses Bodyguard to trace the ways that whiteness is represented in counter-terrorism TV and so draw the links between whiteness, counter-terrorism and culture. It argues that Bodyguard offers a redemptive narrative for British whiteness that recuperates and rearticulates a British white identity after/through the War on Terror. As such it belongs to a later genre of counter-terrorism TV shows that move on from, but nonetheless still propagate, the discursive foundations of the ongoing War on Terror. This reading of Bodyguard is itself important, as popular culture is a site where much of the British population made and continues to make sense of their relationship to the UK during the War on Terror, forging often unspoken ideas about whiteness. It affords the opportunity to draw out the connections between whiteness and counter-terrorism, connections that need further scholarly attention to fully understand the complex relationships between security and race.