Study of the doubly charmed tetraquark $T_{cc}^+$

An exotic narrow state in the D0D0π + mass spectrum just below the D∗+D0 mass threshold is studied using a data set corresponding to an integrated luminosity of 9 fb−1 acquired with the LHCb detector in proton-proton collisions at centre-of-mass energies of 7, 8 and 13 TeV. The state is consistent with the ground isoscalar T+ cc tetraquark with a quark content of ccud and spin-parity quantum numbers JP = 1+. Study of the DD mass spectra disfavours interpretation of the resonance as the isovector state. The decay structure via intermediate off-shell D∗+ mesons is confirmed by the D0π + mass distribution. The mass of the resonance and its coupling to the D∗D system are analysed. Resonance parameters including the pole position, scattering length, effective range and compositeness are measured to reveal important information about the nature of the T+ cc state. In addition, an unexpected dependence of the production rate on track multiplicity is observed.

Violent Extremism in the Northern Frontier Counties of Kenya: Exploring Human Security as a Sustainable Countering Strategy

The contemporary rise of terrorism as a form of violent extremism has led the government to adopt a narrow state-centric security approach to mitigate these threats. Violent extremism compromises peace, security, and communal cohesion, and often thrives on human security deficits such as marginalisation and disenfranchisement from the decision-making processes. The prominence of a state-centric security approach has overshadowed the human security dimension of countering violent extremism, thereby compromising state-society relations. On the contrary, a human security approach which entails freedom from fear and freedom from want, is viewed as a holistic approach to security that secures both the state and society. Less debated, however, is the relationship between countering violent extremism and societal marginalisation as viewed through the lens of human security. This paper argues that the narrow state-centric approach adopted by the Kenyan government in the Northern Frontier Counties has continually marginalised the community living in these counties and is proving unsustainable in countering violent extremism. As a point of departure from this approach, a more human security centred approach is suggested which is likely to be more sustainable in countering violent extremism and more successful in reversing the trend of marginalisation that has arisen from the narrow state-centric approach.

Narrative Pasts

Narrative Pasts explores the narrative power of texts—genealogical, historical, and biographical—in creating communities. It retrieves the social history of a Muslim community in Gujarat, a region that has one of the earliest records of Muslim presence in the Indian subcontinent. By reconstructing the literary, social, and historical world of Sufi preceptors, disciples, and descendants from the fifteenth to the seventeenth century, the book reveals the importance of learned Muslim men in imparting a distinct regional and historical identity to Gujarat. The prominence of Gujarat’s maritime location has often oriented the study of Gujarat towards the commercial world of the western Indian Ocean world. Narrative Pasts demonstrates that Gujarat was also an integral part of the historical and narrative processes that shaped medieval and early modern South Asia. Employing new and rarely used literary materials in Persian and Arabic, this book departs from the narrow state-centred visions of the Muslim past and integrates Gujarat’s sultanate and Mughal past with the larger socio-cultural histories of Islamic South Asia.

Globalizing Education in Times of Hyper-Nationalism, Rising Authoritarianism, and Shrinking Worldviews

With the global political tide pushing increasingly narrow state-framed worldviews there is a retrenchment of how people understand their relational place in, and connection to, the world. This essay argues that precisely because of the rise of hyper-nationalism (and accompanying anti-democratic trends) there is an urgent need to pursue the globalizing of public education and the coproduction of global knowledge more generally. I suggest that the emerging field of Global Studies, which has been gaining ground in the United States and even more so around the world in recent decades, offers a pedagogical pathway to promoting critical interdisciplinary perspectives and fostering equality and respect for others. My basic claim is that Global Studies shares with liberal education a core mission to promote peace in a world of cultural diversity. But in calling for epistemological pluralism – and highlighting the American (western) epistemological underpinnings of the liberal arts that are deeply implicated in colonial histories of racism, oppression and silencing of non-western knowledge – Global Studies also highlights the inherent limitations of liberal education that as a new field of inquiry it seeks to overcome.

More US climate court cases coming

Subject Climate change litigation in the United States. Significance Following a bench trial, on December 10, New York Supreme Court Justice Barry Ostrager ruled against the state of New York in its climate change litigation against ExxonMobil. New York’s failure to prevail on a narrow state securities law claim is not a harbinger of future climate change litigation failures. Impacts Activist investors will seek outright divestiture or pressure companies to confront, accept and mitigate climate change. Some states will try to establish state-level liability; cities and counties will also pursue lawsuits. Meaningful federal-level action will need a Democratic president, yet this is a necessary but not sufficient condition.

Negative cooperativity between Gemin2 and RNA provides insights into RNA selection and the SMN complex's release in snRNP assembly

The assembly of snRNP cores, in which seven Sm proteins, D1/D2/F/E/G/D3/B, form a ring around the nonameric Sm site of snRNAs, is the early step of spliceosome formation and essential to eukaryotes. It is mediated by the PMRT5 and SMN complexes sequentially in vivo. SMN deficiency causes neurodegenerative disease spinal muscular atrophy (SMA). How the SMN complex assembles snRNP cores is largely unknown, especially how the SMN complex achieves high RNA assembly specificity and how it is released. Here we show, using crystallographic and biochemical approaches, that Gemin2 of the SMN complex enhances RNA specificity of SmD1/D2/F/E/G via a negative cooperativity between Gemin2 and RNA in binding SmD1/D2/F/E/G. Gemin2, independent of its N-tail, constrains the horseshoe-shaped SmD1/D2/F/E/G from outside in a physiologically relevant, narrow state, enabling high RNA specificity. Moreover, the assembly of RNAs inside widens SmD1/D2/F/E/G, causes the release of Gemin2/SMN allosterically and allows SmD3/B to join. The assembly of SmD3/B further facilitates the release of Gemin2/SMN. This is the first to show negative cooperativity in snRNP assembly, which provides insights into RNA selection and the SMN complex's release. These findings reveal a basic mechanism of snRNP core assembly and facilitate pathogenesis studies of SMA.

Meson spectroscopy at VES and COMPASS

Diffractive production of π- π- π+ and π- π0 π0 final states is the subject of comprehensive studies performed recently by the VES and the COM-PASS experiments. COMPASS pioneered the application of novel methods of partial-wave analysis: mass-independent PWA inmultiple (m3π, t’)-cells, mass-dependent analysis of spin-density matrices performed simultaneously in all measured t’ bins, the analysis with freed shapes of π+ π- isobars. In addition, COMPASS observed a new narrow state: a1(1420). VES has world-leading data samples on π- π- π+ and π- π0 π0, that yield compatible results and show the potential for a detailed comparison of isospin relations between different decay channels, using the PWA methods with fixed and freed shapes of ππ isobars.

Negative Cooperativity between Gemin2 and RNA provides Insights into RNA Selection and the SMN Complex’s Release in snRNP Assembly

ABSTRACTThe assembly of snRNP cores, in which seven Sm proteins, D1/D2/F/E/G/D3/B, form a ring around the nonameric Sm site of snRNAs, is the early step of spliceosome formation and essential to eukaryotes. It is mediated by the PMRT5 and SMN complexes sequentially in vivo. SMN deficiency causes neurodegenerative disease spinal muscular atrophy (SMA). How the SMN complex assembles snRNP cores is largely unknown, especially how the SMN complex achieves high RNA assembly specificity and how it is released. Here we show, using crystallographic and biochemical approaches, that Gemin2 of the SMN complex enhances RNA specificity of SmD1/D2/F/E/G via a negative cooperativity between Gemin2 and RNA in binding SmD1/D2/F/E/G. Gemin2, independent of its N-tail, constrains the horseshoe-shaped SmD1/D2/F/E/G from outside in a physiologically relevant, narrow state, enabling high RNA specificity. Moreover, the assembly of RNAs inside widens SmD1/D2/F/E/G, causes the release of Gemin2/SMN allosterically and allows SmD3/B to join. The assembly of SmD3/B further facilitates the release of Gemin2/SMN. This is the first to show negative cooperativity in snRNP assembly, which provides insights into RNA selection and the SMN complex’s release. These findings reveal a basic mechanism of snRNP core assembly and facilitate pathogenesis studies of SMA.