Statistical Mechanics of DNA Rupture: Theory and Simulations

We study the effects of the shear force on the rupture mechanism on a double stranded DNA. Motivated by recent experiments, we perform the atomistic simulations with explicit solvent to obtain the distributions of extension in hydrogen and covalent bonds below the rupture force. We obtain a significant difference between the atomistic simulations and the existing results in the iterature based on the coarse-grained models (theory and simulations). We discuss the possible reasons and improve the coarse-grained model by incorporating the consequences of semi-microscopic details of the nucleotides in its description. The distributions obtained by the modified model (simulations and theoretical) are qualitatively similar to the one obtained using atomistic simulations.Comment: 18 pages, 9 figures. Accepted in J. Chem. Phys. (2013). arXiv admin note: text overlap with arXiv:1104.305

Biodiversity Conservation Through Urban Green Spaces: A Case Study of Gujarat University Campus in Ahmedabad

The present study deals with the phytodiversity of Gujarat University campus and the surrounding region which forms an important green space in the urban environment of Ahmedabad city in Gujarat state, India. The extensive field surveys were carried out in the vast study area during 2004 to 2006 covering four different seasons viz. summer, winter, monsoon and spring to cover annual, biennial and perennial plants. A total of 451 species of flowering plants belonging to 338 genera and 101 families were recorded in the study area. Along with these three pteridophytes, two gymnosperms and the algae and fungi group appearing mostly in the monsoon season were also recorded in the study. Among the flowering plants, the herbs were found to be dominant, indicating they favored the climatic factors like less rainfall and high temperature in the study area. Raunkier’s biological life forms revealed the dominance of therophytes and phanerophytes, indicating ‘Thero-Phanerophytic’ phytoclimate in the region. The urban green spaces with such rich plant diversity need to be conserved, especially with the help of the local population, in order to maintain a good environment and biodiversity, thereby improving the overall quality of life

Work and Quantum Phase Transitions: Is there Quantum Latency?

We study the physics of quantum phase transitions from the perspective of non-equilibrium thermodynamics. For first order quantum phase transitions, we find that the average work done per quench in crossing the critical point is discontinuous. This leads us to introduce the quantum latent work in analogy with the classical latent heat of first order classical phase transitions. For second order quantum phase transitions the irreversible work is closely related to the fidelity susceptibility for weak sudden quenches of the system Hamiltonian. We demonstrate our ideas with numerical simulations of first, second, and infinite order phase transitions in various spin chain models.Comment: accepted in PR

Mitochondrial roles of the psychiatric disease risk factor DISC1

Ion transport during neuronal signalling utilizes the majority of the brain's energy supply. Mitochondria are key sites for energy provision through ATP synthesis and play other important roles including calcium buffering. Thus, tightly regulated distribution and function of these organelles throughout the intricate architecture of the neuron is essential for normal synaptic communication. Therefore, delineating mechanisms coordinating mitochondrial transport and function is essential for understanding nervous system physiology and pathology. While aberrant mitochondrial transport and dynamics have long been associated with neurodegenerative disease, they have also more recently been linked to major mental illness including schizophrenia, autism and depression. However, the underlying mechanisms have yet to be elucidated, due to an incomplete understanding of the combinations of genetic and environmental factors contributing to these conditions. Consequently, the DISC1 gene has undergone intense study since its discovery at the site of a balanced chromosomal translocation, segregating with mental illness in a Scottish pedigree. The precise molecular functions of DISC1 remain elusive. Reported functions of DISC1 include regulation of intracellular signalling pathways, neuronal migration and dendritic development. Intriguingly, a role for DISC1 in mitochondrial homeostasis and transport is fast emerging. Therefore, a major function of DISC1 in regulating mitochondrial distribution, ATP synthesis and calcium buffering may be disrupted in psychiatric disease. In this review, we discuss the links between DISC1 and mitochondria, considering both trafficking of these organelles and their function, and how, via these processes, DISC1 may contribute to the regulation of neuronal behavior in normal and psychiatric disease states

Functional outcome of humeral shaft fractures in adults treated with titanium elastic nailing

Background: This study was done to analyse the functional outcome of humeral shaft fractures (upper and middle third) managed with closed ante-grade intramedullary titanium elastic nailing.Methods: This was a prospective study of 20 patients, aged between 18 and 60 years, with humeral shaft fractures treated with titanium elastic nailing from May 2016 to April 2018 at our institute. Upper and middle humeral shaft fractures of both sexes were included in the study.Results: Eighteen (90%) fractures united in 12-20 weeks. Two (10%) patients had delayed union which ultimately united without any intervention. Two (10%) patients developed shoulder stiffness due to nail impingement. By evaluating ASES score, good to excellent results were noted in 18 (90%) and moderate in 2 (10%). There were 15 males and 5 females with an average age 32.75 years (range: 18-60 years).Conclusions: Titanium elastic nailing is a good method for treatment of humeral shaft fractures in adults. It provides early fracture union, high union rates, minimal soft tissue damage, early rehabilitation and short hospital stay

Mainstreaming Underutilized Indigenous and Traditional Crops into Food Systems: A South African Perspective

Business as usual or transformative change? While the global agro-industrial food system is credited with increasing food production, availability and accessibility, it is also credited with giving birth to ‘new’ challenges such as malnutrition, biodiversity loss, and environmental degradation. We reviewed the potential of underutilized indigenous and traditional crops to bring about a transformative change to South Africa’s food system. South Africa has a dichotomous food system, characterized by a distinct, dominant agro-industrial, and, alternative, informal food system. This dichotomous food system has inadvertently undermined the development of smallholder producers. While the dominant agro-industrial food system has led to improvements in food supply, it has also resulted in significant trade-offs with agro-biodiversity, dietary diversity, environmental sustainability, and socio-economic stability, especially amongst the rural poor. This challenges South Africa’s ability to deliver on sustainable and healthy food systems under environmental change. The review proposes a transdisciplinary approach to mainstreaming underutilized indigenous and traditional crops into the food system, which offers real opportunities for developing a sustainable and healthy food system, while, at the same time, achieving societal goals such as employment creation, wellbeing, and environmental sustainability. This process can be initiated by researchers translating existing evidence for informing policy-makers. Similarly, policy-makers need to acknowledge the divergence in the existing policies, and bring about policy convergence in pursuit of a food system which includes smallholder famers, and where underutilized indigenous and traditional crops are mainstreamed into the South African food system

Comparison of UK paediatric consultants’ participation in child health research between 2011 and 2015

Objective To identify whether there have been changes over time in the capacity of paediatric consultants to undertake research and if the activity differs between men and women. Design Comparison of data from two surveys of UK paediatric consultants. Subjects UK consultant members of the Royal College of Paediatrics and Child Health. Interventions Surveys carried out in 2011 and 2015. Main outcome measures The proportion of consultants with allocated time in job plans for research, academic appointments, postgraduate qualifications, publications, grant funding and supervision of PhD students. Results The 2015 survey demonstrated 20% of consultants had one or more programmed activities (PAs) for research, but the average paid PA for research was 0.39 PA. Between the surveys, the proportion of consultants with honorary contracts had declined, and the proportion with a PhD or MDRes was 32% in 2011 compared with 26% in 2015 (p<0.001). In 2015, only 12% of consultants had at least one current grant. In 2011 and 2015, 51% and 54% respectively of consultants had not authored a publication in the preceding 2 years. In 2015, 92% of consultants were not currently supervising a PhD student, and 88% had never supervised a PhD student. In 2015, 25% of men and 12% of women had PAs for research (p<0.001). Women were less likely to hold an honorary or primary academic contract, have authored a publication or supervised a PhD student (all p<0.001). Conclusions Research activity among paediatric consultants remains low, particularly among women