How Does the Coupling of Secondary and Tertiary Interactions Control the Folding of Helical Macromolecules?

The authors study how the simultaneous presence of short-range secondary and long-range tertiary interactions controls the folding and collapse behavior of a helical macromolecule. The secondary interactions stabilize the helical conformation of the chain, while the tertiary interactions govern its overall three-dimensional shape. The authors have carried out Monte Carlo simulations to study the effect of chain length on the folding and collapse behavior of the chain. They have calculated state diagrams for four chain lengths and found that the physics is very rich with a plethora of stable conformational states. In addition to the helix-coil and coil-globule transitions, their model describes the coupling between them which takes place at low temperatures. Under these conditions, their model predicts a cascade of continuous, conformational transitions between states with an increase in the strength of the tertiary interactions. During each transition the chain shrinks, i.e., collapses, in a rapid and specific manner. In addition, the number of the transitions increases with increasing chain length. They have also found that the low-temperature regions of the state diagram between the transition lines cannot be associated with specific structures of the chain, but rather, with ensembles of various configurations of the chain with similar characteristics. Based on these results the authors propose a mechanism for the folding and collapse of helical macromolecules which is further supported by the analysis of configurational, configurational, and thermodynamic properties of the chain

Coupling Between Helix-Coil and Coil-Globule Transitions in Helical Polymers

We explore the coupling between the helix-coil and coil-globule transitions of a helical polymer using Monte Carlo simulations. A very rich state diagram is found. Each state is characterized by a specific configuration of the chain which could be a helix, a random coil, an amorphous globule, or one of various other globular states which carry residual helical strands. We study the boundaries between states and provide further insight into the physics of the system with a detailed analysis of the order parameter and other properties

Intracranial extramedullary hematopoiesis in a thalassemic girl: A Case report

Beta-thalassemia is a haemolytic disorder with ineffective erythropoiesis and red blood cell destruction. Extramedullary hematopoiesis is one of the complications associated with beta-thalassemia. Extramedullary hematopoiesis is the ectopic production of blood cells outside the marrow in liver, spleen, lymph nodes and many other sites. Intracranial involvement is extremely rare. We report a case of 17-year-old girl with thalassemia major and intracranial extramedullary hematopoiesis who came with the complaints of seizure, headache and generalised weakness. Imaging and blood profile leads to the final diagnosis with MRI playing a key role and patient was managed successfully. With this report, we discuss the imaging findings of intracranial extramedullary hematopoiesis in details

The Place of Fieldwork in Geography and Science Qualifications

1. The place of fieldwork in geography and science qualifications across the 14-19 age range remains contested, unclear and sometimes under threat. This report explores these issues and was informed by a one-day, invitation-only workshop that we ran at the behest of the Field Studies Council. 2. We focus on issues relevant for those countries that use GCSEs (General Certificates of Secondary Education) as qualifications for 14-16 year-olds and Advanced Subsidiary (AS) and General Certificate of Education Advanced (A) levels as qualifications for 16-19 year-olds. We hope that this report will also be of value to those working in other jurisdictions that have or are introducing fieldwork at school level. 3. Fieldwork, which can be defined as any curriculum component that involves leaving the classroom and engaging in teaching and learning activities through first-hand experience of phenomena out-of-doors, has a long tradition in geography and in certain of the sciences, notably biology and environmental science/studies. 4. In geography, learning in the ‘real world’ is thought to be absolutely essential, contributing particular qualities that run through geography’s identity as a subject discipline from primary education to undergraduate study. It expresses a commitment to exploration and enquiry, and geography’s concern to discover and to be curious about the world. 5. In the sciences too, fieldwork is crucial. It can be regarded as that sub-set of practical science that is particularly valuable for introducing students to investigating the complexity and messiness of the real world. 6. Despite its benefits for student learning and motivation, fieldwork is perceived by some school managers as expendable; desirable but not a core requirement. 7. High quality qualifications in geography at GCSE and AS/A level require that students have experienced, from start to finish, a first-hand geographical investigation of a specific aspect of the world. 8. In geography, the individual study should be the method of assessment of fieldwork at AS/A level. At GCSE, where the 2014 criteria provide no option but to assess fieldwork through terminal examination, the potential of enhancing the place of fieldwork in specifications in a way that invests in curriculum and pedagogic advancement should be examined further, for example through the use of moderated student portfolios. 9. In the sciences, at both GCSE and AS/A level, it is important that practical work, of which fieldwork is a unique component, is subject to high quality assessment. The use of moderated student portfolios for the assessment of fieldwork has many strengths and should be explored to see if it can be introduced as a component within formal, summative assessment. 10. The more widespread practice of excellent fieldwork in the sciences and geography will require enhanced initial teacher education and subsequent teacher professional development. It takes time to become a teacher who can ensure that students have an outstanding fieldwork experience

Analytical and Decision Support Tools for Genomics-Assisted Breeding

To successfully implement genomics-assisted breeding (GAB) in crop improvement programs, efficient and effective analytical and decision support tools (ADSTs) are ‘must haves’ to evaluate and select plants for developing next-generation crops. Here we review the applications and deployment of appropriate ADSTs for GAB, in the context of next-generation sequencing (NGS), an emerging source of massive genomic information. We discuss suitable software tools and pipelines for marker-based approaches (markers/haplotypes), including large-scale genotypic and phenotypic, data management, and molecular breeding approaches. Although phenotyping remains expensive and time consuming, prediction of allelic effects on phenotypes opens new doors to enhance genetic gain across crop cycles, building on reliable phenotyping approaches and good crop information systems, including pedigree information and target haplotypes