We report a comprehensive statistical analysis of data on 58 DNA markers (mitochondrial [mt], Y-chromosomal, and autosomal) and sequence data of the mtHVS1 from a large number of ethnically diverse populations of India. Our results provide genomic evidence that (1) there is an underlying unity of female lineages in India, indicating that the initial number of female settlers may have been small; (2) the tribal and the caste populations are highly differentiated; (3) the Austro-Asiatic tribals are the earliest settlers in India, providing support to one anthropological hypothesis while refuting some others; (4) a major wave of humans entered India through the northeast; (5) the Tibeto-Burman tribals share considerable genetic commonalities with the Austro-Asiatic tribals, supporting the hypothesis that they may have shared a common habitat in southern China, but the two groups of tribals can be differentiated on the basis of Y-chromosomal haplotypes; (6) the Dravidian tribals were possibly widespread throughout India before the arrival of the Indo-European-speaking nomads, but retreated to southern India to avoid dominance; (7) formation of populations by fission that resulted in founder and drift effects have left their imprints on the genetic structures of contemporary populations; (8) the upper castes show closer genetic affinities with Central Asian populations, although those of southern India are more distant than those of northern India; (9) historical gene flow into India has contributed to a considerable obliteration of genetic histories of contemporary populations so that there is at present no clear congruence of genetic and geographical or sociocultural affinities.[Supplemental Material is available online at www.genome.org. The following individuals kindly provided reagents, samples, or unpublished information as indicated in the paper: C

Supramolecular gels, which demonstrate tunable functionalities, have attracted much interest in a range of areas, including healthcare, environmental protection and energy-related technologies. Preparing these materials in a reliable manner is challenging, with an increased level of kinetic defects observed at higher self-assembly rates. Here, by combining biocatalysis and molecular self-assembly, we have shown the ability to more quickly access higher-ordered structures. By simply increasing enzyme concentration, supramolecular order expressed at molecular, nano-and micro-levels is dramatically enhanced, and, importantly, the gelator concentrations remain identical. Amphiphile molecules were prepared by attaching an aromatic moiety to a dipeptide backbone capped with a methyl ester. Their self-assembly was induced by an enzyme that hydrolysed the ester. Different enzyme concentrations altered the catalytic activity and size of the enzyme clusters, affecting their mobility. This allowed structurally diverse materials that represent local minima in the free energy landscape to be accessed based on a single gelator structure.M olecular self-assembly 1-7 can be controlled using a variety of stimuli, including chemical 8,9 and mechanical 10 triggers, as well as X-rays 11 . Although the traditional premise in selfassembly suggests that supramolecular material properties can be fully encoded into molecular building blocks, it is increasingly apparent that the chosen self-assembly pathway is central to the final structure and its material functionality. Biocatalytic control of self-assembly systems is a novel direction for laboratory-based self-assembly 12-17 , although it is omnipresent in the biological world. Indeed, enzymatically controlled self-assembly and disassembly underlies vital processes such as cell movement, intracellular transport and muscle contraction. In chemists' hands, the combination of biocatalysis and molecular self-assembly has recently emerged as a powerful new approach to make novel stimuli-responsive molecular materials [12][13][14][15][16][17] . We believe that catalytic control of self-assembly provides important new methodology beyond such triggering of material transitions. In particular, the combination of biological selectivity, localized action and operation under constant, physiological conditions provides a new methodology for bottomup nanofabrication of future soft materials and devices, allowing for unprecedented control of supramolecular order.Here, we focus on the control of supramolecular order with few defects. In principle, there are two possible approaches to defect reduction-either improving the fidelity of the self-assembly process (avoiding defects) or using fully reversible systems that operate under thermodynamic control (repairing defects). The latter approach is generally slow and only applicable to cases where the desired structure represents the global equilibrium state and where the system is fully reversible, that is, under thermodynamic control 16 . Many structure...

This version is available at https://strathprints.strath.ac.uk/46260/ Strathprints is designed to allow users to access the research output of the University of Strathclyde. Unless otherwise explicitly stated on the manuscript, Copyright © and Moral Rights for the papers on this site are retained by the individual authors and/or other copyright owners. Please check the manuscript for details of any other licences that may have been applied. You may not engage in further distribution of the material for any profitmaking activities or any commercial gain. You may freely distribute both the url (https://strathprints.strath.ac.uk/) and the content of this paper for research or private study, educational, or not-for-profit purposes without prior permission or charge.Any correspondence concerning this service should be sent to the Abstract: We demonstrate supramolecular peptide nanofibers that display dynamic instability, i.e. they are formed by competing assembly and dis-assembly reactions, where assembly is favoured away from equilibrium. The systems are based on competitive catalytic transacylation and hydrolysis, producing a self-assembling aromatic peptide derivative from amino acid precursors, that temporarily exceeds the critical gelation concentration, until the competing hydrolytic reaction takes over. Analysis by atomic force microscopy shows consecutive nanofiber formation and shortening. The process results in macroscopically observable temporary hydrogelation, which may be repeated upon refuelling the system with further addition of the chemically activated amino acid pre-cursor. Non-equilibrium nanostructures open up opportunities for mimicry of the behaviour dynamic gels found in natural systems and provide components for future adaptive nanotechnologies.Results and Discussion: The combination molecular self-assembly 1 and (bio-)catalysis underlies dynamic processes in biology and also provides a useful paradigm for fabrication of adaptive nanostructures. 2 A key feature of naturally occurring catalytic self-assembling systems is that they are dynamic in nature, with lengthening and breakdown tightly regulated. For example, catalytic formation and degradation of actin filaments 3 and microtubules 4 underlie vital cellular functions such as motility, differentiation, division. Synthetic mimics of these systems have been the focus of considerable research efforts in recent years. 1,2 One feature where most man-made systems differ from their natural counterparts, is that the latter (e.g. microtubules) display dynamic instability, in that they are assembled and lengthened in a process that relies on energy input (away from equilibrium) and shortened when equilibrium is approached. Significant effort is currently invested in developing non-equilibrium molecular systems 5 and materials which may give rise to new features that are normally not associated with synthetic systems, in that they may be reconfigurable, externally fuelled, self-healing, or even self-replicating. 6 Boekhoven et al., recently publish...

Abstract. Stem cells are known to differentiate in response toHowever, identification of these stem cell inducing molecules is non-trivial and rational approaches to discover drugs for achieving reproducible, targeted stem cell control remain elusive. Here, we demonstrate the design of supramolecular hydrogels that allow targeting of a range of stem cell phenotypes, providing a useful platform for discovery of differentiation inducing metabolites. These gels are simple in composition, containing a fibre forming aromatic peptide amphiphile, which is coassembled with a surfactant-like amphiphile that provides hydrophilic surface functionality to the fibres. The stiffness of the gels can be precisely tuned over the entire range that is typically associated with stem cell differentiation (0.1-40 kPa). 3We demonstrate that the gels can be used to direct stem cell differentiation without the need for induction media and they are therefore ideally suited to study stem cell behaviour -including as drug discovery platforms. To achieve this, we study the cell's usage of biological small molecules, metabolites, during differentiation and select bioactive metabolites that can target bone and cartilage formation specifically. This new use of designed supramolecular biomaterials can be envisaged to remove serendipity from discovery of metabolites associated with biological processes as drug candidates. Introduction.

We report on a pronounced specific-ion effect on the intermolecular and chiral organization, supramolecular structure formation, and resulting materials properties for a series of low molecular weight peptide-based hydrogelators, observed in the presence of simple inorganic salts. This effect was demonstrated using aromatic short peptide amphiphiles, based on fluorenylmethoxycarbonyl (Fmoc). Gel-phase materials were formed due to molecular self-assembly, driven by a combination of hydrogen bonding and π-stacking interactions. Pronounced morphological changes were observed by atomic force microscopy (AFM) for Fmoc-YL peptide, ranging from dense fibrous networks to spherical aggregates, depending on the type of anions present. The gels formed had variable mechanical properties, with G' values between 0.8 kPa and 2.4 kPa as determined by rheometry. Spectroscopic analysis provided insights into the differential mode of self-assembly, which was found to be dictated by the hydrophobic interactions of the fluorenyl component, with comparable H-bonding patterns observed in each case. The efficiency of the anions in promoting the hydrophobic interactions and thereby self-assembly was found to be consistent with the Hofmeister anion sequence. Similar effects were observed with other hydrophobic peptides, Fmoc-VL and Fmoc-LL. The effect was found to be less pronounced for a less hydrophobic peptide, Fmoc-AA. To get more insights into the molecular mechanism, the effect of anions on sol-gel equilibrium was investigated, which indicates the observed changes result from the specific-ion effects on gels structure, rather than on the sol-gel equilibrium. Thus, we demonstrate that, by simply changing the ionic environment, structurally diverse materials can be accessed providing an important design consideration in nanofabrication via molecular self-assembly.

There are various conflicting hypotheses regarding the origins of the tribal groups of India, who belong to three major language groups--Austro-Asiatic, Dravidian and Tibeto-Burman. To test some of the major hypotheses we designed a genetic study in which we sampled tribal populations belonging to all the three language groups. We used a set of autosomal DNA markers, mtDNA restriction-site polymorphisms (RSPs) and mtDNA hypervariable segment-1 (HVS-1) sequence polymorphisms in this study. Using the unlinked autosomal markers we found that there is a fair correspondence between linguistic and genomic affinities among the Indian tribal groups. We reconstructed mtDNA RSP haplotypes and found that there is extensive haplotype sharing among all tribal populations. However, there is very little sharing of mtDNA HVS-1 sequences across populations, and none across language groups. Haplogroup M is ubiquitous, and the subcluster U2i of haplogroup U occurs in a high frequency. Our analyses of haplogroup and HVS-1 sequence data provides evidence in support of the hypothesis that the Austro-Asiatic speakers are the most ancient inhabitants of India. Our data also support the earlier finding that some of the western Eurasian haplogroups found in India may have been present in India prior to the entry of Aryan speakers. However, we do not find compelling evidence to support the theory that haplogroup M was brought into India on an "out of Africa" wave of migration through a southern exit route from Ethiopia. On the contrary, our data raise the possibility that this haplogroup arose in India and was later carried to East Africa from India.

A novel class of supramolecular hydrogels derived from amino sugars is reported, where the selfassembly of aromatic carbohydrate amphiphiles is driven by CH-p interactions, rather than p-p stacking and H-bonding associated with gelators based on aromatic peptide amphiphiles. Spectroscopic data is provided as evidence for this mode of self-assembly and in silico studies revealed that a combination of CH-p and T-stacking of the fluorenyl groups contribute to the formation of the aggregated structures.

No abstract