Eating Disorders: The Hidden Hormonal Effect On Fertility

Women who have a history of eating disorders, specifically anorexia nervosa, are more prone to suffer from infertility. There are several hormones which are the driving force in this system and are therefore responsible for this. Fortunately, there are treatments which can help women with a history of eating disorders to reproduce. Using information found on Pubmed and Touro College’s database, this paper will discuss why the body cannot reproduce when it is lacking proper nutrition, as well as the various dynamics in the human reproductive system which are compromised when the body is not properly nourished

ASSEMBLÉIAS E PARAGÊNESES MINERAIS SINGULARES NOS PEGMATITOS DA REGIÃO DE GALILÉIA (MINAS GERAIS).

The Galiléia region is famous worldwide due to the periodic discovery of rare minerals and/or mineral for collectors. Such minerals are related to pegmatitic bodies that have been originated from granitic intrusions of Brasiliano age (550-500 My). Regional rocks in which these granites intrude are micaschists and gneisses of uncertain age. Three geographic areas were recognized, where the mineralized pegmatites occur: Sapucaia do Norte, Fazenda Boa Vista e Serra do Urucum. In these areas, the main deposits are studied emphasizing their mineral assemblages and paragenesis. Thus, pegmatites are classified into five different types, related to the phosphatic mineral phases, that are: (1) Li-rich pegmatites, with primary montebrasite, (2) Li-rich pegmatites, with primary triphylite, (3) pegmatites with primary and secondary apatite, (4) pegmatites without primary phosphates, with paragenesis from the montebrasite alteration, and (5) pegmatites without primary phosphates, with paragenesis from the triphylite alteration. Based on such mineral assemblages, some non-phosphatic rare and very rare minerals (eg., stokesite, helvite, lindbergite, coutinhoite, etc.) that occur in this region are also characterized.A região de Galiléia é conhecida mundialmente pelo encontro periódico de minerais raros e/ou de coleção, originados de corpos pegmatíticos que se relacionam geneticamente a cúpulas graníticas brasilianas (550-500 Ma), intrusivas em rochas xistosas e gnáissicas de idades ainda não determinadas. Três áreas geograficamente características foram identificadas, onde se agrupam os depósitos pegmatíticos mais importantes: Sapucaia do Norte, Fazenda Boa Vista e Serra do Urucum. Nessas áreas, os principais corpos foram detalhados e estudados quanto às suas assembléias e paragêneses minerais. Por conseguinte, reconheceram-se pegmatitos de cinco grupos diferentes tomando-se como base espécies minerais fosfáticas diagnósticas, a saber: (1) pegmatitos ricos em lítio, com montebrasita primária, (2) pegmatitos ricos em lítio, com trifilita primária, (3) pegmatitos com apatitas primária e secundária, (4) pegmatitos sem fosfatos primários, possuindo paragêneses de alteração da montebrasita e (5) pegmatitos sem fosfatos primários, possuindo paragêneses de alteração da trifilita. Em função de tais assembléias minerais, são também contextualizados alguns minerais não fosfáticos raros e muito raros (p. ex., stokesita, helvita, coutinhoíta, lindbergita) que ocorrem na região

Intervals and the deduction of drug binding site models

In the search for new drugs, it often occurs that the binding affinities of several compounds to a common receptor macromolecule are known experimentally, but the structure of the receptor is not known. This article describes an extraordinarily objective computer algorithm for deducing the important geometric and energetic features of the common binding site, starting only from the chemical structures of the ligands and their observed binding. The user does not have to propose a pharmacophore, guess the bioactive conformations of the ligands, or suggest ways to superimpose the active compounds. The method takes into account conformational flexibility of the ligands, stereospecific binding, diverse or unrelated chemical structures, inaccurate or qualitative binding data, and the possibility that chemically similar ligands may or may not bind to the receptor in similar orientations. The resulting model can be viewed graphically and interpreted in terms of one or more binding regions of the receptor, each preferring to be occupied by various sorts of chemical groups. The model always fits the given data completely and can predict the binding of any other ligand, regardless of chemical structure. The method is an outgrowth of distance geometry and Voronoi polyhedra site modeling but incorporates several novel features. The geometry of the ligand molecules and the site is described in terms of intervals of internal distances. Determining the site model consists of reducing the uncertainty in the interregion distance intervals, and this uncertainty is described as intervals of intervals. Similarly, the given binding affinities and their experimental uncertainties are treated as intervals in the affinity scale. The final site model specifies an entire region of interaction energy parameters that satisfy the training set rather than a single set of parameters. Predicted binding for test compounds results in an interval which, when compared to the experimental interval, may be correct, incorrect, or vague. There is a pervasive ternary logic involved in the assessment of predictions, in the search for a satisfactory model, and in judging whether a given molecule may bind in a particular orientation: true, false, or maybe. The approach is illustrated on an extremely simple artificial example and on a real data set of cocaine analogues binding to a nerve membrane receptor in vitro. © 1995 by John Wiley & Sons, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/38288/1/540160412_ftp.pd

Electronic structure and mechanical stability of the graphitic honeycomblattice

A family of crystal structures of carbon composed of alternating sp2 and sp3 bonds is investigated. Graphitic strips are connected by sp3 bonds to form an array of hexagonal pillars exhibiting a honeycomb lattice in the perpendicular plane. The electronic structure and elastic properties of this family of structures are calculated using an ab initio pseudopotential as well as the environment-dependent tight-binding method. Their electronic structure has a similar size dependence to zigzag nanotubes; they are metallic if twice the strip width is a multiple of three hexagonal units, and otherwise semiconducting with a wider range of the band gap than for carbon nanotubes. The structural stability is studied and compared with other carbon structures.open252

Pulsation and stabilization: Contractile forces that underlie morphogenesis

Embryonic development involves global changes in tissue shape and architecture that are driven by cell shape changes and rearrangements within cohesive cell sheets. Morphogenetic changes at the cell and tissue level require that cells generate forces and that these forces are transmitted between the cells of a coherent tissue. Contractile forces generated by the actin–myosin cytoskeleton are critical for morphogenesis, but the cellular and molecular mechanisms of contraction have been elusive for many cell shape changes and movements. Recent studies that have combined live imaging with computational and biophysical approaches have provided new insights into how contractile forces are generated and coordinated between cells and tissues. In this review, we discuss our current understanding of the mechanical forces that shape cells, tissues, and embryos, emphasizing the different modes of actomyosin contraction that generate various temporal and spatial patterns of force generation.American Cancer Society (grant PF-06- 143-01-DDC

Towards crystal structure prediction of complex organic compounds - a report on the fifth blind test

Following on from the success of the previous crystal structure prediction blind tests (CSP1999, CSP2001, CSP2004 and CSP2007), a fifth such collaborative project (CSP2010) was organized at the Cambridge Crystallographic Data Centre. A range of methodologies was used by the participating groups in order to evaluate the ability of the current computational methods to predict the crystal structures of the six organic molecules chosen as targets for this blind test. The first four targets, two rigid molecules, one semi-flexible molecule and a 1: 1 salt, matched the criteria for the targets from CSP2007, while the last two targets belonged to two new challenging categories - a larger, much more flexible molecule and a hydrate with more than one polymorph. Each group submitted three predictions for each target it attempted. There was at least one successful prediction for each target, and two groups were able to successfully predict the structure of the large flexible molecule as their first place submission. The results show that while not as many groups successfully predicted the structures of the three smallest molecules as in CSP2007, there is now evidence that methodologies such as dispersion-corrected density functional theory (DFT-D) are able to reliably do so. The results also highlight the many challenges posed by more complex systems and show that there are still issues to be overcome