Dynamics of chromosome movement

(1) At mitotic prophase unravelling of the chromosome spiral occurs without actual increase in length.(2) The opening out of the secondary split is at mid -prophase. The actual split most probably does not coincide with the opening out of the sister chromatids during mitosis.(3) The commencement of mitosis is the fission of genes and this must occur during the resting stage.(4) The single structure of prophase spiral at mitosis is due to the close association of the homologous genes, chromomeres, and chromatids. The cause of the association is homology, most probably physicochemical in nature.(5) Unravelling of the chromosome spiral is a condition sine qua non for the building up of the matrix of each chromonema'separately.(6) Contraction operates from the undivided attachment constriction. This force acts upon the matrix, causing it to decrease gradually in length. The chromonema does not shorten but adjusts itself by forming a spiral. This structure can be recognised in the prophase of the following division (persist - ance of chromosome individuality).(7) The tertiary split at metaphase was not found in Vicia, Tulipa and Allium. Anaphase separation is due to repulsion which operates between two homologous attachment constrictions.(8) The loci of pairing at zygotene between homologous chromosomes are at random, but always include groups of chromomeres. Polarisation is caused by special attraction between the ends of chromosomes and centrosomes or nuclear Dole. It is most probably genetical in its or(9) At pachytene the homologous chromosomes twist around each other.(10) The opening out of the secondary split is at the end of pachytene.(11) The general rule of pairing - that association always occurs between pairs of homologues, and repulsion always between pairs of paired homologous constituents, - is demonstrated by several observations.(12) At the end of pachytene, attraction and contraction produce a torsion. The secondary split introduces the repulsion and as a result of the interaction of these forces, breaks occur. The fusion of partner chromatids produces the chiasma.(13) Chiasma frequency is not related to the size of the bivalents.(14) The decrease in the number of chiasmata from diplotene to metaphase is caused by two repulsions . The first is general, operating between pairs of paired chromatids; the second is specific and acts between two corresponding homologous attachment constrictions. If the latter is greater, the result of interaction is movement of the chiasmata, towards the distal end.(15) The following data supply evidence in favour of Janssens' chiasmatype hypothesis: (a) Pairing of unequal chromosomes; (b) Interlocking of bivalents at meiotic pro - :phase. (ç) Twisting of sister chromatids on both sides of chiasmata; (d) Decrease in genetical crossing -over parallel to a similar decrease in chiasma frequency.(16) The terminal association of bivalents depends upon a special affinity between terminal chromomeres. If intercalary chromomeres become terminal by trans - location, they attain this special affinity.(17) The movement of chromosomes towards the equatorial plate is a result of repulsion operating between poles and attachment constrictions only.(18) Metaphase equilibrium is a result of repulsion between poles and attachments and between attachmen of similar and dissimilar chromosomes.(19) In some cases the interal affinity of chromosomes will interact with the other forces and determine the mitotic or meiotic metaphase pattern, as it is the case in secondary association and somatic pairing.(20) The spindle mechanism is necessary for normal chromosome movements before and after metaphase. It guides the chromosomes by their attachment constriction towards equilibrium either at the metaphase plate or at the poles. The spindle can be formed only in a normal cytoplasmic environment.(21) At anaphase there is a second period of equilibrium where the repulsion between the corresponding attachment constrictions and poles is equal. Further separation is due to the expansion of the inter-chromosomal spindle, for which new evidence is put forward.(22) At anaphase there is no repulsion between the similar or dissimilar attachments migrating towards the same pole. Repulsion exists only between the corresponding homologous attachment constrictions.(23) The similarity between effects of forces operating at mitotic and meiotic division and those which act in an electro-magnetic field indicates a close relationship in the nature of those forces

Two-point phase correlations of a one-dimensional bosonic Josephson junction

We realize a one-dimensional Josephson junction using quantum degenerate Bose gases in a tunable double well potential on an atom chip. Matter wave interferometry gives direct access to the relative phase field, which reflects the interplay of thermally driven fluctuations and phase locking due to tunneling. The thermal equilibrium state is characterized by probing the full statistical distribution function of the two-point phase correlation. Comparison to a stochastic model allows to measure the coupling strength and temperature and hence a full characterization of the system

Feasibility and acceptance of electronic quality of life assessment in general practice: an implementation study

This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens

Chitin Modulates Innate Immune Responses of Keratinocytes

Chitin, after cellulose the second most abundant polysaccharide in nature, is an essential component of exoskeletons of crabs, shrimps and insects and protects these organisms from harsh conditions in their environment. Unexpectedly, chitin has been found to activate innate immune cells and to elicit murine airway inflammation. The skin represents the outer barrier of the human host defense and is in frequent contact with chitin-bearing organisms, such as house-dust mites or flies. The effects of chitin on keratinocytes, however, are poorly understood. We hypothesized that chitin stimulates keratinocytes and thereby modulates the innate immune response of the skin. Here we show that chitin is bioactive on primary and immortalized keratinocytes by triggering production of pro-inflammatory cytokines and chemokines. Chitin stimulation further induced the expression of the Toll-like receptor (TLR) TLR4 on keratinocytes at mRNA and protein level. Chitin-induced effects were mainly abrogated when TLR2 was blocked, suggesting that TLR2 senses chitin on keratinocytes. We speculate that chitin-bearing organisms modulate the innate immune response towards pathogens by upregulating secretion of cytokines and chemokines and expression of MyD88-associated TLRs, two major components of innate immunity. The clinical relevance of this mechanism remains to be defined

Analysis of Common and Specific Mechanisms of Liver Function Affected by Nitrotoluene Compounds

BACKGROUND: Nitrotoluenes are widely used chemical manufacturing and munitions applications. This group of chemicals has been shown to cause a range of effects from anemia and hypercholesterolemia to testicular atrophy. We have examined the molecular and functional effects of five different, but structurally related, nitrotoluenes on using an integrative systems biology approach to gain insight into common and disparate mechanisms underlying effects caused by these chemicals. METHODOLOGY/PRINCIPAL FINDINGS: Sprague-Dawley female rats were exposed via gavage to one of five concentrations of one of five nitrotoluenes [2,4,6-trinitrotoluene (TNT), 2-amino-4,6-dinitrotoluene (2ADNT) 4-amino-2,6-dinitrotoulene (4ADNT), 2,4-dinitrotoluene (2,4DNT) and 2,6-dinitrotoluene (2,6DNT)] with necropsy and tissue collection at 24 or 48 h. Gene expression profile results correlated well with clinical data and liver histopathology that lead to the concept that hematotoxicity was followed by hepatotoxicity. Overall, 2,4DNT, 2,6DNT and TNT had stronger effects than 2ADNT and 4ADNT. Common functional terms, gene expression patterns, pathways and networks were regulated across all nitrotoluenes. These pathways included NRF2-mediated oxidative stress response, aryl hydrocarbon receptor signaling, LPS/IL-1 mediated inhibition of RXR function, xenobiotic metabolism signaling and metabolism of xenobiotics by cytochrome P450. One biological process common to all compounds, lipid metabolism, was found to be impacted both at the transcriptional and lipid production level. CONCLUSIONS/SIGNIFICANCE: A systems biology strategy was used to identify biochemical pathways affected by five nitroaromatic compounds and to integrate data that tie biochemical alterations to pathological changes. An integrative graphical network model was constructed by combining genomic, gene pathway, lipidomic, and physiological endpoint results to better understand mechanisms of liver toxicity and physiological endpoints affected by these compounds

Convergence in international business ethics? A comparative study of ethical philosophies, thinking style, and ethical decision-making between US and Korean managers

This study investigates the relationship among ethical philosophy, thinking style, and managerial ethical decision-making. Based on the premise that business ethics is a function of culture and time, we attempt to explore two important questions as to whether the national differences in managerial ethical philosophies remain over time and whether the relationship between thinking style and ethical decision-making is consistent across different national contexts. We conducted a survey on Korean managers’ ethical decision-making and thinking style and made a cross-cultural, cross-temporal comparison with the results presented by previous studies that surveyed Korean and US managers with the same questionnaire at different points in time. Our analysis revealed that Korean managers have become more reliant on rule utilitarianism for ethical decision-making over the last two decades, which is dominantly used by US managers, corroborating our convergence hypothesis built on social contracts theory. However, as opposed to previous research, we found that managers with a balanced linear and nonlinear thinking style do not necessarily make more ethical decisions compared to those with a predominantly linear or nonlinear thinking style. This study contributes to international business ethics literature by presenting a theoretical framework that may explain the convergence of ethical philosophies employed by managers in different national contexts over time, and that the relationship between thinking style and managerial ethical decision-making may not be universal, but contingent on contextual factors

Pelvic trauma : WSES classification and guidelines

Complex pelvic injuries are among the most dangerous and deadly trauma related lesions. Different classification systems exist, some are based on the mechanism of injury, some on anatomic patterns and some are focusing on the resulting instability requiring operative fixation. The optimal treatment strategy, however, should keep into consideration the hemodynamic status, the anatomic impairment of pelvic ring function and the associated injuries. The management of pelvic trauma patients aims definitively to restore the homeostasis and the normal physiopathology associated to the mechanical stability of the pelvic ring. Thus the management of pelvic trauma must be multidisciplinary and should be ultimately based on the physiology of the patient and the anatomy of the injury. This paper presents the World Society of Emergency Surgery (WSES) classification of pelvic trauma and the management Guidelines.Peer reviewe