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In this paper, we address the problem of predicting the time to share (real or fake) news items on online social media. Specifically, given the scenario where a user uis influenced on some given (real or fake) news item nby at least one of the people they follow v, we predict when the user uwill re-share the news item namong their followers. We model the problem as a survival analysis task, which is a statistical analysis method aimed at predicting the time to event (the re-sharing event in our case). Survival analysis differs from other methods such as regression in that it also considers the data where the event (sharing) never occurs (censored data) in the considered time window. We considered Twitter data containing information on real and fake news shares to test our proposed survival analysis approach and modeled different aspects of the problem including user, news, and network characteristics. We show the superiority of survival analysis as compared to regression to model this problem in both the cases of real and fake news sharing.

The goal of all medical treatments is a better quality of life for patients. Post-stroke rehabilitation is a long process with uncertain result. The aim of this study was to explore the factors which affect the quality of life of patients recovering from a cerebrovascular disease. This is a prospective study evaluating the quality of life of one hundred patients one month and six months after a stroke, and patients also answered questions retrospectively, of how they felt before the stroke. As assessment tools we used a questionnaire on general and clinical data and Medical Outcomes Study Short Form (SF-36) questionnaire. Physical functioning and Physical role domains of SF-36 show significant differences in both measured periods (p<0.001). Emotional role, Social functioning, Mental health, Vitality and General health domains show a statistically significant change during first six months, while Bodily pain domain did not change (p>0.05). Physical summary score has changed significantly during 6 months (p <0.001). Mental summary score showed no significant difference in both periods (p <0.687; p <0.958). The brain localization is important factor (p<0.0002). Gender, age, education, employment status and previous strokes did not have a statistically significant influence (p> 0.05). Post-stroke physical impairment is not always accompanied by emotional impairment. Emotional functioning impairments generally return to the premorbid level during the period of six months, while physical impairments continue to occur. Further research is needed for better understanding of these relationships.

Shared psychotic disorder characterized by Capgras syndrome is an extremely rare condition. To our knowledge, there are only a few published papers on this condition. This paper presents a case of shared Capgras syndrome in two sisters. The inducer was a younger sister with schizophrenia, who passed on her Capgras delusion to her older sister after the death of their father. After committing a violent offense caused by Capgras delusion, a court ordered the sisters’ involuntary admission to a psychiatric hospital. After being separated and receiving antipsychotic treatment, the sisters showed substantial improvement. However, shortly after hospital discharge, they stopped taking their medication and disappeared. After 15 years, their mother died and shortly afterwards, the sisters were re-admitted for forensic psychiatric evaluation after another violent crime caused by Capgras delusion. Timely recognition, adequate treatment and maintaining a therapeutic alliance could contribute to a better clinical course and outcome of this disorder, and reduce the risk of violent behavior.

High-throughput methods to detect and quantify antibodies in sera and other patient specimens have use for many clinical and laboratory studies, including those associated with cancer detection, microbial exposures, and autoimmune diseases. We developed a new technique, termed layered peptide array (LPA), to serve as a screening tool to detect antibodies in a highly multiplexed format. We demonstrate here that a prototype LPA was capable of producing approximately 5000 measurements per experiment and appeared to be scalable to higher throughput levels. Sera and saliva from Sjögren's syndrome patients served as a test set to examine antibody titers in clinical samples. The LPA platform exhibited both a high sensitivity (100%) and high specificity (94%) for correctly identifying SSB antigen-positive samples. The multiplex capability of the platform was also confirmed when serum and saliva samples were analyzed for antibody reactivity to several peptides, including Sjögren's syndrome antigens A and B. The data indicate that LPA analysis will be a useful method for a number of screening applications.

The molecular profiles of protein expression from hundreds of cell lysates can be determined in a high-throughput manner by using fluorescent bead technologies, enzyme-linked immunosorbent assays (ELISAs), and protein microarrays. Although powerful, these tools are costly and technically challenging and thus have limited accessibility for many research groups. We propose a modification of traditional dot blotting that increases throughput of this approach and provides a simple and cost-effective technique for profiling multiple samples. In contrast to traditional blotting that uses a single membrane, we introduce blotting onto a stack of novel, thin, sieve-like membranes. These membranes have a high affinity for binding proteins, but have a lower capacity of protein binding compared to traditional (nitrocellulose) membranes. We compare the linear binding capacity and variability of these novel membranes with nitrocellulose membranes. Also, we describe the use of these membranes in a multilayer dot blot format for profiling mitogen-mediated signal transduction pathways in T cells.

A large body of evidence from several systems indicates that formation of the vertebrate tail is morphogenetically continuous with gastrulation, including neural inducing activity in descendants of the gastrula organizer. However, the signaling centers and molecular events regulating tail mesoderm induction and its organized elongation remain poorly defined. In mammals, the ventral ectoderm ridge (VER) is essential to maintain ongoing formation of paraxial mesoderm and somitogenesis in cultures of intact tail. Avian tail buds contain a similar VER structure. Here, we report that the chick ventral tail bud operates as a signaling center for paraxial mesoderm induction. By using “organizer” style grafting assays to early host embryos, we found that ventral tail bud was able to induce elongated paraxial mesodermal extensions and that the ventral tail bud mesenchyme underlying the VER is both necessary and sufficient for the induction in this assay system. Our observations combined with those of others suggest that interplay between several different signaling centers in the amniote tail bud regulates the coordinate induction and elongation of axial and paraxial structures in the developing tail. Developmental Dynamics 229:600–606, 2004. Published 2004 Wiley-Liss, Inc. © 2004 Wiley-Liss, Inc.

Northern blots and immunoblots are utilized in laboratories worldwide and offer several important features for analyzing mRNA and protein expression, including accuracy, low cost, evaluation of probe specificity, and information on transcript and protein forms based on molecular size. However, standard blotting techniques are hampered by three factors. They require a significant amount of input material, are laborious, and are capable of measuring only one protein or transcript at a time. Here we describe a simple yet effective technique for the multiplex analysis of standard RNA and protein gels using the layered expression scanning platform. The method relies on a novel membrane with high-affinity low-capacity binding characteristics. Using this approach, multiple blots from an RNA or protein electrophoresis gel can be simultaneously produced. We believe this method will be widely applicable to expression studies for a broad range of biological systems.

During limb development, several signaling centers organize limb pattern. One of these, the apical ectodermal ridge (AER), is critical for proximodistal limb outgrowth mediated by FGFs. Signals from the underlying mesoderm,including WNTs and FGFs, regulate early steps of AER induction. Ectodermal factors, particularly En1, play a critical role in regulating morphogenesis of a mature, compact AER along the distal limb apex, from a broad ventral ectodermal precursor domain. Contribution of mesodermal factors to the morphogenesis of a mature AER is less clear. We previously noted that the chick T gene (Brachyury), the prototypical T-box transcription factor, is expressed in the limb bud as well as axial mesoderm and primitive streak. Here we show that T is expressed in lateral plate mesoderm at the onset of limb bud formation and subsequently in the subridge mesoderm beneath the AER. Retroviral misexpression of T in chick results in anterior extension of the AER and subsequent limb phenotypes consistent with augmented AER extent and function. Analysis of markers for functional AER in mouse T-/- null mutant limb buds reveals disrupted AER morphogenesis. Our data also suggest that FGF and WNT signals may operate both upstream and downstream of T. Taken together, the results show that T plays a role in the regulation of AER formation,particularly maturation, and suggest that T may also be a component of the epithelialmesenchymal regulatory loop involved in maintenance of a mature functioning AER.

The analysis of multiple null mutants generated through targeted disruption indicates that the 5' members of the Hoxd and Hoxa clusters determine the skeletal pattern in the limb by regulating the formation and growth of the different chondrogenic precursors for the skeletal elements. While these studies have established that together these genes are the major players in regulating formation of the limb skeleton, the roles of individual members have often been difficult to evaluate fully due to extensive functional overlap between various 5'Hoxd and 5'Hoxa genes. The analysis of gain-of-function mutants provides a complementary approach to elucidate gene function in the presence of multiple redundancies. This approach has recently revealed that Hoxd-12 can induce Sonic hedgehog and suggests a new role for certain 5'Hoxd genes in the initiation of Sonic hedgehog expression and its maintenance through feedback regulation. Thus, some 5'Hoxd genes may be a part of the regulatory network that positions and reinforces polarizing signals in the posterior-distal limb bud.

Gnot1, a Not (for notochord) family homeobox gene, is expressed in the chick pregastrulation blastoderm. Gnot1expression in the epiblast is upregulated as the posteriorly derived hypoblast moves forward anteriorly to form a layer beneath it, which is of particular interest considering the known inductive role of the hypoblast in axis formation in the chick. Both activin and retinoic acid are able to activate Gnot1expression in cultured blastodermal cells and show a strong synergistic effect when applied in combination. Strong superinduction of Gnot1transcripts in the presence of cycloheximide also indicates the presence of a potent and labile intracellular inhibitor capable of modulating Gnot1expression. During gastrulation, Gnot1transcripts become localized specifically to tissues associated with "organizer" function (Hensen's node, head process, notochord). The expression data and the response to mesoderm inducing factors and axial "caudalizing" signals suggest that Gnot1may be involved in specification of the embryonic body axis and could play a part in regulating features of the trunk/tail organizer in the chick embryo.

Development of the posterior body (lumbosacral region and tail) in vertebrates is delayed relative to gastrulation. In amniotes, it proceeds with the replacement of the regressed node and primitive streak by a caudal blastemalike mass of mesenchyme known as the tail bud. Despite apparent morphological dissimilarities, recent results suggest that tail development in amniotes is in essence a continuation of gastrulation, as is the case in Xenopus. However, this has been inferred primarily from the outcome of fate mapping studies demonstrating discrete, regionalized cell populations in the tail bud, like those present at gastrulation. Our analysis of the tail bud distribution of several molecular markers that are expressed in specific spatial domains during chick gastrulation confirms these results. Furthermore, we present evidence that gastrulation-like ingression movements from the surface continue in the early chick tail bud and that the established tail bud retains organizer activity. This ‘tail organizer’ has the expected properties of being able to recruit uncommitted host cells into a new embryonic axis and induce host neural tissue with posteriorly regionalized gene expression when grafted to competent host cells that are otherwise destined to form only extra-embryonic tissue. Together, these results indicate that chick tail development is mechanistically continuous with gastrulation and that the developing tail in chick may serve as a useful experimental adjunct to investigate the molecular basis of inductive interactions operating during gastrulation, considering that residual tail organizing activity is still present at a surprisingly late stage.

Several 5′ members of the Hoxd cluster are expressed in nested posterior-distal domains of the limb bud suggesting a role in regulating anteroposterior pattern of skeletal elements. While loss-of-function mutants have demonstrated a regulatory role for these genes in the developing limb, extensive functional overlaps between various different Hox genes has hampered elucidation of the roles played by individual members. In particular, the function of Hoxd-12 in the limb remains obscure. Using a gain-offunction approach, we find that Hoxd-12 misexpression in transgenic mice produces apparent transformations of anterior digits to posterior morphology and digit duplications, while associated tibial hemimelia and other changes indicate that formation/growth of certain skeletal elements is selectively inhibited. If the digital arch represents an anterior bending of the main limb axis, then the results are all reconcilable with a model in which Hoxd-12 promotes formation of postaxial chondrogenic condensations branching from this main axis (including the anteriormost digit) and selectively antagonizes formation of ‘true’ preaxial condensations that branch from this main axis (such as the tibia). Hoxd-12 misexpression can also induce ectopic Sonic hedgehog (Shh) expression, resulting in mirror-image polydactyly in the limb. Misexpression of Hoxd-12 in other lateral plate derivatives (sternum, pelvis) likewise phenocopies several luxoid/luxate class mouse mutants that all share ectopic Shh signalling. This suggests that feedback activation of Shh expression may be a major function of Hoxd-12. Hoxd-12 can bind to and transactivate the Shh promoter in vitro. Furthermore, expression of either exogenous Hoxd-11 or Hoxd-12 in cultured limb bud cells, together with FGF, induces expression of the endogenous Shh gene. Together these results suggest that certain 5′ Hoxd genes directly amplify the posterior Shh polarizing signal in a reinforcing positive feedback loop during limb bud outgrowth.

The mouse Brachyury (T) gene plays critical roles in the genesis of normal mesoderm during gastrulation and in the maintenance of a functioning notochord. Abrogation of Brachyury (T) expression within the chordamesoderm of homozygous null mutants nevertheless spares anterior axis formation. An intriguing possibility to explain the preservation of anterior axis formation in these mutants would be the existence of other genes compensating for the loss of Brachyury. This compensation and the recent demonstration that Brachyury is the prototype for an evolutionarily conserved family, prompted a search for other T-box genes participating in axis formation. The chick Brachyury orthologue and two related chick T-box genes that are expressed at the onset of gastrulation have been isolated. One of these novel genes (Ch-TbxT) becomes restricted to the axial mesoderm lineage and is a potential candidate for complementing or extending Brachyury function in the anterior axis (formation of the head process, prechordal plate). The other gene (Ch-Tbx6L), together with chick T, appears to mark primitive streak progenitors before gastrulation. As cells leave the primitive streak, Ch-Tbx6L becomes restricted to the early paraxial mesoderm lineage and could play a role in regulating somitogenesis.