Ensemble learning of linear perceptron; Online learning theory

Within the framework of on-line learning, we study the generalization error of an ensemble learning machine learning from a linear teacher perceptron. The generalization error achieved by an ensemble of linear perceptrons having homogeneous or inhomogeneous initial weight vectors is precisely calculated at the thermodynamic limit of a large number of input elements and shows rich behavior. Our main findings are as follows. For learning with homogeneous initial weight vectors, the generalization error using an infinite number of linear student perceptrons is equal to only half that of a single linear perceptron, and converges with that of the infinite case with O(1/K) for a finite number of K linear perceptrons. For learning with inhomogeneous initial weight vectors, it is advantageous to use an approach of weighted averaging over the output of the linear perceptrons, and we show the conditions under which the optimal weights are constant during the learning process. The optimal weights depend on only correlation of the initial weight vectors.Comment: 14 pages, 3 figures, submitted to Physical Review

Optimization of the Asymptotic Property of Mutual Learning Involving an Integration Mechanism of Ensemble Learning

We propose an optimization method of mutual learning which converges into the identical state of optimum ensemble learning within the framework of on-line learning, and have analyzed its asymptotic property through the statistical mechanics method.The proposed model consists of two learning steps: two students independently learn from a teacher, and then the students learn from each other through the mutual learning. In mutual learning, students learn from each other and the generalization error is improved even if the teacher has not taken part in the mutual learning. However, in the case of different initial overlaps(direction cosine) between teacher and students, a student with a larger initial overlap tends to have a larger generalization error than that of before the mutual learning. To overcome this problem, our proposed optimization method of mutual learning optimizes the step sizes of two students to minimize the asymptotic property of the generalization error. Consequently, the optimized mutual learning converges to a generalization error identical to that of the optimal ensemble learning. In addition, we show the relationship between the optimum step size of the mutual learning and the integration mechanism of the ensemble learning.Comment: 13 pages, 3 figures, submitted to Journal of Physical Society of Japa

The Role of Attachment in Language Brokering and Psychological Well-being among College Students

Emerging adult (EA), college students from immigrant families continue engaging in language brokering (LB), translating documents and other media for their parents, in ways that can affect their well-being. For these language brokers, the relationship between parental attachment and psychological well-being may be through frequency and perceptions of their LB work. In this study, 459 language brokers (Mage = 21.36, Female = 80%) completed an online questionnaire about frequency and perceptions of LB, attachment, and psychological well-being. Attachment anxiety and avoidance had negative indirect effects on anxiety and somatic symptoms through feelings of LB burden. Attachment anxiety had a negative indirect effect on somatic symptoms through LB intrusiveness. There were negative indirect effects of LB burden on attachment avoidance to anxiety and somatic symptoms. There was a negative indirect effect of LB intrusiveness on attachment avoidance to somatic symptoms. Findings indicate that perceptions of LB may relate to psychological well-being when attachment is insecure

Micorrización de plantulas en contendor de Pinus nigra con Suillus granulates bajo condiciones de campo

Seedling mycorrhization acts as an efficient tool for improving the quality of seedlings. In this study, the effectiveness of Suillus granulatus, originating from Pinus heldreichii forests (Montenegro), to produce containerized ectomycorrhizal seedlings of autochthonous Pinus nigra in open field conditions was investigated. Spore (106, 107, 108) and vegetative (1:16, 1:8, 1:4) inoculation on ectomycorrhizal formation and seedling growth were tested. Spore and vegetative inoculums of autochthonous Pisolithus arhizus were used in the same trial as additional control treatments. The utilization of vegetative and spore inoculums of autochthonous S. granulatus has proven to be an effective method of obtaining containerized ectomycorrhizal P. nigra seedlings under open field conditions after 11 months. S. granulatus spore inoculations resulted in well developed ectomycorrhiza, decreasing the growth of the P. nigra seedlings in the first growing season. Mycelial inoculations resulted in slightly developed S. granulatus ectomycorrhiza, which increased the growth of the seedlings. Therefore, it would be feasible to use spore inocula of S. granulatus, with 106 spores per plant, to produce ectomycorrhizal P. nigra plants on a large scale. Controlled mycorrhizal inoculation of seedlings is not a common practice in Montenegrin and Serbian nurseries; as such, the obtained results will contribute to the enhancement of nursery production of Pinus nigra and other conifers. This also could be assumed as a starting point for many further efforts and investigations with autochthonous fungal and plant material in this region.La micorrización de plántulas actúa como una herramienta eficaz para la mejora de la calidad de los brinzales. En este estudio se investiga la eficacia de Suillus granulatus, procedentes de bosques de Pinus heldreichii (Montenegro), para producir plántulas ectomicorrícicas en contenedores de Pinus nigra autóctonos en condiciones de campo. Se ensayaron inoculacion por esporas (106, 107, 108) y vegetativa (1:16, 1:8, 1:4) para la formación ectomicorrízica y el crecimiento de las plántulas. Se utilizó inóculo de esporas y vegetativo de Pisolithus arhizus autóctonos en el mismo ensayo como tratamiento control. La utilización de inóculos vegetativos y esporas de S. granulatus autóctonos ha demostrado ser un método eficaz para la obtención de plantas en contenedor ectomicorrícicas de P. nigra bajo condiciones de campo después de 11 meses. La inoculación de esporas de S. granulatus produjeron un buen desarrollo ectomicorrizas, disminuyendo el crecimiento de las plántulas de P. nigra en la primera estación de crecimiento. Las inoculaciones miceliales produjeron un escaso desarrollo ectomicorrizico de S. granulatus, con aumento en el crecimiento de las plántulas. Por lo tanto, sería factible el uso de inóculos de esporas de S. granulatus, con 106 esporas por planta, para producir plantas ectomicorrícicas de P. nigra a gran escala. La inoculación micorrízica controlada de plántulas no es una práctica común en los viveros de Serbia y Montenegro y, como tal, los resultados obtenidos contribuirán a la mejora de la producción en viveros de Pinus nigra y otras coníferas. Esto también podría ser asumido como un punto de partida para futuras investigaciones con material autóctono de hongos y plantas en esta región

The Role of Effective Leadership in Doing More With Less in Public Universities

Public universities in most developed countries are facing increasing pressure to "do more with less". Many have invariably come to terms with reality by repeatedly restructuring and downsizing to stay lean and survive. Effective leadership to see through drastic organizational changes is a must, whilst resistance to change is also one thing management needs to face squarely in the course of change. This paper offers some provocative thoughts to university management in gaining synergistic effect by the dual priming of Transformational Leadership and an Employee-Centred Resistance to Change Perspective to afford the "doing more with less"

Long-term, multiwavelength light curves of ultra-cool dwarfs: I. An interplay of starspots & clouds likely drive the variability of the L3. 5 dwarf 2MASS 0036+ 18

We present multi-telescope, ground-based, multiwavelength optical and near-infrared photometry of the variable L3.5 ultra-cool dwarf 2MASSW J0036159+182110. We present 22 nights of photometry of 2MASSW J0036159+182110, including 7 nights of simultaneous, multiwavelength photometry, spread over ∼120 days allowing us to determine the rotation period of this ultra-cool dwarf to be 3.080 ± 0.001 hr. Our many nights of multiwavelength photometry allow us to observe the evolution, or more specifically the lack thereof, of the light curve over a great many rotation periods. The lack of discernible phase shifts in our multiwavelength photometry, and that the amplitude of variability generally decreases as one moves to longer wavelengths for 2MASSW J0036159+182110, is generally consistent with starspots driving the variability on this ultra-cool dwarf, with starspots that are ∼100 degrees K hotter or cooler than the ∼1700 K photosphere. Also, reasonably thick clouds are required to fit the spectra of 2MASSW J0036159+182110, suggesting there likely exists some complex interplay between the starspots driving the variability of this ultra-cool dwarf and the clouds that appear to envelope this ultra-cool dwarf.https://arxiv.org/pdf/1609.03586.pdfFirst author draf

Oral and intestinal dysbiosis in Parkinson's disease.

The suspicion of an origin of Parkinson's disease (PD) at the periphery of the body and the involvement of environmental risk factors in the pathogenesis of PD have directed the attention of the scientific community towards the microbiota. The microbiota represents all the microorganisms residing both in and on a host. It plays an essential role in the physiological functioning of the host. In this article, we review the dysbiosis repeatedly demonstrated in PD and how it influences PD symptoms. Dysbiosis is associated with both motor and non-motor PD symptoms. In animal models, dysbiosis only promotes symptoms in individuals genetically susceptible to Parkinson's disease, suggesting that dysbiosis is a risk factor but not a cause of Parkinson's disease. We also review how dysbiosis contributes to the pathophysiology of PD. Dysbiosis induces numerous and complex metabolic changes, resulting in increased intestinal permeability, local and systemic inflammation, production of bacterial amyloid proteins that promote α-synuclein aggregation, as well as a decrease in short-chain fatty acid-producing bacteria that have anti-inflammatory and neuroprotective potential. In addition, we review how dysbiosis decreases the efficacy of dopaminergic treatments. We then discuss the interest of dysbiosis analysis as a biomarker of Parkinson's disease. Finally, we give an overview of how interventions modulating the gut microbiota such as dietary interventions, pro-biotics, intestinal decontamination and fecal microbiota transplantation could influence the course of PD

HMGA1 promotes breast cancer angiogenesis supporting the stability, nuclear localization and transcriptional activity of FOXM1

Background Breast cancer is the most common malignancy in women worldwide. Among the breast cancer subtypes, triple-negative breast cancer (TNBC) is the most aggressive and the most difficult to treat. One of the master regulators in TNBC progression is the architectural transcription factor HMGA1. This study aimed to further explore the HMGA1 molecular network to identify molecular mechanisms involved in TNBC progression. Methods RNA from the MDA-MB-231 cell line, silenced for HMGA1 expression, was sequenced and, with a bioinformatic analysis, molecular partners HMGA1 could cooperate with in regulating common downstream gene networks were identified. Among the putative partners, the FOXM1 transcription factor was selected. The relationship occurring between HMGA1 and FOXM1 was explored by qRT-PCR, co-immunoprecipitation and protein stability assays. Subsequently, the transcriptional activity of HMGA1 and FOXM1 was analysed by luciferase assay on the VEGFA promoter. The impact on angiogenesis was assessed in vitro, evaluating the tube formation ability of endothelial cells exposed to the conditioned medium of MDA-MB-231 cells silenced for HMGA1 and FOXM1 and in vivo injecting MDA-MB-231 cells, silenced for the two factors, in zebrafish larvae. Results Here, we discover FOXM1 as a novel molecular partner of HMGA1 in regulating a gene network implicated in several breast cancer hallmarks. HMGA1 forms a complex with FOXM1 and stabilizes it in the nucleus, increasing its transcriptional activity on common target genes, among them, VEGFA, the main inducer of angiogenesis. Furthermore, we demonstrate that HMGA1 and FOXM1 synergistically drive breast cancer cells to promote tumor angiogenesis both in vitro in endothelial cells and in vivo in a zebrafish xenograft model. Moreover, using a dataset of breast cancer patients we show that the co-expression of HMGA1, FOXM1 and VEGFA is a negative prognostic factor of distant metastasis-free survival and relapse-free survival. Conclusions This study reveals FOXM1 as a crucial interactor of HMGA1 and proves that their cooperative action supports breast cancer aggressiveness, by promoting tumor angiogenesis. Therefore, the possibility to target HMGA1/FOXM1 in combination should represent an attractive therapeutic option to counteract breast cancer angiogenesis