Experiments in Learning Dyck-1 Languages with Recurrent Neural Networks

Considerable work, both theoretical and empirical, has shown that Recurrent Neural Network (RNN) architectures are capable of learning formal languages under specific conditions. In this study, we investigate the ability of linear and ReLU RNNs to learn Dyck-1 languages in whole sequence classification tasks. We observe that counting bracket sequences is learned but performance on full Dyck-1 recognition is poor. Models for both tasks do not generalise well to longer sequences. We determine correct weights for the given tasks with suitable architectures, but the standard setup for classification surprisingly departs from the correct values. We propose a regression setup with clipping that we find to stabilise correct weights, but it makes learning from random weight initialisation even less effective. Our observations suggest that Dyck-1 languages seem unlikely to be learned by ReLU RNNs for most practical applications

PHYSIOLOGICAL RESPONSE OF GAZANIA PLANTS TO GROWING MEDIA AND ORGANIC COMPOST

This work was carried out during two successive seasons of 2017 and 2018 at the Nursery, Department of Floriculture, Ornamental Horticulture and Landscape Gardening, Faculty of Agriculture, Alexandria University, Egypt to investigate the effect of different growing media (calcareous + sand + peat moss at the rate 70 and 40%) and two types of organic compost (rice straw and sugar beet at 30 and 60%) and their interaction on the growth and flowering of Gazania splendens plants. The experimental design in split-plot arrangement, with four replications, in both seasons. The growing media were laid out in the main plots and sub-plots included the different organic composts. Three pots were used as a plot for each treatment. The means of the individual factors and their interactions were compared by L.S.D. test at 5% level of probability. The obtained results can be summarized as follows;  most vegetative growth characteristics such as: number of tillers (54.74), number of leaves (239.76) and leaves fresh weight (100.29 g) were significantly affected by organic compost at 60% sugar beet with peat moss treatment, flowers characteristics (inflorescences diameter (9.34 cm) and number of inflorescences (14.87), and inflorescences dry weights (0.459 g), responded significantly to the interaction between the different media and organic compost, the highest significant values were obtained by organic compost at 30 and/ or 60% sugar beet and peat moss. Total chlorophyll (56.23 mg/g f.w.), nitrogen (3.42%), phosphorus (0.74%) in the leaves were the highest with 60% sugar beet and 40% peat moss in both seasons. However, potassium (2.85%) in the leaves gave the highest significant values by 60% sugar beet with calcareous soil (40%) for both seasons. It can be recommended that producing high quality of Gazania splendens plants for different decorative purposes in landscaping can be accomplished by growing plants in the mixture of peat moss (40%) with organic compost at rate 60% sugar beet led to improve its characteristics

Biogenic Control of Manganese Doping in Zinc Sulfide Nanomaterial Using Shewanella oneidensis MR-1

Bacteria naturally alter the redox state of many compounds and perform atom-by-atom nanomaterial synthesis to create many inorganic materials. Recent advancements in synthetic biology have spurred interest in using biological systems to manufacture nanomaterials, implementing biological strategies to specify the nanomaterial characteristics such as size, shape, and optical properties. Here, we combine the natural synthetic capabilities of microbes with engineered genetic control circuits toward biogenically synthesized semiconductor nanomaterials. Using an engineered strain of Shewanella oneindensis with inducible expression of the cytochrome complex MtrCAB, we control the reduction of manganese (IV) oxide. Cytochrome expression levels were regulated using an inducer molecule, which enabled precise modulation of dopant incorporation into manganese doped zinc sulfide nanoparticles (Mn:ZnS). Thereby, a synthetic gene circuit controlled the optical properties of biogenic quantum dots. These biogenically assembled nanomaterials have similar physical and optoelectronic properties to chemically synthesized particles. Our results demonstrate the promise of implementing synthetic gene circuits for tunable control of nanomaterials made by biological systems

Formal and Empirical Studies of Counting Behaviour in ReLU RNNs

In recent years, the discussion about systematicity of neural network learning has gained renewed interest, in particular the formal analysis of neural network behaviour. In this paper, we investigate the capability of single-cell ReLU RNN models to demonstrate precise counting behaviour. Formally, we start by characterising the semi-Dyck-1 language and semi-Dyck-1 counter machine that can be implemented by a single Rectified Linear Unit (ReLU) cell. We define three Counter Indicator Conditions (CICs) on the weights of a ReLU cell and show that fulfilling these conditions is equivalent to accepting the semi-Dyck-1 language, i.e. to perform exact counting. Empirically, we study the ability of single-cell ReLU RNNs to learn to count by training and testing them on different datasets of Dyck-1 and semi-Dyck-1 strings. While networks that satisfy the CICs count exactly and thus correctly even on very long strings, the trained networks exhibit a wide range of results and never satisfy the CICs exactly. We investigate the effect of deviating from the CICs and find that configurations that fulfil the CICs are not at a minimum of the loss function in the most common setups. This is consistent with observations in previous research indicating that training ReLU networks for counting tasks often leads to poor results. We finally discuss implications of these results and possible avenues for improving network behaviour

Mısırda’ki bakla arı tozlayıcıların bolluğu ve yiyecek arama faaliyetleri üzerine bazı insektisitlerin etkisi: Bir vaka çalışması

Insect pollinators provide many essential ecosystem services including pollination, and many others. However, pollinating insects are currently facing potential threats on an unprecedented scale with many species facing decline. Honeybee Apis mellifera comprise nearly 68% of those affected insect pollinators. Irrational Insecticides application, with special reference to neonicotinoides group is one of the main causes of this decline. The main objective of the current study is to investigate the impact of some insecticides application on the activity of broad bean flower-visiting bees. Tested inseticides were thiamethoxam, acetamiprid, thiacloprid (neonicotinoids), spinosyns A and D, beside some organophosphates. Changes in the daily activity of bees visiting broad bean flowers following insecticide application was recorded and compared to their activity before application, throughout until the end of blooming season.Böcek tozlayıcıları, tozlaşma ve diğerleri dahil olmak üzere birçok temel ekosistem hizmeti sağlar. Bununla birlikte, tozlaşan böcekler şu anda birçok türün düşüşle karşı karşıya kalmasıyla eşi görülmemiş bir ölçekte potansiyel tehditlerle karşı karşıya. Bal arısı Apis mellifera, etkilenen böcek tozlaştırıcılarının yaklaşık %68'ini oluşturur. Neonicotinoides grubuna özel atıfta bulunulan irrasyonel İnsektisit uygulaması bu düşüşün ana nedenlerinden biridir. Mevcut çalışmanın temel amacı, bazı insektisit uygulamalarının bakla çiçeğini ziyaret eden arıların aktivitesi üzerindeki etkisini araştırmaktır. Test edilen insektisitler, bazı organofosfatların yanında tiyametoksam, asetamiprid, tiakloprid (neonikotinoidler), spinosinler A ve D. Bakla çiçeklerini insektisit uygulaması sonrasında ziyaret eden arıların günlük aktivitelerinde meydana gelen değişimler kayıt altına alınmış ve çiçeklenme döneminin sonuna kadar uygulama öncesindeki aktiviteleri ile karşılaştırılmıştır

Unmasking the Ongoing Challenge of Equid Herpesvirus- 1 (EHV-1) : A Comprehensive Review

Equid herpesviruses (EHVs) are a group of highly impactful viral pathogens that affect horses, presenting a substantial risk to the global equine industry. Among these, equid herpesvirus-1 (EHV-1) primarily causes respiratory infections. However, its ability to spread to distant organs can lead to severe consequences such as abortion and neurological diseases. These viruses can enter a dormant phase, with minimal activity, and later reactivate to trigger active infections at any time. Recently, there has been a notable rise in the prevalence of a particularly devastating strains of EHV-1 known as equid herpesviral myeloencephalopathy (EHM). In the light of dynamic nature of EHV-1, this review provides a thorough overview of EHV-1 and explores how advances in viral biology affect the pathophysiology of viral infection. The information presented here is crucial for understanding the dynamics of EHV-1 infections and creating practical plans to stop the virus's global spread among equid populations

Neocentric X-chromosome in a girl with Turner-like syndrome

Abstract Background Neocentromeres are rare human chromosomal aberrations in which a new centromere has formed in a previously non-centromeric location. We report the finding of a structurally abnormal X chromosome with a neocentromere in a 15-year-old girl with clinical features suggestive of Turner syndrome, including short stature and primary amenorrhea. Result G-banded chromosome analysis revealed a mosaic female karyotype involving two abnormal cell lines. One cell line (84% of analyzed metaphases) had a structurally abnormal X chromosome (duplication of the long arm and deletion of the short arm) and a normal X chromosome. The other cell line (16% of cells) exhibited monosomy X. C-banding studies were negative for the abnormal X chromosome. FISH analysis revealed lack of hybridization of the abnormal X chromosome with both the X centromere-specific probe and the “all human centromeres” probe, a pattern consistent with lack of the X chromosome endogenous centromere. A FISH study using an XIST gene probe revealed the presence of two XIST genes, one on each long arm of the iso(Xq), required for inactivation of the abnormal X chromosome. R-banding also demonstrated inactivation of the abnormal X chromosome. An assay for centromeric protein C (CENP-C) was positive on both the normal and the abnormal X chromosomes. The position of CENP-C in the abnormal X chromosome defined a neocentromere, which explains its mitotic stability. The karyotype is thus designated as 46,X,neo(X)(qter- > q12::q12- > q21.2- > neo- > q21.2- > qter)[42]/45,X[8], which is consistent with stigmata of Turner syndrome. The mother of this patient has a normal karyotype; however, the father was not available for study. Conclusion To our knowledge, this is the first case of mosaic Turner syndrome involving an analphoid iso(Xq) chromosome with a proven neocentromere among 90 previously described cases with a proven neocentromere.</p

Spectral Karyotyping for identification of constitutional chromosomal abnormalities at a national reference laboratory

Spectral karyotyping is a diagnostic tool that allows visualization of chromosomes in different colors using the FISH technology and a spectral imaging system. To assess the value of spectral karyotyping analysis for identifying constitutional supernumerary marker chromosomes or derivative chromosomes at a national reference laboratory, we reviewed the results of 179 consecutive clinical samples (31 prenatal and 148 postnatal) submitted for spectral karyotyping. Over 90% of the cases were requested to identify either small supernumerary marker chromosomes (sSMCs) or chromosomal exchange material detected by G-banded chromosome analysis. We also reviewed clinical indications of those cases with marker chromosomes in which chromosomal origin was identified by spectral karyotyping. Our results showed that spectral karyotyping identified the chromosomal origin of marker chromosomes or the source of derivative chromosomal material in 158 (88%) of the 179 clinical cases; the identification rate was slightly higher for postnatal (89%) compared to prenatal (84%) cases. Cases in which the origin could not be identified had either a small marker chromosome present at a very low level of mosaicism (< 10%), or contained very little euchromatic material. Supplemental FISH analysis confirmed the spectral karyotyping results in all 158 cases. Clinical indications for prenatal cases were mainly for marker identification after amniocentesis. For postnatal cases, the primary indications were developmental delay and multiple congenital anomalies (MCA). The most frequently encountered markers were of chromosome 15 origin for satellited chromosomes, and chromosomes 2 and 16 for non-satellited chromosomes. We were able to obtain pertinent clinical information for 47% (41/88) of cases with an identified abnormal chromosome. We conclude that spectral karyotyping is sufficiently reliable for use and provides a valuable diagnostic tool for establishing the origin of supernumerary marker chromosomes or derivative chromosomal material that cannot be identified with standard cytogenetic techniques