The lack of the influence of various species of Mycoplasma spp. on canine semen quality

Mycoplasmas colonize fish, reptiles, birds and mammals, being commensals or causing diseases, sometimes severe in ruminants, swine, poultry, or wildlife animals. So far, 15 species of canine Mycoplasma spp. have been described. Conflicting results have been presented regarding the pathogenicity of Mycoplasma spp. Although many virulence factors of these bacteria have been described, they still require attention. The main aim of our study was to evaluate the presence of known canine Mycoplasmas in the male reproductive tract of clinically healthy dogs. The second aim was to check if Mycoplasma spp. cause any abnormalities in semen quality that could have further consequences and to propose the schemes for managing the carriers. 83.3% of examined dogs were Mycoplasma spp. -positive dogs, and most of them were the carriers of more than one species. Six dogs had azoospermic ejaculates. The total spermatozoa numbers were similar in Mycoplasma -positive and negative groups. Motility was slightly higher in Mycoplasma spp.-negative group, but the difference was not statistically significant. There was no significant difference in semen characteristics between the carriers and Mycoplasma spp.-negative dogs. Neither the individual species nor the number of species strains had a significant effect on sperm morphological parameters as well as viability. Semen quality parameters are not correlated with the species found on the prepuce. Over 70% Mycoplasma spp.- positive dogs have more than one species of this bacteria. Despite finding mycoplasmas in azoospermic dogs, we suggest that they were not the cause of infertility. Mycoplasma spp. could be a part of normal microbiota in canine prepuce in individuals without any clinical signs.

Dystrophin- and Utrophin-Based Therapeutic Approaches for Treatment of Duchenne Muscular Dystrophy: A Comparative Review

Duchenne muscular dystrophy is a devastating disease that leads to progressive muscle loss and premature death. While medical management focuses mostly on symptomatic treatment, decades of research have resulted in first therapeutics able to restore the affected reading frame of dystrophin transcripts or induce synthesis of a truncated dystrophin protein from a vector, with other strategies based on gene therapy and cell signaling in preclinical or clinical development. Nevertheless, recent reports show that potentially therapeutic dystrophins can be immunogenic in patients. This raises the question of whether a dystrophin paralog, utrophin, could be a more suitable therapeutic protein. Here, we compare dystrophin and utrophin amino acid sequences and structures, combining published data with our extended in silico analyses. We then discuss these results in the context of therapeutic approaches for Duchenne muscular dystrophy. Specifically, we focus on strategies based on delivery of micro-dystrophin and micro-utrophin genes with recombinant adeno-associated viral vectors, exon skipping of the mutated dystrophin pre-mRNAs, reading through termination codons with small molecules that mask premature stop codons, dystrophin gene repair by clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 (CRISPR/Cas9)-mediated genetic engineering, and increasing utrophin levels. Our analyses highlight the importance of various dystrophin and utrophin domains in Duchenne muscular dystrophy treatment, providing insights into designing novel therapeutic compounds with improved efficacy and decreased immunoreactivity. While the necessary actin and β-dystroglycan binding sites are present in both proteins, important functional distinctions can be identified in these domains and some other parts of truncated dystrophins might need redesigning due to their potentially immunogenic qualities. Alternatively, therapies based on utrophins might provide a safer and more effective approach.

Cyclic mismatch binding ligands interact with disease-associated CGG trinucleotide repeats in RNA and suppress their translation

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder caused by a limited expansion of CGG repeats in the FMR1 gene. Degeneration of neurons in FXTAS cell models can be triggered by accumulation of polyglycine protein (FMRpolyG), a by-product of translation initiated upstream to the repeats. Specific aims of our work included testing if naphthyridine-based molecules could (i) block FMRpolyG synthesis by binding to CGG repeats in RNA, (ii) reverse pathological alterations in affected cells and (iii) preserve the content of FMRP, translated from the same FMR1 mRNA. We demonstrate that cyclic mismatch binding ligand CMBL4c binds to RNA structure formed by CGG repeats and attenuates translation of FMRpolyG and formation of nuclear inclusions in cells transfected with vectors expressing RNA with expanded CGG repeats. Moreover, our results indicate that CMBL4c delivery can reduce FMRpolyG-mediated cytotoxicity and apoptosis. Importantly, its therapeutic potential is also observed once the inclusions are already formed. We also show that CMBL4c-driven FMRpolyG loss is accompanied by partial FMRP reduction. As complete loss of FMRP induces FXS in children, future experiments should aim at evaluation of CMBL4c therapeutic intervention in differentiated tissues, in which FMRpolyG translation inhibition might outweigh adverse effects related to FMRP depletion.

Therapeutic aspects of cell signaling and communication in Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a devastating chromosome X-linked disease that manifests predominantly in progressive skeletal muscle wasting and dysfunctions in the heart and diaphragm. Approximately 1/5000 boys and 1/50,000,000 girls suffer from DMD, and to date, the disease is incurable and leads to premature death. This phenotypic severity is due to mutations in the DMD gene, which result in the absence of functional dystrophin protein. Initially, dystrophin was thought to be a force transducer; however, it is now considered an essential component of the dystrophin-associated protein complex (DAPC), viewed as a multicomponent mechanical scaffold and a signal transduction hub. Modulating signal pathway activation or gene expression through epigenetic modifications has emerged at the forefront of therapeutic approaches as either an adjunct or stand-alone strategy. In this review, we propose a broader perspective by considering DMD to be a disease that affects myofibers and muscle stem (satellite) cells, as well as a disorder in which abrogated communication between different cell types occurs. We believe that by taking this systemic view, we can achieve safe and holistic treatments that can restore correct signal transmission and gene expression in diseased DMD tissues.

Epigenetic modifications in muscle regeneration and progression of Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is a multisystemic disorder that affects 1:5000 boys. The severity of the phenotype varies dependent on the mutation site in the DMD gene and the resultant dystrophin expression profile. In skeletal muscle, dystrophin loss is associated with the disintegration of myofibers and their ineffective regeneration due to defective expansion and differentiation of the muscle stem cell pool. Some of these phenotypic alterations stem from the dystrophin absence-mediated serine-threonine protein kinase 2 (MARK2) misplacement/downregulation in activated muscle stem (satellite) cells and neuronal nitric oxide synthase loss in cells committed to myogenesis. Here, we trace changes in DNA methylation, histone modifications, and expression of regulatory noncoding RNAs during muscle regeneration, from the stage of satellite cells to myofibers. Furthermore, we describe the abrogation of these epigenetic regulatory processes due to changes in signal transduction in DMD and point to therapeutic treatments increasing the regenerative potential of diseased muscles based on this acquired knowledge.

AON-induced splice-switching and DMPK pre-mRNA degradation as potential therapeutic approaches for Myotonic Dystrophy type 1

Expansion of an unstable CTG repeat in the 3′UTR of the DMPK gene causes Myotonic Dystrophy type 1 (DM1). CUG-expanded DMPK transcripts (CUG^exp) sequester Muscleblind-like (MBNL) alternative splicing regulators in ribonuclear inclusions (foci), leading to abnormalities in RNA processing and splicing. To alleviate the burden of CUG^exp, we tested therapeutic approach utilizing antisense oligonucleotides (AONs)-mediated DMPK splice-switching and degradation of mutated pre-mRNA. Experimental design involved: (i) skipping of selected constitutive exons to induce frameshifting and decay of toxic mRNAs by an RNA surveillance mechanism, and (ii) exclusion of the alternative exon 15 (e15) carrying CUG^exp from DMPK mRNA. While first strategy failed to stimulate DMPK mRNA decay, exclusion of e15 enhanced DMPK nuclear export but triggered accumulation of potentially harmful spliced out pre-mRNA fragment containing CUG^exp. Neutralization of this fragment with antisense gapmers complementary to intronic sequences preceding e15 failed to diminish DM1-specific spliceopathy due to AONs’ chemistry-related toxicity. However, intronic gapmers alone reduced the level of DMPK mRNA and mitigated DM1-related cellular phenotypes including spliceopathy and nuclear foci. Thus, a combination of the correct chemistry and experimental approach should be carefully considered to design a safe AON-based therapeutic strategy for DM1.

Recent advances in the role of AMP-activated protein kinase in metabolic reprogramming of metastatic cancer cells: targeting cellular bioenergetics and biosynthetic pathways for anti-tumor treatment

Growing data indicate that tumor progression and metastasis is dependent on the reprograming of cellular metabolism. Rapidly growing cancer cells undergo metabolic stress in a harsh microenvironment. AMP-activated protein kinase (AMPK) is an energy sensing factor that regulates bioenergetics and biosynthetic pathways within the cell, but its role under metastasis is in dispute. The best studied phenotype of cancer cells is aerobic glycolysis (the Warburg effect), an increased catabolism of glucose to lactate. However, glycolysis and mitochondrial oxidative phosphorylation may operate simultaneously in cancer cells. Many tumors may switch between these pathways accordingly to the current requirements. The alterations in metabolism of cancer cells combined with the overexpression of oncogenes (c-Myc) and transcription factors (Hypoxia-inducible factor 1a) confer a great advantage to malignant cells to avoid reactive oxygen species induced apoptosis. The determination of the role of AMPK network in metabolic reprogramming of metastatic cancer cells may help to identify the selective molecular targets for efficient anti-cancer therapies. In this review, we discuss the implications of AMPK activation in metabolic reprogramming of cancer cells and we present several potential therapeutic strategies targeting cancer cell metabolism. AMPK activator, biguanide metformin, either alone or in combination with other drugs, may selectively modulate signaling pathways, expresses the chemopreventive potential and can be used in current anti-cancer approaches. However, the ambiguous data suggest that the activation of AMPK may induce multiple effects and thus potential therapeutic anti-cancer approach should be carefully considered in relation to metabolic network of cancer cell signaling and other determinants such tumor stage and origin as well.

Quantitative Evaluation of Toxic Polyglycine Biosynthesis and Aggregation in Cell Models Expressing Expanded CGG Repeats

Fragile X-associated tremor/ataxia syndrome (FXTAS) is a late-onset neurodegenerative disorder caused by expanded CGG (CGG^exp) trinucleotides in the 5′UTR of the FMR1 gene encoding fragile X mental retardation protein (FMRP). The patients, with the number of the repeats ranging from 55 to 200, show specific manifestation of clinical symptoms that include intention tremor, gait ataxia, cognitive deficits, and brain atrophy. Accumulation of toxic polyglycine (FMRpolyG), a by-product of the CGG^exp repeat-associated non-ATG (RAN) translation, is considered to be one of the main factors triggering neurodegenerative processes in FXTAS patients. Nevertheless, the nature of the FMRpolyG-induced cell damage, especially in the context of its soluble and inclusion-associated forms, is still elusive. Targeting either biosynthesis, cellular stability or aggregation capacity of toxic FMRpolyG could be considered as a potential therapeutic strategy for FXTAS. Therefore, we tested a variety of quantitative methods based on forced expression of genetic constructs carrying CGG^exp repeats in the context of the FMR1 5′UTR fused to GFP, mCherry or Firefly luciferase gene in or out of frame to the polyglycine encoding sequence. We show that FMRpolyG translation either from native or an AUG-induced start codon as well as the translation yield of the FMRP open reading frame equivalent located downstream of the CGG^exp element can be effectively estimated using fluorescence microscopy, flow cytometry or luciferase assay. We also quantitatively estimated soluble fraction and insoluble form of FMRpolyG aggregated in foci using an electrophoretic separation of cell lysates and fluorescence microscopy, respectively. Importantly, we show that dependent on a fusion tag, FMRpolyG has a different potential for aggregate formation. Our established protocols enable sensitive tracking of FMRP and FMRpolyG quantitative and qualitative changes after treatment with potential therapeutic agents for FXTAS. Furthermore, they can be modified for application to other RAN translation- and aggregation-related diseases.

Two-step magnetic transition in hybrid organic–inorganic materials of the (m-xylylenediamine)MeSO4 (Me – Mn, Fe, Co, Ni) type

Layered hybrid materials of the type (MXDA)Me^IISO₄ (Me – Mn^II, Fe^II, Co^II, Ni^II) with a two step magnetic transition.

MBNL expression in autoregulatory feedback loops

Muscleblind-like (MBNL) proteins bind to hundreds of pre- and mature mRNAs to regulate their alternative splicing, alternative polyadenylation, stability and subcellular localization. Once MBNLs are withheld from transcript regulation, cellular machineries generate products inapt for precise embryonal/adult developmental tasks and myotonic dystrophy, a devastating multi-systemic genetic disorder, develops. We have recently demonstrated that all three MBNL paralogs are capable of fine-tuning cellular content of one of the three MBNL paralogs, MBNL1, by binding to the first coding exon (e1) of its pre-mRNA. Intriguingly, this autoregulatory feedback loop grounded on alternative splicing of e1 appears to play a crucial role in delaying the onset of myotonic dystrophy. Here, we describe this process in the context of other autoregulatory and regulatory loops that maintain the content and diverse functions of MBNL proteins at optimal level in health and disease, thus supporting the overall cellular homeostasis.

Autoregulation of MBNL1 function by exon 1 exclusion from MBNL1 transcript

Muscleblind-like proteins (MBNLs) are regulators of RNA metabolism. During tissue differentiation the level of MBNLs increases, while their functional insufficiency plays a crucial role in myotonic dystrophy (DM). Deep sequencing of RNA molecules cross-linked to immunoprecipitated protein particles (CLIP-seq) revealed that MBNL1 binds to MBNL1 exon 1 (e1) encoding both the major part of 5΄UTR and an amino-terminal region of MBNL1 protein. We tested several hypotheses regarding the possible autoregulatory function of MBNL1 binding to its own transcript. Our data indicate that MBNLs induce skipping of e1 from precursor MBNL1 mRNA and that e1 exclusion may impact transcript association with polysomes and translation. Furthermore, e1-deficient protein isoform lacking the first two zinc fingers is highly unstable and its EGFP fusion protein has severely compromised splicing activity. We also show that MBNL1 can be transcribed from three different promoters and that the transcription initiation site determines the mode of e1 regulation. Taken together, we demonstrate that MBNL proteins control steady-state levels of MBNL1 through an interaction with e1 in its precursor mRNA. Insights from our study open a new avenue in therapies against DM based on manipulation of the transcription initiation site and e1 splicing of MBNL1 mRNA.

Mechanistic determinants of MBNL activity

Muscleblind-like (MBNL) proteins are critical RNA processing factors in development. MBNL activity is disrupted in the neuromuscular disease myotonic dystrophy type 1 (DM1), due to the instability of a non-coding microsatellite in the DMPK gene and the expression of CUG expansion (CUG^exp) RNAs. Pathogenic interactions between MBNL and CUG^exp RNA lead to the formation of nuclear complexes termed foci and prevent MBNL function in pre-mRNA processing. The existence of multiple MBNL genes, as well as multiple protein isoforms, raises the question of whether different MBNL proteins possess unique or redundant functions. To address this question, we coexpressed three MBNL paralogs in cells at equivalent levels and characterized both specific and redundant roles of these proteins in alternative splicing and RNA foci dynamics. When coexpressed in the same cells, MBNL1, MBNL2 and MBNL3 bind the same RNA motifs with different affinities. While MBNL1 demonstrated the highest splicing activity, MBNL3 showed the lowest. When forming RNA foci, MBNL1 is the most mobile paralog, while MBNL3 is rather static and the most densely packed on CUG^exp RNA. Therefore, our results demonstrate that MBNL paralogs and gene-specific isoforms possess inherent functional differences, an outcome that could be enlisted to improve therapeutic strategies for DM1.

Association of complement receptor 2 polymorphisms with innate resistance to HIV-1 infection

HIV-1 induces activation of complement through the classical and lectin pathways. However, the virus incorporates several membrane-bound or soluble regulators of complement activation (RCA) that inactivate complement. HIV-1 can also use the complement receptors (CRs) for complement-mediated antibody-dependent enhancement of infection (Ć-ADE). We hypothesize that hypofunctional polymorphisms in RCA or CRs may protect from HIV-1 infection. For this purpose, 139 SNPs located in 19 RCA and CRs genes were genotyped in a population of 201 Spanish HIV-1-exposed seronegative individuals (HESN) and 250 HIV-1-infected patients. Two SNPs were associated with infection susceptibility, rs1567190 in CR2 (odds ratio (OR) = 2.27, P = 1 × 10(-4)) and rs2842704 in C4BPA (OR = 2.11, P = 2 × 10(-4)). To replicate this finding, we analyzed a cohort of Italian, sexually HESN individuals. Although not significant (P = 0.25, OR = 1.57), similar genotypic proportions were obtained for the CR2 marker rs1567190. The results of the two association analyses were combined through a random effect meta-analysis, with a significant P-value of 2.6 x 10(-5) (OR = 2.07). Furthermore, we found that the protective CR2 genotype is correlated with lower levels CR2 mRNA as well as differences in the ratio of the long and short CR2 isoforms.

MBNL proteins and their target RNAs, interaction and splicing regulation

Muscleblind-like (MBNL) proteins are key regulators of precursor and mature mRNA metabolism in mammals. Based on published and novel data, we explore models of tissue-specific MBNL interaction with RNA. We portray MBNL domains critical for RNA binding and splicing regulation, and the structure of MBNL's normal and pathogenic RNA targets, particularly in the context of myotonic dystrophy (DM), in which expanded CUG or CCUG repeat transcripts sequester several nuclear proteins including MBNLs. We also review the properties of MBNL/RNA complex, including recent data obtained from UV cross-linking and immunoprecipitation (CLIP-Seq), and discuss how this interaction shapes normal MBNL-dependent alternative splicing regulation. Finally, we review how this acquired knowledge about the pathogenic RNA structure and nature of MBNL sequestration can be translated into the design of therapeutic strategies against DM.

Response of hydroponically grown head lettuce on residual monomer from polyacrylamide

The aim was to assess acrylamide monomer (AMD) uptake by hydroponically grown lettuce. Lettuce was cultivated by applying plant tissue testing in a recycled system by the use of nutrient solutions prepared with two water-soluble flocculants F3 and F4 containing 176 and 763 mg kg(-1) of AMD, respectively. The effects on growth, fresh weight and plant leaf quality were evaluated by comparing these treatments and one control standard nutrient solution typically recommended for lettuce hydroponic cultivation. To assess the nutritional status of lettuce, samples were collected and lyophilised before determination of the selected micro- and macro-element contents. An HPLC with photodiode array detector method was applied to determine AMD in both selected flocculants and dried plant samples. Results show that lettuces cultivated under the conditions described above absorb AMD from nutrient solutions into their leaves. The AMD presence in recycled nutrient solutions has a negative influence on the growth of lettuce, reducing their average fresh weight and average number of leaves. The study confirmed that the problem of AMD mobility and its accumulation risk in plants should to be an important topic with respect to safe polyacrylamide (PAM) handling in the agro food area.

Adeno-associated viral (AAV) vectors do not efficiently target muscle satellite cells

Adeno-associated viral (AAV) vectors are becoming an important tool for gene therapy of numerous genetic and other disorders. Several recombinant AAV vectors (rAAV) have the ability to transduce striated muscles in a variety of animals following intramuscular and intravascular administration, and have attracted widespread interest for therapy of muscle disorders such as the muscular dystrophies. However, most studies have focused on the ability to transduce mature muscle cells, and have not examined the ability to target myogenic stem cells such as skeletal muscle satellite cells. Here we examined the relative ability of rAAV vectors derived from AAV6 to target myoblasts, myocytes, and myotubes in culture and satellite cells and myofibers in vivo. AAV vectors are able to transduce proliferating myoblasts in culture, albeit with reduced efficiency relative to postmitotic myocytes and myotubes. In contrast, quiescent satellite cells are refractory to transduction in adult mice. These results suggest that while muscle disorders characterized by myofiber regeneration can be slowed or halted by AAV transduction, little if any vector transduction can be obtained in myogenic stems cells that might other wise support ongoing muscle regeneration.

Gene and cell-mediated therapies for muscular dystrophy

Duchenne muscular dystrophy (DMD) is a devastating muscle disorder that affects 1 in 3,500 boys. Despite years of research and considerable progress in understanding the molecular mechanism of the disease and advancement of therapeutic approaches, there is no cure for DMD. The current treatment options are limited to physiotherapy and corticosteroids, and although they provide a substantial improvement in affected children, they only slow the course of the disorder. On a more optimistic note, more recent approaches either significantly alleviate or eliminate muscular dystrophy in murine and canine models of DMD and importantly, many of them are being tested in early phase human clinical trials. This review summarizes advancements that have been made in viral and nonviral gene therapy as well as stem cell therapy for DMD with a focus on the replacement and repair of the affected dystrophin gene.

Animal models of muscular dystrophy

The muscular dystrophies (MDs) represent a diverse collection of inherited human disorders, which affect to varying degrees skeletal, cardiac, and sometimes smooth muscle (Emery, 2002). To date, more than 50 different genes have been implicated as causing one or more types of MD (Bansal et al., 2003). In many cases, invaluable insights into disease mechanisms, structure and function of gene products, and approaches for therapeutic interventions have benefited from the study of animal models of the different MDs (Arnett et al., 2009). The large number of genes that are associated with MD and the tremendous number of animal models that have been developed preclude a complete discussion of each in the context of this review. However, we summarize here a number of the more commonly used models together with a mixture of different types of gene and MD, which serves to give a general overview of the value of animal models of MD for research and therapeutic development.

Myofiber integrity depends on desmin network targeting to Z-disks and costameres via distinct plectin isoforms

Dysfunction of plectin, a 500-kD cytolinker protein, leads to skin blistering and muscular dystrophy. Using conditional gene targeting in mice, we show that plectin deficiency results in progressive degenerative alterations in striated muscle, including aggregation and partial loss of intermediate filament (IF) networks, detachment of the contractile apparatus from the sarcolemma, profound changes in myofiber costameric cytoarchitecture, and decreased mitochondrial number and function. Analysis of newly generated plectin isoform-specific knockout mouse models revealed that IF aggregates accumulate in distinct cytoplasmic compartments, depending on which isoform is missing. Our data show that two major plectin isoforms expressed in muscle, plectin 1d and 1f, integrate fibers by specifically targeting and linking desmin IFs to Z-disks and costameres, whereas plectin 1b establishes a linkage to mitochondria. Furthermore, disruption of Z-disk and costamere linkages leads to the pathological condition of epidermolysis bullosa with muscular dystrophy. Our findings establish plectin as the major organizer of desmin IFs in myofibers and provide new insights into plectin- and desmin-related muscular dystrophies.

Plectin 1f scaffolding at the sarcolemma of dystrophic (mdx) muscle fibers through multiple interactions with beta-dystroglycan

In skeletal muscle, the cytolinker plectin is prominently expressed at Z-disks and the sarcolemma. Alternative splicing of plectin transcripts gives rise to more than eight protein isoforms differing only in small N-terminal sequences (5-180 residues), four of which (plectins 1, 1b, 1d, and 1f) are found at substantial levels in muscle tissue. Using plectin isoform-specific antibodies and isoform expression constructs, we show the differential regulation of plectin isoforms during myotube differentiation and their localization to different compartments of muscle fibers, identifying plectins 1 and 1f as sarcolemma-associated isoforms, whereas plectin 1d localizes exclusively to Z-disks. Coimmunoprecipitation and in vitro binding assays using recombinant protein fragments revealed the direct binding of plectin to dystrophin (utrophin) and beta-dystroglycan, the key components of the dystrophin-glycoprotein complex. We propose a model in which plectin acts as a universal mediator of desmin intermediate filament anchorage at the sarcolemma and Z-disks. It also explains the plectin phenotype observed in dystrophic skeletal muscle of mdx mice and Duchenne muscular dystrophy patients.

Numerical model of a Q-switched double-clad fiber laser

The time-energy characteristics of a Q-switched neodymiumdoped double-clad fiber laser are presented. Based on the proposed differential equations, a numerical model is developed to simulate this fiber laser. Using this model pulse duration and the energy of generated pulses can be predicted.

[Multiple primary malignant neoplasms]

The laryngological ward of the district hospital in Piła has been carrying out the diagnosis of neoplastic cases. There were 34 cases of carcinoma of the larynx and or with the lower part of the pharynx were discovered. 4 out of there were confirmed to have second primary neoplastic region. Two patients the neoplasm synchronously developed and in two other patients the neoplasm metachronously developed. In there cases the region of second primary neoplasm was found in the area of the head and neck (thyroid gland, lower lip and the side of the nose) and in one case the second region was found in the urinary bladder, Amongst the patients treated for neoplasms in the laryngological ward of the district hospital in Piła in 1994, 11.7% were patients with second primary malignant neoplasm.