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Cyanobacteria increasingly threaten recreational water use and drinking water resources globally. They require dynamic monitoring to account for variability in their distribution arising from diel cycles associated with oscillatory vertical migration. While this has been discussed in marine and eutrophic freshwater contexts, reports of diurnal vertical migration of cyanobacteria in oligotrophic freshwater lakes are scant. Typical monitoring protocols do not reflect these dynamics and frequently focus only on surface water sampling approaches, and either ignore sampling time or recommend large midday timeframes (e.g., 10AM-3PM), thereby preventing accurate characterization of cyanobacterial community dynamics. To evaluate the impact of diurnal migrations and water column stratification on cyanobacterial abundance and composition, communities were characterized in a shallow well-mixed lake interconnected to a thermally stratified lake in the Turkey Lakes Watershed (Ontario, Canada) using amplicon sequencing of the 16S rRNA gene across a multi-time point sampling series in 2018 and 2022. This work showed that cyanobacteria are present in oligotrophic lakes and their community structure varies (i) diurnally, (ii) across the depth of the water column, (iii) interannually within the same lake and (iv) between different lakes that are closely interconnected within the same watershed. It underscored the need for integrating multi-timepoint, multi-depth discrete sampling guidance into lake and reservoir monitoring programs to describe cyanobacteria community dynamics and signal change to inform risk management associated with the potential for cyanotoxin production. Ignoring variability in cyanobacterial community dynamics (such as that reported herein) and reducing sample numbers can lead to a false sense of security and missed opportunities to identify and mitigate changes in trophic status and associated risks such as toxin or taste and odor production, especially in sensitive, oligotrophic systems.
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Cianobacterias , ARN Ribosómico 16S , Lagos/química , Agua , Ontario , EutrofizaciónRESUMEN
Introduction: Alopecia areata (AA) is a non-scarring hair loss condition, subclassified into AA, alopecia universalis, and alopecia totalis. There are indications that people with AA experience adverse psychosocial outcomes, but previous studies have not included a thorough meta-analysis and did not compare people with AA to people with other dermatological diagnoses. Therefore, the aim of this systematic review and meta-analysis was to update and expand previous systematic reviews, as well as describing and quantifying levels of anxiety, depression, and quality of life (QoL) in children and adults with AA. Methods: A search was conducted, yielding 1,249 unique records of which 93 were included. Results: Review results showed that people with AA have higher chances of being diagnosed with anxiety and/or depression and experience impaired QoL. Their psychosocial outcomes are often similar to other people with a dermatological condition. Meta-analytic results showed significantly more symptoms of anxiety and depression in adults with AA compared to healthy controls. Results also showed a moderate impact on QoL. These results further highlight that AA, despite causing little physical impairments, can have a significant amount on patients' well-being. Discussion: Future studies should examine the influence of disease severity, disease duration, remission and relapse, and medication use to shed light on at-risk groups in need of referral to psychological care. Systematic review registration: [https://www.crd.york.ac.uk/prospero/], identifier [CRD42022323174].
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The end-of-life period of individuals with Alzheimer disease and related dementias receiving home health care (HHC) is understudied. We sought to describe characteristics of HHC patients with Alzheimer disease and related dementias at risk of death within a year, based on clinician assessment. We conducted a secondary data analysis of a 5% random sample of the Outcome and Assessment Information Set data set for the year 2017. We used Outcome and Assessment Information Set-C item M1034 to identify HHC patients with overall status of progressive condition leading to death within a year. Multivariable logistic regression model was used to examine the association between sociodemographic, functional, clinical, and caregiving factors and likelihood of decline leading to death within a year, as identified by HHC clinicians. Clinician perception of decline leading to death within a year was higher for Whites (vs Blacks or Hispanics) (odds ratio [OR], 0.74 [95% confidence interval (CI), 0.69-0.80], and OR, 0.63 [95% CI, 0.57-0.69], respectively). Factors associated with increased odds of decline leading to death within a year included daily pain (OR, 1.11 [95% CI, 1.06-1.17]), anxiety daily or more often (OR, 1.58 [95% CI, 1.49-1.67]), shortness of breath (OR, 1.45 [95% CI, 1.34-1.57]), use of oxygen (OR, 1.60 [95% CI, 1.52-1.69]), disruptive behavior (OR, 1.26 [95% CI, 1.20-1.31]), and feeding difficulty (OR, 2.25 [95% CI, 2.09-2.43]). High symptom burden exists among HHC patients with Alzheimer disease and related dementias identified to have a status of decline leading to death within a year.
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Diversity analysis of amplicon sequencing data has mainly been limited to plug-in estimates calculated using normalized data to obtain a single value of an alpha diversity metric or a single point on a beta diversity ordination plot for each sample. As recognized for count data generated using classical microbiological methods, amplicon sequence read counts obtained from a sample are random data linked to source properties (e.g., proportional composition) by a probabilistic process. Thus, diversity analysis has focused on diversity exhibited in (normalized) samples rather than probabilistic inference about source diversity. This study applies fundamentals of statistical analysis for quantitative microbiology (e.g., microscopy, plating, and most probable number methods) to sample collection and processing procedures of amplicon sequencing methods to facilitate inference reflecting the probabilistic nature of such data and evaluation of uncertainty in diversity metrics. Following description of types of random error, mechanisms such as clustering of microorganisms in the source, differential analytical recovery during sample processing, and amplification are found to invalidate a multinomial relative abundance model. The zeros often abounding in amplicon sequencing data and their implications are addressed, and Bayesian analysis is applied to estimate the source Shannon index given unnormalized data (both simulated and experimental). Inference about source diversity is found to require knowledge of the exact number of unique variants in the source, which is practically unknowable due to library size limitations and the inability to differentiate zeros corresponding to variants that are actually absent in the source from zeros corresponding to variants that were merely not detected. Given these problems with estimation of diversity in the source even when the basic multinomial model is valid, diversity analysis at the level of samples with normalized library sizes is discussed.
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Amplicon sequencing has revolutionized our ability to study DNA collected from environmental samples by providing a rapid and sensitive technique for microbial community analysis that eliminates the challenges associated with lab cultivation and taxonomic identification through microscopy. In water resources management, it can be especially useful to evaluate ecosystem shifts in response to natural and anthropogenic landscape disturbances to signal potential water quality concerns, such as the detection of toxic cyanobacteria or pathogenic bacteria. Amplicon sequencing data consist of discrete counts of sequence reads, the sum of which is the library size. Groups of samples typically have different library sizes that are not representative of biological variation; library size normalization is required to meaningfully compare diversity between them. Rarefaction is a widely used normalization technique that involves the random subsampling of sequences from the initial sample library to a selected normalized library size. This process is often dismissed as statistically invalid because subsampling effectively discards a portion of the observed sequences, yet it remains prevalent in practice and the suitability of rarefying, relative to many other normalization approaches, for diversity analysis has been argued. Here, repeated rarefying is proposed as a tool to normalize library sizes for diversity analyses. This enables (i) proportionate representation of all observed sequences and (ii) characterization of the random variation introduced to diversity analyses by rarefying to a smaller library size shared by all samples. While many deterministic data transformations are not tailored to produce equal library sizes, repeatedly rarefying reflects the probabilistic process by which amplicon sequencing data are obtained as a representation of the amplified source microbial community. Specifically, it evaluates which data might have been obtained if a particular sample's library size had been smaller and allows graphical representation of the effects of this library size normalization process upon diversity analysis results.
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BACKGROUND: The Syrian conflict has led to a dramatic increase of Old World cutaneous leishmaniasis (CL), triggered by continuous population displacements, disrupted control programmes, poor shelter and sanitation. METHODS: A retrospective patient record study was conducted at the Institute of Tropical Medicine and International Health in Berlin. Records of all refugees from Syria treated for CL between January 2015 and March 2020 were reviewed. RESULTS: Twenty refugees from Syria were treated. Seventeen refugees (85%) had complex lesions, mainly due to previous therapy failure or localization on the face. A long disease duration (50% > 1 year), pronounced facial scarring (20%), recurrences (20%), or worsening of existing lesions (20%) were observed. Nine patients (45%) had been pretreated in Syria. Complete remission was achieved in 10 of 16 patients (63%) treated with perilesional antimony. Eight patients (40%) required systemic treatment, thereof four (20%) repeated systemic treatment. Eight patients (40%) reported a delay of therapy ≥3 months in Germany, thereof one patient with a delay of 12 months and one patient with a delay of 32 months. CONCLUSION: Between 2015 and 2020, Syrian refugees presented with severe morbidities of CL frequently requiring systemic and even consecutive systemic treatments. We assume a combination of socioeconomic and environmental factors associated with the ongoing Syrian conflict and migration to be responsible for the complex clinical presentations in this case series. More attention should be drawn to the situation of Syrian refugees with CL in countries where they are displaced to.
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Leishmaniasis Cutánea , Refugiados , Berlin , Alemania , Humanos , Leishmaniasis Cutánea/diagnóstico , Leishmaniasis Cutánea/tratamiento farmacológico , Leishmaniasis Cutánea/epidemiología , Estudios Retrospectivos , SiriaRESUMEN
Skin is the largest organ of the body and represents the primary physical barrier between mammals and their external environment, yet the factors that govern skin microbial community composition among mammals are poorly understood. The objective of this research was to generate a skin microbiota baseline for members of the class Mammalia, testing the effects of host species, geographic location, body region, and biological sex. Skin from the back, torso, and inner thighs of 177 nonhuman mammals was sampled, representing individuals from 38 species and 10 mammalian orders. Animals were sampled from farms, zoos, households, and the wild. The DNA extracts from all skin swabs were amplified by PCR and sequenced, targeting the V3-V4 regions of bacterial and archaeal 16S rRNA genes. Previously published skin microbiome data from 20 human participants, sampled and sequenced using an identical protocol to the nonhuman mammals, were included to make this a comprehensive analysis. Human skin microbial communities were distinct and significantly less diverse than all other sampled mammalian orders. The factor most strongly associated with microbial community data for all samples was whether the host was a human. Within nonhuman samples, host taxonomic order was the most significant factor influencing skin microbiota, followed by the geographic location of the habitat. By comparing the congruence between host phylogeny and microbial community dendrograms, we observed that Artiodactyla (even-toed ungulates) and Perissodactyla (odd-toed ungulates) had significant congruence, providing evidence of phylosymbiosis between skin microbial communities and their hosts.
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Bacterias/genética , Mamíferos/microbiología , Microbiota/genética , Piel/microbiología , Simbiosis/genética , Animales , ADN/genética , Humanos , Filogenia , ARN Ribosómico 16S/genéticaRESUMEN
Surface mining extraction of bitumen from oil sand in Alberta, Canada results in the accumulation of oil sands process-affected water (OSPW). In attempts to maximize water recycling, and because its constituents are recognized as being toxic, OSPW is retained in settling basins. Consequently, research efforts are currently focused on developing remediation strategies capable of detoxifying OSPW to allow for eventual release. One potential bioremediation strategy proposes to utilize phytoplankton native to the Alberta oil sand region to sequester, break down, or modify the complex oil sands acid extractable organic (AEO) mixtures in OSPW. Preliminary attempts to quantify changes in total oil sands AEO concentration in test solutions by ESI-MS following a 14-day algal remediation period revealed the presence of unknown organic acids in control samples, likely released by the phytoplankton strains and often of the same atomic mass range as the oil sands AEO under investigation. To address the presence of these "biogenic" organic acids in test samples, ESI-MS in MRM mode was utilized to identify oil sands AEO "marker ions" that were a) present within the tested oil sands AEO extract and b) unique to the oil sands AEO extract only (e.g. atomic masses different from biogenic organic acids). Using this approach, one of the 21 tested algal strains, Stichococcus sp. 1, proved capable of significantly reducing the AEO marker ion concentration at test concentrations of 10, 30, and 100mgL(-1). This result, along with the accelerated growth rate and recalcitrance of this algal strain with exposure to oil sands AEO, suggests the strong potential for the use of the isolated Stichococcus sp. 1 as a candidate for bioremediation strategies.
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Ácidos/metabolismo , Chlorophyta/metabolismo , Minería , Yacimiento de Petróleo y Gas , Compuestos Orgánicos/metabolismo , Fitoplancton/metabolismo , Contaminantes Químicos del Agua/metabolismo , Ácidos/toxicidad , Alberta , Biodegradación Ambiental , Hidrocarburos , Compuestos Orgánicos/toxicidad , Agua/química , Contaminantes Químicos del Agua/toxicidadRESUMEN
Northern hemisphere rockweeds (Fucus) are thought to have evolved in the North Pacific and then spread to the North Atlantic following the opening of the Bering Strait. They have dispersed and widely speciated in the North Atlantic and its tributary seas. Fucus distichus is likely near the ancestral member of this genus, and studies have shown that there are several species/subspecies in this complex (i.e. F. evanescens and F. gardneri). We used phylogenetic and haplotype analyses to test the phylogenetic relationships and biogeography of F. distichus. Our data and subsequent analyses demonstrate that, unlike previous studies that lacked samples from an extensive geographical area of the Arctic and Subarctic, there is a distinct Arctic haplotype that is the source of subspecies in both the North Pacific and North Atlantic. Fucus distichus occupies a low tide zone habitat, and in Arctic/Subarctic regions it is adapted to the severe stress of sea ice coverage and disturbance during many months per year. We hypothesize that the very large geographic area of Arctic and Subarctic rocky shores available to this species during interglacials, supported by large Arctic/Subarctic fringe areas as well as unglaciated refugia during glacial cycles, provided a robust population and gene pool (described by the Thermogeographic Model). This gene pool dilutes that of the more fragmented and area-limited Temperate/Boreal area populations when they are brought together during glacial cycles. We suggest that similar subspecies complexes for a variety of Arctic/Subarctic shore biota should be examined further in this context, rather than arbitrarily being split up into numerous species.
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Fucus/genética , Regiones Árticas , ADN de Algas/genética , ADN Mitocondrial/genética , ADN Espaciador Ribosómico/genética , Evolución Molecular , Fucus/clasificación , Variación Genética , Océanos y Mares , Filogenia , Filogeografía , Especificidad de la EspecieRESUMEN
Embryonic growth of the yellow-spotted salamander (Ambystoma maculatum) is enhanced by the presence of the green alga Oophila amblystomatis, in the egg capsule. To further assess potential impacts of herbicides on this relationship, A. maculatum egg masses were exposed to atrazine (0-338 µg/L) until hatching (up to 66 days). Exposure to atrazine reduced PSII yield of the symbiotic algae in a concentration-dependent manner, but did not significantly affect visible algal growth or any metrics associated with salamander development. Algal cells were also cultured in the laboratory for toxicity testing. In the 96-h growth inhibition test (0-680 µg/L), ECx values were generally greater than those reported for standard algal test species. Complete recovery of growth rates occurred within 96-h of transferring cells to untreated media. Overall, development of A. maculatum embryos was not affected by exposure to atrazine at concentrations and durations exceeding those found in the environment.
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Ambystoma/embriología , Atrazina/toxicidad , Chlorophyta/efectos de los fármacos , Herbicidas/toxicidad , Óvulo/efectos de los fármacos , Simbiosis/efectos de los fármacos , Animales , Chlorophyta/fisiología , Óvulo/crecimiento & desarrollo , Pruebas de ToxicidadRESUMEN
The oil sands of northern Alberta, Canada contain an estimated 170 billion barrels of crude oil. Extraction processes produce large amounts of liquid tailings known as oil sand process affected water (OSPW) that are toxic to aquatic organisms. Naphthenic acids (NAs), and their sodium salts, represent a significant contributor to the toxicity of these waters. Due to the recalcitrant nature of these compounds, an effective mode of remediation has yet to be established. This study investigates the suitability of the use of phytoplankton for remediation efforts based on two criteria: the ability of phytoplankton strains to withstand the toxic effects of NAs, and their rate of biomass accumulation. A total of 21 phytoplankton strains were isolated from waters containing NAs, cultured, and maintained under unialgal conditions. These strains were then exposed to NAs in concentrations ranging from 0mg L(-1) to 1000mg L(-1) over a 14 day period. Inhibition of growth was observed at 30mg L(-1) NA (one strain), 100mg L(-1) NA (one strain), 300mg L(-1) NA (six strains), and 1000mg L(-1) NA (six strains). Five strains failed to show any growth inhibition at any test concentration and two strains could not be analysed due to poor growth during the test period. Strains were then ranked based on their suitability for use in remediation efforts.
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Biomasa , Ácidos Carboxílicos/toxicidad , Petróleo/toxicidad , Fitoplancton/efectos de los fármacos , Contaminantes Químicos del Agua/toxicidad , Alberta , Biodegradación Ambiental , Cianobacterias/efectos de los fármacos , Cianobacterias/crecimiento & desarrollo , Euglenozoos/efectos de los fármacos , Euglenozoos/crecimiento & desarrollo , Yacimiento de Petróleo y Gas , Fitoplancton/crecimiento & desarrollo , Contaminantes Químicos del Agua/análisisRESUMEN
The red seaweed Porphyra (Bangiophyceae) and related Bangiales have global economic importance. Here, we report the analysis of a comprehensive transcriptome comprising ca. 4.7 million expressed sequence tag (EST) reads from P. umbilicalis (L.) J. Agardh and P. purpurea (Roth) C. Agardh (ca. 980 Mbp of data generated using 454 FLX pyrosequencing). These ESTs were isolated from the haploid gametophyte (blades from both species) and diploid conchocelis stage (from P. purpurea). In a bioinformatic analysis, only 20% of the contigs were found to encode proteins of known biological function. Comparative analysis of predicted protein functions in mesophilic (including Porphyra) and extremophilic red algae suggest that the former has more putative functions related to signaling, membrane transport processes, and establishment of protein complexes. These enhanced functions may reflect general mesophilic adaptations. A near-complete repertoire of genes encoding histones and ribosomal proteins was identified, with some differentially regulated between the blade and conchocelis stage in P. purpurea. This finding may reflect specific regulatory processes associated with these distinct phases of the life history. Fatty acid desaturation patterns, in combination with gene expression profiles, demonstrate differences from seed plants with respect to the transport of fatty acid/lipid among subcellular compartments and the molecular machinery of lipid assembly. We also recovered a near-complete gene repertoire for enzymes involved in the formation of sterols and carotenoids, including candidate genes for the biosynthesis of lutein. Our findings provide key insights into the evolution, development, and biology of Porphyra, an important lineage of red algae.
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The red algal order Bangiales has been revised as a result of detailed regional studies and the development of expert local knowledge of Bangiales floras, followed by collaborative global analyses based on wide taxon sampling and molecular analyses. Combined analyses of the nuclear SSU rRNA gene and the plastid RUBISCO LSU (rbcL) gene for 157 Bangiales taxa have been conducted. Fifteen genera of Bangiales, seven filamentous and eight foliose, are recognized. This classification includes five newly described and two resurrected genera. This revision constitutes a major change in understanding relationships and evolution in this order. The genus Porphyra is now restricted to five described species and a number of undescribed species. Other foliose taxa previously placed in Porphyra are now recognized to belong to the genera Boreophyllum gen. nov., Clymene gen. nov., Fuscifolium gen. nov., Lysithea gen. nov., Miuraea gen. nov., Pyropia, and Wildemania. Four of the seven filamentous genera recognized in our analyses already have generic names (Bangia, Dione, Minerva, and Pseudobangia), and are all currently monotypic. The unnamed filamentous genera are clearly composed of multiple species, and few of these species have names. Further research is required: the genus to which the marine taxon Bangia fuscopurpurea belongs is not known, and there are also a large number of species previously described as Porphyra for which nuclear SSU ribosomal RNA (nrSSU) or rbcL sequence data should be obtained so that they can be assigned to the appropriate genus.
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A collection of 233 rhizobia strains from 30 different sites across Saskatchewan, Canada was assayed for 1-aminocyclopropane-1-carboxylate (ACC) deaminase activity, with 27 of the strains displaying activity. When all 27 strains were characterized based on 16S rRNA gene sequences, it was noted that 26 strains are close to Rhizobium leguminosarum and one strain is close to Rhizobium gallicum. Polymerase chain reaction (PCR) was used to rapidly isolate ACC deaminase structural genes from the above-mentioned 27 strains; 17 of them have 99% identities with the previously characterized ACC deaminase structural gene (acdS) from R. leguminosarum bv. viciae 128C53K, whereas the other ten strains are 84% identical (864-866/1,020 bp) compared to the acdS from strain 128C53K. Southern hybridization showed that each strain has only one ACC deaminase gene. Using inverse PCR, the region upstream of the ACC deaminase structural genes was characterized for all 27 strains, and 17 of these strains were shown to encode a leucine-responsive regulatory protein. The results are discussed in the context of a previously proposed model for the regulation of bacterial ACC deaminase in R. leguminosarum 128C53K.
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Proteínas Bacterianas/metabolismo , Liasas de Carbono-Carbono/metabolismo , Rhizobium/genética , Proteínas Bacterianas/genética , Secuencia de Bases , Liasas de Carbono-Carbono/genética , Dosificación de Gen , Regulación Bacteriana de la Expresión Génica , Genes Bacterianos , Datos de Secuencia Molecular , Filogenia , ARN Bacteriano/genética , ARN Ribosómico 16S/genética , Rhizobium/enzimología , Rhizobium/aislamiento & purificación , Saskatchewan , Análisis de Secuencia de ADNRESUMEN
Checkpoint kinase 2 (CHK2) plays a central and conserved role in the eukaryotic DNA damage response. Few cell cycle checkpoint proteins have been examined in aquatic organisms, and this study is the first to characterize CHK2 expression in a fish species. CHK2 was cloned from Oncorhynchus mykiss, the rainbow trout. The coding region extends over 5741 nucleotides in the genome, including 13 introns, and specifies a predicted 533 amino acid protein. Southern blot analysis revealed that CHK2 exists as a single copy in the rainbow trout genome. Recombinant protein representing the FHA domain was used to generate polyclonal anti-CHK2 antibodies. While CHK2 transcript levels were relatively low in gill and high in brain, the opposite was true for protein levels. Both gill and brain cell cultures were treated with bleomycin, which induces double-strand DNA breaks. There was no effect on levels of CHK2 in gill cells, suggesting that the protein is constitutively active in this tissue. In contrast, brain cells upregulated CHK2 in a dose-dependent manner. The tissue specific expression of CHK2 and its ability to respond to bleomycin treatment suggests that some checkpoint proteins may serve as suitable biomarkers for DNA damage in rainbow trout and other fish species.
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Biomarcadores/análisis , Oncorhynchus mykiss/genética , Proteínas Serina-Treonina Quinasas/metabolismo , Secuencia de Aminoácidos , Animales , Secuencia de Bases , Bleomicina/farmacología , Células Cultivadas , Quinasa de Punto de Control 2 , Clonación Molecular , Daño del ADN , Datos de Secuencia Molecular , Proteínas Serina-Treonina Quinasas/genética , ARN Mensajero/metabolismo , Alineación de Secuencia , Regulación hacia ArribaRESUMEN
BACKGROUND: Clostridial neurotoxins (CNTs) are the most deadly toxins known and causal agents of botulism and tetanus neuroparalytic diseases. Despite considerable progress in understanding CNT structure and function, the evolutionary origins of CNTs remain a mystery as they are unique to Clostridium and possess a sequence and structural architecture distinct from other protein families. Uncovering the origins of CNTs would be a significant contribution to our understanding of how pathogens evolve and generate novel toxin families. RESULTS: The C. botulinum strain A genome was examined for potential homologues of CNTs. A key link was identified between the neurotoxin and the flagellin gene (CBO0798) located immediately upstream of the BoNT/A neurotoxin gene cluster. This flagellin sequence displayed the strongest sequence similarity to the neurotoxin and NTNH homologue out of all proteins encoded within C. botulinum strain A. The CBO0798 gene contains a unique hypervariable region, which in closely related flagellins encodes a collagenase-like domain. Remarkably, these collagenase-containing flagellins were found to possess the characteristic HEXXH zinc-protease motif responsible for the neurotoxin's endopeptidase activity. Additional links to collagenase-related sequences and functions were detected by further analysis of CNTs and surrounding genes, including sequence similarities to collagen-adhesion domains and collagenases. Furthermore, the neurotoxin's HCRn domain was found to exhibit both structural and sequence similarity to eukaryotic collagen jelly-roll domains. CONCLUSION: Multiple lines of evidence suggest that the neurotoxin and adjacent genes evolved from an ancestral collagenase-like gene cluster, linking CNTs to another major family of clostridial proteolytic toxins. Duplication, reshuffling and assembly of neighboring genes within the BoNT/A neurotoxin gene cluster may have lead to the neurotoxin's unique architecture. This work provides new insights into the evolution of C. botulinum neurotoxins and the evolutionary mechanisms underlying the origins of virulent genes.
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Toxinas Botulínicas/genética , Clostridium botulinum/genética , Evolución Molecular , Familia de Multigenes/genética , Neurotoxinas/genética , Secuencia de Aminoácidos , Toxinas Botulínicas/química , Colagenasas/química , Colagenasas/genética , Regiones Determinantes de Complementariedad/genética , Flagelina/química , Flagelina/genética , Duplicación de Gen , Orden Génico , Modelos Moleculares , Datos de Secuencia Molecular , Neurotoxinas/química , Estructura Cuaternaria de Proteína , Estructura Terciaria de Proteína , Homología de Secuencia de AminoácidoRESUMEN
The Arctic is geologically and biogeographically young, and the origin of its seaweed flora has been widely debated. The Arctic littoral biogeographic region dates from the latest Tertiary and Pleistocene. Following the opening of Bering Strait, about 3.5 mya, the "Great Trans-Arctic Biotic Interchange" populated the Arctic with a fauna strongly dominated by species of North Pacific origin. The Thermogeographic Model (TM) demonstrates why climate and geography continued to support this pattern in the Pleistocene. Thus, Arctic and Atlantic subarctic species of seaweeds are likely to be evolutionarily "based" in the North Pacific, subarctic species are likely to be widespread in the warmer Arctic, and species of Atlantic Boreal or warmer origin are unlikely in the Arctic and Subarctic. Although Arctic seaweeds have been thought to have a greater affinity with the North Atlantic, we have reanalyzed the Arctic endemic algal flora, using the Thermogeographic Model and evolutionary trees based on molecular data, to demonstrate otherwise. There are 35 congeneric species of the six, abundant Arctic Rhodophyta that we treat in this paper; 32 of these species (91%) occur in the North Pacific, two species (6%) occur in the Boreal or warmer Atlantic Ocean, and a single species is panoceanic, but restricted to the Subarctic. Laminaria solidungula J. Agardh, a kelp Arctic "endemic" species, has 18 sister species. While only eleven (61%) occur in the North Pacific, this rapidly dispersing and evolving genus is a terminal member of a diverse family and order (Laminariales) widely accepted to have evolved in the North Pacific. Thus, both the physical/time-based TM and the dominant biogeographic pattern of relatives of Arctic macrophytes suggest strong compliance with the evidence of zoology, geology, and paleoclimatology that the Arctic marine flora is largely of Pacific origin.
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AIMS AND OBJECTIVES: . The aim of this article is to investigate the way malignant fungating wounds affect femininity, sexuality and daily life in women with progressive breast cancer. Malignant wounds occur when the underlying localized tumour filtrates into the skin, blood capillaries and/or lymph vessels. DESIGN: The study was a prospective and exploratory intervention study. The intervention was tested on 12 consecutively selected women with progressive breast cancer and malignant fungating wounds. METHODS: The 12 women participated in a 4-week wound care intervention programme that comprised evidence-based wound care principles and psychosocial support. Data were generated by means of interviewing prior to and following the intervention period. RESULTS: The women described how malodorous and oozing wounds trigger anxiety about seepage, prevent them from wearing feminine attire and cause them to suppress the need for physical closeness and sexual activity. The results showed that by using modern wound care products, the patients could be secured against seepage and odour. The women experienced a sense of comfort, were able to dress again as they wished, no longer felt caged in and isolated and were given a sense of freedom which they had not felt for a long time. CONCLUSIONS: The intervention succeeded in increasing breast cancer patients' psychosocial well-being and reducing social isolation. RELEVANCE TO CLINICAL PRACTICE: There is a lack of standard methods of practice for care of malignant wounds in women with breast cancer. This article describes an intervention for wound care which could improve daily live in women with progressive breast cancer.