Mating type (MAT) switching in Saccharomyces cerevisiae is initiated by a double-strand break (DSB) created at MAT by HO endonuclease. MATa cells activate the entire left arm of chromosome III; thus MATa preferentially recombines with the silent donor HML. In contrast, MAT alpha cells inactivate the left arm, including HML, and thus preferentially recombine with HMR, 100 kb to the right of MAT. We present a novel competition assay, in which the DSB at MAT can be repaired either by MAT switching or by single-strand annealing (SSA) between two URA3 genes flanking MAT. With preferred donors, MATa or MAT alpha switching occurs 65-70% of the time in competition with SSA. When HML is deleted, 40% of MATa cells recombine with the "wrong" donor HMR; however, when HMR is deleted, only 18% of MAT alpha cells recombine with HML. In interchromosomal switching, with donors on chromosome III and MAT on chromosome V, MATa retains its strong preference for HML and switching is efficient, when the chromosome III recombination enhancer is present. However, MAT alpha donor preference is lost and interchromosomal switching is very inefficient. These experiments demonstrate the utility of using competition between two outcomes to measure the relative efficiency of recombination.

This report compares the pathogenetic influences of selective deletion and triplicaton of chromosome 13 derived from a familial 12;13 insertional translocation. In the proband a heritable chromosomal basis for his bilateral retinoblastomas is established [46,XY,del (13) (pter leads to q12.5: :q22.1 leads to qter)mat], and in his sister the relatively modest effects of triplication of the mid-portions of 13q are demonstrated [46,XX,ins(12;13) (12pter leads to 12p11.2: :13q22.1 leads to 13q12.5: :12p11.2 leads to 12qter)mat]. Qualitative and quantitative gene marker studies and chromosomal staining techniques to differentiate timing of DNA replication failed to indicate functional gene changes about the breakpoints.

Spatial and temporal gait asymmetry is common after stroke. Such asymmetric gait is inefficient, can contribute to instability and may lead to musculoskeletal injury. However, understanding of the determinants of such gait asymmetry remains incomplete. The current study is focused on revealing if there is a link between asymmetry during the control of standing balance and asymmetry during walking. This study involved review of data from 94 individuals with stroke referred to a gait and balance clinic. Participants completed three tests: (1) walking at their usual pace; (2) quiet standing; and (3) standing with maximal loading of the paretic side. A pressure sensitive mat recorded placement and timing of each footfall during walking. Standing tests were completed on two force plates to evaluate symmetry of weight bearing and contribution of each limb to balance control. Multiple regression was conducted to determine the relationships between symmetry during standing and swing time, stance time, and step length symmetry during walking. Symmetry of antero-posterior balance control and weight bearing were related to swing time and step length symmetry during walking. Weight-bearing symmetry, weight-bearing capacity, and symmetry of antero-posterior balance control were related to stance time symmetry. These associations were independent of underlying lower limb impairment. The results support the hypothesis that impaired ability of the paretic limb to control balance may contribute to gait asymmetry post-stroke. Such work suggests that rehabilitation strategies that increase the contribution of the paretic limb to standing balance control may increase symmetry of walking post-stroke.

The microbial diversity of intertidal hot springs on the seashore of northwest Iceland was examined by combining directed in situ enrichments, artificial support colonization, and mat sampling. Analysis of 16S rRNA genes revealed the presence of clones related to both marine and terrestrial, thermophilic, mesophilic, and psychrophilic microorganisms scattered among 11 bacterial divisions. No archaea were found. The species composition of the enrichments was affected by the length of the hot periods experienced at low tide and was very different from those found in the biomass. A total of 36 chitinase genes were detected by molecular screening of the samples with degenerate primers for glycoside hydrolase family 18. The chitinase gene diversity was at least twofold higher in the enrichment samples than in the controls, indicating that a much higher diversity of hydrolytic genes can be accessed with this approach.

During homothallic switching of the mating-type (MAT) gene in Saccharomyces cerevisiae, a- or alpha-specific sequences are replaced by opposite mating-type sequences copied from one of two silent donor loci, HML alpha or HMRa. The two donors lie at opposite ends of chromosome III, approximately 190 and 90 kb, respectively, from MAT. MAT alpha cells preferentially recombine with HMR, while MATa cells select HML. The mechanisms of donor selection are different for the two mating types. MATa cells, deleted for the preferred HML gene, efficiently use HMR as a donor. However, in MAT alpha cells, HML is not an efficient donor when HMR is deleted; consequently, approximately one-third of HO HML alpha MAT alpha hmr delta cells die because they fail to repair the HO endonuclease-induced double-strand break at MAT. MAT alpha donor preference depends not on the sequence differences between HML and HMR or their surrounding regions but on their chromosomal locations. Cloned HMR donors placed at three other locations to the left of MAT, on either side of the centromere, all fail to act as efficient donors. When the donor is placed 37 kb to the left of MAT, its proximity overcomes normal donor preference, but this position is again inefficiently used when additional DNA is inserted in between the donor and MAT to increase the distance to 62 kb. Donors placed to the right of MAT are efficiently recruited, and in fact a donor situated 16 kb proximal to HMR is used in preference to HMR. The cis-acting chromosomal determinants of MAT alpha preference are not influenced by the chromosomal orientation of MAT or by sequences as far as 6 kb from HMR. These data argue that there is an alpha-specific mechanism to inhibit the use of donors to the left of MAT alpha, causing the cell to recombine most often with donors to the right of MAT alpha.

Speleothems such as stalactites and stalagmites are usually considered to be mineralogical in composition and origin; however, microorganisms have been implicated in the development of some speleothems. We have identified and characterized the biological and mineralogical composition of mat-like biofabrics in two novel kinds of speleothems from a 50 degrees C geothermal mine adit near Glenwood Springs, CO. One type of structure consists of 2- to 3-cm-long, 3- to 4-mm-wide, leather-like, hollow, soda straw stalactites. Light and electron microscopy indicated that the stalactites are composed of a mineralized biofabric with several cell morphotypes in a laminated form, with gypsum and sulfur as the dominant mineral components. A small-subunit rRNA gene phylogenetic community analysis along the stalactite length yielded a diverse gradient of organisms, with a relatively simple suite of main constituents: Thermus spp., crenarchaeotes, Chloroflexi, and Gammaproteobacteria. PCR analysis also detected putative crenarchaeal ammonia monooxygenase subunit A (amoA) genes in this community, the majority related to sequences from other geothermal systems. The second type of speleothem, dumpling-like rafts floating on a 50 degrees C pool on the floor of the adit, showed a mat-like fabric of evidently living organisms on the outside of the dumpling, with a multimineral, amorphous, gypsum-based internal composition. These two novel types of biofabrics are examples of the complex roles that microbes can play in mineralization, weathering, and deposition processes in karst environments.

Microbial communities in a shallow submarine hydrothermal system near Taketomi Island, Japan, were investigated using cultivation-based and molecular techniques. The main hydrothermal activity occurred in a craterlike basin (depth, approximately 23 m) on the coral reef seafloor. The vent fluid (maximum temperature, >52 degrees C) contained 175 microM H2S and gas bubbles mainly composed of CH4 (69%) and N2 (29%). A liquid serial dilution cultivation technique targeting a variety of metabolism types quantified each population in the vent fluid and in a white microbial mat located near the vent. The most abundant microorganisms cultivated from both the fluid and the mat were autotrophic sulfur oxidizers, including mesophilic Thiomicrospira spp. and thermophilic Sulfurivirga caldicuralii. Methane oxidizers were the second most abundant organisms in the fluid; one novel type I methanotroph exhibited optimum growth at 37 degrees C, and another novel type I methanotroph exhibited optimum growth at 45 degrees C. The number of hydrogen oxidizers cultivated only from the mat was less than the number of sulfur and methane oxidizers, although a novel mesophilic hydrogen-oxidizing member of the Epsilonproteobacteria was isolated. Various mesophilic to hyperthermophilic heterotrophs, including sulfate-reducing Desulfovibrio spp., iron-reducing Deferribacter sp., and sulfur-reducing Thermococcus spp., were also cultivated. Culture-independent 16S rRNA gene clone analysis of the vent fluid and mat revealed highly diverse archaeal communities. In the bacterial community, S. caldicuralii was identified as the predominant phylotype in the fluid (clonal frequency, 25%). Both bacterial clone libraries indicated that there were bacterial communities involved in sulfur, hydrogen, and methane oxidation and sulfate reduction. Our results indicate that there are unique microbial communities that are sustained by active chemosynthetic primary production rather than by photosynthetic production in a shallow hydrothermal system where sunlight is abundant.

Leptothrix ochracea is a common inhabitant of freshwater iron seeps and iron-rich wetlands. Its defining characteristic is copious production of extracellular sheaths encrusted with iron oxyhydroxides. Surprisingly, over 90% of these sheaths are empty, hence, what appears to be an abundant population of iron-oxidizing bacteria, consists of relatively few cells. Because L. ochracea has proven difficult to cultivate, its identification is based solely on habitat preference and morphology. We utilized cultivation-independent techniques to resolve this long-standing enigma. By selecting the actively growing edge of a Leptothrix-containing iron mat, a conventional SSU rRNA gene clone library was obtained that had 29 clones (42% of the total library) related to the Leptothrix/Sphaerotilus group (≤96% identical to cultured representatives). A pyrotagged library of the V4 hypervariable region constructed from the bulk mat showed that 7.2% of the total sequences also belonged to the Leptothrix/Sphaerotilus group. Sorting of individual L. ochracea sheaths, followed by whole genome amplification (WGA) and PCR identified a SSU rRNA sequence that clustered closely with the putative Leptothrix clones and pyrotags. Using these data, a fluorescence in-situ hybridization (FISH) probe, Lepto175, was designed that bound to ensheathed cells. Quantitative use of this probe demonstrated that up to 35% of microbial cells in an actively accreting iron mat were L. ochracea. The SSU rRNA gene of L. ochracea shares 96% homology with its closet cultivated relative, L. cholodnii, This establishes that L. ochracea is indeed related to this group of morphologically similar, filamentous, sheathed microorganisms.

Benthic cyanobacterial mats with the filamentous Microcoleus chthonoplastes as the dominant phototroph grow in oxic hypersaline environments such as Solar Lake, Sinai. The cyanobacteria are in situ exposed to chemical variations between 200 mumol of sulfide liter at night and 1 atm pO(2) during the day. During experimental H(2)S to O(2) transitions the microbial community was shown to shift from anoxygenic photosynthesis, with H(2)S as the electron donor, to oxygenic photosynthesis. Microcoleus filaments could carry out both types of photosynthesis concurrently. Anoxygenic photosynthesis dominated at high sulfide levels, 500 mumol liter, while the oxygenic reaction became dominant when the sulfide level was reduced below 100 to 300 mumol liter (25 to 75 mumol of H(2)S liter). An increasing inhibition of the oxygenic photosynthesis was observed upon transition to oxic conditions from increasing sulfide concentrations. Oxygen built up within the Microcoleus layer of the mat even under 5 mmol of sulfide liter (500 mumol of H(2)S liter) in the overlying water. The implications of such a localized O(2) production in a highly reducing environment are discussed in relation to the evolution of oxygenic photosynthesis during the Proterozoic era.

Abnormal elevation of plasma methionine may result from several different genetic abnormalities, including deficiency of cystathionine beta-synthase (CBS) or of the isoenzymes of methionine adenosyltransferase (MAT) I and III expressed solely in nonfetal liver (MAT I/III deficiency). Classically, these conditions have been distinguished most readily by the presence or absence, respectively, of elevated plasma free homocystine, detected by amino acid chromatography in the former condition, but absent in the latter. During the present work, we have assayed methionine, S-adenosylmethionine, S-adenosylhomocysteine, total homocysteine (tHcy), cystathionine, N-methylglycine (sarcosine), and total cysteine (tCys) in groups of both MAT I/III- and CBS-deficient patients to provide more evidence as to their metabolite patterns. Unexpectedly, we found that MAT I/III-deficient patients with the most markedly elevated levels of plasma methionine also had elevations of plasma tHcy and often mildly elevated plasma cystathionine. Evidence is presented that methionine does not inhibit cystathionine beta-synthase, but does inhibit cystathionine gamma-lyase. Mechanisms that may possibly underlie the elevations of plasma tHcy and cystathionine are discussed. The combination of elevated methionine plus elevated tHcy may lead to the mistaken conclusion that an MAT I/III-deficient patient is instead CBS-deficient. Less than optimal management is then a real possibility. Measurements of plasma cystathionine, S-adenosylmethionine, and sarcosine should permit ready distinction between the 2 conditions in question, as well as be useful in several other situations involving abnormalities of methionine and/or homocysteine derivatives.

The primary cell walls of growing and fleshy plant tissue mostly share a common set of molecular components, cellulose, xyloglucan (XyG), and pectin, that are required for both inherent strength and the ability to respond to cell expansion during growth. To probe molecular mechanisms underlying material properties, cell walls and analog composites from Acetobacter xylinus have been measured under small deformation and uniaxial extension conditions as a function of molecular composition. Small deformation oscillatory rheology shows a common frequency response for homogenized native cell walls, their sequential extraction residues, and bacterial cellulose alone. This behavior is characteristic of structuring via entanglement of cellulosic rods and is more important than cross-linking with XyG in determining shear moduli. Compared with cellulose alone, composites with XyG have lower stiffness and greater extensibility in uniaxial tension, despite being highly cross-linked at the molecular level. It is proposed that this is due to domains of cross-linked cellulose behaving as mechanical elements, whereas cellulose alone behaves as a mat of individual fibrils. The implication from this work is that XyG/cellulose networks provide a balance of extensibility and strength required by primary cell walls, which is not achievable with cellulose alone.

We used haploid yeast cells that express both the MATa and MAT alpha mating-type alleles and contain the spo13-1 mutation to characterize meiotic recombination within single, unpaired chromosomes in Rec+ and Rec- Saccharomyces cerevisiae. In Rec+ haploids, as in diploids, intrachromosomal recombination in the ribosomal DNA was detected in 2 to 6% of meiotic divisions, and most events were unequal reciprocal sister chromatid exchange (SCE). By contrast, intrachromosomal recombination between duplicated copies of the his4 locus occurred in approximately 30% of haploid meiotic divisions, a frequency much higher than that reported in diploids; only about one-half of the events were unequal reciprocal SCE. The spo11-1 mutation, which virtually eliminates meiotic exchange between homologs in diploid meiosis, reduced the frequency of intrachromosomal recombination in both the ribosomal DNA and the his4 duplication during meiosis by 10- to greater than 50-fold. This Rec- mutation affected all forms of recombination within chromosomes: unequal reciprocal SCE, reciprocal intrachromatid exchange, and gene conversion. Intrachromosomal recombination in spo11-1 haploids was restored by transformation with a plasmid containing the wild-type SPO11 gene. Mitotic intrachromosomal recombination frequencies were unaffected by spo11-1. This is the first demonstration of a gene product required for recombination between homologs as well as recombination within chromosomes during meiosis.

Three isozymes of methionine adenosyltransferase (EC 2.5.1.6; MAT-I, -II, and -III) exist in normal rat liver and are conveniently purified (MAT-III to homogeneity) by a three-step column chromatography procedure. MAT-I shows Michaelis-Menten kinetics with a Km (L-methionine) of 41 microM and a molecular weight of 208 000 and is slightly inhibited by S-adenosyl-L-methionine (Adomet). MAT-II, which is also the only isozyme found in normal rat kidney, shows negative cooperativity with a Hill coefficient of 0.7. It has a L-methionine concentration required for half-maximal velocity [S0.5(Met)] of 8 microM and a molecular weight of 120 000 and is strongly inhibited by Adomet. MAT-I and -II comprise 15% and 5%, respectively, of total MAT activity in rat liver. The predominant isozyme in rat liver, MAT-III, demonstrates positive cooperativity with a Hill coefficient of 1.8. It has a molecular weight of 97 000 and apparently consists of two subunits of identical molecular weight (47 000). This liver-specific isozyme is strongly activated by both dimethyl sulfoxide and Adomet and has a S0.5(Met) of 215 microM.

Individual cyanobacterial cells are normally identified in environmental samples only on the basis of their pigmentation and morphology. However, these criteria are often insufficient for the differentiation of species. Here, a whole-cell hybridization technique is presented that uses horseradish peroxidase (HRP)-labeled, rRNA-targeted oligonucleotides for in situ identification of cyanobacteria. This indirect method, in which the probe-conferred enzyme has to be visualized in an additional step, was necessary since fluorescently monolabeled oligonucleotides were insufficient to overstain the autofluorescence of the target cells. Initially, a nonfluorescent detection assay was developed and successfully applied to cyanobacterial mats. Later, it was demonstrated that tyramide signal amplification (TSA) resulted in fluorescent signals far above the level of autofluorescence. Furthermore, TSA-based detection of HRP was more sensitive than that based on nonfluorescent substrates. Critical points of the assay, such as cell fixation and permeabilization, specificity, and sensitivity, were systematically investigated by using four oligonucleotides newly designed to target groups of cyanobacteria.

The regulation of maturation (MAT)- and late embryogenesis (LEA)-specific gene expression in dicots involves factors related to ABI3, a seed-specific component of the abscisic acid signal transduction pathways from Arabidopsis. In French bean (Phaseolus vulgaris), the ABI3-like factor, PvALF, activates transcription from MAT promoters of phytohemagglutinin (DLEC2) and beta-phaseolin (PHS beta) genes. We describe the regulator of MATMAT promoters. ROM2 antagonizes trans-activation of the DLEC2 promoter by PvALF in transient expression assays. Repression was abolished by mutations that prevented binding of ROM2 to the DLEC2 seed enhancer region. Moreover, a hybrid protein composed of a PvALF activation domain and the DNA binding and dimerization domain of ROM2 activated gene expression, indicating that ROM2 recognizes the DLEC2 enhancer in vivo; consequently, ROM2 functions as a DNA binding site-dependent repressor. Supershift analysis of nuclear proteins, using a ROM2-specific antibody, revealed an increase in ROM2 DNA binding activity during seed desiccation. A corresponding increase in ROM2 mRNA coincided with the period when DLEC2 mRNA levels declined in embryos. These results demonstrate developmental regulation of the ROM2 repressor and point to a role for this factor in silencing DLEC2 transcription during late embryogenesis.

Strains of the yeast Saccharomyces cerevisiae that are heterozygous for the mating-type locus (MATa/MAT alpha) undergo meiosis and spore formation when they are starved for nitrogen and are provided with a nonfermentable carbon source such as potassium acetate. Haploids and diploids homozygous for the mating-type locus (MAT alpha/MAT alpha or MATa/MATa) are asporogenous and undergo neither meiosis nor spore formation when incubated under the same conditions. A small number of genes produce transcripts that appear to be induced specifically in sporulating cells. These transcripts either are not found or are present at much lower levels both in vegetatively growing cells and in cells from asporogenous strains that have been incubated in sporulation medium. Several genes complementary to these MATa/MAT alpha-dependent sporulation-induced transcripts were isolated from a gene-size insert yeast-lambda recombinant DNA library, by differential-plaque filter hybridization. An attempt was made to determine the function of three of these genes by mutating them in the yeast genome with in vitro mutagenesis and one-step gene replacement techniques. One gene was extensively disrupted by both a 0.3-kilobase deletion and the insertion of two large DNA sequences at different sites within the gene. Surprisingly, this compound mutation did not appear to affect meiosis or the production of viable ascospores, indicating that this gene was dispensable for differentiation. The other two genes were disrupted by simple insertion mutations at a site where it was possible that they might still possess some gene activity. These mutations also did not appear to affect sporulation. These results suggest that not all sporulation-induced genes are essential for meiosis and the production of viable ascospores under the conditions examined.

We investigated the diversity, distribution, and phenotypes of uncultivated Chloroflexaceae-related bacteria in photosynthetic microbial mats of an alkaline hot spring (Mushroom Spring, Yellowstone National Park). By applying a directed PCR approach, molecular cloning, and sequence analysis of 16S rRNA genes, an unexpectedly large phylogenetic diversity among these bacteria was detected. Oligonucleotide probes were designed to target 16S rRNAs from organisms affiliated with the genus Chloroflexus or with the type C cluster, a group of previously discovered Chloroflexaceae relatives of this mat community. The application of peroxidase-labeled probes in conjunction with tyramide signal amplification enabled the identification of these organisms within the microbial mats by fluorescence in situ hybridization (FISH) and the investigation of their morphology, abundance, and small-scale distribution. FISH was combined with oxygen microelectrode measurements, microscope spectrometry, and microautoradiography to examine their microenvironment, pigmentation, and carbon source usage. Abundant type C-related, filamentous bacteria were found to flourish within the cyanobacterium-dominated, highly oxygenated top layers and to predominate numerically in deeper orange-colored zones of the investigated microbial mats, correlating with the distribution of bacteriochlorophyll a. Chloroflexus sp. filaments were rare at 60 degrees C but were more abundant at 70 degrees C, where they were confined to the upper millimeter of the mat. Both type C organisms and Chloroflexus spp. were observed to assimilate radiolabeled acetate under in situ conditions.

Kinsky, Stephen C. (Washington University, St. Louis, Mo.). Alterations in the permeability of Neurospora crassa due to polyene antibiotics. J. Bacteriol. 82:889-897. 1961.-Thirty-three antibiotics and synthetic fungicides were examined for their effect on the growth and morphology of Neurospora crassa. Only the polyene antibiotics (nystatin, amphotericin B, and filipin) caused a decrease in the dry weight of mycelial mats, which was accompanied by the appearance of cytoplasmic constituents in the medium. The influence of polyene concentration, incubation time, mycelial age, various metabolic inhibitors, pH, and media composition on this phenomenon are described. The present evidence indicates that the polyenes exert their primarily fungicidal effect by an alteration of permeability, probably due to direct action on the membrane of sensitive organisms.

The sizes and shapes (physiognomy) of fossil leaves are widely applied as proxies for paleoclimatic and paleoecological variables. However, significant improvements to leaf-margin analysis, used for nearly a century to reconstruct mean annual temperature (MAT), have been elusive; also, relationships between physiognomy and many leaf ecological variables have not been quantified. Using the recently developed technique of digital leaf physiognomy, correlations of leaf physiognomy to MAT, leaf mass per area, and nitrogen content are quantified for a set of test sites from North and Central America. Many physiognomic variables correlate significantly with MAT, indicating a coordinated, convergent evolutionary response of fewer teeth, smaller tooth area, and lower degree of blade dissection in warmer environments. In addition, tooth area correlates negatively with leaf mass per area and positively with nitrogen content. Multiple linear regressions based on a subset of variables produce more accurate MAT estimates than leaf-margin analysis (standard errors of ±2 vs. ±3°C); improvements are greatest at sites with shallow water tables that are analogous to many fossil sites. The multivariate regressions remain robust even when based on one leaf per species, and the model most applicable to fossils shows no more signal degradation from leaf fragmentation than leaf-margin analysis.

The genetical analysis, by protoplast fusion, of the sterile strain ED22 of Schizosaccharomyces pombe is described. Two major mutations are harboured by this strain. One, cdc 25.22, is conditionally defective in mitosis. The other mutation, ste 1.1, causes sterility in strains of h-, h+ or mat 2.102 mating-type. Sterility is due to the failure of cell agglutination. We present evidence that ste 1.1 is defective in the production of a non-diffusible and non-mating-type specific factor. ste 1 and cdc 25 both map on chromosome I and are loosely linked.

For the first time, the cyanobacterial diversity from microbial mats in lakes of Eastern Antarctica was investigated using microscopic and molecular approaches. The present study assessed the biogeographical distribution of cyanobacteria in Antarctica. Five samples were taken from four lakes spanning a range of different ecological environments in Larsemann Hills, Vestfold Hills and Rauer Islands to evaluate the influence of lake characteristics on the cyanobacterial diversity. Seventeen morphospecies and 28 16S rRNA gene-based operational taxonomic units belonging to the Oscillatoriales, Nostocales and Chroococcales were identified. The internal transcribed spacer was evaluated to complement the 16S rRNA gene data and showed similar but more clear-cut tendencies. The molecular approach suggested that potential Antarctic endemic species, including a previously undiscovered diversity, are more abundant than has been estimated by morphological methods. Moreover, operational taxonomic units, also found outside Antarctica, were more widespread over the continent than potential endemics. The cyanobacterial diversity of the most saline lakes was found to differ from the others, and correlations between the sampling depth and the cyanobacterial communities can also be drawn. Comparison with database sequences illustrated the ubiquity of several cyanobacterial operational taxonomic units and their remarkable range of tolerance to harsh environmental conditions.

Vertical jump height is frequently used by coaches, health care professionals, and strength and conditioning professionals to objectively measure function. The purpose of this study is to determine the concurrent validity of the jump and reach method (Vertec) and the contact mat method (Just Jump) in assessing vertical jump height when compared with the criterion reference 3-camera motion analysis system. Thirty-nine college students, 25 females and 14 males between the ages of 18 and 25 (mean age 20.65 years), were instructed to perform the countermovement jump. Reflective markers were placed at the base of the individual's sacrum for the 3-camera motion analysis system to measure vertical jump height. The subject was then instructed to stand on the Just Jump mat beneath the Vertec and perform the jump. Measurements were recorded from each of the 3 systems simultaneously for each jump. The Pearson r statistic between the video and the jump and reach (Vertec) was 0.906. The Pearson r between the video and contact mat (Just Jump) was 0.967. Both correlations were significant at the 0.01 level. Analysis of variance showed a significant difference among the 3 means F(2,235) = 5.51, p < 0.05. The post hoc analysis showed a significant difference between the criterion reference (M = 0.4369 m) and the Vertec (M = 0.3937 m, p = 0.005) but not between the criterion reference and the Just Jump system (M = 0.4420 m, p = 0.972). The Just Jump method of measuring vertical jump height is a valid measure when compared with the 3-camera system. The Vertec was found to have a high correlation with the criterion reference, but the mean differed significantly. This study indicates that a higher degree of confidence is warranted when comparing Just Jump results with a 3-camera system study.

In fungi, sexual identity is determined by specialized genomic regions called MAT loci which are the equivalent to sex chromosomes in some animals and plants. Usually, only two sexes or mating types exist, which are determined by two alternate sets of genes (or alleles) at the MAT locus (bipolar system). However, in the phylum Basidiomycota, a unique tetrapolar system emerged in which four different mating types are generated per meiosis. This occurs because two functionally distinct molecular recognition systems, each encoded by one MAT region, constrain the selection of sexual partners. Heterozygosity at both MAT regions is a pre-requisite for mating in both bipolar and tetrapolar basidiomycetes. Tetrapolar mating behaviour results from the absence of genetic linkage between the two regions bringing forth up to thousands of mating types. The subphylum Pucciniomycotina, an early diverged lineage of basidiomycetes encompassing important plant pathogens such as the rusts and saprobes like Rhodosporidium and Sporidiobolus, has been so far poorly explored concerning the content and organization of MAT loci. Here we show that the red yeast Sporidiobolus salmonicolor has a mating system unlike any previously described because occasional disruptions of the genetic cohesion of the bipolar MAT locus originate new mating types. We confirmed that mating is normally bipolar and that heterozygosity at both MAT regions is required for mating. However, a laboratory cross showed that meiotic recombination may occur within the bipolar MAT locus, explaining tetrapolar features like increased allele number and evolution rates of some MAT genes. This pseudo-bipolar system deviates from the classical bipolar-tetrapolar paradigm and, to our knowledge, has never been observed before. We propose a model for MAT evolution in the Basidiomycota in which the pseudo-bipolar system may represent a hitherto unforeseen gradual form of transition from an ancestral tetrapolar system to bipolarity.

A novel hydrothermal field has been discovered at the base of Lōihi Seamount, Hawaii, at 5000 mbsl. Geochemical analyses demonstrate that 'FeMO Deep', while only 0.2 °C above ambient seawater temperature, derives from a distal, ultra-diffuse hydrothermal source. FeMO Deep is expressed as regional seafloor seepage of gelatinous iron- and silica-rich deposits, pooling between and over basalt pillows, in places over a meter thick. The system is capped by mm to cm thick hydrothermally derived iron-oxyhydroxide- and manganese-oxide-layered crusts. We use molecular analyses (16S rDNA-based) of extant communities combined with fluorescent in situ hybridizations to demonstrate that FeMO Deep deposits contain living iron-oxidizing Zetaproteobacteria related to the recently isolated strain Mariprofundus ferroxydans. Bioenergetic calculations, based on in-situ electrochemical measurements and cell counts, indicate that reactions between iron and oxygen are important in supporting chemosynthesis in the mats, which we infer forms a trophic base of the mat ecosystem. We suggest that the biogenic FeMO Deep hydrothermal deposit represents a modern analog for one class of geological iron deposits known as 'umbers' (for example, Troodos ophilolites, Cyprus) because of striking similarities in size, setting and internal structures.