Sizing of ballistic arm protection for the VIRTUS body armour and load carriage system.

INTRODUCTION: Severe haemorrhage from the arm that is unresponsive to direct pressure necessitates the application of a tourniquet. Detachable arm protection, referred to as brassards, are used by the UK Armed Forces to protect the upper arm from fragmentation threats. However, the coverage they originally provided was based on limited medical evidence. Medical consensus has determined that the dimensions of arm protection should in future be related to how far up the arm a tourniquet can be applied. METHOD: CT scans of 120 male Armed Forces personnel were analysed to ascertain the vertical distances from acromion process to the point at which a tourniquet can applied, equating to the anterior axillary fold. These values were statistically compared with those derived from the 2007 UK Military anthropometric survey using a paired t-test. Additional distances were added to account for tourniquet width and slippage, with the total value compared with VIRTUS brassard length. RESULTS: No significant difference (p<0.01) was found in mean acromion to axilla length (114 mm) compared with that found in the anthropometric survey confirming sample validity. The deltoid insertion lay 24 mm below the axillary fold for the 50th percentile value from CT. Essential arm coverage for the 99th percentile male in this study was calculated as 201 mm. CONCLUSIONS: Based on this research, a single new brassard for the VIRTUS body armour and load carriage system was recommended and manufactured based on the 99th percentile. This is over 30% shorter than the existing VIRTUS brassard, reducing the overall weight burden for the soldier and improving heat dispersion, integration and interoperability. The new brassard has been issued to Armed Forces personnel since October 2018. The reduced mass of ballistic protective material in conjunction with requiring only a single size of brassard has already saved the Ministry of Defence £20 000 in procurement costs.

Phylogeny of the Celastraceae inferred from 26S nuclear ribosomal DNA, phytochrome B, rbcL, atpB, and morphology.

Phylogenetic relationships within Celastraceae (spindle-tree family) were inferred from nucleotide sequence characters from the 5' end of 26S nuclear ribosomal DNA (including expansion segments D1-D3; 84 species sampled), phytochrome B (58 species), rbcL (31 species), atpB (23 species), and morphology (94 species). Among taxa of questionable affinity, Forsellesia is a member of Crossosomataceae, and Goupia is excluded from Celastraceae. However, Brexia, Canotia, Lepuropetalon, Parnassia, Siphonodon, and Stackhousiaceae are supported as members of Celastraceae. Gymnosporia and Tricerma are distinct from Maytenus, Cassine is supported as distinct from Elaeodendron, and Dicarpellum is distinct from Salacia. Catha, Maytenus, and Pristimera are not resolved as natural genera. Hippocrateaceae (including Plagiopteron and Lophopetalum) are a clade nested within a paraphyletic Celastraceae. These data also suggest that the Loesener's classification of Celastraceae sensu stricto and Hallé's classification of Hippocrateaceae are artificial. The diversification of the fruit and aril within Celastraceae appears to be complex, with multiple origins of most fruit and aril forms.

Mutations in MCT1 cDNA in patients with symptomatic deficiency in lactate transport.

We identified 5 patients with subnormal erythrocyte lactate transport plus symptoms and signs of muscle injury on exercise and heat exposure. All had transport rates below the 95% envelope for normals. Three cases had rates 40-50% of mean normal. One was found to have a missense mutation in monocarboxylate transporter 1 (MCT1), the gene for the red cell lactate transporter (also expressed in skeletal muscle), at a conserved site, which was not mutated in a cohort of 90 normal humans. The other 2 cases had a different missense mutation (at a nonconserved site), which was also not mutated in the normal cohort. All 3 patients were heterozygotes. We presume that these mutations are responsible for their subnormal lactate transport, and hence their muscle injury under environmental stress; homozygous patients should be more seriously compromised. The other 2 cases had lactate transport rates 60-65% of mean normal, and their MCT1 revealed a third mutation, which proved to be a common polymorphism in the normal cohort. These 2 patients may be physiologic outliers in lactate transport, with their muscle damage arising from some other genetic defect.

Data decisiveness, data quality, and incongruence in phylogenetic analysis: an example from the monocotyledons using mitochondrial atp A sequences.

We examined three parallel data sets with respect to qualities relevant to phylogenetic analysis of 20 exemplar monocotyledons and related dicotyledons. The three data sets represent restriction-site variation in the inverted repeat region of the chloroplast genome, and nucleotide sequence variation in the chloroplast-encoded gene rbcL and in the mitochondrion-encoded gene atpA, the latter of which encodes the alpha-subunit of mitochondrial ATP synthase. The plant mitochondrial genome has been little used in plant systematics, in part because nucleotide sequence evolution in enzyme-encoding genes of this genome is relatively slow. The three data sets were examined in separate and combined analyses, with a focus on patterns of congruence, homoplasy, and data decisiveness. Data decisiveness (described by P. Goloboff) is a measure of robustness of support for most parsimonious trees by a data set in terms of the degree to which those trees are shorter than the average length of all possible trees. Because indecisive data sets require relatively fewer additional steps than decisive ones to be optimized on nonparsimonious trees, they will have a lesser tendency to be incongruent with other data sets. One consequence of this relationship between decisiveness and character incongruence is that if incongruence is used as a criterion of noncombinability, decisive data sets, which provide robust support for relationships, are more likely to be assessed as noncombinable with other data sets than are indecisive data sets, which provide weak support for relationships. For the sampling of taxa in this study, the atpA data set has about half as many cladistically informative nucleotides as the rbcL data set per site examined, and is less homoplastic and more decisive. The rbcL data set, which is the least decisive of the three, exhibits the lowest levels of character incongruence. Whatever the molecular evolutionary cause of this phenomenon, it seems likely that the poorer performance of rbcL than atpA, in terms of data decisiveness, is due to both its higher overall level of homoplasy and the fact that it is performing especially poorly at nonsynonymous sites.

Detection of very-rare-copy DNA in 0.2-ml dried human blood blots.

A nested PCR assay for chromosome 7 inversions (as identified by the presence of T-cell receptor trans-rearrangements) can detect as rare a frequency as 1 copy in 300,000 leukocytes. To identify such rare occurrences from dried blood blots, the most conveniently obtained and stored samples for field population studies, demands a DNA extraction method that will provide both high quality and high yield. We have satisfied this requirement by extracting proteins and other components directly from the minced filter with phenol, before extracting the DNA with Chelex-water. This provides a near maximal yield of denatured DNA of sufficient quality to detect these translocations with a sensitivity equivalent to that of DNA purified from whole blood samples. Blots stored 6 months worked as well as fresh blots. In addition, we present a method for obtaining native DNA from the dried blots, although at a much lower yield. The successful use of blood blots to detect such rare events signals the feasibility of large-scale field studies involving diagnostic molecular epidemiology.

Comparative enzymology of AMP deaminase, adenylate kinase, and creatine kinase in vertebrate heart and skeletal muscle: the characteristic AMP deaminase levels of skeletal versus cardiac muscle are reversed in the North American toad.

The specific activity of three characteristic enzymes, adenylate deaminase, adenylate kinase, and creatine kinase, in the skeletal muscles and heart of a variety of vertebrate land animals, including the human, are surveyed. Data from this study and available studies in the literature suggest that adenosine monophosphate deaminase in land vertebrates is quite high in white skeletal muscle, usually somewhat lower in red muscle, and 15- to 500-fold lower in cardiac muscle. Adenosine monophosphate deaminase is active primarily under ischemic or hypoxic conditions which occur frequently in white muscle, only occasionally in red muscle, and ought never occur in heart muscle, and this may therefore account for observed enzyme levels. The common North American toad, Bufo americanus, provides a striking exception to the rule with cardiac adenosine monophosphate deaminase as high as in mammalian skeletal muscle, whereas its skeletal muscle level of adenosine monophosphate deaminase is several times lower. The exceptional levels in the toad are not due to a change in substrate binding and are not accompanied by comparable change in the level of adenylate or creatine kinase. Nor do they signal any major change in isozyme composition, since a human muscle adenosine monophosphate deaminase-specific antiserum reacts with toad muscle adenosine monophosphate deaminase, but not with toad heart adenosine monophosphate deaminase. They do not represent any general anuran evolutionary strategy, since the bullfrog (Rana catesbeiana) and the giant tropic toad (Bufo marinus) have the usual vertebrate pattern of adenosine monophosphate deaminase distribution.(ABSTRACT TRUNCATED AT 250 WORDS)

Chloroplast DNA inversions and the origin of the grass family (Poaceae).

The phylogenetic affinities of the grass family (Poaceae) have long been debated. The chloroplast genomes of at least some grasses have been known to possess three inversions relative to the typical gene arrangement found in most flowering plants. We have surveyed for the presence of these inversions in grasses and other monocots by polymerase chain reaction amplification with primers constructed from sequences flanking the inversion end points. Amplification phenotypes diagnostic for the largest inversion (28 kilobase pairs) were found in genera representing all grass subfamilies, and in the nongrass families Restionaceae, Ecdeiocoleaceae, and Joinvilleaceae, but not in any other monocots--notably, Flagellariaceae, Anarthriaceae, Cyperaceae, or Juncaceae. This finding is consistent with one of the two principal views of grass phylogeny in suggesting that Poaceae and Cyperaceae (sedges) are not closest relatives. A second (approximately 6 kilobases) inversion appears to occur in a subset of the families possessing the 28-kilobase inversion and links Joinvilleaceae and Poaceae, while the smallest inversion appears unique to grasses. These inversions thus provide a nested set of phylogenetic characters, indicating a hierarchy of relationships in the grasses and allies, with Joinvilleaceae identified as the likely sister group to the Poaceae.

Medical implications of the lactate and ammonia relationship in anaerobic exercise.

The genesis of the modern ischemic forearm exercise test (IFET) employing the measurement of lactate and ammonia as countervailing metabolites is briefly reviewed, along with the application of the lactate ammonia exercise ratio in the diagnosis of myoadenylate deaminase deficiency and disorders of glycolysis and glycogenolysis. Two cases are presented to illustrate the response patterns elicited, their reproducibility, the types of parameters that can be quantified, and the role the IFET may play in the differential diagnosis of fitness failures. The role of the ammonia measurement is emphasized here because the lactate response is more familiar. The roles of hypoxanthine responses and of muscle ammonia measurements in the evaluation of cases are examined, and some pertinent and recently introduced analytic methods are cited. The applications of newer approaches, such as aspiration biopsy and N-14 NMR spectroscopy, are discussed, along with an example of the new clinical defects in enzymes and membrane carriers that should be anticipated during the utilization of the IFET.

Clinical assay of the human erythrocyte lactate transporter. II. Analysis and display of normal human data.

We have applied a lactate efflux assay to human red cells at two temperatures and with initial lactic acid loads up to 8 mM, metabolically generated. Efflux was about 1.5 times faster at external pH of 8.5 than at 7.5; the latter was the standard pH used thereafter. Multiple lactate loads in a single blood specimen demonstrated clear evidence of saturation kinetics at both pH levels, since the efflux rate did not increase proportionally with the lactate load. Best-fitting rectangular hyperboles were determined for 129-131 assays from 43 volunteers at 20 degrees and 30 degrees. In most cases high and low lactate loads permitted a two-point evaluation of saturation kinetics, and a positive indication was obtained in 88 of 89 tests. The apparent efflux Km and Vm values may be influenced by pH as well as by lactate levels and cannot be taken as rigorous, although they agree reasonably well with literature data on influx and exchange velocities. The data displayed a Hill constant of 1, a 30 degrees/20 degrees velocity ratio of 2.7, and no significant clustering by sex or age. A single assay with initial lactate level above 5 mM at 30 degrees should be sufficient to identify cases with a defective transporter, using the 95% tolerance limits developed in this report.

Clinical assay of the human erythrocyte lactate transporter. I. Principles, procedure, and validation.

A clinically applicable method for the assay of lactate efflux from human red cells has been developed and described in detail. It requires only small volumes of blood and routine chemicals, and evaluates the process under physiological conditions and direction of lactate loading and transport. The decline of red cell lactate level fit a first order decay curve reasonably well, and better than the fit to zero order or second order plots. Bias is controlled by the use of least-squares curve fitting for all assays, and constraints on the elimination of outlier points. The assay shows a variety of inhibitor effects that may be considered typical for this transporter: potent inhibition by p-hydroxymercuribenzoate, but not by other types of sulfhydryl reagents; marked inhibition by phloretin, quercitin, and 1-fluoro-2,4-dinitrobenzene; lack of inhibition by the amine-reactive agents that block the chloride/carbonate exchanger, DIDS and SITS; and reversible competitive inhibition by alpha-cyano-4-OH-cinnamic acid. Harmaline and N-I-succinimide also produced effective inhibition. The assay also demonstrated transacceleration of L-lactate efflux in the presence of external additions of D-lactate, glycollate, iodoacetate, fluoropyruvate, and bromopyruvate, which are substituted monocarboxylates like lactate, but not by iodoacetamide or L-alanine. Such activation is a manifestation of a macromolecular carrier in operation, and cannot be explained by a pore or channel. These findings satisfy all reasonable criteria for a satisfactory and sensitive lactate transporter assay, which should be adequate to evaluate volunteers and patients for the normal range of this carrier, and to seek possible deficient states.

Levels of adenylate deaminase, adenylate kinase, and creatine kinase in frozen human muscle biopsy specimens relative to type 1/type 2 fiber distribution: evidence for a carrier state of myoadenylate deaminase deficiency.

Myoadenylate deaminase deficiency is believed to reflect a genetic deficiency of skeletal muscle, but its pattern of inheritance has not been established. We examined, histochemically and by quantitative biochemical assay, muscle biopsy specimens from 3 putative carriers of this disorder. Adenylate kinase and creatine kinase were assayed in parallel with adenylate deaminase in order to establish enzyme activity ratios and the variation of each enzyme with fiber-type distribution. Control tissue consisted of 34 biopsy specimens without notable abnormalities from 30 patients, and included 4 specimen pairs with disparate fiber-type contributions. By linear regression analysis, adenylate deaminase level averaged 2.8-fold higher, and adenylate kinase 4.5-fold higher, in type 2 than in type 1 fibers, whereas creatine kinase level did not differ. The slopes of the regression lines resulting from analysis of the four specimen pairs from individual patients agreed well with the overall regression line in each plot. The 3 putative carriers had adenylate deaminase levels 2.5 to 5.7 times lower than the mean control value for their fiber-type distribution, but at least 20 times higher than their enzyme-deficient kinfolk. This finding indicates that a carrier state does exist, and that the deficiency state reflects an autosomal recessive inheritance pattern. Three additional biopsy specimens were excluded from evaluation when preliminary analysis showed elevated adenylate kinase/adenylate deaminase ratios that were outliers at the 1% level. This result suggests a carrier incidence of 10% in the muscle biopsy specimen population, which would markedly bias population estimates if undetected.

Kinetic and immunologic evidence for a complete gene block in myoadenylate deaminase deficiency.

Muscle biopsies from patients with myoadenylate deaminase deficiency (mADD) have been evaluated kinetically and immunologically to ascertain the origin of residual enzyme activity. Kinetic evaluation employed 5 mM AMPS/1 mM AMP ratios, which were 0.7-0.8 for the human muscle isozyme, but 0-0.25 for the isozyme(s) of all other human blood cells and tissues examined. Of 14 control biopsies, 13 showed a ratio greater than 0.60 (one gave 0.47) regardless of the enzyme specific activity, while all 14 mADD biopsies showed a ratio less than 0.24, suggesting that a fetal muscle isozyme and/or blood cell isozyme were responsible for the residual activity. Confirmation was provided by rabbit antisera to purified human muscle AMP deaminase. These antisera fully precipitate the isozyme from crude human muscle biopsy homogenates, regardless of fiber-type composition, and cross-react effectively with the muscle isozyme of Rhesus monkeys and thoroughbred horses, but are inactive toward the isozymes of all other human blood cells and tissues examined. Of 18 mADD homogenates tested, 14 showed less than 20% reactivity with the antisera, at levels that precipitated 10 x more enzyme in control specimens. The residual activity in most cases of mADD must therefore arise from some source other than normal AMP deaminase. To evaluate the possibility of a single common determinant, 9 mADD homogenates were tested for soluble immune complexes. Seven of the 9 then showed 20-42% reactivity, suggesting that part of their residual activity may be due to an isozyme sharing one antigenic determinant with the normal muscle isozyme. Competitive antigen binding was used to assess whether catalytically inactive AMP deaminase was present in mADD. The method was demonstrated effective in identifying spontaneously inactivated purified enzyme and alkaline-inactivated crude enzyme. Nevertheless, homogenates from 17 mADD cases failed to produce more than 14% activation, under conditions in which 63-99% activation was expected. Triton X-100 extracts of homogenate residues of 11 mADD cases were also tested, in a search for insoluble antigen; none produced significant competition. The evidence thus indicates that most cases of mADD are due to a complete gene block, with total absence of all normal muscle AMP deaminase protein.

Consideration of atmospheric turbulence in laser systems design.

The physical basis for various effects of atmospheric turbulence on laser systems is briefly discussed, and certain limitations of the theoretical results given by Tatarski are summarized. The most important conclusion is that Tatarski's results for amplitude and phase fluctuations, while they are not applicable for a laser beam of arbitrary diameter, do provide an adequate approximation when the beam diameter is at least a factor of 2 greater than the lateral correlation length for amplitude fluctuations, which is true in many applications. The effects analyzed in some detail are beam steering, beam spreading, image dancing, image blurring, scintillation, and phase fluctuations, certain of which are intimately related. As to specific applications, the signal-to-noise ratio for an AM signal passing through the turbulent atmosphere is derived in terms of the power fluctuation, and communication links are considered in terms of this ratio; the effect of power fluctuations on the probability of detection for the laser radar is discussed in general, and a special example is given; finally, the spot size on the moon's surface for a transmitter located on the earth's surface is calculated for different turbulence conditions.