Aspergillus myositis in a patient with a myelodysplastic syndrome

We present the case of an elderly man who, while being treated with corticosteroids for a myelodysplastic syndrome, developed myositis of the calf due to Aspergillus fumigatus. Despite therapy with amphotericin B the myositis failed to resolve and he died. At autopsy, a localized necrotizing myositis of the right calf was found with no evidence of disseminated Aspergillus infection. Myositis in the setting of disseminated candidiasis or cryptococcosis has been previously reported. This case is unique in that it is the first reported case of localized fungal myositis and of myositis caused by Aspergillus.     

Numerical solutions of the Lamm equation. II. Equilibrium sedimentation

The Lamm equation has been solved numerically for conditions corresponding to equilibrium runs for a nonlinear concentration dependence of the form s/s₀ = (1 + kc)^?1. It is shown that the approach to equilibrium is very close to being exponential (in time) as in the case k = 0. We also compare results for the nonlinear case given above with results obtained for linear c-dependence of the form s/s₀ = 1 – kc. For relatively high speeds the time required to attain equilibrium may be greatly underestimated by use of the latter approximation. Finally, we present analytic approximations for the concentration distribution at equilibrium and as a function of time.     

A net reproductive number for periodic matrix models

We give a definition of a net reproductive number R ₀ for periodic matrix models of the type used to describe the dynamics of a structured population with periodic parameters. The definition is based on the familiar method of studying a periodic map by means of its (period-length) composite. This composite has an additive decomposition that permits a generalization of the Cushing–Zhou definition of R ₀ in the autonomous case. The value of R ₀ determines whether the population goes extinct (R ₀<1) or persists (R ₀>1). We discuss the biological interpretation of this definition and derive formulas for R ₀ for two cases: scalar periodic maps of arbitrary period and periodic Leslie models of period 2. We illustrate the use of the definition by means of several examples and by applications to case studies found in the literature. We also make some comparisons of this definition of R ₀ with another definition given recently by Bacaër.     

Primary subcutaneous Nocardia asteroides infection in a renal allograft recipient

Nocardia asteroides is an important opportunistic pathogen in immunocompromised hosts. The primary infection is usually in the lungs and is followed by dissemination to other parts of the body. Primary subcutaneous infection with Nocardia asteroides has been reported rarely (three reports) and no such case has been reported in a renal transplant recipient. We describe here a case of renal transplant recipient who developed primary subcutaneous infection with Nocardia asteroides within one and half years of the transplantation. This revised version was published online in June 2006 with corrections to the Cover Date.     

The Hawaiian amphibious caterpillar guild: new species of Hyposmocoma (Lepidoptera: Cosmopterigidae) confirm distinct aquatic invasions and complex speciation patterns

Although aquatic caterpillars are a globally rare lifestyle, we have found them in multiple, independent lineages of the endemic moth genus Hyposmocoma across all of the Hawaiian Islands with flowing water. We formally describe 11 new species of Hyposmocoma that belong to four different larval case types: cone, bugle, medium burrito, and large burrito: Hyposmocoma kahamanoa sp. nov. from Oahu Island, Hyposmocoma kamakou sp. nov. from Molokai Island, Hyposmocoma kahaiao sp. nov. , Hyposmocoma waihohonu sp. nov. , and Hyposmocoma moopalikea sp. nov. from Maui Island, and Hyposmocoma aumakuawai sp. nov. , Hyposmocoma eepawai sp. nov. , Hyposmocoma ipowainui sp. nov. , Hyposmocoma kawaikoi sp. nov. , Hyposmocoma uhauiole sp. nov. , and Hyposmocoma wailua sp. nov. from Kauai Island. We also illustrate and describe in detail the aquatic case‐bearing larva of Hyposmocoma kahamanoa. Despite having similar ecologies as algae and lichen grazers at and below the water line of streams, prior research indicates that species with each case type constitute an independent lineage, with terrestrial sister taxa, and therefore the different groups of species bearing unique case types each represent an independent aquatic invasion. The case‐bearing larvae often occur sympatrically, and on Kauai even species with similar case‐types occur together, suggesting complex patterns of speciation and either past periods of isolation or sympatric speciation. Phylogenetic analysis of 2243 base pairs from two nuclear and one mitochondrial gene for 18 species confirm that each species is endemic to a single volcano, and that morphological divergence within case‐types has not been dramatic. Diversification has been complex, and superficially similar case type lineages are not all monophyletic. Kauai, the oldest but smallest of the major high islands, supports more species in the aquatic guild than any other island, thus island age, rather than size, may be important in generating diversity in this group. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 162 , 15–42.     

On the industrial use of Bacillus licheniformis: a review

We document here that in those rare cases where disease has been related to Bacillus licheniformis, infection was associated with bypassing the normal biological protective barriers or severely debililated patients. No case suggests any invasive properties of this bacterium. B. licheniformis can therefore be considered non-pathogenic to humans in general. Food-borne illness caused by possible B. licheniformis toxins have been reported, but only in a very few cases and only in connection with consumption of inappropriately prepared food. Considerable experience concerning the industrial use of recombinant B. licheniformis strains has now accumulated and authorities in the United States, Europe and Japan have approved production with and products from recombinant B. licheniformis strains. We conclude that B. licheniformis is a safe host for the production of harmless, industrial products. Correspondence to: B. Diderichsen     

Superinfections can induce evolutionarily stable coexistence of pathogens

Parasites reproduce and are subject to natural selection at several different, but intertwined, levels. In the recent paper, Gilchrist and Coombs (Theor. Popul. Biol. 69:145–153, 2006) relate the between-host transmission in the context of an SI model to the dynamics within a host. They demonstrate that within-host selection may lead to an outcome that differs from the outcome of selection at the host population level. In this paper we combine the two levels of reproduction by considering the possibility of superinfection and study the evolution of the pathogen’s within-host reproduction rate p. We introduce a superinfection function φ = φ(p,q), giving the probability with which pathogens with trait q, upon transmission to a host that is already infected by pathogens with trait p, “take over” the host. We consider three cases according to whether the function q → φ(p,q) (i) has a discontinuity, (ii) is continuous, but not differentiable, or (iii) is differentiable in q = p. We find that in case (i) the within-host selection dominates in the sense that the outcome of evolution at the host population level coincides with the outcome of evolution in a single infected host. In case (iii), it is the transmission to susceptible hosts that dominates the evolution to the extent that the singular strategies are the same as when the possibility of superinfections is ignored. In the biologically most relevant case (ii), both forms of reproduction contribute to the value of a singular trait. We show that when φ is derived from a branching process variant of the submodel for the within-host interaction of pathogens and target cells, the superinfection functions fall under case (ii). We furthermore demonstrate that the superinfection model allows for steady coexistence of pathogen traits at the host population level, both on the ecological, as well as on the evolutionary time scale.      

First Report of <Emphasis Type="Italic">Tritirachium oryzae</Emphasis> Infection of Human Scalp

The natural habitat of Tritirachium oryzae is soil and decaying plant material. It is also an insect pathogen. As a human pathogen, it has been reported as a cause of corneal ulcers and otomycosis. The case of a 4-year-old infant is reported with Tritirachium oryzae infection of the scalp. Diagnosis was established by direct mycological study and culture that showed Tritirachium oryzae as the only agent in a pure culture. The topical treatment involved an antifungal medication to a complete cure. We report the first case of scalp dermatomycosis due to Tritirachium oryzae infection, illustrating a novel clinical manifestation.     

Cannibalism in the Andean lizard Liolaemus orientalis

Cannibalism is a recurrent behavior across the animal kingdom, with important ecological and evolutionary consequences due to its potential trade-offs on the fitness of involved individuals and demography dynamics. Cannibalism has been reported in eight species of several phylogenetic lineages within Liolaemus, a highly diverse genus of Neotropical lizards. Within the Liolaemus montanus series, two species are reported to eat juveniles in captivity. We observed a female Liolaemus orientalis, another L. montanus series member, which had ingested a juvenile of its own species in the wild. As it generally happens with other lizards, cannibalism in Liolaemus has been suggested to be performed by the larger sex, with L. chiliensis being the only other case observed until now in which the cannibalistic individual was a female. The fact that females are slightly smaller than males in L. orientalis means that our observation is an exception to previously observed trends. We suggest that there is a relationship between this behavior and the presence of a masculine trait in the cannibalistic female: developed precloacal pores. We also discuss how refuge availability may influence demography and the probability of dispersing juveniles encountering adults, increasing the chances for cannibalism to play some role in population density regulation.     

Formation of recombinant lacZ+ DNA in conjugational crosses with a recB mutant of Escherichia coli K12 depends on recF, recJ, and recO

Summary Conjugational recombination in Escherichia coli was investigated by monitoring synthesis of the lacZ ⁺ product, -galactosidase, in crosses between lacZ mutants. We report here that mutation of recB and any combination of recF, recJ, or recO reduces enzyme production by a factor of between 10- and 25-fold whereas mutation of only one of these genes or any combination of recF, recJ, or recO has no more than a 2-fold effect. Mutation of recN has no effect either alone or in combination with the other mutations. We suggest that the products of recF, recJ, and recO may provide an efficient alternative to the RecBCD enzyme for the initiation of recombination in conjugational crosses but that RecBCD activity is needed in this case to produce a viable recombinant product.     

<Emphasis Type="Italic">Histoplasma capsulatum</Emphasis> Sinusitis: Case Report and Review

Histoplasma capsulatum has not typically been associated with sinusitis in either immunocompetent or immunocompromised hosts. We report a case of sinusitis caused by H. capsulatum in a patient with chronic lymphocytic leukemia and discuss the reported cases of this rare clinical manifestation of histoplasmosis in the medical literature.     

Why pollinators visit only a fraction of the open flowers on a plant: The plant's point of view

We analyze the so-called ‘exponential decay’ model of pollen transfer for the case in which pollinators visit a fraction of the open flowers on a plant. The analysis is limited to the simplest case of a self-incompatible species, in which self pollen does not interfere with seed set. Plants can manipulate the number of flowers visited per pollinator approach by adjusting attractiveness of flowers so as to maximize pollen export (male fitness). In the model the length of the visitation sequence that is optimal for the plant f? always decreases with pollen deposition rate k₁, pollen uptake rate k₂, and the number of pollinator approaches to the plant X, but increases with the total number of flowers F. We assume that the average number of pollinator approaches X increases with the total number of flowers F, but slower than proportionality. It then follows that the optimal fraction of flowers a pollinator visits after arriving on the plant (f?/F) decreases with the total number of flowers F. Furthermore, the male fitness gain per flower generally decreases with number of flowers, except for the condition of ‘inefficient’ pollen transfer with very small values of k₁, k₂, and X, or when the plant has only a few flowers. The latter conditions should favour high nectar production and mass blooming. The known range of parameters suggests that male fitness increases with the total number of flowers slower than proportionality.     

Genealogy with seasonality,the basic reproduction number,and the influenza pandemic

The basic reproduction number R ₀ has been used in population biology, especially in epidemiology, for several decades. But a suitable definition in the case of models with periodic coefficients was given only in recent years. The definition involves the spectral radius of an integral operator. As in the study of structured epidemic models in a constant environment, there is a need to emphasize the biological meaning of this spectral radius. In this paper we show that R ₀ for periodic models is still an asymptotic per generation growth rate. We also emphasize the difference between this theoretical R ₀ for periodic models and the “reproduction number” obtained by fitting an exponential to the beginning of an epidemic curve. This difference has been overlooked in recent studies of the H1N1 influenza pandemic.     

Modeling the Dynamics of Viral Evolution Considering Competition Within Individual Hosts and at Population Level: The Effects of Treatment

We consider two viral strains competing against each other within individual hosts (at cellular level) and at population level (for infecting hosts) by studying two cases. In the first case, the strains do not mutate into each other. In this case, we found that each individual in the population can be infected by only one strain and that co-existence in the population is possible only when the strain that has the greater basic intracellular reproduction number, R _0c , has the smaller population number R _0p . Treatment against the one strain shifts the population equilibrium toward the other strain in a complicated way (see Appendix B). In the second case, we assume that the strain that has the greater intracellular number R _0c can mutate into the other strain. In this case, individual hosts can be simultaneously infected by both strains (co-existence within the host). Treatment shifts the prevalence of the two strains within the hosts, depending on the mortality induced by the treatment, which is, in turn, dependent upon the doses given to each individual. The relative proportions of the strains at the population level, under treatment, depend both on the relative proportions within the hosts (which is determined by the dosage of treatment) and on the number of individuals treated per unit time, that is, the rate of treatment. Implications for cases of real diseases are briefly discussed.     

Ricerche Citotassonomiche in Artemisia Vulgaris L. Ed Artemisia Verlotorum Lamotte

Abstract

Cytotaxonomical studies in Artemisia vulgaris L. and Artemisia verlotorum Lamotte. — Karyotype analysis of A. vulgaris and A. verlotorum has shown in the first species, in agreement with previous data, a chromosome number of 2n=16 and in the second the chromosome number of 2n=48 which does not agree with previous data. This seems to be the first case of polyploidy observed in Artemisia with basic number eight. A few specimens of A. verlotorum had shown 2n=48 + 2B chromosomes. The comparison of karyotypes has shown that, while the two species have, in some respect, the same degree of symmetry (ΣL%=57; ΣC9% = 43), the quality of their chromosomes is different (see karyotype formulas). We see no explanation for such an unlikely phenomenon.     

Male territoriality and ‘sex confusion’ in recently adapted lizards at White Sands

The evolution of intersexual interactions, like mate choice, during ecological speciation has received widespread attention. However, changes in intrasexual interactions, like male territoriality, during ecological divergence are largely unexamined. We conducted field experiments with adaptively diverged populations of the eastern fence lizard (Sceloporus undulatus) to determine whether territorial males behaved differently towards ecologically similar vs. dissimilar intruders. We performed trials with light‐coloured males from White Sands, New Mexico and dark‐coloured males from the surrounding desert. We found that intruders from White Sands elicited more aggression than intruders from dark‐soil habitat. We also documented a case of ‘sex confusion’ where white‐sand males courted dark‐soil intruders. We found population differences in signalling patch size that can explain both aggression bias and sex misidentification. We argue that direct selection (for population recognition or optimal signal transmission) and indirect selection (by‐products of ecological adaptation) should influence both intersexual and intrasexual interactions during ecological speciation.     

Island life – classification,speciation and cryptic species of Pycnandra (Sapotaceae) in New Caledonia

Pycnandra (Sapotaceae), the largest endemic genus in New Caledonia, comprises 66 species classified in six subgenera. We tested phylogenetic relationships and a proposed infrageneric classification by sampling 60 species for sequences of nuclear ribosomal DNA (ETS, ITS, RPB2) and plastid DNA (trnH–psbA) and nine morphological characters. Data were analysed with Bayesian inference, parsimony jackknifing and lineage through time. We recovered a phylogenetic tree supporting the recognition of six proposed subgenera (Achradotypus, Leptostylis, Pycnandra, Sebertia, Trouettia and Wagapensia). Because a subgeneric classification is used, the nomenclature will be stable when the members are transferred to Pycnandra. Morphological traits were optimized in the BEAST analysis, adding evidence to earlier work that morphology has limited value for successfully diagnosing groups in Sapotaceae. We confirm a previously suspected case of cryptic species that exhibit the same morphological features and require the same abiotic conditions, but are distantly related in the phylogenetic tree. We detected two possible new cases of cryptic sibling species that might warrant recognition. A slowdown in speciation rate in several genera has been suggested as evidence that New Caledonia was once submerged after rifting from Australia. Plotting lineages through time reveals two important intervals at 7.5–8.6 Ma and present to 1.5 Ma, when net molecular diversification within the genus was zero. This indicates that the genus presently has reached a dynamic equilibrium, providing additional evidence that New Caledonia is an old Darwinian island, being submerged during the Eocene and colonized after re‐emergence c. 37 Ma. © 2015 The Linnean Society of London, Botanical Journal of the Linnean Society, 2015, 179 , 57–77.     

To hatch and hatch not: similar selective trade-offs but different responses to egg predators in two closely related, syntopic treefrogs

Risk-sensitive hatching is adaptive for species facing a trade-off between egg-stage and post-hatching risks, and environmental variation in one or both stages. Such plasticity has been found in amphibians, fishes, reptiles and spiders, with red-eyed treefrogs (Agalychnis callidryas) being the best-studied case. We assessed hatching plasticity and egg- and larval-stage risks in a closely related, syntopic species, the gliding leaf-frog (Agalychnis spurrelli). We found a lower hatching response to egg-eating snakes in A. spurrelli (9–28% of embryos escaped) than in A. callidryas (59–80% escaped). Levels of snake predation were similarly high for clutches of both species monitored at a pond in Costa Rica, and in fish predation experiments early-hatched A. spurrelli tadpoles were more vulnerable than later hatchlings, as has been shown for A. callidryas. A. spurrelli thus face a risk trade-off similar to A. callidryas, and likely would benefit from predator-induced hatching; their lower responsiveness to snakes appears nonadaptive. A. spurrelli embryos showed a stronger hatching response (57% hatched in 1 h) to submergence underwater than to snake attacks even though submergence is a less frequent risk. This suggests they have a greater capacity for early hatching than is expressed in the context of snake attacks, but have much lower sensitivity to snake cues than to flooding cues. Development in A. spurrelli is accelerated compared to syntopic A. callidryas, and spontaneous hatching is earlier and more synchronous. This is congruent with predictions based on selection by egg predators in the absence of a strong escape hatching response.