Ancient Ephemeroptera–Collembola Symbiosis Fossilized in Amber Predicts Contemporary Phoretic Associations

X-ray computed tomography is used to identify a unique example of fossilized phoresy in 16 million-year-old Miocene Dominican amber involving a springtail being transported by a mayfly. It represents the first evidence (fossil or extant) of phoresy in adult Ephemeroptera and only the second record in Collembola (the first is also preserved in amber). This is the first record of Collembola using winged insects for dispersal. This fossil predicts the occurrence of similar behaviour in living springtails and helps explain the global distribution of Collembola today.     

Serial extraction of endosperm drillings (SEED)—A method for detecting transgenes and proteins in single viable maize kernels

We have developed a method for detecting a transgene and its protein product in maize endosperm that allows the kernel to be germinated after analysis. This technique could be highly useful for several monocots and dicots. Our method involves first sampling the endosperm with a hand-held rotary grinder so that the embryo is preserved and capable of germination. This tissue is then serially extracted, first with SDS-PAGE sample buffer to extract proteins, then with an aqueous buffer to extract DNA. The product of the transgene can be detected in the first extract by SDS-PAGE with visualization by total protein staining or immuno-blot detection. The second extract can be purified and used as template DNA in PCR reactions to detect the transgene. This method is particularly useful for screening transgenic kernels in breeding experiments and testing for gene silencing in kernels.     

Orbital hydatid cyst of Echinococcus oligarthrus in a human in Venezuela

This study reports the first known case of human hydatid disease caused by the larval stage of Echinococcus oligarthrus. The patient, a native Venezuelan female, presented a single cyst localized intraorbitally behind the left eye (retroocular), which was discovered by computed tomography. The cyst was removed by surgery, and after parasitological studies it was identified as an E. oligarthrus hydatid cyst. This is also the first case of intraorbital hydatid cyst in humans in Venezuela.     

Palpebral paracoccidioidomycosis

This paper describes two cases of eyelid paracoccidioidomycosis (South American blastomycosis) in which it was the first signal of the disease. In both cases the first clinical diagnosis made was not a fungal infection, but a neoplastic disease that was not confirmed by the pathology study. In the first patient we suspected a primary infection on the eyelid, because there was no other systemic signs of the disease, and in the second patient we noted a very advanced pulmonary lesions caused by the Paracoccidioides brasiliensis. We believe that, in endemic areas, the histopathological study should be made before every excisional procedures to avoid unnecessary palpebral mutilation. This revised version was published online in June 2006 with corrections to the Cover Date.     

Ultrastructure and Ultracytochemistry of Fertilization Envelope Formation in the Carp Egg

This paper describes ultrastructural and ultracytochemical events occurring during the process of transformation of the vitelline envelope (VE) into the fertilization envelope (FE) in the egg of Cyprinus carpio. The VE is composed of four layers, except the micropylar region. The outermost (first) layer can be subdivided into a double layer (upper and lower halves) by cytochemical differences. The upper half is more protein-rich and positive for acid phosphatase (AcPase) activity, while the lower one is more carbohydrate-rich and negative for AcPase.
The most striking differences between the VE and the FE appear in the first layer component and the thickness. The FE first layer, ultrastructurally and cytochemically consisting of a single layer, gradually grows to be about five-fold as thick as the VE first layer by 40 min after fertilization. This may be due to displacement of the former VE first layer by deposits of the cortical alveolar exudate.     

The binding of diazepam in the mitochondria of Tetrahymena pyriformis as detected by quantitative high resolution autoradiography

Tritiated diazepam accumulates mainly in the mitochondria of the unicellular Tetrahymena. This is the case in both a single (the first encounter) and a repeated (one day or a week after the first) administration of the drug. When imprinting of Tetrahymena by diazepam (the first encounter) is followed a week later by the administration of the labelled drug, the membranes of the vesicles, too, show the appearance of label. Regarding the studies presented here, the unicellular Tetrahymena also contain diazepam receptors in the mitochondria as suggested for cells of higher rank animals.     

A novel method for measuring lag times in division of individual bacterial cells using image analysis

A method is presented for determining the time to first division of individual bacterial cells growing on agar media. Bacteria were inoculated onto agar-coated slides and viewed by phase-contrast microscopy. Digital images of the growing bacteria were captured at intervals and the time to first division estimated by calculating the "box area ratio". This is the area of the smallest rectangle that can be drawn around an object, divided by the area of the object itself. The box area ratios of cells were found to increase suddenly during growth at a time that correlated with cell division as estimated by visual inspection of the digital images. This was caused by a change in the orientation of the two daughter cells that occurred when sufficient flexibility arose at their point of attachment. This method was used successfully to generate lag time distributions for populations of Escherichia coli, Listeria monocytogenes and Pseudomonas aeruginosa, but did not work with the coccoid organism Staphylococcus aureus. This method provides an objective measure of the time to first cell division, whilst automation of the data processing allows a large number of cells to be examined per experiment.     

First Passage Time Analysis of Animal Movement and Insights into the Functional Response

Movement plays a role in structuring the interactions between individuals, their environment, and other species. Although movement models coupled with empirical data are widely used to study animal distribution, they have seldom been used to study search time. This paper proposes first passage time as a novel approach for understanding the effect of the landscape on animal movement and search time. In the context of animal movement, first passage time is the time taken for an animal to reach a specified site for the first time. We synthesize current first passage time theory and derive a general first passage time equation for animal movement. This equation is related to the Fokker–Planck equation, which is used to describe the distribution of animals in the landscape. We illustrate the first passage time method by analyzing the effect of territorial behavior on the time required for a red fox to locate prey throughout its home range. Using first passage time to compute search times, we consider the effect of two different searching modes on a functional response. We show that random searching leads to a Holling type III functional response. First passage time analysis provides a new tool for studying how animal movement may influence ecological processes.     

Adiaspiromycosis of human skin caused by Emmonsia crescens

Two cases of cutaneous adiaspiromycosis by Emmonsia crescens are reported. This is the first human skin infection by this species and is the first report of its kind in man from India. In the first patient, the agent was demonstrated in KOH mounts, histology and culture from irregular, pigmented skin plaques on the right gluteal area. The lesion also contained calcium. In the second patient the fungus was demonstrated histologically in a knee lesion. The agent had elicited a histiocytic and giant cell reaction in the dermis in both cases. The first patient suffered from anaemia and epilepsy and the second suffered from nephropathy with chyluria. The skin lesions were surgically excised with skin grafting in the first patient.     

溜下盾螨染色体组型及其G带的研究

本文首次报道了溜下盾螨(Hypoaspis lubrica)染色体组型及其G带的研究。结果表明,溜下盾螨组型为n=7,2n=14。具有单二倍体性决定系统。常规染色下未见明显的着丝粒。G带分析显示单倍体组有28～30条带。 对溜下盾螨的组型和分带研究以及革螨染色体制片方法进行了讨论。并首次报道了一种适合于革螨染色体研究的方法——改良气干法。     

Familial chylomicronemia caused by a novel type of mutation in the APOE-CI-CIV-CII gene cluster encompassing both the APOCII gene and the first APOCIV gene mutation: APOCII-CIV(Nijmegen)

Apolipoprotein CII (ApoCII) deficiency is a relatively rare cause of the chylomicronemia syndrome, a disorder characterized by severe fasting hypertriglyceridemia and massive accumulation of chylomicrons in plasma. Here we present a case which is the first example of apoCII deficiency caused by a major rearrangement in the APOCII gene. Southern blot analysis revealed an approximately 7.5-kb deletion disrupting the APOCII gene including the promotor region and first exon. Interestingly, the deletion also encompasses the APOCIV gene, a recently discovered novel gene upstream of APOCII. This deletion is the first mutation to be reported in the APOCIV gene.     

Pythium vexans causing patch canker of rubber trees on Hainan Island,China

This is the first report of patch canker disease of rubber trees (clone RRIM600) in China. It is characterized by discrete irregular patches of rotted, discolored bark and wood, accompanied by a decrease in latex flow. A total of seven isolates of Pythium vexans were obtained from the diseased bark of the trunks and roots of rubber trees. Inoculating these isolates into healthy, mature rubber trees resulted in symptoms similar to patch canker and the same fungal species was re-isolated from the diseased tissues. This is also the first record of Py. vexans in Hainan.     

A fossil fern indicator of epiphytism in a Tertiary flora

The first known indicator of probable fern epiphytism in the Tertiary fossil record is documented from the Eocene London Clay of southeast England. This pyritised fern rachis exhibits major deviation from the basic form of petiolar vascular trace morphology shown by the other London Clay fossil ferns and is here attributed to the Polypodiaceae. This represents the first known occurrence of this family in the London Clay macroflora, and brings the total of distinct fern rachis types from the Lower Tertiary of southeast England to six. The significance of this find is interpreted in relation to its probable origins from a tropical rainforest palaeoflora in which it is proposed that this specimen represents the first occurrence of an epiphytic component.     

Identification of extra-villous trophoblast cells in human decidua using an apparently unique murine monoclonal antibody to trophoblast

Summary Murine monoclonal antibodies were raised to human first trimester trophoblast cells. Eleven antibodies reacted with first trimester trophoblast, tested by immunoperoxidase staining on frozen sections, but only one had apparent specificity for trophoblast after examining reactivities with a panel of other cells and tissues. This antibody, designated FD0161G, bound selectively to syncytiotrophoblast and non-villous trophoblast in first trimester and term placentae. Villous cytotrophoblast was negative. This was clearly demonstrated on freeze-dried, paraffin embedded tissue sections which have superior architecture to frozen sections. FD0161G reacted with extra-villous trophoblast cells in human decidua which are also delineated by a monoclonal anti-cytokeratin antibody. Unlike the latter, however, FD0161G did not react with decidual glands. Thus FD0161G could be used as a specific probe for extra-villous trophoblast in decidual tissue     

Developmental study onHypolepis punctata (Thunb.) Mett.

The third petiolar bud ofHypolepis punctata appears on the basiscopic lateral side of the petiole above the fairly developed first petiolar bud. This investigation clarified the fact that the third bud is formed neither by the activity of the meristem of the first bud nor by the meristem directly detached from the shoot apical meristem, but is initiated in the cells involved in the abaxial basal part of the elevated portion of the leaf primordium. Thus the third bud is of phyllogenous origin. This investigation further revealed that the cells to initiate the third bud are originally located in the abaxial side of the leaf apical cell complex like the cells to initiate the first bud, but are not incorporated into the meristem of the first. After the first, second and third petiolar buds have been initiated, they are carried up into fairly high regions on the petiolar base by the intercalary growth which occurs in the leaf base below the insertion level of the first and the second buds.     

Exploring the Science of Sound

This investigation-based lesson is geared toward third through fifth grade students. The lesson presented in this article was the first of three lessons designed and taught by us for our first preservice teaching course. UTeach is a teacher preparation program for undergraduate STEM majors, which originated at the University of Austin, Texas. The first course taken by UTeach interns is STEP 1—Inquiry Approaches to Teaching. All UTeach courses promote the use of the 5E (Engage, Explore, Explain, Elaborate, and Evaluate) instructional model. We planned this first lesson by incorporating only Exploration, Explanation, and Elaboration and addressed the most basic principle of sound, which is that sounds are caused by vibrations that travel through some materials (mediums) better than others.     

The morphogenetic significance of the first quartet micromeres for the development of the snailBithynia tentaculata

Summary The significance of the first quartet of micromeres for the morphogenesis ofBithynia — a polar lobe-forming gastropod-has been studied by deletion experiments. After removal of the whole first quartet at the 8-cell stage a dorsoventrally organized veliger larva is formed. Apparently, an interaction between the animal micromeres and a vegetal macromere, which is essential for the origin of a dorsoventral organization in equally cleaving gastropods, is not required in polar lobe forming eggs. It is concluded that in these eggs dorsoventrality is determined by segregation of the polar lobe. The embryos, in which the first quartet has been removed, never develop head structures. This indicates that the capacity to form head structures is restricted to the first quartet of micromeres. Deletion of a specific first quartet micromere (1a, 1b, 1c or 1d) showed, however, that the individual cells of this quartet are not strictly determined right from their origin. Frequently regulative development was observed after removal of individual first quartet cells.