Habitat alters the effect of false starts on seasonal‐wetland invertebrates

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Developmental and Ultrastructural Characterization and Phylogenetic Analysis of Trypanosoma herthameyeri n. sp. of Brazilian Leptodactilydae Frogs

We described the phylogenetic affiliation, development in cultures and ultrastructural features of a trypanosome of Leptodacylus chaquensis from the Pantanal biome of Brazil. In the inferred phylogeny, this trypanosome nested into the Anura clade of the basal Aquatic clade of Trypanosoma, but was separate from all known species within this clade. This finding enabled us to describe it as Trypanosoma herthameyeri n. sp., which also infects other Leptodacylus species from the Pantanal and Caatinga biomes. Trypanosoma herthameyeri multiplies as small rounded forms clumped together and evolving into multiple‐fission forms and rosettes of epimastigotes released as long forms with long flagella; scarce trypomastigotes and glove‐like forms are common in stationary‐phase cultures. For the first time, a trypanosome from an amphibian was observed by field emission scanning electron microscopy, revealing a cytostome opening, well‐developed flagellar lamella, and many grooves in pumpkin‐like forms. Transmission electron microscopy showed highly developed Golgi complexes, relaxed catenation of KDNA, and a rich set of spongiome tubules in a regular parallel arrangement to the flagellar pocket as confirmed by electron tomography. Considering the basal position in the phylogenetic tree, developmental and ultrastructural data of T. herthameyeri are valuable for evolutionary studies of trypanosome architecture and cell biology.     

Concentrations of heavy metals in fish species targeted by anglers in central New Jersey: A pilot study

The purpose of this study was to investigate the concentrations of toxic metals in the edible portion of fish tissue obtained from the Raritan River in New Brunswick, New Jersey (NJ) between April and May of 2014. Species collected for this study included commonly caught fish such as bluegill, small and large mouth bass, brown and rainbow trout, bullhead catfish, and white perch. Samples were filleted and the muscle tissue subsequently dehydrated and then chemically digested. Samples were analyzed using Gas chromatography mass spectrometry (GC–MS). Levels of 28 different metals were quantified for each specimen. In general, metal contamination in fish tissues was below the recommended limits. However, lead was found in one sample at a tissue concentration of 88 µg per 225 g fillet, which is above the recommended daily consumption limit as set by the Food and Safety Authority of Ireland. The maximum level found for arsenic was 23 µg per 225 g fillet. The fish samples taken from the Raritan River in New Brunswick, NJ for this study did not contain dangerous levels of most of the metals tested.     

The effect of severe eccentric exercise-induced muscle damage on plasma elastase, glutamine and zinc concentrations

The aim of this study was to determine if severe exercise-induced muscle damage alters the plasma concentrations of glutamine and zinc. Changes in plasma concentrations of glutamine, zinc and polymorphonuclear elastase (an index of phagocytic cell activation) were examined for up to 10 days following eccentric exercise of the knee extensors of one leg in eight untrained subjects. The exercise bout consisted of 20 repetitions of electrically stimulated eccentric muscle actions on an isokinetic dynamometer. Subjects experienced severe muscle soreness and large increases in plasma creatine kinase activity indicative of muscle fibre damage. Peak soreness occurred at 2 days post-exercise and peak creatine kinase activity [21714 (6416) U · l⁻¹, mean (SEM)] occurred at 3 days post-exercise (P < 0.01 compared with pre-exercise). Plasma elastase concentration was increased at 3 days post-exercise compared with pre-exercise (P < 0.05), and is presumably indicative of ongoing phagocytic leucocyte infiltration and activation in the damaged muscles. There were no significant changes in plasma zinc and glutamine concentrations in the days following eccentric exercise. We conclude that exercise-induced muscle damage does not produce changes in plasma glutamine or zinc concentrations despite evidence of phagocytic neutrophil activation. Accepted: 3 November 1997     

Conserved structure and function of the Arabidopsis flowering time gene CONSTANS in Brassica napus

The Arabidopsis thaliana CONSTANS (CO) gene which promotes flowering in long days was recently isolated by chromosome walking. The mapping of QTLs controlling flowering time in Brassica species has identified genomic regions that contain homologues of the CO gene. Four genes homologous to the Arabidopsis CO gene were isolated from a pair of homoeologous loci in each of two doubled-haploid Brassica napus lines displaying different flowering times, N-o-1 and N-o-9. The four genes, BnCOa1, BnCOa9, BnCOb1 and BnCOb9, are located on linkage groups N10 and N19, and are highly similar to each other and to the Arabidopsis CO gene. Two regions of the proteins are particularly well conserved, a N-terminal region with two putative zinc fingers and a C-terminal region which may contain a nuclear localization signal. All four genes appear to be expressed in B. napus. The BnCOa1 allele was shown to complement the co-2 mutation in Arabidopsis in a dosage-dependent manner causing earlier flowering than in wild type under both long- and short-day conditions.     

Characterization of a Variant ofAutographa californicaNuclear Polyhedrosis Virus with a Nonfunctional ORF 603

A new genotypic variant ofAutographa californicanuclear polyhedrosis virus (AcMNPV), the V8 variant, was originally identified by an additionalHindIII site in theHindIII–F fragment. Insect bioassays of this variant displayed a decreased time of mortality compared with the L1 variant of AcMNPV inSpodoptera frugiperdalarvae but not inTrichoplusia nilarvae. A 1.8-kb region containing the 3′ end of ORF 5,lef-2,ORF 603, and the 5′ end of the polyhedrin gene (polh) of both L1 and V8 was sequenced. V8 exhibited extensive sequence variation in the region between the 3′ end oflef-2and the 5′ end ofpolh; V8 had six amino acid substitutions in thelef-2gene product and a nonfunctional ORF 603. A site-specific frameshift mutation in ORF 603 of the L1 variant was constructed to determine the effect of ORF 603 inS. frugiperdalarvae. Truncation of ORF 603 was found to decrease the time of mortality inS. frugiperdalarvae. The insect-selective toxin gene,tox34, was inserted into the V8 variant by direct cloning. The efficacy of this recombinant as a biopesticide was equivalent to similar L1 recombinants.     

Factors affecting the heat resistance of Escherichia coli O157 : H7

Escherichia coli O157 : H7 has been reported as being not particularly heat resistant. However, several factors which might increase its heat resistance have been investigated in this study using five strains. Increase in growth temperature to 40 °C, as found in the cow gut, heat-shock at sub-lethal temperatures of 42, 45, 48 and 50 °C, and variable heating rate (1 °C min⁻¹ to 23 °C min⁻¹) had no dramatic effect on heat resistance. Growth phase had a marked impact on heat resistance ; late stationary phase cells were more heat-resistant than were log phase cells. The difference in heat resistance between the two phases of growth became more pronounced when cells were resuspended in fresh nutrient broth ; heat resistance of late stationary phase cells increased dramatically whereas no such effect was observed with log phase cells. The addition of polyphosphates to the heating medium did not increase heat resistance. A reduction in water activity of the heating medium from 0·995 to levels between 0·980 and 0·960 also resulted in a marked increase in heat resistance. This effect was more pronounced under conditions of extremely low water activity created by resuspending late stationary phase cells in sunflower oil. Survivors were detected even after a heat treatment at 60 °C for 1 h or 70 °C for 5 min. It can be confirmed that this serotype has no unusual heat resistance and that the heating environment markedly affects resistance.     

Rapid mapping of markers applying vectorette technology to YAC fragmentation allows easy assembly of a high-density STS bacterial clone contig spanning the markers D6S1260-D6S1918

We have generated a detailed physical map of the 6p21.3/p22.1 boundary, using a combination of yeast artificial chromosome (YAC) fragmentation and high-resolution sequence tagged site (STS) content mapping. YACs from the CEPH, St. Louis, and ICRF libraries have been used to construct a 4.5-Mb contig spanning the markers D6S306 to D6S1571. YAC insert sizes were determined by pulsed field gel electrophoresis (PFGE). Chimerism of YACs was determined by fluorescent in situ hybridization (FISH), and their integrity was determined by fingerprinting with Alu-PCR. We have identified 10 new CA repeat loci in this region as well as over 50 novel STSs, several tRNA genes, a new histone H2B gene and the phospholipase D gene. Using these new markers, we have rapidly generated a bacterial clone contig of over 250 kb, spanning the markers D6S1260 to D6S1918 (WI-3111) with STSs spaced on average every 6 kb. Received: 18 September 1997 / Accepted: 13 November 1997     

Fair shares in health care? Ethnic and socioeconomic influences on recording of preventive care in selected inner London general practices. Healthy Eastenders Project.

OBJECTIVE--To describe the association of ethnic and socioeconomic status with recording of preventive care information by selected general practitioners. DESIGN--Random selection of people aged 20-64 registered with 43 general practitioners. Ethnic and social characteristics of stratified samples were determined at interview in the subject''s home. Recording of preventive information was ascertained from general practitioners'' medical records. SETTING--Inner London borough of Tower Hamlets. SUBJECTS--505 ut of 739 people confirmed as residents at their home address (190 white, 86 black, 112 Bangladeshi, 105 Chinese or Vietnamese, 12 other). MAIN OUTCOME MEASURES--Socioeconomic characteristics, consultation with general practitioner, and recorded preventive activities for ethnic groups. RESULTS--Minority ethnic groups were considerably more disadvantaged than white people and five times more likely to be overcrowded (31% v 6%), three times less likely to own their own home(11% v 37%), twice as likely to be in social classes IV and V (54% v 28%) and less likely to be employed (34% v 63%). There were no significant differences between white, black, Bangladeshi, and Chinese or Vietnamese subjects in recording smoking, blood pressure, alcohol consumption, weight, and height in the general practitioners'' medical records. White women were more likely to have a record of mammography (46% v 20%; P=0.03) and of cervical smears than women in minority ethnic groups. CONCLUSION--Despite major socioeconomic inequity, equitable recording of preventive activity for the major causes of death for white, black and Bangladeshi populations is possible. Chinese and Vietnamese people had lower levels of recording and consultation. Mammography and, to a lesser extent, cervical cytology are inequitably recorded and require additional support at practice level.     

Polarized Growth of Fungal Hyphae Is Defined by an Alkaline pH Gradient

Robson, G. D., Prebble, E., Rickers, A., Hosking, S., Denning, D. W., Trinci, A. P. J., and Robertson, W. 1996. Polarized growth of fungal hyphae is defined by an alkaline pH gradient. Fungal Genetics and Biology 20, 289-298. Polarized cell growth is exhibited by a diverse range of eukaryotic and prokaryotic cells. The events which are responsible for this growth are poorly understood. However, the existence of ion gradients may play an important role in establishing and driving cell polarity. Using a pH-sensitive, ratiometric fluorescent dye to monitor intracellular pH in growing fungal hyphae, we report a gradient at the extending hyphal tip that is up to 1.4 pH units more alkaline than more distal regions. Both the magnitude and the length of the pH gradient were strongly correlated with the rate of hyphal extension and eradication of the gradient-arrested growth. These results suggest that alkaline pH gradients may be integral to hyphal extension in fungi.