Male mating season range expansion results from an increase in scale of daily movements for a polygynous-promiscuous bird

Males of species with promiscuous mating systems are commonly observed to use larger ranges during the mating season relative to non-mating seasons, which is often attributed to a change in movements related to reproductive activities. However, few studies link seasonal range sizes to variation in daily space use patterns to provide insight into the behavioral mechanisms underlying mating season range expansion. We studied 20 GPS-tagged male wild turkeys (Meleagris gallopavo), a large upland gamebird, during the mating and summer non-mating seasons to test the hypothesis that larger mating season ranges resulted from male wild turkeys expanding the scale of daily movement activities to locate and court females. We delineated mating and non-mating seasons based on intensity of gobbling, a vocalization tied to courtship behavior, recorded by autonomous recording units distributed across the study area. Mating season ranges were significantly larger than non-mating season ranges. Daily ranges were larger in the mating season, as were distances between roost sites used on consecutive nights. Variance in daily range size was greater in the mating season, but low temporal autocorrelation suggested considerable daily variability in both seasons. We found no evidence that male wild turkeys changed how they distributed daily movements within seasonal ranges, or differences in habitat use, suggesting larger mating season ranges result from male wild turkeys increasing the scale of their daily movements, rather than a systematic shift to a nomadic movement strategy. Likely, the distribution of females is more dynamic and ephemeral compared to other resources, prompting males to traverse larger daily ranges during the mating season to locate and court females. Our work illustrates the utility of using daily movement to understand the behavioral process underlying larger space use patterns.

Movement ecology of diploid and triploid grass carp in a large reservoir and upstream tributaries

Grass carp Ctenopharyngodon idella, is an herbivorous fish originally brought to North America from Asia in 1963 to control nuisance aquatic vegetation. Since their arrival, detrimental alterations to aquatic ecosystems have sometimes occurred in waterways where they were initially stocked and into which they have escaped. The movements of grass carp from lentic systems into tributaries required for spawning is poorly understood, and understanding environmental conditions associated with upstream migrations may aid in management of the species. We stocked 43 fertile diploid and 43 sterile triploid grass carp implanted with acoustic transmitters into Truman Reservoir, Missouri, USA between January 2017 and October 2018 to characterize movements during spring and summer when spawning conditions occur. Twenty fish (11 diploid/9 triploid) exhibited upstream migration behavior in the Osage River, a major tributary, in 2018 and 2019. Migration primarily occurred in April and May, during high discharge events associated with increasing river stage when water temperatures were between 15 and 28°C. Observed migrations ranged from 3.0-108 river km in length, and six individuals were observed making multiple upstream migrations in one season. Eleven fish initiated upstream migrations while in the lentic main body of the reservoir. These findings provide some evidence for upstream migrations by diploid and triploid grass carp as well both lake and river residents. Evidence of similar upstream migration behavior by both diploid and triploid grass carp suggests that triploids may be suitable surrogates for diploids for study of movement ecology. Removal efforts in tributaries targeting periods of increasing river stage during spring may provide the best opportunity of encountering large concentrations of grass carp.

Food resources affect territoriality of invasive wild pig sounders with implications for control

Interest in control methods for invasive wild pigs (Sus scrofa) has increased due to their range expansion, population growth, and an improved understanding of their destructive ecological and economic effects. Recent technological advances in traps for control of pig populations facilitate capture of entire social groups (sounders), but the efficacy of “whole-sounder” trapping strategies is heavily dependent on the degree of territoriality among sounders, a topic little research has explored. We assessed territoriality in wild pig sounders on the Savannah River Site, South Carolina, USA, and examined whether availability of food resources provided by a municipal-waste landfill affected among-sounder territoriality. We estimated utilization distribution overlap and dynamic interactions among 18 neighboring sounders around a landfill. We found that although neighboring sounders overlapped in space, intensity of use in shared areas was uniformly low, indicating territorial behavior. Neighbors tended to share slightly more space when closer to the landfill waste cells, indicating availability of a super-abundant resource somewhat weakens the degree of territoriality among sounders. Nevertheless, we conclude that sounders behaved in a generally territorial manner, and we discuss implications for whole-sounder trapping programs, particularly near concentrated resources such as landfills and crop fields.

GPS-coupled contaminant monitors on free-ranging Chernobyl wolves challenge a fundamental assumption in exposure assessments

Measurements of external contaminant exposures on individual wildlife are rare because of difficulties in using contaminant monitors on free-ranging animals. Most wildlife contaminant exposure data are therefore simulated with computer models. Rarely are empirical exposure data available to verify model simulations, or to test fundamental assumptions inherent in exposure assessments. We used GPS-coupled contaminant monitors to quantify external exposures to individual wolves (Canis lupus) living within the Belarus portion of Chernobyl's 30-km exclusion zone. The study provided data on animal location and contaminant exposure every 35 min for 6 months, resulting in ~6600 individual locations and ¹³⁷Cs external exposure readings per wolf, representing the most robust external exposure data published to date on free ranging animals. The data provided information on variation in external exposure for each animal over time, as well as variation in external exposure among the eight wolves across the landscape of Chernobyl. The exposure data were then used to test a fundamental assumption in screening-level risk assessments, espoused in guidance documents of the U.S. Environmental Protection Agency and U.S. Department of Energy, - Mean contaminant concentrations conservatively estimate individual external exposures. We tested this assumption by comparing our empirical data to a series of simulations using the ERICA modeling tool. We found that modeled simulations of mean external exposure (10.5 mGy y^-1), based on various measures of central tendency, under-predicted mean exposures measured on five of the eight wolves wearing GPS-contaminant monitors (i.e., 12.3, 26.3, 28.0, 28.8 and 35.7 mGy y^-1). If under-prediction of exposure occurs for some animals, then arguably the use of averaged contaminant concentrations to predict external exposure is not as conservative as proposed by current risk assessment guidance. Thus, a risk assessor's interpretation of simulated exposures in a screening-level risk analysis might be misguided if contaminant concentrations are based on measures of central tendency. We offer three suggestions for risk assessors to consider in order to reduce the probability of underestimating exposure in a screening-level risk assessment.

Evidence of niche differentiation for two sympatric vulture species in the Southeastern United States

BACKGROUND

As obligate scavengers utilizing similar habitats, interspecific competition undoubtedly occurs between resident black (Coragyps atratus) and turkey (Cathartes aura) vultures. In the interest of exploring how sympatric species coexist through habitat segregation, we examined resource selection of resident black and turkey vultures in the southeastern United States (US) for evidence of niche differentiation.

METHODS

Using fine-scale movement data, we assessed interspecific seasonal differences in monthly roost reuse frequency and roost site fidelity, as well as monthly flight, roost, and diurnal rest site resource selection based on > 2.8 million locations of 9 black vultures and 9 turkey vultures tracked from September 2013 to August 2015 using Groupe Spécial Mobile/Global Positioning System (GSM/GPS) transmitters.

RESULTS

Black vultures generally exhibited greater roost fidelity as well as a greater maximum number of nights spent at a single roost than turkey vultures. Patterns of flight, roost, and resting habitat selection within the home range varied monthly as well as between species, providing evidence for habitat segregation and niche differentiation by sympatric vultures. In particular, our results indicate the importance of wooded wetlands for resting and roosting locations for both species, and revealed clear differences in the use of forested habitats between species during flight, resting, and roosting behavioral states.

CONCLUSIONS

By examining differences in resource selection and spatial ecology of black and turkey vultures across a range of behaviors, this study demonstrates mechanisms of niche differentiation in these ecologically similar species, and enhances potential for conservation and informed management of this important group of birds.

Satellite telemetry reveals higher fishing mortality rates than previously estimated, suggesting overfishing of an apex marine predator

Overfishing is a primary cause of population declines for many shark species of conservation concern. However, means of obtaining information on fishery interactions and mortality, necessary for the development of successful conservation strategies, are often fisheries-dependent and of questionable quality for many species of commercially exploited pelagic sharks. We used satellite telemetry as a fisheries-independent tool to document fisheries interactions, and quantify fishing mortality of the highly migratory shortfin mako shark (Isurus oxyrinchus) in the western North Atlantic Ocean. Forty satellite-tagged shortfin mako sharks tracked over 3 years entered the Exclusive Economic Zones of 19 countries and were harvested in fisheries of five countries, with 30% of tagged sharks harvested. Our tagging-derived estimates of instantaneous fishing mortality rates (F = 0.19-0.56) were 10-fold higher than previous estimates from fisheries-dependent data (approx. 0.015-0.024), suggesting data used in stock assessments may considerably underestimate fishing mortality. Additionally, our estimates of F were greater than those associated with maximum sustainable yield, suggesting a state of overfishing. This information has direct application to evaluations of stock status and for effective management of populations, and thus satellite tagging studies have potential to provide more accurate estimates of fishing mortality and survival than traditional fisheries-dependent methodology.

Fine-scale assessment of home ranges and activity patterns for resident black vultures (Coragyps atratus) and turkey vultures (Cathartes aura)

Knowledge of black vulture (Coragyps atratus) and turkey vulture (Cathartes aura) spatial ecology is surprisingly limited despite their vital ecological roles. Fine-scale assessments of space use patterns and resource selection are particularly lacking, although development of tracking technologies has allowed data collection at finer temporal and spatial resolution. Objectives of this study were to conduct the first assessment of monthly home range and core area sizes of resident black and turkey vultures with consideration to sex, as well as elucidate differences in monthly, seasonal, and annual activity patterns based on fine-scale movement data analyses. We collected 2.8-million locations for 9 black and 9 turkey vultures from June 2013 –August 2015 using solar-powered GSM/GPS transmitters. We quantified home ranges and core areas using the dynamic Brownian bridge movement model and evaluated differences as a function of species, sex, and month. Mean monthly home ranges for turkey vultures were ~50% larger than those of black vultures, although mean core area sizes did not differ between species. Turkey vulture home ranges varied little across months, with exception to a notable reduction in space-use in May, which corresponds with timing of chick-rearing activities. Black vulture home ranges and core areas as well as turkey vulture core areas were larger in breeding season months (January–April). Comparison of space use between male and female vultures was only possible for black vultures, and space use was only slightly larger for females during breeding months (February–May). Analysis of activity patterns revealed turkey vultures spend more time in flight and switch motion states (between flight and stationary) more frequently than black vultures across temporal scales. This study reveals substantive variability in space use and activity rates between sympatric black and turkey vultures, providing insights into potential behavioral mechanisms contributing to niche differentiation between these species.

Quantifying the spatial and temporal variation in dose from external exposure to radiation: a new tool for use on free-ranging wildlife

Inadequate dosimetry is often the fundamental problem in much of the controversial research dealing with radiation effects on free-ranging wildlife. Such research is difficult because of the need to measure dose from several potential pathways of exposure (i.e., internal contamination, external irradiation, and inhalation). Difficulties in quantifying external exposures can contribute significantly to the uncertainties of dose-effect relationships. Quantifying an animal's external exposure due to spatial-temporal use of habitats that can vary by orders of magnitude in radiation levels is particularly challenging. Historically, wildlife dosimetry studies have largely ignored or been unable to accurately quantify variability in external dose because of technological limitations. The difficulties of quantifying the temporal-spatial aspects of external irradiation prompted us to develop a new dosimetry instrument for field research. We merged two existing technologies [Global Positioning Systems (GPS) and electronic dosimeters] to accommodate the restrictive conditions of having a combined unit small enough to be unobtrusively worn on the neck of a free-ranging animal, and sufficiently robust to withstand harsh environmental conditions. The GPS-dosimeter quantifies the spatial and temporal variation in external dose as wildlife traverse radioactively contaminated habitats and sends, via satellites, an animal's location and short term integrated dose to the researcher at a user-defined interval. Herein we describe: (1) the GPS-dosimeters; (2) tests to compare their uniformity of response to external irradiation under laboratory conditions; (3) field tests of their durability when worn on wildlife under natural conditions; and (4) a field application of the new technology at a radioactively contaminated site. Use of coupled GPS-dosimetry will allow, for the first time, researchers to better understand the relationship of animals to their contaminated habitats and better assess animal responses to the stress of radiological exposures.

A behaviorally-explicit approach for delivering vaccine baits to mesopredators to control epizootics in fragmented landscapes

Despite the widespread use of aerial baiting to manage epizootics among free-ranging populations, particularly in rabies management, bait acceptance and seroconversion rates often are lower than required to eliminate spread of disease. Our objectives in this study, therefore, were to evaluate the performance of stratified bait distribution models derived from resource selection functions (RSF) on uptake of placebo rabies baits by raccoons (Procyon lotor) and Virginia opossums (Didelphis virginiana), as well as the probability of bait uptake as a function of proximity to bait distribution areas in fragmented agricultural ecosystems. Among 478 raccoons and 108 opossums evaluated for presence of Rhodamine B (RB) across 8 sites, only 26% of raccoons and 20% of opossums exhibited marking consistent with bait consumption 14-24 days post-baiting. The effective area treated, based on 90% kernel density estimators of marked individuals, ranged from 99-240 ha larger than bait distribution zones, with RB marked individuals captured up to 753 m beyond the bait zone. Despite incorporation of RSF data into bait distribution models, no differences in uptake rates were observed between treatment and control sites. These data likely reflect the underlying constraints imposed by the loss and fragmentation of habitat on animal movement in heterogeneous landscapes, forcing individuals to optimize movements at coarse (i.e., patch-level) rather than fine spatial scales in highly fragmented environments. Our data also confirm that the probability of bait acceptance decreases with increasing distance from bait zone interiors, even within the zone itself. Thus, although bait acceptance was confirmed beyond bait zone boundaries, the proportion of vaccinated individuals may comprise a small minority of the population at increasing distances from baiting interiors. These data suggest focal baiting creates a buffered area of treated individuals around bait zones or bait stations, but repeated treatments may be needed to achieve sufficient uptake to eradicate disease.

Using dynamic Brownian bridge movement modelling to measure temporal patterns of habitat selection

Accurately describing animal space use is vital to understanding how wildlife use habitat. Improvements in GPS technology continue to facilitate collection of telemetry data at high spatial and temporal resolutions. Application of the recently introduced dynamic Brownian bridge movement model (dBBMM) to such data is promising as the method explicitly incorporates the behavioural heterogeneity of a movement path into the estimated utilization distribution (UD). Utilization distributions defining space use are normally estimated for time-scales ranging from weeks to months, obscuring much of the fine-scale information available from high-volume GPS data sets. By accounting for movement heterogeneity, the dBBMM provides a rigorous, behaviourally based estimate of space use between each set of relocations. Focusing on UDs generated between individual sets of locations allows us to quantify fine-scale circadian variation in habitat use. We used the dBBMM to estimate UDs bounding individual time steps for three terrestrial species with different life histories to illustrate how the method can be used to identify fine-scale variations in habitat use. We also demonstrate how dBBMMs can be used to characterize circadian patterns of habitat selection and link fine-scale patterns of habitat use to behaviour. We observed circadian patterns of habitat use that varied seasonally for a white-tailed deer (Odocoileus virginianus) and coyote (Canis latrans). We found seasonal patterns in selection by the white-tailed deer and were able to link use of conifer forests and agricultural fields to behavioural state of the coyote. Additionally, we were able to quantify the date in which a Rio Grande wild turkey (Meleagris gallopavo intermedia) initiated laying as well as when during the day, she was most likely to visit the nest site to deposit eggs. The ability to quantify circadian patterns of habitat use may have important implications for research and management of wildlife. Additionally, the ability to link such patterns to behaviour may aid in the development of mechanistic models of habitat selection.

Sustained in vivo release from imprinted therapeutic contact lenses

In this paper, we demonstrate the successful in vivo extended release of a small molecular weight therapeutic, ketotifen fumarate (MW=425), from molecularly imprinted, therapeutic contact lenses. This is the first time that a steady, effective concentration of drug is maintained in the tear film from a contact lens for an extended period of time for the entire duration of lens wear. Poly(HEMA-co-AA-co-AM-co-NVP-co-PEG200DMA) soft contact lenses were prepared (100±5 μm thickness, diameter 11.8 mm, power zero), and a constant tear film concentration of 170±30 μg/mL was measured for up to 26 hrs in a New Zealand white rabbit model. The results showed a dramatic increase in ketotifen mean residence time (MRT) and bioavailability compared to topical drop therapy and drug soaked lenses. The MRT for imprinted lenses was 12.47±3.99 hrs, ~4 and 50 fold greater than non-imprinted lenses and 0.035% eye drops (Zaditor®), respectively. Furthermore, AUC(0-26 hrs) was 9 and 94 fold greater for imprinted lenses than non-imprinted lenses and eye drops, respectively. The results indicate that molecular imprinting provides an exciting rational engineering strategy for sustained release. It is clear that imprinted lenses are very promising combination devices and are much more effective and efficient delivery devices than eye drops.

Shoot development – genetic interactions in the meristem

Development of the plant shoot is dependent on the shoot apical meristem. Interactions between KNOX homeodomain transcription factors and the myb domain transcription factor AS1 (ASYMMETRIC LEAVES1) regulate both meristem function as well as leaf patterning. This review summarizes these interactions.

Asymmetric leaves1 mediates leaf patterning and stem cell function in Arabidopsis

Meristem function in plants requires both the maintenance of stem cells and the specification of founder cells from which lateral organs arise. Lateral organs are patterned along proximodistal, dorsoventral and mediolateral axes. Here we show that the Arabidopsis mutant asymmetric leaves1 (as1) disrupts this process. AS1 encodes a myb domain protein, closely related to PHANTASTICA in Antirrhinum and ROUGH SHEATH2 in maize, both of which negatively regulate knotted-class homeobox genes. AS1 negatively regulates the homeobox genes KNAT1 and KNAT2 and is, in turn, negatively regulated by the meristematic homeobox gene SHOOT MERISTEMLESS. This genetic pathway defines a mechanism for differentiating between stem cells and organ founder cells within the shoot apical meristem and demonstrates that genes expressed in organ primordia interact with meristematic genes to regulate shoot morphogenesis.

Pragmatic language behaviors of adults diagnosed with chronic schizophrenia

35 adults diagnosed with schizophrenia provided samples of narrative and conversational discourse and completed a criterion-referenced test of pragmatic language ability. There was a significant relationship between performance on pragmatic language tasks and perceived over-all functioning of schizophrenic subjects as measured by psychological assessment. Subjects who were perceived as functioning at low levels on the Global Assessment of Functioning Scale from the Diagnostic and 1994 Statistical Manual of Mental Disorders had low self-disclosure in conversation, produced less information in narratives, and produced more nonscorable items on a criterion-referenced test of pragmatic language. Appropriateness of speech suprasegmentals was also related to patients' perceived effectiveness as communicators as well as to their perceived over-all functioning as measured by the Global Assessment of Functioning Scale.

A retrospective molecular analysis of gentamicin resistance in Staphylococcus aureus strains from UK hospitals

The composite transposon Tn4001 and a related chromosomal Tn4001-like element, encode resistance to the aminoglycosides gentamicin, tobramycin and kanamycin (GmTmKmr) in Australian strains of Staphylococcus aureus. Southern hybridisation analysis of GmTmKmr S. aureus strains isolated from various hospitals in the UK between 1975 and 1985 indicated that they predominantly encoded chromosomal copies of Tn4001 or a Tn4001-like element. However, a strain isolated in 1985 was found to carry Tn4001 on a plasmid related to pSK1, the prototypical multiresistance plasmid commonly detected in S. aureus strains from Australian hospitals.

Metalinguistic and pragmatic abilities of participants in adult literacy programs

The relationship between oral and written language skills was explored in this study involving 97 participants enrolled in an adult literacy program. Pragmatic language skills were assessed in videotaped conversational dyads which were later analyzed for level of conversational assertiveness and responsiveness and for the status of basic interactional skills. Those behaviors which were judged as being most likely to detract from communicative effectiveness were body movement, eye gaze, and facial expression. Metalinguistic/ semantic language skills were assessed with the Test of Word Knowledge (TOWK) (Wiig & Secord, 1991). A significant relationship was found between total scores on the TOWK and reading levels of subjects as they entered the program. Post-testing was conducted approximately 6 to 8 months after the initial testing. These results were available for 22 of the subjects and indicated that, even for adults, some aspects of oral language improve as reading levels increase.

Possible role of insertion sequence IS257 in dissemination and expression of high- and low-level trimethoprim resistance in staphylococci

The transposon-like structure Tn4003 and related elements were found to encode high- and low-level trimethoprim resistance (Tpr) in Staphylococcus aureus and coagulase-negative staphylococci. By using transcriptional fusions in Escherichia coli, the variation in resistance levels was found to correlate with the transcriptional activity of the region presumed to carry the promoter for the operon containing the Tpr dihydrofolate reductase gene, dfrA, encoded by these elements. The reduced transcriptional activities exhibited by elements encoding low-level Tpr appear to be a consequence of deletions adjacent to the copy of IS257 which normally encodes the -35 sequences of these promoters. The data obtained not only support the involvement of IS257 in the transcription of the proposed thyE-dfrA-orf-140 operon of Tn4003 but may also implicate this insertion sequence in the mechanisms resulting in the variation in Tpr levels observed in staphylococci.

Analysis of a transfer region from the staphylococcal conjugative plasmid pSK41

The nucleotide sequence of a 14.4-kb region (tra) associated with DNA transfer of the staphylococcal conjugative plasmid, pSK41, has been determined. Analysis of the sequence revealed the presence of 15 genes potentially involved in the conjugative process. Polypeptide products likely to correspond to ten of these genes have been identified, of which one was found to be a lipoprotein. Comparison of the deduced tra products to the protein databases revealed several interesting similarities, one of which suggests an evolutionary link between this Gram+ bacterial conjugation system and DNA transfer systems of Gram- bacteria, such as Escherichia coli and Agrobacterium tumefaciens. The nt sequence also provided an insight into the transcriptional organisation and regulation of the region.

The nurse clinician: role conflict in research

In a recent pilot study focusing on stroke rehabilitation, four clinical nurse specialists (CNSs) experienced role conflict when assuming the nurse researcher-interviewer role. Presenting an overview of the pilot study and the experiences that occurred, the authors question the reliability of the interviews. They propose that outcomes of research can be biased by role conflict when CNSs serve as interviewers and collect data. The authors suggest that interviewing training specifically address role conflict.

Symptomatic choroid plexus xanthogranuloma of the lateral ventricle. Case report and brief critical review of xanthogranulomatous lesions of the brain

Xanthogranulomas of the choroid plexus are found relatively frequently at autopsy; however only 8 cases of symptomatic choroid plexus xanthogranuloma of the lateral ventricle have been reported. We describe an additional case in a 63-year-old man who presented with headache. A well circumscribed mass located in the trigone of the right lateral ventricle and extending into the periventricular white matter was detected on imaging studies. The clinical impression was metastasis. The resected material had the typical histological appearance of a xanthogranuloma of the choroid plexus. The clinical and histopathologic features of these lesions are reviewed and other xanthogranulomatous processes involving the brain are briefly discussed.

4',4'' adenyltransferase activity on conjugative plasmids isolated from Staphylococcus aureus is encoded on an integrated copy of pUB110

In staphylococci, linked resistance to the aminoglycosides kanamycin, neomycin, paromomycin, and tobramycin (KmNmPmTmr) is generally mediated by an aadD determinant which encodes production of an adenyltransferase aminoglycoside modifying enzyme, AAD(4',4''). The aadD resistance determinant is located on small multicopy plasmids such as pUB110, and has also been found on large multiresistance plasmids and on the chromosome in some strains. Examination of two conjugative plasmids from strains of Staphylococcus aureus isolated in North America indicated that the aadD determinant on these plasmids is located on an integrated copy of pUB110. The integrated pUB110 is flanked by direct repeats of the staphylococcal insertion sequence IS257. Analysis of the conjugative plasmid pSK41 showed an 8-bp duplication of the pUB110 sequence immediately adjacent to flanking IS257 elements, suggesting that integration of pUB110 was mediated by IS257.

Molecular analysis of a gentamicin resistance transposonlike element on plasmids isolated from North American Staphylococcus aureus strains

Plasmid-encoded resistance to the aminoglycosides gentamicin (Gm), tobramycin (Tm), and kanamycin (Km) (GmTmKmr) in strains of Staphylococcus aureus isolated in Australia and North America appears to be mediated by one resistance determinant. In Australian isolates, this determinant is flanked by inverted copies of a 1.3-kb insertion sequence, IS256, thereby forming a composite transposon, Tn4001. Analysis of two conjugative plasmids and a related nonconjugative plasmid from strains of S. aureus isolated in North America showed that the GmTmKmr determinant on these plasmids is also flanked by inverted repeats. In the nonconjugative plasmid, these repeats include only 425 bp of IS256 immediately adjacent to the GmTmKmr region and identical to that on Tn4001. This truncated Tn4001 element is flanked by copies of the insertion element IS257, and together these elements form a truncated Tn4001-IS257 hybrid transposonlike structure. A third copy of IS257 was located 418 bp from the hybrid structure. The truncated Tn4001 and three repeats of IS257 were present at a conserved site on the plasmids studied. Four additional copies of IS257 were identified on the two conjugative plasmids. These elements flank determinants for resistance to the aminoglycosides neomycin and paromomycin and to ethidium bromide and quaternary ammonium compounds, as well as the region involved in conjugative plasmid transfer.

Wound healing. Oral and topical activity of Aloe vera

The influence of Aloe vera, orally and topically, on wound healing was studied. Wounds were induced on both sides of the vertebral column of ICR mice using a biopsy punch. For the oral study, experimental animals received A. vera in their drinking water for 2 months, whereas the control animals received only water. In the topical study, experimental animals were given 25% A. vera in Eucerin cream topically. The control animals received cream only. A 62.5% reduction in wound diameter was noted in mice receiving 100 mg/kg/day oral A. vera and a 50.8% reduction was recorded in animals receiving topical 25% A. vera. These data suggest that A. vera is effective by both oral and topical routes of administration.

Nucleotide sequence analysis of IS256 from the Staphylococcus aureus gentamicin-tobramycin-kanamycin-resistance transposon Tn4001

Resistance to the aminoglycosides gentamicin, tobramycin and kanamycin (GmTmKmR) in Australian clinical strains of Staphylococcus aureus is commonly carried on the composite transposon Tn4001. The resistance gene aacA-aphD of Tn4001, which encodes a bifunctional AAC(6')-APH(2") modifying enzyme, is flanked by two 1324-bp inverted repeats, IS256L and IS256R, that are identical in sequence. Analysis of the IS256 sequence revealed structural features characteristic of IS elements including 26-bp imperfect terminal inverted repeats and a single open reading frame with coding capacity for a 45.6 kDa protein. The nucleotide sequence of IS256 described here, together with the sequence of the aacA-aphD gene reported previously [Rouch et al., J. Gen. Microbiol. 133 (1987) 3039-3052], completes the entire sequence of Tn4001, which totals 4566 bp.

Anti-inflammatory activity of Aloe vera against a spectrum of irritants

The authors have evaluated the spectrum of anti-inflammatory activity of A. vera in a number of models of inflammation in the hind paw of the experimental rat induced by kaolin, carrageenan, albumin, dextran, gelatin, and mustard. Croton oil was used in a topical model of inflammation to determine the oral activity and time-dependent dosing of A. vera. The authors found that A. vera was active in all models of inflammation. Of the various irritants tested, A. vera was especially active against gelatin-induced and kaolin-induced edema and, in contrast, had minimal activity when tested against dextran-induced edema. Oral activity of A. vera was demonstrated to be dependent on the presence of anthraquinones. The various irritant-induced edema models provided a broad spectrum of anti-inflammatory activity for A. vera.

Rural health, family practice, and area health education centers: a national study

The National Area Health Education Center (AHEC) Program and the family practice specialty were both created around 1970, in part to help meet the health care needs of medically underserved populations. Because these two entities share the common goal of alleviating physician shortages in rural areas, a study was conducted to determine the nature and extent of their interaction. Questionnaires were mailed to all AHEC projects and all nonmilitary family practice residency programs. Response rates were 100% and 79%, respectively. Elective rural rotations (usually preceptorships) are offered by 135 (49%) residencies, but only 84 (31%) require them. Fourteen (64%) AHEC projects interact with family practice residencies; however, only 9% (15/167) of the programs in those states utilize AHEC resources. The authors conclude that additional rural rotations could be offered to family practice residents by taking advantage of under-utilized resources of the National AHEC Program.

Multiresistant Staphylococcus aureus: genetics and evolution of epidemic Australian strains

Molecular and genetic analysis of multiresistant isolates of Staphylococcus aureus from widely separated hospitals in Australia has demonstrated that these are clearly related, and that the predominant strains possess up to three different plasmids, which fall into the following classes: (i) small 1.6 kb plasmids, such as pSK3, which are phenotypically cryptic, (ii) 4.5 kb chloramphenicol resistance plasmids, such as pSK2, and (iii) the pSK1 family of multiresistance plasmids, which range in size from 20 to 42 kb and variously encode resistance to antiseptics and disinfectants, trimethoprim (Tpr), penicillin (Pcr) and the aminoglycosides gentamicin, tobramycin and kanamycin (Gmr Tmr Kmr). Gmr Tmr Kmr is encoded on the pSK1 family plasmids by transposon Tn4001, which was also detected on the chromosomes of some clinical isolates. Tn4001 is composed of inverted repeats of the insertion sequence IS256; these repeats flank a Gmr Tmr Kmr sequence encoding for a 57,000 dalton bifunctional protein with aminoglycoside acetyltransferase [AAC(6')] and phosphotransferase [APH(2")] activities. A Tn4001-like structure, which is defective in transposition but encodes for a Gmr Tmr Kmr determinant homologous with that on Tn4001, occurs on conjugative plasmids from strains isolated in North America. Physical studies indicate that Pcr, via a beta-lactamase, and Tpr, via a trimethoprim-insensitive dihydrofolate reductase (DHFR), are also encoded on the pSK1 family by transposons; these transposons have been designated Tn4002 and Tn4003, respectively. Tn4003 is flanked by direct repeats of the insertion sequence IS257. The evolution of the pSK1 family of multiresistance plasmids is traced through the transposition and genetic rearrangement of resistance determinants. Transposition and genetic rearrangement have also contributed to the evolution of a multiresistant chromosome in Staph. aureus. In the majority of contemporary multiply resistant Staph. aureus strains the determinants for resistance to erythromycin (Emr), fusidic acid, methicillin (Mcr), minocycline, rifampicin, spectinomycin, streptomycin, sulphonamides, tetracycline (Tcr), cadmium (Cdr), and mercury (Hgr) are chromosomally encoded; these strains also possess chromosomally encoded Pcr, via a beta-lactamase. Evidence indicates that some of these determinants, Pcr, Cdr, Hgr, and Tcr, were plasmid encoded in isolates collected from Australian hospitals prior to 1970. Through transposition and site-specific integration, they have since been acquired by the chromosome in more recent Staph. aureus strains.(ABSTRACT TRUNCATED AT 400 WORDS)

Nucleotide and complete amino acid sequences of Kunjin virus: definitive gene order and characteristics of the virus-specified proteins

A Kunjin (KUN) virus cDNA sequence of 10664 nucleotides was obtained and it encoded a single open reading frame for 3433 amino acids. Partial N-terminal amino acid analyses of KUN virus-specified proteins identified the polyprotein cleavage sites and the definitive gene order. The gene order relative to that proposed for yellow fever (YF) virus is as follows: KUN 5'-C.GP20.E.GP44.P19.P10.P71.(?).P21.P98-3' YF 5'-C.prM.E.NS1.ns2a.ns2b.NS3.ns4a.ns4b. NS5-3'. The order of putative signal sequences and stop transfer sequences indicated that KUN NS1, NS2A and NS4B are probably cleaved in the lumen of the endoplasmic reticulum, at a consensus site Val-X-Ala decreases where X is an uncharged residue, and NS2B, NS3 and NS5 are cleaved in the cytosol at the site Lys-Arg decreases Gly. Comparisons with the complete amino acid sequences of YF and West Nile (WN) viruses showed that KUN virus shared 93% homology with WN virus, but only 46% homology with YF virus. Comparisons among individual gene products of six flaviviruses showed that E, NS1, NS3 and NS5 tended to be the most highly conserved, and C among the least conserved. Homologous cleavage sites were evident, and six domains in NS5, a total of over 170 residues, shared at least 85% homology. Comparisons with the KUN C to NS2B sequence defined a gradient of relationships of all gene products in decreasing order WN greater than Murray Valley greater than Japanese encephalitis greater than St Louis encephalitis viruses within this closely related serological complex. A non-coding 5' sequence (75 nucleotides) of KUN virus shared 95% homology with WN virus and a shorter imperfect match with Murray Valley encephalitis virus (15 of 18 nucleotides). The KUN non-coding 3' sequence of 290 nucleotides contained several short and imperfectly matched sequences, and shared 87% homology over the distal region of 191 nucleotides with the corresponding region of WN virus RNA.

The aacA-aphD gentamicin and kanamycin resistance determinant of Tn4001 from Staphylococcus aureus: expression and nucleotide sequence analysis

The aacA-aphD aminoglycoside resistance determinant of the Staphylococcus aureus transposon Tn4001, which specifies resistance to gentamicin, tobramycin and kanamycin, has been cloned and shown to express these resistances in Escherichia coli. The determinant encoded a single protein with an apparent size of 59 kDa which specified both aminoglycoside acetyltransferase [AAC(6')] and aminoglycoside phosphotransferase [APH(2")] activities. Nucleotide sequence analysis of the determinant showed it to be capable of encoding a 479-amino-acid protein of 56.9 kDa. analysis of Tn1725 insertion mutants of the determinant indicated that resistance to tobramycin and kanamycin is due to the AAC activity specified by, approximately, the first 170 amino acids of the predicted protein sequence and is consistent with the gentamicin resistance, specified by the APH activity, being encoded within the C-terminal region of the protein. Comparison of the C-terminal end of the predicted amino acid sequence with the reported sequences of 13 APHs and a viomycin phosphotransferase revealed a region which is highly conserved among these phosphotransferases.

Plasmid-mediated resistance to gentamicin in Staphylococcus aureus: the involvement of a transposon

Resistance to gentamicin, tobramycin and kanamycin (GmrTmrKmr) in strains of Staphylococcus aureus isolated from clinical sources in Australia is mediated by a 4.7 kb transposable element, designated Tn4001. A 2.5 kb HindIII fragment which maps symmetrically within Tn4001, and encompasses the aminoglycoside-resistance coding region, has been shown to hybridise with fragments of identical size in HindIII digests of three different GmrTmrKmr plasmids, two of which were self-transmissible, from strains of S. aureus isolated in the USA. Examination by electronmicroscopy of self-annealed molecules of the North American GmrTmrKmr plasmids revealed the presence of stem and loop structures similar to those produced by Tn4001, but with shorter inverted repeats. These results suggest that GmrTmrKmr in strains of S. aureus isolated in the USA is, or once was, transposable, and that transposable elements analogous to Tn4001 may be found in isolates of GmrTmrKmr S. aureus worldwide.