Community detection in hypergraphs via mutual information maximization

The hypergraph community detection problem seeks to identify groups of related vertices in hypergraph data. We propose an information-theoretic hypergraph community detection algorithm which compresses the observed data in terms of community labels and community-edge intersections. This algorithm can also be viewed as maximum-likelihood inference in a degree-corrected microcanonical stochastic blockmodel. We perform the compression/inference step via simulated annealing. Unlike several recent algorithms based on canonical models, our microcanonical algorithm does not require inference of statistical parameters such as vertex degrees or pairwise group connection rates. Through synthetic experiments, we find that our algorithm succeeds down to recently-conjectured thresholds for sparse random hypergraphs. We also find competitive performance in cluster recovery tasks on several hypergraph data sets.

A comprehensive guide to CAN IDS data and introduction of the ROAD dataset

Although ubiquitous in modern vehicles, Controller Area Networks (CANs) lack basic security properties and are easily exploitable. A rapidly growing field of CAN security research has emerged that seeks to detect intrusions or anomalies on CANs. Producing vehicular CAN data with a variety of intrusions is a difficult task for most researchers as it requires expensive assets and deep expertise. To illuminate this task, we introduce the first comprehensive guide to the existing open CAN intrusion detection system (IDS) datasets. We categorize attacks on CANs including fabrication (adding frames, e.g., flooding or targeting and ID), suspension (removing an ID's frames), and masquerade attacks (spoofed frames sent in lieu of suspended ones). We provide a quality analysis of each dataset; an enumeration of each datasets' attacks, benefits, and drawbacks; categorization as real vs. simulated CAN data and real vs. simulated attacks; whether the data is raw CAN data or signal-translated; number of vehicles/CANs; quantity in terms of time; and finally a suggested use case of each dataset. State-of-the-art public CAN IDS datasets are limited to real fabrication (simple message injection) attacks and simulated attacks often in synthetic data, lacking fidelity. In general, the physical effects of attacks on the vehicle are not verified in the available datasets. Only one dataset provides signal-translated data but is missing a corresponding "raw" binary version. This issue pigeon-holes CAN IDS research into testing on limited and often inappropriate data (usually with attacks that are too easily detectable to truly test the method). The scarcity of appropriate data has stymied comparability and reproducibility of results for researchers. As our primary contribution, we present the Real ORNL Automotive Dynamometer (ROAD) CAN IDS dataset, consisting of over 3.5 hours of one vehicle's CAN data. ROAD contains ambient data recorded during a diverse set of activities, and attacks of increasing stealth with multiple variants and instances of real (i.e. non-simulated) fuzzing, fabrication, unique advanced attacks, and simulated masquerade attacks. To facilitate a benchmark for CAN IDS methods that require signal-translated inputs, we also provide the signal time series format for many of the CAN captures. Our contributions aim to facilitate appropriate benchmarking and needed comparability in the CAN IDS research field.

Correction: Nielson et al. Similarity Downselection: Finding the n Most Dissimilar Molecular Conformers for Reference-Free Metabolomics. Metabolites 2023, 13, 105

There were missing figures and associated legends for Figure 3 and Figure 4 as published due to a publication error [...].

Magnetotelluric support for edge-driven convection and shear-driven upwelling in the Newer Volcanics Province

Intraplate volcanic provinces present significant natural hazards to many populated regions globally but their origins are poorly understood. Though hypotheses involving mantle plumes are predominant, the Newer Volcanics Province of southeast Australia-a relatively young (< 4.5 Ma), EW trending collection of over 400 volcanic centres-is increasingly attributed to some combination of edge-driven convection (EDC) and shear-driven upwelling (SDU). In this paper, we provide magnetotelluric (MT) data in support of these geodynamic processes. Three-dimensional inversion of 49 new broadband MT sites, in combination with 143 previously collected broadband, long-period, and geomagnetic depth soundings, reveals an elongate zone of moderately low resistivity (∼ 10-300 Ω m) spanning the Mt Gambier subprovince at a depth of between 20 and 40 km. The newly defined Gambier Conductor is contiguous to, and orientationally aligned with, significant step in the seismically-defined lithosphere-asthenosphere boundary (LAB) presented by earlier studies. Moderately low resistivity is interpreted as fluid-catalysed alteration of iron-bearing crust resulting from percolating magmatic volatiles. We argue that localised low resistivity (< 10 Ω m) at ~ 25 km depth in the mid-lower crust is associated with 1.2-3.6% partial melt. Supporting evidence indicates possible crustal thickening from 5.8 Ma at a rate comparable to estimates of SDU-induced surface eruptions and previous NVP production rate estimates.

Similarity Downselection: Finding the n Most Dissimilar Molecular Conformers for Reference-Free Metabolomics

Computational methods for creating in silico libraries of molecular descriptors (e.g., collision cross sections) are becoming increasingly prevalent due to the limited number of authentic reference materials available for traditional library building. These so-called "reference-free metabolomics" methods require sampling sets of molecular conformers in order to produce high accuracy property predictions. Due to the computational cost of the subsequent calculations for each conformer, there is a need to sample the most relevant subset and avoid repeating calculations on conformers that are nearly identical. The goal of this study is to introduce a heuristic method of finding the most dissimilar conformers from a larger population in order to help speed up reference-free calculation methods and maintain a high property prediction accuracy. Finding the set of the n items most dissimilar from each other out of a larger population becomes increasingly difficult and computationally expensive as either n or the population size grows large. Because there exists a pairwise relationship between each item and all other items in the population, finding the set of the n most dissimilar items is different than simply sorting an array of numbers. For instance, if you have a set of the most dissimilar n = 4 items, one or more of the items from n = 4 might not be in the set n = 5. An exact solution would have to search all possible combinations of size n in the population exhaustively. We present an open-source software called similarity downselection (SDS), written in Python and freely available on GitHub. SDS implements a heuristic algorithm for quickly finding the approximate set(s) of the n most dissimilar items. We benchmark SDS against a Monte Carlo method, which attempts to find the exact solution through repeated random sampling. We show that for SDS to find the set of n most dissimilar conformers, our method is not only orders of magnitude faster, but it is also more accurate than running Monte Carlo for 1,000,000 iterations, each searching for set sizes n = 3-7 out of a population of 50,000. We also benchmark SDS against the exact solution for example small populations, showing that SDS produces a solution close to the exact solution in these instances. Using theoretical approaches, we also demonstrate the constraints of the greedy algorithm and its efficacy as a ratio to the exact solution.

Opportunities for neuromorphic computing algorithms and applications

Neuromorphic computing technologies will be important for the future of computing, but much of the work in neuromorphic computing has focused on hardware development. Here, we review recent results in neuromorphic computing algorithms and applications. We highlight characteristics of neuromorphic computing technologies that make them attractive for the future of computing and we discuss opportunities for future development of algorithms and applications on these systems.

Risk and protective factors for falls on stairs in young children: multicentre case-control study

AIM

To investigate risk and protective factors for stair falls in children aged <5 years.

METHODS

Multicentre case-control study at hospitals, minor injury units and general practices in and around four UK study centres. Cases were children with medically attended stair fall injuries. Controls were matched on age, sex, calendar time and study centre. A total of 610 cases and 2658 controls participated.

RESULTS

Cases' most common injuries were bangs on the head (66%), cuts/grazes not requiring stitches (14%) and fractures (12%). Parents of cases were significantly more likely not to have stair gates (adjusted OR (AOR) 2.50, 95% CI 1.90 to 3.29; population attributable fraction (PAF) 21%) or to leave stair gates open (AOR 3.09, 95% CI 2.39 to 4.00; PAF 24%) both compared with having closed stair gates. They were more likely not to have carpeted stairs (AOR 1.52, 95% CI 1.09 to 2.10; PAF 5%) and not to have a landing part-way up their stairs (AOR 1.34, 95% CI 1.08 to 1.65; PAF 18%). They were more likely to consider their stairs unsafe to use (AOR 1.46, 95% CI 1.07 to 1.99; PAF 5%) or to be in need of repair (AOR 1.71, 95% CI 1.16 to 2.50; PAF 5%).

CONCLUSION

Structural factors including having landings part-way up the stairs and keeping stairs in good repair were associated with reduced stair fall injury risk. Family factors including having stair gates, not leaving gates open and having stair carpets were associated with reduced injury risk. If these associations are causal, addressing these factors in housing policy and routine child health promotion could reduce stair fall injuries.

A Clinical Comparison of Orally Administered Aspirin, Dextropropoxyphene and Pentazocine in the Treatment of Post-Operative Pain

A double-blind between-patient study involving 225 adult patients was carried out to compare the efficacy of oral aspirin ( 650 mg), dextropropoxyphene (65 mg) and pentazocine ( 50 mg) in post-operative pain. All the patients were initially in moderate or severe pain and all three drugs produced some degree of pain relief. The onset of action of pentazocine was significantly more rapid than that of aspirin or dextropropoxyphene. The analgesia provided by dextropropoxyphene was significantly inferior to that achieved with aspirin or pentazocine and the duration of action, assessed by patient demand for further analgesic drugs, was also significantly shorter than that of the other two drugs. The incidence and severity of side-effects was greatest in the dextropropoxyphene group and it is concluded from these results that pentazocine should be the oral analgesic of choice in the treatment of post-operative pain.

Physical demands of elite Rugby League referees, part two: heart rate responses and implications for training and fitness testing

The purpose of this study was to assess whether any characteristic patterns of heart rate (HR) responses could be identified in National Rugby League (NRL) referees (n= 6) during matches played in the 2001 season. The data have been plotted and discussed, in order that exercise program planning practitioners may gain improved understandings of the physiological requirements for referees. Some specific training suggestions have also been made.

METHODS

The HR was recorded every five seconds throughout six competition NRL matches; using a heart rate monitor with a built-in memory.

RESULTS

The specific magnitudes of referees' HR mean values varied between individuals, possibly due to specific game intensities, referee fitness, and age. All referees however exhibited similar HR response patterns; characterised by frequent (13-20 per match) large transient upward and downward shifts (>20 beats.minute(-1)). Periods of elevated HR extended for between five sec and eight min at a time, and were further characterised as a typical cyclic wave of HR elevation and recovery (ranging from 99.2+/-12.4 beats.minute(-1) to 176.5+/-11.8 beats.minute(-1) [mean +/-95% CI]), with a work to rest ratio of 2:1. Steady state HR was not achieved at any time during any match.

CONCLUSIONS

The findings of the present study, taken together with a recent motion analysis, indicate that Rugby League refereeing is a highly intermittent, variable intensity activity. Significant anaerobic contribution to performance appears likely. It is suggested that training and fitness assessment of athletes should reflect their specific demands; some specific recommendations have therefore been provided.

Physical demands of elite Rugby League referees: Part one — time and motion analysis

The purpose of the present study was to accurately and reliably analyse the nature of movement undertaken by National Rugby League (NRL) referees during matches played in the 2000 season. The movements of NRL referees (n=5) were analysed from videotape footage of ten games. The researchers assigned each movement to one of six defined categories (stationary, walking forwards, jogging forwards, sprinting, sideways, and backwards), and recorded number of repetitions, movement durations, and distances covered during each specific movement category. Distance was estimated using on-field markings as known points. Mean total distance per game was 6.7 km +/- 0.4 km (mean +/- standard deviation), and was made up of approximately 940 movements per game. The data showed 87% of distance was made up of a cyclic activity comprising jogging forwards, then backwards at mean running speeds of 7.2 km x h(-1) and 10.8 km x h(-1) respectively (made up of 9s bursts on average, each separated by 3s breaks). However, this cyclic activity accounted for only 47% of time, as referees were stationary 41% of time. Play was continuous for 90s +/- 71s at each phase of play, and was followed by rest of 45s +/- 36s throughout matches (work to rest ratio was 2:1). These findings suggest Rugby League refereeing is a highly intermittent activity and therefore training and fitness assessments should reflect these specific demands experienced during a game.

The complexity of TNF-related apoptosis-inducing ligand

One of the major goals of researchers in the field of apoptosis is to understand the molecular mechanisms of the various components of the apoptotic pathways, with the hope to identify targets for novel cancer therapies. The discovery of a TNF-related, apoptosis-inducing ligand, TRAIL, that kills transformed cells with great specificity in vitro, has provided the hope that TRAIL may be used to induce cell death in tumor cells without affecting normal tissues. However, TRAIL signaling is very complex and a clear understanding of its function is necessary before it can be used in cancer therapy. Complexity of TRAIL-induced signaling is apparent from its ubiquitous expression, its ability to interact with five receptors, and its tumor-selective induction of apoptosis. The signaling events that mediate the tumor selectivity of TRAIL-induced apoptosis and the biological functions of each of the TRAIL receptors are not well characterized. This review will focus on the complexity of TRAIL and the role of c-FLIP in mediating TRAIL function.

Dengue vector surveillance and control

This review describes efforts being undertaken to develop new tools and strategies to monitor and control dengue fever mosquitoes, mainly Aedes aegypti. With the growing realization that the magnitude of the global dengue/dengue haemorrhagic fever problem rivals that of malaria and infectious diseases such as hepatitis, and that old strategies are unsuitable in today's world, this problem requires urgent attention. The new tactics involve proper targeting of important breeding sites and diverse control methodologies ranging from biological control to molecular transformation of the vectors themselves.

Peritrophins of adult dipteran ectoparasites and their evaluation as vaccine antigens

Several peritrophins of larvae of Lucilia cuprina (sheep blowfly) have demonstrated potential as vaccine antigens, and some have been characterised and cloned. These proteins are tightly associated with the peritrophic matrix, a chitinous tube or sac lining the lumen of the gut of most insects. The peritrophins require strong denaturants for their removal from peritrophic matrix. We now report the preliminary characterisation of peritrophins of the adult stage of L. cuprina and Haematobia irritans exigua (buffalo fly). Similar SDS-PAGE profiles were obtained for proteins extracted in SDS or urea from isolated adult peritrophic matrices of both species. Radioiodination of urea-extracted peritrophins improved sensitivity, indicating numerous proteins of 15-75 kDa. Direct radioiodination of L. cuprina peritrophic matrix preferentially labelled high molecular weight complexes and proteins of 80-90 kDa. Two-dimensional gel analyses of a urea extract of adult L. cuprina peritrophic matrix revealed that most proteins were moderately acidic. Antibodies produced against SDS-extracted peritrophins, or against sonicated peritrophic matrices of these two flies were crossreactive. The sera also appeared to recognise SDS-extracted components of Triton X-100 treated and washed adult peritrophic matrix of the mosquito, Aedes vigilax (Skause). This profile altered as the peritrophic matrix matured. In concordance with extracts from the adult L. cuprina and H.i. exigua peritrophic matrices, proteins in the 50-75 kDa region were immunodominant. The vaccine potential of the peritrophins of these Diptera were examined following vaccination of cattle and rabbits with adult H.i. exigua or L. cuprina peritrophins. When the adult life stages of H.i. exigua or two mosquitoes, A. vigilax and A. aegypti (Linnaeus), were fed on the sera or blood of vaccinated hosts, there were no detrimental effects to any life cycle stages of these Diptera.

Spinal cord ultrasonography in children with myelomeningocele

Secondary tethering of the spinal cord in people with myelomeningocele (MMC) is almost universal but there is a relatively low incidence of the secondary tethered cord syndrome (S-TCS). In view of this, we wish to explore the notion that cord pulsation, as demonstrated by ultrasound of the spinal cord, can become an independent measure for increased tension of the spinal cord in patients with MMC. One-hundred and six patients with MMC underwent ultrasonographic examination of their back, a thorough physical examination, and a careful review of their clinical history. Of these patients, 53 had MRI of their back. Cord pulsation was graded and the statistical relation between pulsation and various clinical and MRI findings was analysed. Age and arm span were not correlated with grades of cord pulsation. The absence of cord pulsation correlated with the presence of symptoms but this relation may be explained by MRI findings of certain structural cord malformations and not by tethering per se. Assuming that cord pulsation is a reliable marker for the tension within the spinal cord, the results of our study suggest that overstretching of the cord is not the main cause for the development of the S-TCS.

Dynamics of intergestural timing: a perturbation study of lip-larynx coordination

In this study, downward-directed mechanical perturbations were applied to the lower lip during both repetitive (/...paepaepae.../) and discrete (/pe'saepaepl/) utterances in order to examine the perturbation-induced changes of intergestural timing between syllables (i.e., between the bilabial and laryngeal gestures for successive /p/'s) and within phonemes (i.e., between the bilabial and laryngeal gestures within single /p/'s). Our findings led us to several conclusions. First, steady-state (phase-resetting) analyses of the repetitive utterances indicated both that "permanent" phase shifts existed for both the lips and the larynx after the system returned to its pre-perturbation rhythm and that smaller steady-state shifts occurred in the relative phasing of these gestures. These results support the hypothesis that central intergestural dynamics can be reset by peripheral articulatory events. Such resetting was strongest when the perturbation was delivered within a "sensitive phase" of the cycle, during which the downwardly directed lower-lip perturbation opposed the just-initiated, actively controlled bilabial closing gesture for /p/. Although changes in syllable duration were found for other perturbed phases, these changes were simply transient effects and did not indicate a resetting of the central "clock." Second, analyses of the transient portions of the perturbed cycles of the repetitive utterances indicated that the perturbation-induced steady-state phase shifts are almost totally attributable to changes occurring during the first two perturbed cycles. Finally, the transient changes in speech timing induced by perturbations in the discrete sequences appeared to share a common dynamical basis with the changes to the repetitive sequences. We conclude by speculating on the type of dynamical system that could generate these temporal patterns.

Exploring the NHS executive document Signposts for Success

The recent document 'Signposts for Success' (Department of Health (DoH), 1988a) offers an extensive blueprint for the strategic development of services for people with a learning disability in the next decade. This article discusses the key issues raised and some of the controversial aspects that have to be addressed.

Breastfeeding and the risk of life-threatening enterotoxigenic Escherichia coli diarrhea in Bangladeshi infants and children

OBJECTIVE

To assess the relationship between breastfeeding and the risk of life-threatening enterotoxigenic Escherichia coli (ETEC) diarrhea among Bangladeshi infants and young children <36 months of age.

DESIGN

Case-control study.

SETTING

A rural Bangladesh community.

PARTICIPANTS

A total of 168 cases with clinically severe ETEC diarrhea detected in a treatment center-based surveillance system during 1985 to 1986 and 3679 controls selected in three surveys of the same community during the same calendar interval.

OUTCOMES

Cases and controls were compared for the frequency of antecedent breastfeeding patterns.

RESULTS

Compared with other feeding modes, exclusive breastfeeding of infants was associated with significant protection against severe ETEC diarrhea (relative risk [RR] = 0.51; 95% confidence interval [CI]: 0.28,0.96). However, during the second and third years of life, the risk of this outcome was similar in both breastfed and nonbreastfed children (RR = 0.98; 95% CI: 0.45,2.12), and no significant overall protective association between breastfeeding and severe ETEC diarrhea was evident during the first 3 years of life (RR = 0.86; 95% CI: 0.43,1. 74).

CONCLUSIONS

Exclusive breastfeeding appeared to protect infants against severe ETEC diarrhea, but breastfeeding was not associated with protection after infancy, nor was it associated with a major overall reduction of severe ETEC disease during the first 3 years of life. Although not diminishing the importance of breastfeeding, our findings suggest that other interventions, such as immunization and education about proper food hygiene, may also be required in efforts to prevent this major pediatric disease.

Movements and Home Ranges of Feral Pigs (Sus Scrofa) in Kosciusko National Park, New South Wales

The movements of a subalpine population of feral pigs were examined at Kosciusko National Park in southeastern New South Wales. Sufficient data were collected to estimate the home-range area of 20 pigs on the basis of 782 telemetry and trap locations. Mean (+/- s.d.) home-range size (minimum convex polygon method) for males (35.0 t 22.2 km*2) was significantly greater than that for females (1 1.1 +/- 5.2 km*2). Use of capture-recapture distances to estimate home-range size was considered inappropriate. A test for nomadism suggests that, although home ranges of pigs in this environment were larger than those reported for other pigs in Australia, the pigs were essentially sedentary. Management implications for this population are discussed.

Colonization factors of enterotoxigenic E. coli (ETEC) from residents of northern Egypt

Infection caused by enterotoxigenic Escherichia coli (ETEC) poses a serious health problem to children in developing countries. Colonization of the small intestinal mucosa by ETEC strains is mediated by antigenically specific fimbriae, also known as colonization factor antigens (CFA). The importance of this study arises from reports that active and passive immunization with ETEC strains harboring CFAs induced protective immunity against diarrhea in animal models with preformed antibodies. In humans, ETEC containing CFA/I, II, III and IV have been identified. The aim of this study was to define CFAs of ETEC isolated in Alexandria, Egypt. One hundred and seven ETEC isolates from 132 human residents in Alexandria, Egypt were isolated during a birth cohort study. ETEC isolates were screened for heat labile (LT) and heat stable (ST) toxins using a 32P oligonucleotide hybridization probe and a GM1 ELISA. These isolates were examined using monoclonal antibodies against CFA/I, II, III, IV, and against the putative colonization antigens PCF0159 and PCF0166, CS 7 and CS 17. CFAs were found in 48% of ETEC strains. CFA/I was found in 18% of the strains, CFA/II in 10% and CFA/IV in 14%. CFA III was not found. All fifteen strains expressing CFA/IV expressed CS6 and produced ST. CFA/IV was not found in non-ST producing strains, while CFA/I was absent in ST-only producing strains.

Impaired immune response to natural infection as a correlate of vaccine failure in a field trial of killed oral cholera vaccines

In a field trial carried out in 1985 in Matlab, Bangladesh, the authors evaluated whether subjects who developed Vibrio cholerae 01 infections during the first year after earlier receipt of B subunit-killed whole cell (BS-WC) or killed whole cell-only (WC) oral cholera vaccines exhibited deficient serum vibriocidal immune responses to these infections. After severe V. cholerae 01 infections (n = 70) in subjects > 5 years of age, the age group in which both vaccines were efficacious, a 6.5 geometric mean-fold rise of serum vibriocidal antibodies was observed among vaccinees, compared with an 18.6 geometric mean-fold rise in placebo-recipients (p < 0.01). Depressions of serum vibriocidal responses among vaccinees were even more marked after asymptomatic infections (n = 30): a 1.1 geometric mean-fold rise in vaccinees versus a 5.9 geometric mean-fold rise in placebo-recipients (p < 0.01). The authors conclude that subjects who failed to be protected by BS-WC and WC, despite being in the age group for which these vaccines were protective, exhibited poor immune responses even to the vigorous stimulus of natural infection. These findings raise the possibility that immune hyporesponsiveness may limit the potential efficacy attainable by cholera vaccines in populations with endemic cholera.

Impact of infection by Helicobacter pylori on the risk and severity of endemic cholera

To evaluate the relationship between Helicobacter pylori infection and the subsequent risk and severity of endemic Vibrio cholerae O1 diarrhea among rural Bangladeshis, 285 children and adults with cholera (cases) and 881 contemporaneously selected community controls were studied. Cases and controls were contrasted for H. pylori infection, as manifested by serum IgG anti-H. pylori antibodies. Although the overall risk of cholera was not significantly increased among H. pylori-infected subjects, the risk of cholera of life-threatening severity was significantly elevated (relative risk [RR] = 1.61; 95% confidence interval [CI] = 1.07-2.42). A significant increase in the risk of severe cholera was seen in subjects who lacked natural serum vibriocidal antibodies (RR = 2.88; 95% CI = 1.28-6.48) but not in those with such antibodies. Thus, H. pylori infection was associated with a significant increase in the risk of life-threatening cholera, but only among persons lacking natural vibriocidal immunity.

Community integration of people with learning disabilities must continue

When Mr and Mrs Goodfellow were first informed that their 4-year-old son Tommy had a learning disability (was mentally subnormal) the experience was painful and memorable and was similar to the majority of parents in this situation in the 1960s and early 1970s. A busy, caring but somewhat abrupt consultant psychiatrist, based in a strange and foreboding hospital, usually some miles away from the parents' home would, in the space of 15 minutes, advise them that: ‘Your son is clearly mentally subnormal, with an IQ of below 50.’ The usual pattern of advice to follow would be in the nature of:

Grasping the research nettle in learning disabilities nursing

This article addresses the need for ongoing research into clinical nursing practice in learning disabilities nursing. In particular, it explores the issues of informed consent and paternalism and promotes the development of ethics committees in learning disabilities nursing.

Emotions and medicine

So could we rate ourselves, or be rated QA-style, by an 'objective' other, along a scale of five or ten divisions with 'inhuman' at one end and 'emotional basketcase' at the other? And would this rating be a constant, an enduring label of an aspect of our personality, or something more flexible that might vary with one's emotional resource level at a particular time? Does it matter? All, I guess, I really want to say is that it's OK for a doctor to cry when it hurts.

Safety, immunogenicity, and transmissibility of single-dose live oral cholera vaccine strain CVD 103-HgR in 24- to 59-month-old Indonesian children

Recombinant A-B+ Vibrio cholerae O1 strain CVD 103-HgR is a safe, highly immunogenic, single-dose live oral vaccine in adults in industrialized countries. Safety, excretion, immunogenicity, vaccine transmissibility, and environmental introduction of CVD 103-HgR were investigated among 24- to 59-month-old children in Jakarta. In 81 households, 1 child was randomly allocated a single dose of vaccine (5 x 10(9) cfu) and another, placebo. Additionally, 139 unpaired children were randomly allocated vaccine or placebo. During 9 days of follow-up, diarrhea or vomiting did not occur more often among vaccines than controls. Vaccine was minimally excreted and was isolated from no controls and from 1 (0.6%) of 177 unvaccinated family contacts. A 4-fold or higher rise in serum vibriocidal antibody was observed in 75% of vaccines (10-fold rise in geometric mean titer over baseline). Of 135 paired placebo recipients or household contacts, 5 had vibriocidal seroconversions. Moore swabs placed in sewers and latrines near 97 households failed to detect vaccine. These observations pave the way for a large-scale field trial of efficacy.

Breast-feeding and the risk of life-threatening rotavirus diarrhea: prevention or postponement?

PURPOSE

To assess the relationship between breast-feeding and the risk of life-threatening rotavirus diarrhea among Bangladeshi infants and children younger than 24 months of age.

DESIGN

Case-control study.

SETTING

A rural Bangladesh community.

PARTICIPANTS

One hundred two cases with clinically severe rotavirus diarrhea detected in a treatment center-based surveillance system during 1985 and 1986, and 2587 controls selected in three surveys of the same community during the same calendar interval.

OUTCOMES

Cases and controls were compared for the frequency of antecedent breast-feeding patterns.

RESULTS

Compared with other feeding modes, exclusive breast-feeding of infants was associated with significant protection against severe rotavirus diarrhea (relative risk (RR) = 0.10; 95% confidence interval [CI] = 0.03, 0.34). However, during the second year of life, the risk of this outcome was higher in breast-fed than in non-breast-fed children (RR = 2.85; 95% CI = 0.37, 21.71), and no overall protection was associated with breast-feeding during the first 2 years of life (RR = 2.61; 95% CI = 0.62, 11.02).

CONCLUSIONS

Although exclusive breast-feeding appeared to protect infants against severe rotavirus diarrhea, breast-feeding per se conferred no overall protection during the first 2 years of life, suggesting that breast-feeding temporarily postponed rather than prevented this outcome. While not detracting from efforts to promote breast-feeding to alleviate the burden of diarrhea due to nonrotaviral enteropathogens, our findings cast doubt on whether such efforts will impact on the problem of severe rotavirus diarrhea.

Use of vaginal tampons in sewer surveys for non-O1. Vibrio cholerae

Vaginal tampons were shown to be a practical alternative to conventional Moore swabs for isolating Vibrio cholerae from sewage. Associated laboratory investigations demonstrated improved isolation of V. cholerae by using 12- or 18-h enrichments in alkaline peptone water, in comparison with 6-h enrichments, when cultures were incubated at ambient temperatures.

The design and analysis of cholera vaccine trials: recent lessons from Bangladesh

The recent spread of cholera to Latin America, together with the persistent burden of this disease in Asia and Africa, have stimulated efforts to evaluate new cholera vaccines in field settings. Although the standard experimental paradigm for vaccine field trials is well established, the success of these trials will also depend on suitable consideration of the epidemiology of cholera and of cholera vaccination in the setting under study. Epidemiological studies done in Bangladesh emphasize the importance of appreciating the poorly predictable, multifocal occurrence of cholera in estimating a probable incidence of cholera for a field trial. They also underscore how the filtering effect of enrolling subjects into a prospective trial can dramatically reduce the available population for study, and can yield a study sample whose expected risk of cholera differs markedly from that for the source population. Finally, the data highlight the subtle effects that the mode of surveillance and the choice of an outcome definition can have upon protective efficacy, and emphasize the need for subgroup analyses that address the distinctive variations in vaccine protection that may occur in subjects differing in age and in ABO blood groups, and in subjects exposed to classical versus El Tor cholera.

Extracting dynamic parameters from speech movement data

A quantitative characterization of articulatory movements, using the parameter values of a linear second-order dynamical system, was developed in order to compare classes of movements, in particular, classes defined by linguistic factors such as syllable position, stress, and vowel quality. Movements of the lower lip in utterances such as ['bibebib] and [babe'bab] were partitioned into sections ("windows") in two ways: at successive displacement peaks and valleys, and at the right edge of plateau regions around such extreme values. The linguistic factors affected natural frequency in similar ways regardless of whether damping ratio was permitted to vary or held fixed at one of several different values. Damping ratio was generally unaffected by the linguistic factors. For the most part, the type of partition or window did not affect the patterns of the results, with the exception of the closing gesture out of the reduced syllable.

Factors Affecting Bait Uptake and Trapping Success for Feral Pigs (Sus Scrofa) in Kosciusko National Park

An evaluation of the rate and extent of population reduction that can be achieved by trapping feral pigs was conducted in a subalpine area of Kosciusko National Park in south-eastern New South Wales. Movements of pigs during the programme were monitored by radio-telemetry. In total, 142 pigs, including 12-17 (71%) previously fitted with transmitters and known to be still on the study site, were captured over 330 trap-nights at a cost of $A104 per pig. A model fitted to the change in percentage of bait stations eaten per day relative to the cumulative number of pigs caught estimated a population reduction of 62% of animals exposed to traps and only 28% of the entire population. Determinants of trap success are discussed. During the trapping evaluation and in 2 preceding seasons, factors that influenced the rate at which bait stations were found and eaten were also examined. Both the locality characteristics of bait stations and the time of year were found to have significant effects on this rate.

Evidence that inactivated oral cholera vaccines both prevent and mitigate Vibrio cholerae O1 infections in a cholera-endemic area

In a randomized, placebo-controlled field trial of B subunit-killed whole cell (BS-WC) and killed whole cell only (WC) inactivated oral cholera vaccines in rural Bangladesh, active surveillance of selected neighborhoods during the first year after vaccination identified 127 Vibrio cholerae O1 infections among 3285 three-dose recipients. For each vaccine, protective efficacy was greater against symptomatic (57%, P < .05 for BS-WC; 58%, P < .05 for WC) than against asymptomatic infections (46%, P < .05 for BS-WC; 32%, P = .09 for WC), and protection against each grade of infection was demonstrable for both the classical and El Tor biotypes. Although vaccine protection against symptomatic infections was evident in both young children and older persons, only persons vaccinated at age > 5 years were protected against asymptomatic infections. These results suggest that the inactivated oral vaccines acted both to protect against intestinal colonization by V. cholerae O1 and to interrupt the pathogenic sequence of established infections.

Evaluation in volunteers of a candidate live oral attenuated Salmonella typhi vector vaccine

Candidate vector vaccine strain CVD 906 (aroC- and aroD- derivative of virulent Salmonella typhi strain ISP1820) was evaluated in phase 1 clinical trials. The first nine volunteers ingested a single dose of 5 x 10(7) CVD 906 bacilli. At this dose CVD 906 stimulates remarkable systemic and mucosal immune responses, inasmuch as 89% of volunteers developed marked serum antibody levels to S. typhi antigens and high numbers of antigen-specific gut-derived antibody-secreting cells. Four (44%) volunteers developed asymptomatic vaccinemia 4-10 d after immunization and all volunteers excreted CVD 906 on at least one occasion. However, two volunteers developed febrile adverse reactions, one on the day of vaccination and the other on day 4. Of 11 volunteers who ingested a single dose of 5 x 10(3) CVD 906 bacilli, none displayed side effects but 27% developed significant serum responses to S. typhi LPS. In vitro, CVD 906 replicates for only nine generations in pooled human serum, indicating that CVD 906 growth is limited in this physiologically relevant medium. In phorbol myristate acetate-induced U937 human macrophage-like cells, CVD 906 replicates intracellularly to a lesser extent than parent strain ISP1820. Although, strain CVD 906 is attenuated and highly immunogenic, the occasional febrile reactions at high doses indicate that further attenuation of this strain is necessary.