Fewer butterflies seen by community scientists across the warming and drying landscapes of the American West.

Uncertainty remains regarding the role of anthropogenic climate change in declining insect populations, partly because our understanding of biotic response to climate is often complicated by habitat loss and degradation among other compounding stressors. We addressed this challenge by integrating expert and community scientist datasets that include decades of monitoring across more than 70 locations spanning the western United States. We found a 1.6% annual reduction in the number of individual butterflies observed over the past four decades, associated in particular with warming during fall months. The pervasive declines that we report advance our understanding of climate change impacts and suggest that a new approach is needed for butterfly conservation in the region, focused on suites of species with shared habitat or host associations.

Predicting patch occupancy reveals the complexity of host range expansion.

Specialized plant-insect interactions are a defining feature of life on earth, yet we are only beginning to understand the factors that set limits on host ranges in herbivorous insects. To better understand the recent adoption of alfalfa as a host plant by the Melissa blue butterfly, we quantified arthropod assemblages and plant metabolites across a wide geographic region while controlling for climate and dispersal inferred from population genomic variation. The presence of the butterfly is successfully predicted by direct and indirect effects of plant traits and interactions with other species. Results are consistent with the predictions of a theoretical model of parasite host range in which specialization is an epiphenomenon of the many barriers to be overcome rather than a consequence of trade-offs in developmental physiology.

Quantifying diet breadth through ordination of host association.

Many areas of research in ecology and evolutionary biology depend on the quantification of dietary niche width. For herbivorous insects, diet breadth has most often been measured as simply the number and type of host plant taxa attacked. We propose an index of host range (which we refer to as "ordinated diet breadth") based on observed associations between plants and insects, and the calculation of multivariate distances among plants in ordination space. Similarities and distances are calculated based on host association and, in this context, potentially encompass multiple properties of plants, including phytochemistry, phenology, and other plant traits. This approach can distinguish between herbivores that utilize suites of hosts that are commonly used together and herbivores that attack unusual host combinations, and thus have a relatively broad diet breadth. For illustration, we use a data set of nymphalid butterfly host records, and compare taxonomic and ordinated host range. For a large number of butterfly taxa, we find that host use is clustered in multivariate space with respect to associations observed across all of the butterfly taxa. Applications are discussed, including a hypothesis test of nonrandom host association, and prediction of shifts and expansions of diet breadth.

Wolbachia infection and Lepidoptera of conservation concern.

Conservation of at-risk species requires multi-faceted and carefully-considered management approaches to be successful. For arthropods, the presence of endosymbiotic bacteria, such as Wolbachia (Rickettsiales: Rickettsiaceae), may complicate management plans and exacerbate the challenges faced by conservation managers. Wolbachia poses a substantial and underappreciated threat to the conservation of arthropods because infection may induce a number of phenotypic effects, most of which are considered deleterious to the host population. In this study, the prevalence of Wolbachia infection in lepidopteran species of conservation concern was examined. Using standard molecular techniques, 22 species of Lepidoptera were screened, of which 19 were infected with Wolbachia. This rate is comparable to that observed in insects as a whole. However, this is likely an underestimate because geographic sampling was not extensive and may not have included infected segments of the species' ranges. Wolbachia infections may be particularly problematic for conservation management plans that incorporate captive propagation or translocation. Inadvertent introduction of Wolbachia into uninfected populations or introduction of a new strain may put these populations at greater risk for extinction. Further sampling to investigate the geographic extent of Wolbachia infections within species of conservation concern and experiments designed to determine the nature of the infection phenotype(s) are necessary to manage the potential threat of infection.

Specificity, rank preference, and the colonization of a non-native host plant by the Melissa blue butterfly.

Animals often express behavioral preferences for different types of food or other resources, and these preferences can evolve or shift following association with novel food types. Shifts in preference can involve at least two phenomena: a change in rank preference or a change in specificity. The former corresponds to a change in the order in which hosts are preferred, while a shift in specificity can be an increase in the tendency to utilize multiple hosts. These possibilities have been examined in relatively few systems that include extensive population-level replication. The Melissa blue butterfly, Lycaeides melissa, has colonized exotic alfalfa, Medicago sativa, throughout western North America. We assayed the host preferences of 229 females from ten populations associated with novel and native hosts. In four out of five native-associated populations, a native host was preferred over the exotic host, while preference for a native host characterized only two out of five of the alfalfa-associated populations. Across all individuals from alfalfa-associated populations, there appears to have been a decrease in specificity: females from these populations lay fewer eggs on the native host and more eggs on the exotic relative to females from native-host populations. However, females from alfalfa-associated populations did not lay more eggs on a third plant species, which suggests that preferences for specific hosts in this system can potentially be gained and lost independently. Geographic variation in oviposition preference in L. melissa highlights the value of surveying a large number of populations when studying the evolution of a complex behavioral trait.

The impact of social context on male mate preference in a unisexual--bisexual mating complex.

Male sailfin mollies Poecilia latipinna were tested in five different treatments that varied in the relative frequency of heterospecific gynogens (Amazon molly Poecilia formosa) to conspecific females to determine whether social interactions among males within a population causes some males to mate with heterospecific females. Male P. latipinna inseminated a significantly higher proportion of conspecific females and fertilized a significantly higher number of conspecific eggs regardless of the treatment. Nonetheless, preference for conspecific females was not exclusive as a range of 20 to 50% of heterospecific females were fertilized. Social interactions among males may best explain the results and may therefore play an important role in the maintenance of unisexual--bisexual mating complexes.

Varices of the round ligament mimicking an inguinal hernia--an important differential diagnosis during pregnancy.

Pregnancy is a recognised risk factor for the development of inguinal hernias due to an increase in intra-abdominal pressure. Whilst often managed conservatively until after the pregnancy, if the hernia presents acutely as a painful or tender groin lump, urgent or emergency repair may be required. Many clinicians rely heavily on clinical examination alone in order to diagnose the presence of such a hernia. In pregnancy, however, in order to prevent unnecessary surgery, the use of ultrasound has a more important role to play in reaching this diagnosis. We report a cautionary case that highlights the need for ultrasound evaluation of all painful groin lumps in pregnant women prior to considering surgery.

Retrograde vs. antegrade puncture for infra-inguinal angioplasty.

This study was done to compare antegrade punctures with a retrograde puncture technique for infrainguinal angioplasty. A group of 100 consecutive patients (71 men, 29 women) were randomized for antegrade puncture or retrograde puncture of the common femoral artery. Following retrograde puncture the guidewire was 'turned' and placed into the superficial femoral artery. The time for gaining access, screening time, radiation dose, patient height, weight and complications were recorded. All patients were reviewed the day after the procedure and within 3 months. Data from 46 patients (34 males and 12 females) in the retrograde group and 44 (28 males and 16 females) in the antegrade group were available for analysis. Mean procedure time, screening time, radiation dose, height and weight were 8.3 minutes (range 3-22), 2.1 minutes (0.3-6.5), 7950 mGy cm(-2) (820-71250), 169 cm (149-204) and 79 kg (32-108) for retrograde puncture and 8 min (2-60), 0.7 min (0.0-3.2), 1069 mGy cm(-2) (0-15400), 169 cm (152-186) and 75 kg (39-125) for antegrade punctures, respectively. An average of 1.2 (1-2) punctures was required for retrograde and 1.75 (1-8) for antegrade. Seven small hematomas occurred with antegrade and three for retrograde puncture. Retrograde puncture is technically easier with a tendency to fewer complications but results in a higher radiation dose. This technique should be used in difficult patients at high risk of haematoma formation.

Patterns of morphological, biochemical, and molecular evolution in the Oeneis chryxus complex (Lepidoptera: Satyridae): a test of historical biogeographical hypotheses.

Surveys of allozyme allele frequency and mitochondrial DNA (mtDNA) sequence variation were employed to test historical biogeographical hypotheses on the origin and unique distribution of the synchronized biennial, high-altitude butterflies of the Oeneis chryxus complex in western North America. Populations of O. c. stanislaus and O. ivallda from the central and northern Sierra Nevada are indistinguishable by use of allozyme allele frequency data, possessed nearly identical mtDNA cytochrome oxidase subunit 1 (COI) haplotypes, and were found to be relatively distantly related to O. c. chryxus from the Snake Range in eastern Nevada. However, individuals of O. ivallda from Piute Pass in the southern Sierra Nevada are more variable, with some individuals sharing mtDNA characteristics with O. c. chryxus. We find little support for the hypothesis proposed by W. Hovanitz in 1940 that O. c. stanislaus invaded the central Sierra Nevada from across the Great Basin and displaced O. ivallda, but cannot reject the hypothesis that ancestral Oeneis dispersed across the Great Basin to California. This result is congruent with hypotheses of dispersal across the Great Basin for the origin of some Sierran alpine organisms.

A prospective audit of wound infection rates after caesarean section in five West Yorkshire hospitals.

A three month prospective audit of wound infection following emergency and elective caesarean section was carried out in five West Yorkshire hospitals. Among 4076 women undergoing delivery in the five obstetric departments, the caesarean rate was 15.4%. The overall infection rate was 45/628 (7.2%) with a range of 2.5-17.2% between the five centres. The infection rate was 14/226 (6.2%) when antibiotics were used compared with 31/402 (7.7%) without antibiotics. The use of prophylactic antibiotics made no significant difference to the infection rate, which did not correlate with duration of labour or of ruptured membranes. The number of vaginal examinations correlated with the infection rate. In conclusion, the caesarean section rate observed was higher than that estimated for the UK as a whole, but was distorted by one centre with a high rate. For the other four hospitals the caesarean rate was unexceptional. The ratio of emergency to elective operations was comparable with recently reported values in the UK and the wound infection rate was within the widely varying limits found in previous studies. In view of the relatively low infection rate recorded without antibiotics, in the interests of cost effectiveness, prophylaxis may be limited in future to selected women at high risk. Because this was an audit rather than a randomized study we cannot exclude that this is already happening on an empirical basis.

Management and control of a large outbreak of diarrhoea due to Clostridium difficile.

In the six-month period 1 November 1991 to 1 May 1992 175 patients developed diarrhoea due to Clostridium difficile in three hospitals in Manchester, UK. Most patients (90%) were over 60 years old and had been admitted to acute geriatric or medical wards with other illnesses. Infection is thought to have contributed to 17 deaths. Twenty-two patients relapsed clinically after antibiotic treatment. The outbreak began in one ward and affected 15 patients and two nurses. During the following months cases occurred on 34 wards. The pattern of spread suggested that a ward index case was followed by several secondary cases. Pyrolysis mass spectrometry showed that 79% of isolates of C. difficile belong to a single cluster and this putative outbreak strain also extensively colonizes the hospital environment. It was also responsible for a smaller outbreak in 1991 and many 'sporadic' cases in our hospitals before then. An outbreak control team was convened at an early stage and expert opinion co-opted. Infection control measures included: intensive education of staff; increased vigilance; strict enteric precautions; cohort nursing in a designated ward; rigorous cleaning procedures including emptying and 'deep' cleaning of wards where several cases had occurred; restriction of staff and patient movement; and restriction of antibiotic use. Subsequent to these measures there has been a substantial and sustained decrease in the number of new cases.

Blood-brain barrier disruption due to cerebral arteriography: CT findings.

Computed tomography was performed in two cases of blood-brain barrier (BBB) disruption due to cerebral arteriography. The first case showed diffuse contrast enhancement in the right frontotemporal region in the distribution of the middle cerebral artery; in the second case patchy contrast enhancement in both gray and white matter of both hemispheres was demonstrated. The possible mechanism for BBB disruption in these patients is discussed.