The global distribution of diet breadth in insect herbivores.

Understanding variation in resource specialization is important for progress on issues that include coevolution, community assembly, ecosystem processes, and the latitudinal gradient of species richness. Herbivorous insects are useful models for studying resource specialization, and the interaction between plants and herbivorous insects is one of the most common and consequential ecological associations on the planet. However, uncertainty persists regarding fundamental features of herbivore diet breadth, including its relationship to latitude and plant species richness. Here, we use a global dataset to investigate host range for over 7,500 insect herbivore species covering a wide taxonomic breadth and interacting with more than 2,000 species of plants in 165 families. We ask whether relatively specialized and generalized herbivores represent a dichotomy rather than a continuum from few to many host families and species attacked and whether diet breadth changes with increasing plant species richness toward the tropics. Across geographic regions and taxonomic subsets of the data, we find that the distribution of diet breadth is fit well by a discrete, truncated Pareto power law characterized by the predominance of specialized herbivores and a long, thin tail of more generalized species. Both the taxonomic and phylogenetic distributions of diet breadth shift globally with latitude, consistent with a higher frequency of specialized insects in tropical regions. We also find that more diverse lineages of plants support assemblages of relatively more specialized herbivores and that the global distribution of plant diversity contributes to but does not fully explain the latitudinal gradient in insect herbivore specialization.

Machine learning method for the classification of the state of living organisms' oscillations.

The World Health Organization highlights the urgent need to address the global threat posed by antibiotic-resistant bacteria. Efficient and rapid detection of bacterial response to antibiotics and their virulence state is crucial for the effective treatment of bacterial infections. However, current methods for investigating bacterial antibiotic response and metabolic state are time-consuming and lack accuracy. To address these limitations, we propose a novel method for classifying bacterial virulence based on statistical analysis of nanomotion recordings. We demonstrated the method by classifying living Bordetella pertussis bacteria in the virulent or avirulence phase, and dead bacteria, based on their cellular nanomotion signal. Our method offers significant advantages over current approaches, as it is faster and more accurate. Additionally, its versatility allows for the analysis of cellular nanomotion in various applications beyond bacterial virulence classification.

Assessing possible visitor-use impacts on water quality in Yosemite National Park, California.

There is concern that visitor-use associated activities, such as bathing, dish washing, wastewater production, and stock animal use near lakes and streams, could cause degradation of water quality in Yosemite National Park. A study was conducted during 2004-2007 to assess patterns in nutrient and Escherichia coli (E. coli) concentrations in the Merced and Tuolumne Rivers and characterize natural background concentrations of nutrients in the park. Results indicated that nutrient and E. coli concentrations were low, even compared to other undeveloped sites in the United States. A multiple linear regression approach was used to model natural background concentrations of nutrients, with basin characteristics as explanatory variables. Modeled nitrogen concentrations increased with elevation, and modeled phosphorus concentrations increased with basin size. Observed concentrations (±uncertainty) were compared to modeled concentrations (±uncertainty) to identify sites that might be impacted by point sources of nutrients, as indicated by large model residuals. Statistically significant differences in observed and modeled concentrations were observed at only a few locations, indicating that most sites were representative of natural background conditions. The empirical modeling approach used in this study can be used to estimate natural background conditions at any point along a study reach in areas minimally impacted by development, and may be useful for setting water-quality standards in many national parks.

Prevalence of chronic venous disorders among employees working in prolonged sitting and standing postures.

Research was conducted to determine the prevalence and severity of chronic venous disorders (CVD) among people working in prolonged sitting or static standing postures. Clinical examination and duplex Doppler sonography were performed on 126 employees working in a sitting (96 individuals) or a standing posture (30 individuals). Evidence of CVD was found in 59.4% of individuals working in a sitting posture and in 83.4% of those working in a standing posture, and was significantly higher in employees working in a standing posture (p = .015). Incompetent perforating veins and vena saphena magna valves, and bilateral changes were the more frequent signs of CVD. The investigation showed that prolonged standing and sitting at work increases risk of developing CVD. Further, people working in a standing posture are at a significantly greater risk for CVD than those working in a prolonged sitting posture. They should thus be the subject of specific prophylaxis interventions.

Postpartum endoanal ultrasound findings in primiparous women after vaginal delivery.

BACKGROUND: Natural childbirth is regarded as the most frequent cause of anal sphincter defects. The majority of obstetric injuries are detectable only by anal endosonography (AES), in from 6.8% to 35% of women after vaginal delivery. PURPOSE: To evaluate prospectively anal sphincters in primiparous women in the first days after delivery to estimate the prevalence of anal sphincter defects and to correlate selected risk factors with the recognized injuries. MATERIAL AND METHODS: A total of 112 consecutive primiparous women aged 19-40 years (mean 29.3 years) underwent three-dimensional (3D) AES with the use of a BK Medical scanner Profocus 2202 in the first weeks after delivery. RESULTS: Twelve tears (10.7%) in the perineum, including three extending to anal sphincters (2.6%) were found on AES. As many as 86 (76.8%) women had medio-lateral episiotomies due to the practice pattern in our hospital or as a consequence of obstetric factors. The statistical analysis did not prove a significant association between diagnosed injuries and episiotomy (P=0.73), nor a traumatic effect of epidural anesthesia, fetus head circumference > or =34 cm, or birth weight > or =3525 g. CONCLUSION: Anal sphincter tears following childbirth were found in only 2.6% of primiparous women, suggesting that vaginal delivery might not imply high risk of pelvic floor damage as has previously been assumed. The results do not confirm that medio-lateral episiotomy is conducive to obstetric anal sphincter defects.

Anal endosonographic findings in women after vaginal delivery.

OBJECTIVE: To estimate a frequency of obstetric anal sphincters defects in women after vaginal delivery. METHODS: The study included 102 women, aged from 16 to 40 years (mean age 28.6 years). 28 women had perineal lacerations of 3rd and 4th degree. 22 women had instrumental delivery. Anal endosonography was performed on all participants using BK Medical scanner Pro focus with a 3D endoprobe during the first week after delivery. Starck's classification was used to score sphincters defects. RESULTS: The endosonographic images were abnormal in 8 out of 102 women (7.8%). Follow-up examinations after 6 weeks confirmed defects in 6 out of 102 women (5.8%). Five women had external anal sphincter torn, and 1 woman had both sphincters, internal and external, defected. Discordance between endosonographic diagnosis of defect and clinical assessment of sphincters continuity was demonstrated in 6 (5.9%) out of 8 initially found, including 2 (1.9%) false endosonographic results and 4 (3.9%) false clinical diagnosis (occult sphincter defects). The endosonography sensitivity and accuracy in sphincter defect diagnostic amounted to 100% and 98%, respectively. CONCLUSIONS: (1) Anal sphincters' tears in symptomatic women are not as frequent as it was believed. (2) The defect diagnosis in the first week after delivery should be verified by a follow-up endosonography in 6 weeks, after regression of the edema and hematoma.

Comparison of contrast-enhanced with non-contrast endosonography in the diagnostics of anal fistulas.

The objective of this paper is to compare the accuracy of standard, non-contrast endosonography (EAS) with contrast-enhanced endosonography (CE-EAS) in the diagnosis of anal fistulas. The group consisted of 126 patients (mean age: 43.1 years) with the clinical diagnosis of anal fistula. For anal endosonography, a Bruel & Kjaer unit with a 7.0-MHz transducer was used with a 3% solution of hydrogen peroxide as the contrast agent (1, 2, 3). In each case, EAS and CE-EAS diagnoses of the type and complexity of anal fistula, as well as the location of the internal opening, were determined. Results showed that CE-EAS was significantly more accurate in diagnosing the type of anal fistulas than NC-EAS (97 vs. 94%, respectively; P=02275), and in differentiating simple from complex tracks (92 vs. 75%, respectively; P<0.00001). CE-EAS was much more accurate in patients with recurrent fistulas (57 vs. 92%, respectively; P<0.00006), whereas in a subgroup of primary tracks, both methods were of comparable accuracy. Sensitivities of CE-EAS and EAS for internal opening were 89 and 65%, respectively. The conclusion of this paper is that CE-EAS significantly increases the accuracy of standard non-contrast EAS and is especially beneficial for the differentiation between simple and complex tracks.