A camouflaged diversity: taxonomic revision of the thorny lacewing subfamily Symphrasinae (Neuroptera, Rhachiberothidae)

Species of the thorny lacewing subfamily Symphrasinae (Neuroptera: Rhachiberothidae) are revised. Prior to this work, 42 species were known in the genera Anchieta Navás, 1909, Plega Navás, 1928, and Trichoscelia Westwood, 1852. Herein, the number of species is increased to 60, 23 of which are newly described. Species previously known are redescribed, and their taxonomic status is revised. Keys, diagnoses, and high-resolution images for all species are presented. The distribution range of Anchieta is now known from Costa Rica to southern Brazil with a total of 11 species, of which three are newly described. The genus Plega is known from southwestern United States to southern Brazil and includes 28 species of which 14 are described as new. Moreover, the genus Trichoscelia occurs from central and southern Mexico to Argentina, with a total of 21 species, of which six are herein newly described. A phylogenetic analysis of Symphrasinae based on morphological characters recovered the three symphrasine genera as monophyletic, with Anchieta sister to Plega + Trichoscelia. The three genera are newly diagnosed based on a cladistic framework. Within the genus Anchieta, bee-mimicking species comprise a monophyletic group, while wasp-mimicking species form a laddered sequence to that lineage. Within Plega, three lineages are recovered, the first mostly composed of South and Mesoamerican species, the second with species predominantly from Central America and central and southern Mexico, and a third clade encompassing species mostly from central and northern Mexico and southwestern United States. By contrast, relationships between species of Trichoscelia were poorly resolved because of a simplified and conserved morphology of this group.

From Molecular Constraints to Macroscopic Dynamics in Associative Networks Formed by Ionizable Polymers: A Neutron Spin Echo and Molecular Dynamics Simulations Study

The association of ionizable polymers strongly affects their motion in solutions, where the constraints arising from clustering of the ionizable groups alter the macroscopic dynamics. The interrelation between the motion on multiple length and time scales is fundamental to a broad range of complex fluids including physical networks, gels, and polymer-nanoparticle complexes where long-lived associations control their structure and dynamics. Using neutron spin echo and fully atomistic, multimillion atom molecular dynamics (MD) simulations carried out to times comparable to that of chain segmental motion, the current study resolves the dynamics of networks formed by suflonated polystryene solutions for sulfonation fractions 0 ≤ f ≤ 0.09 across time and length scales. The experimental dynamic structure factors were measured and compared with computational ones, calculated from MD simulations, and analyzed in terms of a sum of two exponential functions, providing two distinctive time scales. These time constants capture confined motion of the network and fast dynamics of the highly solvated segments. A unique relationship between the polymer dynamics and the size and distribution of the ionic clusters was established and correlated with the number of polymer chains that participate in each cluster. The correlation of dynamics in associative complex fluids across time and length scales, enabled by combining the understanding attained from reciprocal space through neutron spin echo and real space, through large scale MD studies, addresses a fundamental long-standing challenge that underline the behavior of soft materials and affect their potential uses.

Structural insight into the cooperativity of spin crossover compounds

Spin-crossover (SCO) compounds are promising materials for a wide variety of industrial applications. However, the fundamental understanding of their nature of transition and its effect on the physical properties are still being fervently explored; the microscopic knowledge of their transition is essential for tailoring their properties. Here an attempt is made to correlate the changes in macroscopic physical properties with microscopic structural changes in the orthorhombic and monoclinic polymorphs of the SCO compound Fe(PM-Bia)2(NCS)2 (PM = N-2'-pyridylmethylene and Bia = 4-aminobiphenyl) by employing single-crystal X-ray diffraction, magnetization and DSC measurements. The dependence of macroscopic properties on cooperativity, highlighting the role of hydrogen bonding, π-π and van der Waals interactions is discussed. Values of entropy, enthalpy and cooperativity are calculated numerically based on the Slichter-Drickamer model. The particle size dependence of the magnetic properties is probed along with the thermal exchange and the kinetic behavior of the two polymorphs based on the dependence of magnetization on temperature scan rate and a theoretical model is proposed for the calculation of the non-equilibrium spin-phase fraction. Also a scan-rate-dependent two-step behavior observed for the orthorhombic polymorph, which is absent for the monoclinic polymorph, is reported. Moreover, it is found that the radiation dose from synchrotron radiation affects the spin-crossover process and shifts the transition region to lower temperatures, implying that the spin crossover can be tuned with radiation damage.

2214. National Testing Assessment of Select Bacterial STIs During the COVID-19 Pandemic

Background

Chlamydia, gonorrhea, and syphilis infections rose in the US for 6 consecutive years before the COVID-19 pandemic. Patterns of sexually transmitted infection (STI) testing during the COVID-19 pandemic have yet to be fully assessed.

Methods

We performed a retrospective study of STI testing in the Veteran’s Health Administration (VHA) healthcare system during each calendar year 2019-2021 using electronic health record data. We determined the number of chlamydia (CT) and gonorrhea (GC), and syphilis tests performed overall and in demographic groups defined by age, birth sex, self-reported race, region, and HIV status.

Results

VHA performed 202,503 CT tests, 201,314 GC tests and 250,790 syphilis tests in 2019, followed by a 23% and 25% decrease in 2020 for CT/GC and syphilis testing, respectively. We observed decreases among all subgroups defined by age, sex, race, and geography. Race groups with the biggest decreases in 2020 include Asian Americans (-28%) and Hawaiian and Pacific Islanders (-27%). By 2021, overall testing rates demonstrated a partial recovery to 89.8% of their 2019 levels. Testing rates in 2021 in rural/ highly rural residents remained 17% below baseline, compared with 10% for urban dwellers. Veterans living in the Northeast, South, or Midwest had the least recovery among geographic regions (16%, 11% and 11% below baseline, respectively). People with HIV experienced a decline in CT/GC testing of 15% but by the end of 2021 this had recovered to 1.9% below baseline. Women experienced both a steeper drop and a smaller recovery in CT and GC testing relative to men (Figure 1), except for women under age 25 (Figure 2). Figure 1STI testing rates by CY and sexFigure 2Percent change in STI testing rates versus 2019

Conclusion

After dramatic reductions in STI testing during the COVID-19 pandemic, rates returned to near-baseline levels nationally by 2021. Testing rates have lagged in some patient groups, most notably rural and highly rural populations, women, and Black and Asian American Veterans, placing them at risk for disparities in STI diagnosis, and therefore treatment. Testing rates in Veterans under age 25 years have reached or exceeded pre-pandemic levels.

Disclosures

All Authors: No reported disclosures.

Sexually Transmitted Infection Testing in the National Veterans Health Administration Patient Cohort During the Coronavirus Disease 2019 Pandemic

Background

We performed a retrospective study of chlamydia, gonorrhea, syphilis, and human immunodeficiency virus (HIV) testing in the Veterans Health Administration (VHA) during 2019-2021.

Methods

We determined the annual number of chlamydia, gonorrhea, syphilis, and HIV tests from 2019 through 2021 using electronic health record data. We calculated rates by age, birth sex, race, census region, rurality, HIV status, and use of preexposure prophylaxis.

Results

The VHA system experienced a 24% drop in chlamydia/gonorrhea testing, a 25% drop in syphilis testing, and a 29% drop in HIV testing in 2020 versus 2019. By the conclusion of 2021, testing rates had recovered to 90% of baseline for chlamydia/gonorrhea, 91% for syphilis, and 88% for HIV. Declines and subsequent improvements in sexually transmitted infection (STI) testing occurred unequally across age, sex, race, and geographic groups. Testing for all 4 STIs in 2021 remained below baseline in rural Veterans. Excluding those aged <25 years, women experienced a steeper decline and slower recovery in chlamydia/gonorrhea testing relative to men, but quicker recovery in HIV testing. Asian Americans and Hawaiian/Pacific Islanders had a steeper decline and a slower recovery in testing for chlamydia/gonorrhea. Black and White Veterans had slower recovery in HIV testing compared with other race groups. People living with HIV experienced a smaller drop in testing for syphilis compared with people without HIV, followed by a near-total recovery of testing by 2021.

Conclusions

After dramatic reductions from 2019 to 2020, STI testing rates returned to near-baseline in 2021. Testing recovery lagged in rural, female, Asian American, Hawaiian/Pacific Islander, and Black Veterans.

Contributions to the biodiversity of Vietnam – Results of VIETBIO inventory work and field training in Cuc Phuong National Park

VIETBIO [Innovative approaches to biodiversity discovery and characterisation in Vietnam] is a bilateral German-Vietnamese research and capacity building project focusing on the development and transfer of new methods and technology towards an integrated biodiversity discovery and monitoring system for Vietnam. Dedicated field training and testing of innovative methodologies were undertaken in Cuc Phuong National Park as part and with support of the project, which led to the new biodiversity data and records made available in this article collection.

VIETBIO is a collaboration between the Museum für Naturkunde Berlin – Leibniz Institute for Evolution and Biodiversity Science (MfN), the Botanic Garden and Botanical Museum, Freie Universität Berlin (BGBM) and the Vietnam National Museum of Nature (VNMN), the Institute of Ecology and Biological Resources (IEBR), the Southern Institute of Ecology (SIE), as well as the Institute of Tropical Biology (ITB); all Vietnamese institutions belong to the Vietnam Academy of Science and Technology (VAST).

The article collection "VIETBIO" (https://doi.org/10.3897/bdj.coll.63) reports original results of recent biodiversity recording and survey work undertaken in Cuc Phuong National Park, northern Vietnam, under the framework of the VIETBIO project. The collection consist of this “main” cover paper – characterising the study area, the general project approaches and activities, while also giving an extensive overview on previous studies from this area – followed by individual papers for higher taxa as studied during the project. The main purpose is to make primary biodiversity records openly available, including several new and interesting findings for this biodiversity-rich conservation area. All individual data papers with their respective primary records are expected to provide useful baselines for further taxonomic, phylogenetic, ecological and conservation-related studies on the respective taxa and, thus, will be maintained as separate datasets, including separate GUIDs also for further updating.

Data reduction strategies at a time-of-flight NSE for a lamellar microemulsion

Neutron spin echo (NSE) spectroscopy provides the ultimate energy resolution in quasi-elastic thermal and cold neutron scattering spectroscopy. A peculiarity of the SNS-NSE, the only NSE spectrometer at a pulsed beam port at the moment, is that the wavelength spread δλ/λ can be chosen during evaluation with an appropriate time channel binning. The Q-resolution can be adjusted in certain limits a posteriori by choosing the appropriate detector binning (as on a continuous source) and time channel binning. This can be exploited for samples with a strongly varying scattering function S (Q, t), e.g. due to Bragg peaks in a crystal or lamellar ordering in microemulsions. The data reduction software DrSpine allows for appropriate slicing and masking for this task. In this contribution the correlation function of microemulsions, thermodynamically stable mixtures of oil, water and surfactant, is measured with NSE on length scales where structural correlations are important, and data reduction strategies varying the Q-resolution by pixel and time channel grouping are discussed. The typical ”de Gennes narrowing” or structural narrowing is observed with a relaxation time proportional to I(Q). In these regions of strongly varying intensity it is shown that a too coarse grouping has an influence on the data reduction, with a broadened in Q of the apparent slowing down.

857. Discussion and Initiation of HIV Pre-exposure Prophylaxis Were Rare Following Diagnoses of Sexually Transmitted Infections among Veterans

Background

Healthcare encounters for the diagnosis and treatment of sexually transmitted infections (STIs) are common and represent a window of opportunity to discuss and initiate HIV pre-exposure prophylaxis (PrEP). Little is known about how frequently PrEP is discussed and initiated in association with encounters for STIs.

Methods

We conducted a retrospective cohort and nested case control study in the national Veterans Administration (VA) healthcare system to determine the frequency of PrEP discussion and initiation in association with clinical encounters for bacterial STIs (i.e. early syphilis, gonorrhea, and chlamydia). We used administrative data to identify patients with a first STI based on ICD 9 / 10 codes from January 2013–December 2018 , excluding patients with prior HIV diagnosis or PrEP use, or STI diagnosed in context of a visit to initiate PrEP (Figure 1). We used pharmacy data to determine the frequency of PrEP initiation within 90 days of the encounter for STI in this cohort. In the case control study, we matched 90 PrEP starters to 180 non-starters by day of STI diagnosis and reviewed chart notes from the STI diagnosis encounter to determine frequency of documentation of sexual history taking and PrEP discussions among subsequent PrEP initiators and non-initiators.

Results

We identified 23,312 patients with a first STI, of whom 90 (0.4%) started PrEP within 90 days. Adjusting for age, PrEP initiation was associated with urban residence (OR=5.0, 95Cl 1.8–13.4), White compared to Black race (OR=1.7, 95 Cl 1.1–2.8), and syphilis diagnosis (OR = 7.4, 95 Cl 4.7–11.6, table 1). Chart review revealed that discussion of PrEP was rare among people with STIs who did not subsequently start PrEP (1.1%, 95 CI 0.1–4.0, table 2). PrEP initiation was associated with documentation of any sexual history (80.0% of initiators vs. 51.0% of non-initiators, p &lt; 0.01) and discussion of PrEP (52.2% vs. 1.1%, p &lt; 0.01) during the initial STI diagnosis encounter.

Conclusion

Discussion and initiation of PrEP were rare in association with healthcare encounters for STIs. Not all individuals with STIs will benefit from starting PrEP, but interventions are needed to improve low rates of sexual history-taking and discussion of PrEP during healthcare encounters for STIs.

Disclosures

Bruce Alexander, PharmD, Bruce Alexander Consulting (Independent Contractor)

Antibiotic Stewardship Implementation and Antibiotic Use at Hospitals With and Without On-site Infectious Disease Specialists

BACKGROUND

Many US hospitals lack infectious disease (ID) specialists, which may hinder antibiotic stewardship efforts. We sought to compare patient-level antibiotic exposure at Veterans Health Administration (VHA) hospitals with and without an on-site ID specialist, defined as an ID physician and/or ID pharmacist.

METHODS

This retrospective VHA cohort included all acute-care patient admissions during 2016. A mandatory survey was used to identify hospitals' antibiotic stewardship processes and their access to an on-site ID specialist. Antibiotic use was quantified as days of therapy per days present and categorized based on National Healthcare Safety Network definitions. A negative binomial regression model with risk adjustment was used to determine the association between presence of an on-site ID specialist and antibiotic use at the level of patient admissions.

RESULTS

Eighteen of 122 (14.8%) hospitals lacked an on-site ID specialist; there were 525 451 (95.8%) admissions at ID hospitals and 23 007 (4.2%) at non-ID sites. In the adjusted analysis, presence of an ID specialist was associated with lower total inpatient antibacterial use (odds ratio, 0.92; 95% confidence interval, .85-.99). Presence of an ID specialist was also associated with lower use of broad-spectrum antibacterials (0.61; .54-.70) and higher narrow-spectrum β-lactam use (1.43; 1.22-1.67). Total antibacterial exposure (inpatient plus postdischarge) was lower among patients at ID versus non-ID sites (0.92; .86-.99).

CONCLUSIONS

Patients at hospitals with an ID specialist received antibiotics in a way more consistent with stewardship principles. The presence of an ID specialist may be important to effective antibiotic stewardship.

Differences in Syphilis Incidence Using a Laboratory Algorithm in People With and Without HIV in an 11-Year Nationwide Cohort Study

Background

To measure the incidence of syphilis diagnoses among people with HIV vs those without HIV in a national multiyear retrospective cohort.

Methods

Treponemal and nontreponemal tests, HIV status, and demographic data were identified among all individuals receiving Veterans Health Administration (VHA) care between January 1, 2009, and December 31, 2019. Syphilis testing rates and incident syphilis diagnoses as defined by a laboratory algorithm were stratified by HIV status.

Results

Syphilis was diagnosed in 1.2% (n = 2283) of 194 322 tested individuals in VHA care in 2019. Among individuals with HIV tested for syphilis, 6.1% met criteria for syphilis compared with 0.7% without HIV. Syphilis incidence in 2019 was 35/100 000, a 17% increase from 2009 (30/100 000). In 2019, syphilis incidence was 3381 per 100 000 persons among individuals with HIV and 19 per 100 000 in those without HIV.

Conclusions

Using a laboratory-based diagnostic algorithm, a 178-fold difference in syphilis incidence was observed between individuals with and without HIV in 2019. US syphilis incidence data that incorporate HIV status are needed. Interventions to monitor and prevent sexually transmitted infections should address the role of HIV status.

Growth of electronic consultations in the Veterans Health Administration

OBJECTIVES

To evaluate the growth and variation of electronic consultation, or e-consult, use in the Veterans Health Administration (VHA) across regions and specialties.

STUDY DESIGN

Observational cohort study using administrative data of all veterans who received an e-consult for 41 specialties across 1269 VHA medical centers and associated clinical sites from January 1, 2012, through December 31, 2018.

METHODS

Assessments included (1) the number and characteristics of all e-consults, (2) growth of e-consult use, (3) e-consults as a proportion of all consults by region and by specific specialty, (4) need for an in-person visit with the same specialty within 12 months after an e-consult, and (5) potential miles of driving saved for patients and mileage reimbursement costs avoided for VHA due to e-consult use.

RESULTS

Over the 7-year study period, VHA providers completed 3,117,998 e-consults (5.5% of all specialty consults). e-Consults increased by 309% for all specialties. By 2018, for 16 of 41 specialties, e-consults accounted for greater than 10% of all consults. Overall, 21.5% of e-consults resulted in an in-person visit with the same specialty within 12 months. On average, each e-consult resulted in approximately 84.3 (SD, 89.9; interquartile range, 25.1-115.0) miles in driving saved, equating to potential driving reimbursement savings of $46 million.

CONCLUSIONS

Use of e-consults in the VHA grew substantially between 2012 and 2018, with variability across specialties. In-person follow-up after an e-consult was low, suggesting that e-consults may substitute for in-person visits and reduce considerable patient travel burden.

263. An Evaluation of Quality Indicators for the Management of Staphylococcus aureus Bacteremia: A Nested Case-Control Study

Background

Community-acquired Staphylococcus aureus bacteremia (CA SAB) is a common infection with high mortality. Ten Oever et al. recently used expert consensus methods to develop a set of 25 quality indicators for SAB care in five domains (i.e., follow up blood cultures, echocardiography, non-antibiotic interventions including source control, antibiotic treatment, and other management aspects). Associations between these quality indicators and patient outcomes have not been evaluated. We assessed associations between proposed quality indicators and all-cause 30-day mortality among patients with CA SAB.

Methods

We conducted a nested case-control study within a described national multicenter cohort of patients with SAB in the Veterans Health Administration (VHA). The cohort included 2,093 patients who were: 1) admitted to acute care hospitals between 1/2012 and 12/2014 for CA SAB (the first positive blood culture before or within 48 hours of admission with no recent healthcare exposure); 2) survived at least 96 hours after the SAB onset. We identified paired cases (who died within 30 days) and controls (who survived an equal time), matched 1:1 for age (+/- 5 years), gender, admission year and month, and methicillin susceptibility of isolates. We reviewed charts to extract information for quality indicators. We estimated associations between quality indicators and mortality using logistic regression, adjusting for patient demographics and comorbidity.

Results

164 patients (82 cases and 82 controls) were included. The median patient age was 68.5 (IQR: 62–80) years, and 74 (45.1%) had methicillin-resistant isolates. All patients received at least one domain of quality indicator (median: 3 [IQR: 2–4]). When analyzed individually, only two domains (follow-up blood cultures: OR 0.27 [95% CI: 0.11–0.68]; source control: OR: 0.13 [0.05–0.31]) were associated with mortality. There was a dose-response relationship in which more domains received was associated with decreased mortality (Figure).

Association Between the Number of Satisfied Quality Indicator Domains and All-Cause 30-day Mortality

Conclusion

Among patients with CA-SAB, the number of satisfied quality indicator domains was associated with 30-day mortality with a dose-response relationship. This finding supports the relevance of these quality indicators for SAB management.

Disclosures

All Authors: No reported disclosures

Testing practices and incidence of chlamydial and gonococcal infection in the Veterans Health Administration, 2009-2019

BACKGROUND

Chlamydia trachomatis and Neisseria gonorrhoeae cases reached a record high in the United States in 2018. Although active duty military servicemembers have high rates of chlamydia and gonorrhea infection, trends in chlamydia and gonorrhea in the Veterans Health Administration (VHA) system have not been previously described, including among patients with human immunodeficiency virus (HIV) and young women.

METHODS

We identified all Veterans in VHA care from 2009-2019. Tests and cases of chlamydia and gonorrhea were defined based on lab results in the electronic health record. Chlamydia and gonorrhea incidence rates were calculated each year by demographic group and HIV status.

RESULTS

In 2019, testing for chlamydia and gonorrhea occurred in 2.3% of patients, 22.6% of women ages 18-24, and 34.1% of persons with HIV. 2019 incidence of chlamydia and gonorrhea was 100.8 and 56.3 cases per 100,000 VHA users, an increase of 267% and 294%, respectively, since 2009. Veterans aged <34 years accounted for 9.5% of the VHA population but 66.9% of chlamydia and 42.9% of gonorrhea cases. Chlamydia and gonorrhea incidence rates in persons with HIV were 1,432 and 1,687 per 100,000, respectively.

CONCLUSIONS

The incidence of chlamydia and gonorrhea rose dramatically from 2009-2019. Among tested persons, those with HIV had a 15.2-fold higher unadjusted incidence of chlamydia and 34.9-fold higher unadjusted incidence of gonorrhea compared to those without HIV. VHA-wide adherence to chlamydia and gonorrhea testing in high-risk groups merits improvement.

Co-nonsolvency in concentrated aqueous solutions of PNIPAM: effect of methanol on the collective and the chain dynamics

The polymer dynamics in concentrated solutions of poly(N-isopropyl acrylamide) (PNIPAM) in D2O/CD3OD mixtures is investigated in the one-phase region. Two polymer concentrations (9 and 25 wt%) and CD3OD contents in the solvent mixture of 0, 10 and 15 vol% are chosen. Temperature-resolved dynamic light scattering (DLS) reveals the collective dynamics. Two modes are observed, namely the fast relaxation of polymer segments within the blobs and the slow collective relaxation of the blobs. As the cloud point is approached, the correlation length related to the fast mode increases with CD3OD content. It features critical scaling behavior, which is consistent with mean-field behavior for the 9 wt% PNIPAM solution in pure D2O and with 3D Ising behavior for all other solutions. While the slow mode is not very strong in the 9 wt% PNIPAM solution in pure D2O, it is significantly more prominent as CD3OD is added and at all CD3OD contents in the 25 wt% solution, which may be attributed to enhanced interaction between the polymers. Neutron spin-echo spectroscopy (NSE) reveals a decay in the intermediate structure factor which indicates a diffusive process. For the polymer concentration of 9 wt%, the diffusion coefficients from NSE are similar to the ones from the fast relaxation observed in DLS. In contrast, they are significantly lower for the solutions having a polymer concentration of 25 wt%, which is attributed to the influence of the dominant large-scale dynamic heterogeneities. To summarize, addition of cosolvent leads to enhanced large-scale heterogeneities, which are reflected in the dynamic behavior at small length scales.

Cretaceous diversity and disparity in a lacewing lineage of predators (Neuroptera: Mantispidae)

Mantidflies (Mantispidae) are an unusual and charismatic group of predatory lacewings (Neuroptera), whereby the adults represent a remarkable case of morphological and functional convergence with praying mantises (Mantodea). The evolutionary history of mantidflies remains largely unknown due to a scarcity of fossils. Here, we report the discovery of a highly diverse palaeofauna of mantidflies from the mid-Cretaceous (lowermost Cenomanian) of Myanmar. The raptorial forelegs of these mantidflies possess highly divergent morphological modifications, some of which are unknown among modern mantidflies, e.g. the presence of forked basal profemoral spines or even the complete loss of foreleg spine-like structures. A phylogenetic analysis of Mantispidae reveals a pattern of raptorial foreleg evolution across the family. The high species diversity and disparate foreleg characters might have been driven by diverse niches of predator-prey interplay in the complex tropical forest ecosystem of the mid-Cretaceous.

The genus Chalybion Dahlbom, 1843 (Hymenoptera: Sphecidae) from Northwest Vietnam, with description of a new species

The genus Chalybion Dahlbom, 1843 from northwest Vietnam is studied. Six species of the genus are recorded for the area. Of these, C. dolichothorax (Kohl, 1918) and C. gracile Hensen, 1988 are new records, whereas C. tanvinhensis sp. nov. is described as a new species. Notes on the nest of the new species and keys to both sexes of the six species reported from northwest Vietnam are provided.

1072. The Role of an On-site Infectious Disease Specialist in Hospital-Based Antimicrobial Stewardship Programs

Background

Antimicrobial stewardship programs (ASPs) are now a requirement for many hospitals, but a large proportion of US hospitals lack an on-site Infectious Disease (ID) specialist. We sought to compare the processes and outcomes of ASPs at Veterans Health Administration (VHA) hospitals with and without an on-site ID specialist.

Methods

This retrospective cohort included all acute-care patients in VHA hospitals admitted during 2016, or 2 years after a VHA mandate for hospital-based ASPs. Data from a mandatory nationwide survey were used to identify hospitals that self-reported the absence of an on-site ID specialist, including an ID physician or ID pharmacist, in 2016. Antimicrobial use was quantified at the hospital-level as days-of-therapy (DOTs) per 1,000 days present and categorized based on National Healthcare Safety Network definitions. A facility-level negative binomial regression model with risk adjustments made for aggregated case-mix and facility-level factors was used to determine the association between the presence of an on-site ID specialist and antimicrobial use.

Results

Eighteen of 122 (14.8%) hospitals lacked an on-site ID specialist. Non-ID hospitals had fewer admissions per month than ID sites (mean 107.3 vs. 425.4, P < 0.01). An ASP policy and an ASP pharmacy champion were present at ≥90% of hospitals with and without an ID specialist. Core ASP strategies were frequently used in both ID and non-ID sites, including prior authorization (90.4% vs. 83.3%, P = 0.41) and prospective audit-and-feedback (76.9% vs. 66.7%, P = 0.38). Broad-spectrum antibacterial use (263.9 vs. 317.6 DOTs per 1,000 days-present, P = 0.01) but not total antimicrobial use (600.8 vs. 634.3 DOTs per 1,000 days-present, P = 0.34) was lower at ID vs. non-ID hospitals. After facility-level risk-adjustment, broad-spectrum antibacterial use (OR = 0.81, 95% CI 0.69–0.94) but not total antimicrobial use (OR = 0.92, 95% CI 0.70–1.21) was lower at ID hospitals.

Conclusion

An on-site ID specialist was not associated with greater use of core ASP strategies, but the presence of an on-site ID specialist was associated with less frequent prescribing of broad-spectrum antibacterial agents. An on-site ID specialist may be an important part of an effective hospital-based ASP.

Disclosures

All authors: No reported disclosures.

198. Chart Validation of an Algorithm for Identifying Patients with Intravenous Drug Use-Associated Endocarditis Using Administrative Code Data

Background

Studies using administrative data have described increasing rates of intravenous drug use (IVDU)-associated infective endocarditis (IE) in the United States. These studies used International Classification of Disease (ICD) diagnosis codes to identify hospitalized patients with IE and any illicit drug use (i.e., opioid, amphetamine, cocaine or sedative), but were hindered by absence of specific ICD codes for IVDU. We reviewed charts to determine the positive predictive value (PPV) of ICD codes for identifying patients with IE and IVDU.

Methods

We examined national Veterans Affairs (VA) administrative data from January 2010 to December 2017 to identify patients hospitalized for a first episode of potential IVDU-associated IE based on inpatient ICD 9 and 10 codes for both IE and any illicit drug use, the algorithm used to identify IVDU-IE in most prior studies. We randomly selected 100 of these patients nationally and reviewed hospital charts to confirm clinical documentation of: (1) IE, (2) any illicit drug use, and (3) current or past IVDU.

Results

We identified 340 patients with concurrent ICD codes for IE and drug use, increasing from 28 in 2010 to 51 in 2017 (82% increase). In chart review of 100 randomly selected patients, the PPV of ICD codes was 93% (95% CI 88–98%) for a documented clinical diagnosis of IE; 96% (95% CI 92–100%) for documented drug use by any route; and 63% (95% CI 53–73%) for documented IVDU. Among the 37% of patients without clinically documented IVDU, 30% (i.e.,11% of total patients) had clinical documentation stating that drug use was only by non-IV routes, 59% (22% of total) had documented drug use without mention of route of use, and 11% (4% of total) had clinical documentation that patients denied any drug use.

Conclusion

The incidence of first hospitalization for IE among patients with ICD codes for drug use increased by 82% from 2010 to 2017 in VA care. Concurrent ICD codes for illicit drug use had moderate PPV for identifying IVDU in setting of IE, largely due to identification of patients using drugs without documented intravenous use. There is a need to develop more accurate case-finding algorithms for identifying patients with IVDU-associated endocarditis, for both epidemiologic surveillance and quality improvement applications.

Disclosures

All authors: No reported disclosures.

Health Care Facility Characteristics are Associated with Variation in Human Immunodeficiency Virus Pre-exposure Prophylaxis Initiation in Veteran's Health Administration

To quantify health care facility-level variation in pre-exposure prophylaxis (PrEP) use in the Veteran's Health Administration (VHA); to identify facility characteristics associated with PrEP use. Retrospective analysis of the health care facility-level rate of PrEP initiation in VHA through June 30, 2017. Standardized PrEP initiation rates were used to rank facilities. Characteristics of facilities, prescribers, and PrEP recipients were examined within quartiles. Multiple linear regression was used to identify associations between facility characteristics and PrEP use. We identified 1600 PrEP recipients. Mean PrEP initiation rate was 20.0/100,000 (SD 22.8), ranging from 3.0/100,000 (SD 2.0) in the lowest quartile to 48.1/100,000 (SD 29.1) in the highest. PrEP prescribing was positively associated with proportions of urban dwellers and individuals < 45, tertiary care status, and location. Variability in PrEP uptake across a national health care system highlights opportunities to expand access in non-tertiary care facilities and underserved areas.

1299. Iowa TelePrEP: Preliminary Experience with a Public Health-Partnered, Telemedical PrEP Delivery Model in a Rural State

Background

Access to HIV pre-exposure prophylaxis (PrEP) is often poor in small urban and rural areas due to long distances to PrEP providers and stigma. In 2017, the Iowa Department of Public Health (IDPH), University of Iowa (UI), and community representatives collaborated to develop a public health-partnered telemedical PrEP delivery model to overcome these barriers (TelePrEP). IDPH personnel working in five sexually transmitted infection (STI) clinics and partner services (PS) programs in Eastern Iowa screened clients for PrEP indications and referred those with need to TelePrEP pharmacist providers at UI. Via collaborative practice, pharmacists completed initial and follow-up PrEP home video visits with clients on smart phones and laptops. Clients obtained laboratory monitoring and STI screening in public health-affiliated and local laboratories in accordance with USPHS/CDC guidelines, and received PrEP medication by mail. PS personnel linked TelePrEP clients with newly-identified STIs to local treatment.

Methods

Using the PrEP continuum as framework, we used IDPH databases and UI medical records to conduct a retrospective process evaluation of the TelePrEP model (February 2017–April 2018).

Results

TelePrEP received 44 referrals from public health and 59 self-referrals via advertising. Pharmacists completed 84 initial visits (81% of referrals), including 37 visits (84%) with clients referred by public health. Most (94%) started emtricitabine/tenofovir after initial visits. Retention in TelePrEP at 6 months was 87%. 96% of guideline-indicated laboratory tests (HIV, creatinine, STI, hepatitis) were completed at baseline and follow-up. Rates of extragenital chlamydia and gonorrhea screening were lower (74 of 104 completed screens) due to variable availability of swabs at local laboratories. 15 clients were diagnosed with 20 STIs on screening (6 syphilis, four gonorrhea, 10 chlamydia) and one unrecognized pregnancy was identified. PS linked all clients with STIs on screens to treatment within 14 days (80% in 3 days).

Conclusion

Using telemedicine, healthcare systems can partner with public health administered STI clinics and PS programs to create virtual PrEP delivery models in rural settings. Public health partnerships enhance client identification and ensure linkage to care for new STI diagnoses in telemedicine programs.

Disclosures

A. Hoth, Gilead Sciences, Inc.: Research team member, Research support. M. Ohl, Gilead Sciences, Inc.: Grant Investigator, Research grant.

1031. Nationwide Temporal Trends of Candidemia Incidence Over 18 Years Within the Veteran Health Administration System

Background

Bloodstream infection due to Candida spp. is common and associated with significant mortality and morbidity. Previous population-based studies in 2000s and early 2010s have suggested that the incidence of candidemia might be increasing, presumably due to widespread use of central lines and broad-spectrum antibiotics. However, recent trends of candidemia incidence have not been not well described.

Methods

We conducted a retrospective cohort study of all veterans cared for in the Veterans Health Administration (VHA) system from January 2000 to December 2017 to determine the incidence of candidemia. All patients who had positive blood cultures were identified using data available in the electronic medical record data warehouse, and the number of unique patients for each month was calculated. Patient-days was used as a denominator, and the incidence rate was expressed as the number of unique patients with candidemia per patient-days for each month. Temporal trends were analyzed by joinpoint regression models to identify statistically significant changes in trend.

Results

Over the study period, 31,370 positive blood cultures for Candida spp. from 15,763 unique patients were identified. The mean monthly incidence rate was 22.5 per 100,000 patient-days (IQR: 15.6–28.4). Incidence rates were increasing in the early 2000s and relatively stable in the mid-2000s, followed by a sustained decline (figure). Joinpoint regression analysis revealed there were two statistically significant changes in slope, one in September 2003 (95% CI: 2/2002–1/2005) and another in 6/2007 (95% CI: 4/2006–3/2009).

Conclusion

In the VHA system, there were significant changes in temporal trends of candidemia incidence rates over 18 years, including a substantial increase in the early 2000s followed by a sustained decline in later years. The incidence rates during 2016–2017 were nearly one-third of their peak in the mid-2000s. Possible explanations for the sustained decline include prevention efforts for healthcare-associated infections, such as central-line associated bloodstream infections. Further study is needed to investigate etiologies of these changes in temporal trends to identify potential effective prevention for candidemia.

Disclosures

M. Ohl, Gilead Sciences, Inc.: Grant Investigator, Research grant

1164. County-Level Geographic Distribution of Extended-Spectrum Cephalosporin-Resistant Enterobacteriaceae Across Outpatient Settings of the Veterans Health Administration, 2000–2017

Background

Extended-spectrum cephalosporin resistance (ESCR) among Enterobacteriaceae has emerged globally over the last two decades, with increased prevalence in the community. Data from European countries and healthcare-associated isolates in the United States have demonstrated substantial geographic variability in the prevalence of ESCR, but community-onset isolates in the United States have been less studied. We aimed to describe geographic distribution and spread of ESCR among outpatient settings across the Veterans Health Administration (VHA) over 18 years.

Methods

We analyzed a retrospective cohort of all patients who had any positive clinical culture specimen for ESCR Enterobacteriaceae collected in an outpatient setting; ESCR was defined by phenotypic nonsusceptibility to at least one extended-spectrum cephalosporin agent or detection of an extended-spectrum β-lactamase. Patient-level data were grouped by county of residence, and the total number of unique patients who received care within VHA for each county was used as a denominator. We aggregated data by time terciles (2000–2005, 2006–2011, and 2012–2017), and overall and county-level incidence rates were calculated as the number of unique patients in each year with ESCR Enterobacteriaceae per person-year.

Results

During the study period, there were 1,980,095 positive cultures for Enterobacteriaceae from 870,797 unique patients across outpatient settings of VHA, from a total of 107,404,504 person-years. Among those, 136,185 cultures (6.9%) from 75,500 unique patients (8.7%) were ESCR. The overall incidence rate was 9.0 cases per 10,000 person-years, which increased from 6.3 per 10,000 person-years in 2000 to 14.6 per 10,000 person-years in 2017. County-level incidence rates ranged widely but increased overall (interquartile range [IQR] in 2000–2005: 0–6.7; 2006–2011: 0–9.1; 2012–2017: 3.1–14.3 per 10,000 person-years), with some geographic clustering (figure).

Conclusion

This study demonstrates that there has been geographic variation both in incidence rates and trends of ESCR Enterobacteriaceae in outpatient settings of VHA, which suggests the importance of tailoring local antibiotic-prescribing guidelines incorporating geographic variability in epidemiology.

Disclosures

M. Ohl, Gilead Sciences, Inc.: Grant Investigator, Research grant.

Ion Dynamics in Ionic-Liquid-Based Li-Ion Electrolytes Investigated by Neutron Scattering and Dielectric Spectroscopy

A detailed understanding of the diffusion mechanisms of ions in pure and doped ionic liquids remains an important aspect in the design of new ionic-liquid electrolytes for energy storage. To gain more insight into the widely used imidazolium-based ionic liquids, the relationship between viscosity, ionic conductivity, diffusion coefficients, and reorientational dynamics in the ionic liquid 3-methyl-1-methylimidazolium bis(trifluoromethanesulfonyl)imide (DMIM-TFSI) with and without lithium bis(trifluoromethanesulfonyl)imide (Li-TFSI) was examined. The diffusion coefficients for the DMIM⁺ cation and the role of ion aggregates were investigated by using the quasielastic neutron scattering (QENS) and neutron spin echo techniques. Two diffusion mechanisms are observed for the DMIM⁺ cation with and without Li-TFSI, that is, translational and local. The data additionally suggest that Li⁺ ion transport along with ion aggregates, known as the vehicle mechanism, may play a significant role in the ion diffusion process. These dielectric-spectroscopy investigations in a broad temperature and frequency range reveal a typical α-β-relaxation scenario. The α relaxation mirrors the glassy freezing of the dipolar ions, and the β relaxation exhibits the signatures of a Johari-Goldstein relaxation. In contrast to the translational mode detected by neutron scattering, arising from the decoupled faster motion of the DMIM⁺ ions, the α relaxation is well coupled to the dc charge transport, that is, the average translational motion of all three ion species in the material. The local diffusion process detected by QENS is only weakly dependent on temperature and viscosity and can be ascribed to the typical fast dynamics of glass-forming liquids.

A substitute name for a genus of fossil mantispid (Insecta: Neuroptera: Mesomantispinae) from the Jurassic of Kazakhstan

In a recent paper (Jepson et al., 2018) a new genus of Mesomantispinae from Karatau, Kazakhstan was described. The name given to the genus, Longicollum, is unavailable, because it is preoccupied by a senior homonym, Longicollum Yamaguti, 1935 (Acanthocephala: Pomphorhynchidae). In accordance with Art. 60.1. of the ICZN, we herein propose a replacement name for the genus: Longipronotum nom. nov.

A revision of and keys to the genera of the Mantispinae of the Oriental and Palearctic regions (Neuroptera: Mantispidae)

The Mantispinae (Neuroptera: Mantispidae) genera of the Oriental and Palearctic regions are revised. A morphological key to the genera is generated. Austroclimaciella, Campancella, Mantispa, Mantispilla, Necyla, Stenomantispa and Tuberonotha are redescribed. The Ohl (2004) catalogue is updated for the relevant genera. Sagittalata (= Perlamantispa) is assigned as a synonym of Mantispilla which is restored as a valid genus. Orientispa is assigned as a synonym of Necyla.

Dynamics in the Plastic Crystalline Phases of Cyclohexanol and Cyclooctanol Studied by Quasielastic Neutron Scattering

Plastic crystals are a promising candidate for solid state ionic conductors. In this work, quasielastic neutron scattering is employed to investigate the center of mass diffusive motions in two types of plastic crystalline cyclic alcohols: cyclohexanol and cyclooctanol. Two separate motions are observed which are attributed to long-range translational diffusion (α-process) and cage rattling (fast β-process). Residence times and diffusion coefficients are calculated for both processes, along with the confinement distances for the cage rattling. In addition, a binary mixture of these two materials is measured to understand how the dynamics change when a second type of molecule is added to the matrix. It is observed that, upon the addition of the larger cyclooctanol molecules into the cyclohexanol solution, the cage size decreases, which causes a decrease in the observed diffusion rates for both the α- and fast β-processes.

Phylogenomic analysis of Apoidea sheds new light on the sister group of bees

Background

Apoid wasps and bees (Apoidea) are an ecologically and morphologically diverse group of Hymenoptera, with some species of bees having evolved eusocial societies. Major problems for our understanding of the evolutionary history of Apoidea have been the difficulty to trace the phylogenetic origin and to reliably estimate the geological age of bees. To address these issues, we compiled a comprehensive phylogenomic dataset by simultaneously analyzing target DNA enrichment and transcriptomic sequence data, comprising 195 single-copy protein-coding genes and covering all major lineages of apoid wasps and bee families.

Results

Our compiled data matrix comprised 284,607 nucleotide sites that we phylogenetically analyzed by applying a combination of domain- and codon-based partitioning schemes. The inferred results confirm the polyphyletic status of the former family “Crabronidae”, which comprises nine major monophyletic lineages. We found the former subfamily Pemphredoninae to be polyphyletic, comprising three distantly related clades. One of them, Ammoplanina, constituted the sister group of bees in all our analyses. We estimate the origin of bees to be in the Early Cretaceous (ca. 128 million years ago), a time period during which angiosperms rapidly radiated. Finally, our phylogenetic analyses revealed that within the Apoidea, (eu)social societies evolved exclusively in a single clade that comprises pemphredonine and philanthine wasps as well as bees.

Conclusion

By combining transcriptomic sequences with those obtained via target DNA enrichment, we were able to include an unprecedented large number of apoid wasps in a phylogenetic study for tracing the phylogenetic origin of bees. Our results confirm the polyphyletic nature of the former wasp family Crabonidae, which we here suggest splitting into eight families. Of these, the family Ammoplanidae possibly represents the extant sister lineage of bees. Species of Ammoplanidae are known to hunt thrips, of which some aggregate on flowers and feed on pollen. The specific biology of Ammoplanidae as predators indicates how the transition from a predatory to pollen-collecting life style could have taken place in the evolution of bees. This insight plus the finding that (eu)social societies evolved exclusively in a single subordinated lineage of apoid wasps provides new perspectives for future comparative studies.

Electronic supplementary material

The online version of this article (10.1186/s12862-018-1155-8) contains supplementary material, which is available to authorized users.

New Mesomantispinae (Insecta: Neuroptera: Mantispidae) from the Jurassic of Karatau, Kazakhstan

Two new genera and species, and one indeterminate genera and species of fossil Mantispidae, Mesomantispinae are described from the Upper Jurassic of Karatau, Kazakhstan: Longicollum benmaddoxi gen. et sp. nov., Ovalofemora abbottae gen. et sp. nov., and Mesomantispinae sp. et gen. indet. Karataumantispa monstruosa is removed from the genus Karataumantispa and placed in the new genus Ovalofemora gen. nov. due to its different foreleg morphology (stout coxae, trochanter, and oval shaped femur), in addition to differences in wing venation. These taxa are all placed within the subfamily Mesomantispinae. An updated key to the genera of Mesomantispinae is given.

The first green lacewing (Insecta: Neuroptera: Chrysopidae) from the mid-Cretaceous amber of Myanmar

The lacewing family Chrysopidae is here reported from the mid-Cretaceous amber of Myanmar for the first time. A new genus and species, Parabaisochrysa xingkei gen. et sp. nov., is described. The new genus belongs to the extinct subfamily Limaiinae and is characterized by the presence of three gradate series of crossveins in both fore- and hind wing, and by the MP1 coalescent with RP+MA in the hind wing.

Accessibility and Uptake of Pre-Exposure Prophylaxis for HIV Prevention in the Veterans Health Administration

To increase access, the National PrEP Working Group is expanding outreach outside of primary care and among nonspecialists, ensuring uniformly high-quality care and targeting high-risk populations.

Glycerol Hydrogen-Bonding Network Dominates Structure and Collective Dynamics in a Deep Eutectic Solvent

The deep eutectic solvent glyceline formed by choline chloride and glycerol in 1:2 molar ratio is much less viscous compared to glycerol, which facilitates its use in many applications where high viscosity is undesirable. Despite the large difference in viscosity, we have found that the structural network of glyceline is completely defined by its glycerol constituent, which exhibits complex microscopic dynamic behavior, as expected from a highly correlated hydrogen-bonding network. Choline ions occupy interstitial voids in the glycerol network and show little structural or dynamic correlations with glycerol molecules. Despite the known higher long-range diffusivity of the smaller glycerol species in glyceline, in applications where localized dynamics is essential (e.g., in microporous media), the local transport and dynamic properties must be dominated by the relatively loosely bound choline ions.

Predictors of First-Year Medication Adherence in a National Cohort of Veterans Initiating Pre-Exposure Prophylaxis (PrEP) to Prevent HIV Infection

Background

Current guidelines for HIV Pre-Exposure Prophylaxis (PrEP) recommend daily use of tenofovir disoproxil fumarate / emtricitabine (TDF/FTC). Little is known about levels and predictors of long-term PrEP medication adherence in routine clinical settings.

Methods

We used a previously-validated algorithm and national Veterans Health Administration (VHA) administrative data to identify a cohort of Veterans initiating PrEP during 2012–2015 (i.e., TDF/FTC use, no other antiretroviral use, and no diagnosis codes for HIV, hepatitis B, or needle-stick injury). We used pharmacy refill data to calculate the proportion of days covered (PDC) by TDF/FTC in the 365 days after initiation, and multivariable logistic regression to identify patient characteristics associated with high adherence (i.e., PDC > 0.80).

Results

Most (96%) of the 706 Veterans initiating PrEP were men, reflecting the overall demographics of patients in VHA. The median age was 38. Reported race in administrative data was 141 (20.0%) black, 485 (68.7%) white, 42 (5.9%) other, and 38 (5.4%) missing. Only 30 PrEP users (4.2%) lived in rural areas. Co-existing diagnoses included substance use disorder in 264 (37.4%), hypertension in 250 (35.4%), and diabetes in 95 (13.5%). The median PDC for TDF/FTC in the first year was 0.78 (IQR 0.41–0.96), and a minority (N = 120, 17%) had only a single TDF/FTC fill. Predictors of high adherence were older age (OR 1.88, 95% CI 1.20–2.84 for age 50–64 compared with age < 35); white compared with black race (OR 1.96, 1.30–2.94), Male sex (OR 4.17, 1.67–12.50), absence of a substance use diagnosis (OR 1.47, 1.05–2.04), and presence of diabetes (OR 1.66, 1.02–2.75).

Conclusion

Adherence to TDF/FTC in the first year of PrEP was overall high. Racial, gender, and substance-use-related differences in PrEP adherence mirrored those previously described for PrEP uptake. Interventions to promote equitable PrEP uptake should include strategies to support adherence.

Disclosures

All authors: No reported disclosures.

Bacillus subtilis Lipid Extract, A Branched-Chain Fatty Acid Model Membrane

Lipid extracts are an excellent choice of model biomembrane; however at present, there are no commercially available lipid extracts or computational models that mimic microbial membranes containing the branched-chain fatty acids found in many pathogenic and industrially relevant bacteria. We advance the extract of Bacillus subtilis as a standard model for these diverse systems, providing a detailed experimental description and equilibrated atomistic bilayer model included as Supporting Information to this Letter and at ( http://cmb.ornl.gov/members/cheng ). The development and validation of this model represents an advance that enables more realistic simulations and experiments on bacterial membranes and reconstituted bacterial membrane proteins.

Nanoscale rheology at solid-complex fluid interfaces

Here we present an approach to measure dynamic membrane properties of phospholipid membranes close to an interface. As an example we show results of the membrane dynamics of a phospholipid membrane multilayer-stack on a solid substrate (silicon). On this sample we were able to measure local interaction and friction parameters using Grazing Incidence Neutron Spin Echo Spectroscopy (GINSES), where an evanescent neutron wave probes the fluctuations close to a rigid interface. With this method it is possible to access length scales in the nano to micrometer region as well as energies in the μeV range. Using a new neutron resonator structure we achieved the required intensity gain for this experiment. During our investigations we found an excitation mode of the phospholipid membrane that has not been reported previously and only became visible using the new methodology. We speculate that the energy transported by that undulation can also serve to distribute energy over a larger area of the membrane, stabilizing it. This new methodology has the capability to probe the viscoelastic effects of biological membranes, becoming a new tool for tribology on the nanoscale and has allowed the observation of the hitherto invisible property of phospholipid membranes using neutrons.

Incorporation of aspirin modulates the dynamical and phase behavior of the phospholipid membrane

Effect of aspirin on the microscopic dynamics of a membrane has been investigated using quasielastic neutron scattering and neutron spin echo techniques.

Effect of adding nanometre-sized heterogeneities on the structural dynamics and the excess wing of a molecular glass former

We present the relaxation dynamics of glass-forming glycerol mixed with 1.1 nm sized polyhedral oligomeric silsesquioxane (POSS) molecules using dielectric spectroscopy (DS) and two different neutron scattering (NS) techniques. Both, the reorientational dynamics as measured by DS and the density fluctuations detected by NS reveal a broadening of the α relaxation when POSS molecules are added. Moreover, we find a significant slowing down of the α-relaxation time. These effects are in accord with the heterogeneity scenario considered for the dynamics of glasses and supercooled liquids. The addition of POSS also affects the excess wing in glycerol arising from a secondary relaxation process, which seems to exhibit a dramatic increase in relative strength compared to the α relaxation.

Nanoscale Motion of Soft Nanoparticles in Unentangled and Entangled Polymer Matrices

We have studied the motion of polyhedral oligomeric silsesquioxane (POSS) nanoparticles modified with poly(ethylene glycol) (PEG) arms immersed in PEG matrices of different molecular weight. Employing neutron spin echo spectroscopy in combination with pulsed field gradient (PFG) NMR we found the following. (i) For entangled matrices the center of mass mean square displacement (MSD) of the PEG-POSS particles is subdiffusive following a t^{0.56} power law. (ii) The diffusion coefficient as well as the crossover to Fickian diffusion is independent of the matrix molecular weight and takes place as soon as the center of mass has moved a distance corresponding to the particle radius-this holds also for unentangled hosts. (iii) For the entangled matrices Rubinstein's scaling theory is validated; however, the numbers indicate that beyond Rouse friction the entanglement constraints appear to strongly increase the effective friction even on the nanoparticle length scale imposing a caveat on the interpretation of microrheological experiments. (iv) The oligomer decorated PEG-POSS particles exhibit the dynamics of a Gaussian star with an internal viscosity that rises with an increase of the host molecular weight.

Thermoreversible Morphology and Conductivity of a Conjugated Polymer Network Embedded in Block Copolymer Self-Assemblies

Self-assembly of block copolymers provides numerous opportunities to create functional materials, utilizing self-assembled microdomains with a variety of morphology and periodic architectures as templates for functional nanofillers. Here new progress is reported toward the fabrication of thermally responsive and electrically conductive polymeric self-assemblies made from a water-soluble poly(thiophene) derivative with short poly(ethylene oxide) side chains and Pluronic L62 block copolymer solution in water. The structural and electrical properties of conjugated polymer-embedded self-assembled architectures are investigated by combining small-angle neutron and X-ray scattering, coarse-grained molecular dynamics simulations, and impedance spectroscopy. The L62 solution template organizes the conjugated polymers by stably incorporating them into the hydrophilic domains thus inhibiting aggregation. The changing morphology of L62 during the micellar-to-lamellar phase transition defines the embedded conjugated polymer network. As a result, the conductivity is strongly coupled to the structural change of the templating L62 phase and exhibits thermally reversible behavior with no signs of quenching of the conductivity at high temperature. This study shows promise for enabling more flexibility in processing and utilizing water-soluble conjugated polymers in aqueous solutions for self-assembly based fabrication of stimuli-responsive nanostructures and sensory materials.

BaitFisher: A Software Package for Multispecies Target DNA Enrichment Probe Design

Target DNA enrichment combined with high-throughput sequencing technologies is a powerful approach to probing a large number of loci in genomes of interest. However, software algorithms that explicitly consider nucleotide sequence information of target loci in multiple reference species for optimizing design of target enrichment baits to be applicable across a wide range of species have not been developed. Here we present an algorithm that infers target DNA enrichment baits from multiple nucleotide sequence alignments. By applying clustering methods and the combinatorial 1-center sequence optimization to bait design, we are able to minimize the total number of baits required to efficiently probe target loci in multiple species. Consequently, more loci can be probed across species with a given number of baits. Using transcript sequences of 24 apoid wasps (Hymenoptera: Crabronidae, Sphecidae) from the 1KITE project and the gene models of Nasonia vitripennis, we inferred 57,650, 120-bp-long baits for capturing 378 coding sequence sections of 282 genes in apoid wasps. Illumina reduced-representation library sequencing confirmed successful enrichment of the target DNA when applying these baits to DNA of various apoid wasps. The designed baits furthermore enriched a major fraction of the target DNA in distantly related Hymenoptera, such as Formicidae and Chalcidoidea, highlighting the baits' broad taxonomic applicability. The availability of baits with broad taxonomic applicability is of major interest in numerous disciplines, ranging from phylogenetics to biodiversity monitoring. We implemented our new approach in a software package, called BaitFisher, which is open source and freely available at https://github.com/cmayer/BaitFisher-package.git.

Characteristic length scales of the secondary relaxations in glass-forming glycerol

We investigate the secondary relaxations and their link to the main structural relaxation in glass-forming liquids using glycerol as a model system. We analyze the incoherent neutron scattering signal dependence on the scattering momentum transfer, Q , in order to obtain the characteristic length scale for different secondary relaxations. Such a capability of neutron scattering makes it somewhat unique and highly complementary to the traditional techniques of glass physics, such as light scattering and broadband dielectric spectroscopy, which provide information on the time scale, but not the length scales, of relaxation processes. The choice of suitable neutron scattering techniques depends on the time scale of the relaxation of interest. We use neutron backscattering to identify the characteristic length scale of 0.7 Å for the faster secondary relaxation described in the framework of the mode-coupling theory (MCT). Neutron spin-echo is employed to probe the slower secondary relaxation of the excess wing type at a low temperature ( ∼ 1.13T g . The characteristic length scale for this excess wing dynamics is approximately 4.7 Å. Besides the Q -dependence, the direct coupling of neutron scattering signal to density fluctuation makes this technique indispensable for measuring the length scale of the microscopic relaxation dynamics.

Observational natural history and morphological taxonomy are indispensable for future challenges in biodiversity and conservation

Global biodiversity is rapidly declining, leading inevitably to a loss of ecosystem functionality when species and their associated life-history traits vanish. Unfortunately, even in the 21(st) century, a large proportion of Earth's species are yet unknown and also for most described species science lacks a deeper understanding of the functional role of species and thus of ecosystems. In this Addendum we use the recent discovery of a new spider wasp with a unique natural history as an example to emphasize the importance to conduct basic observational natural history and traditional taxonomic research. We aim to encourage such 'old-fashioned' research and biologists from various research fields to report the many fascinating phenomena holding valuable natural history information they may encounter. Such detailed knowledge on species, their life-history traits, and their trophic interactions will be crucial to reliably address the challenges global change brings to the persistence of ecosystems.