Changes in Lower-Extremity Gait Biomechanics Following High-Cadence Cycling.

We sought to investigate the lower-extremity biomechanics underlying increased gait velocity following high-cadence cycling. Ground reaction forces (GRF) and lower-extremity kinematics and kinetics were recorded as 15 healthy adults walked at a self-selected pace prior to and immediately following a 15 min bout of cycling at a cadence of 75 rotations per minute. Propulsive GRF and stance-phase peak dorsiflexion and knee extension angles increased, while peak plantarflexion and hip extension angles decreased. Swing-phase peak dorsiflexion, plantarflexion, knee flexion, and hip flexion angles increased, while peak knee extension angle decreased. Peak dorsiflexion, knee extension, and hip extension angular velocity also increased during swing. No changes in peak joint moments were observed; however, peak positive ankle, knee, and hip joint power generation increased following cycling. Completing high-cadence cycling improves gait velocity by increasing propulsive GRF; increasing joint angular velocity during the swing phase of gait for the ankle, knee, and hip; and increasing positive power production by the ankle, knee, and hip during the stance phase. Increased gait velocity post cycling exercise did not increase lower-extremity joint moments. Cycling may be a viable exercise-based modality for increasing gait velocity, especially in populations where gait ability or joint loading is of particular concern.

Biolistics-mediated transformation of hornworts and its application to study pyrenoid protein localization.

Hornworts are a deeply diverged lineage of bryophytes that are sister to mosses and liverworts. Hornworts have an array of unique features that can be leveraged to illuminate not only the early evolution of land plants, but also alternative paths for nitrogen and carbon assimilation via cyanobacterial symbiosis and a pyrenoid-based CO2-concentrating mechanism (CCM), respectively. Despite this, hornworts are one of the few plant lineages with limited available genetic tools. Here we report an efficient biolistics method for generating transient-expression and stable transgenic lines in the model hornwort, Anthoceros agrestis. An average of 569 (± 268) cells showed transient expression per bombardment, with green fluorescent protein expression observed within 48-72 hours. A total of 81 stably transformed lines were recovered across three separate experiments, averaging six lines per bombardment. We followed the same method to transiently transform nine additional hornwort species, and obtained stable transformants from one. This method was further used to verify the localization of Rubisco and Rubisco activase in pyrenoids, which are central proteins for CCM function. Together, our biolistics approach offers key advantages over existing methods as it enables rapid transient expression and can be applied to widely diverse hornwort species.

High cadence cycling not high work rate, increases gait velocity post-exercise.

Gait velocity, or walking speed, has been referred to as the sixth vital sign, and research suggests that it is highly sensitive to change. Previous research has demonstrated the utility of cycling to improve gait parameters and in particular gait velocity in a variety of populations. However, it is unclear if the benefits from cycling to gait velocity stem from increased cadence, increased work rate, or the interaction between them. Therefore, the objective of the current research was to explicitly test the relationship between cycling work rate, cycling cadence, and gait velocity. 45 recreationally active young adults were randomly assigned to cycle at a normalised cadence and work rate, a higher cadence, or a higher work rate (CONTROL, FAST, HARD). All participants completed two ten-metre walk tests (10 MWT) pre- and post-cycling intervention. There was a significant interaction between group and time and post hoc comparisons showed that the FAST group walked significantly faster than the HARD group post-cycling. These results support the hypothesis that cycling at a cadence greater than the comfortable walking cadence, and not cycling at an increased work rate, increased gait velocity post-exercise for all members of our sample of healthy young adults.

Assessing the importance of multireference correlation in predicting reversed conductance decay.

In a classical electronic resistor, conductance decays as the device length increases according to Ohm's Law. While most molecular series display a comparable exponential decay in conductance with increasing molecular length, a class of single-molecule device series exists where conductance instead increases with molecular/device length, a phenomenon called reversed conductance decay. While reversals of conductance decay have been repeatedly theoretically predicted, they have been far more difficult to demonstrate experimentally. Previous studies have suggested that theoretical multi-reference(static) correlation errors may be a major cause of this discrepancy, yet most single-molecule transport methods are unable to treat multireference correlation. Using our unique multireference transport method based on non-equilibrium Green's function and multiconfigurational pair-density functional theory (NEGF-MCPDFT), we examined a previously predicted case of reversed conductance decay in systems of linear chains of phenyl rings with varying lengths and electrode designs. We compare our NEGF-MCPDFT results to those of non-multireference NEGF methods to quantify the exact role of static correlation in conductance decay reversals and clarify their relative importance to geometric and electrode design/coupling considerations.

Antimicrobial susceptibilities of Campylobacter fetus: report from a reference laboratory.

Campylobacter fetus is known to cause human disease, particularly in elderly and immunocompromised hosts. There are limited published data for antimicrobial susceptibility patterns with this organism, and no interpretive criteria are available. We reviewed antimicrobial susceptibilities of C. fetus isolates tested at a tertiary care center and reference laboratory over an 11-year period. C. fetus isolates from patients treated at Mayo Clinic and those sent as referrals for identification and susceptibility were included. Antimicrobial susceptibility testing was performed using agar dilution for ciprofloxacin, doxycycline, erythromycin, gentamicin, meropenem, and tetracycline. Geographic distribution, culture source, organism minimal inhibitory concentration (MIC) distributions, and MIC50 and MIC90 were examined. Excluding duplicates, 105 unique isolates were identified from 110 positive cultures. Blood cultures represented the most common source, followed by body fluids, skin and soft tissue, and central nervous system. Gentamicin and meropenem had favorable MIC50 and MIC90 of 1 µg/mL. Ciprofloxacin demonstrated an MIC50 of 1 µg/mL; however, the MIC90 was >2 µg/mL. Erythromycin demonstrated MIC50 and MIC90 of 2 µg/mL. Tetracycline and doxycycline were tested on a limited number of isolates and showed a wide range of MICs. Gentamicin and meropenem demonstrated favorable MICs in C. fetus isolates. These may represent therapeutic options for consideration in serious C. fetus infections, pending susceptibility results. Ciprofloxacin, which showed variable results, may be more appropriate for use only after susceptibility testing. C. fetus interpretive criteria are needed to aid clinicians in selection of both empiric and definitive therapies. IMPORTANCE: Our findings contribute to the scant literature on Campylobacter fetus antimicrobial susceptibility test results. We used a reference test method of agar dilution and provide MICs for a large number of organisms and antimicrobial agents.

Nonsolvent-induced phase separation inside liquid droplets.

Nonsolvent-induced phase separation (NIPS) is a popular method for creating polymeric particles with internal microstructure, but many fundamental questions remain surrounding the kinetics of the complex coupled mass transfer and phase separation processes. In this work, we use simulations of a phase-field model to examine how (i) finite domain boundaries of a polymer droplet and (ii) solvent/nonsolvent miscibility affect the NIPS process. To isolate the effects of phase separation kinetics and solvent/nonsolvent mass transfer on the NIPS process, we study two different cases. First, we investigate droplet concentrations that originate inside the two-phase region, where phase separation kinetics alone governs the microstructure. Second, we investigate the effects of solvent/nonsolvent mass transfer by studying droplet concentrations that begin outside the two-phase region, where both phase separation kinetics and mass transfer play a role. In both cases, we find that qualitative NIPS behavior is a strong function of the relative location of the initial droplet composition with respect to the phase diagram. We also find that polymer/nonsolvent miscibility competes with solvent/nonsolvent miscibility in driving NIPS kinetic behavior. Finally, we examine polymer droplets undergoing solvent/nonsolvent exchange and find that the model predicts droplets that shrink with nearly Fickian diffusion kinetics. We conclude with a brief perspective on the state of simulations of NIPS processes and some recommendations for future work.

LGBTQ+ Grassroots Activism: An Opportunity for Resilience.

Lesbian, gay, bisexual, transgender, queer, and other gender and sexual minority (LGBTQ+) individuals have a long history of mobilizing to raise awareness and initiate social and political change for LGBTQ+ related issues. The present study explored how grassroots activism impacted resilience among LGBTQ+ people. In-depth and semi-structured interviews were conducted with 15 LGBTQ+ activists from one statewide grassroots organization aiming to ban conversion therapy. Grounded theory analysis was used to identify a central theme and six interrelated subthemes. The central theme was that outness, activism, and resilience have cyclical relationships. Subthemes were related to identity exploration, affirmation, and synthesis; responsibility and humility; psychological skills; coping; social support; and negative experiences. These data may be helpful for LGBTQ+ grassroots activism and community leaders aiming to boost the resilience and strengthen well-being of their organization members.

The known species of the genus Achagua Rindge, 1983, with the description of three new species from the Neotropics (Geometridae: Ennominae).

The previously monotypic geometrid genus Achagua (Ennominae: Nacophorini) is reviewed following the discovery of three undescribed species. New species are as follows: A. cooperae n. sp. described from Costa Rica, A. magna n. sp. described from Ecuador, Peru, and Bolivia; and Achagua velata n. sp. described from French Guiana. Available COI barcode data is briefly reviewed, and adult and genitalic illustrations are provided for each of the four known species.

Dynamics of equilibrium-linked colloidal networks.

Colloids that attractively bond to only a few neighbors (e.g., patchy particles) can form equilibrium gels with distinctive dynamic properties that are stable in time. Here, we use a coarse-grained model to explore the dynamics of linked networks of patchy colloids whose average valence is macroscopically, rather than microscopically, constrained. Simulation results for the model show dynamic hallmarks of equilibrium gel formation and establish that the colloid-colloid bond persistence time controls the characteristic slow relaxation of the self-intermediate scattering function. The model features re-entrant network formation without phase separation as a function of linker concentration, centered at the stoichiometric ratio of linker ends to nanoparticle surface bonding sites. Departures from stoichiometry result in linker-starved or linker-saturated networks with reduced connectivity and shorter characteristic relaxation times with lower activation energies. Underlying the re-entrant trends, dynamic properties vary monotonically with the number of effective network bonds per colloid, a quantity that can be predicted using Wertheim's thermodynamic perturbation theory. These behaviors suggest macroscopic in situ strategies for tuning the dynamic response of colloidal networks.

A New Monotypic Genus from the American Southwest to accommodate Semiothisa kuschea (Geometridae: Ennominae).

The monotypic Metrica new genus is described for Metrica kuschea (Guedet, 1939) new combination. The genus is placed in the tribe Ennomini Duponchel and hypothesized to be most closely related to a Neotropical species of Isochromodes Warren. Adult morphology, including male and female genitalia are illustrated, and molecular data supporting the transfer of Semiothisa kuschea (Macariini Guene) to the Ennomini are presented.

Recruiting and retaining first-year college students in online health research: Implementation considerations.

Objective: Decreasing participation in intervention research among college students has implications for the external validity of behavioral intervention research. We describe recruitment and retention strategies used to promote participation in intervention research across a series of four randomized experiments. Method: We report the recruitment and retention rates by school for each experiment and qualitative feedback from students about recommendations for improving research participation. Results: There was considerable variation among schools' recruitment (4.9% to 64.7%) and retention (12% to 67.8%) rates. Student feedback suggested study timing (e.g., early in the semester), communication strategies (e.g., social media), and incentive structure (e.g., guaranteed incentives) could improve research participation. The highest survey participation rate was observed at the university which mandated students to complete the intervention (but not the survey). Conclusions: Intervention scientists must consider the population and study context to make informed decisions related to recruitment and retention strategies.

Pilot study of the Collaborative Assessment and Management of Suicidality-Group.

INTRODUCTION: Few evidence-based options exist for outpatient treatment of patients at risk of suicide, and to-date almost all research has focused on individually delivered psychotherapy. Group therapy for veterans at risk of suicide is a promising alternative. METHODS: Thirty veterans receiving care at an urban Veterans Affairs Medical Center in the southern United States were randomized to either care as usual (CAU) or to CAU plus the Collaborative Assessment and Management of Suicide-Group (CAMS-G). Veterans were assessed prior to randomization to condition and at 1, 3, and 6 months post-randomization on a range of suicide-specific measures, burdensomeness, belonging, treatment satisfaction, and group cohesion. RESULTS: Across measures and follow-up assessments, veterans in CAMS-G reported good satisfaction with the intervention, a sense of cohesion with other members of the group, and reduced symptom distress. Veterans in both conditions reported decreases in suicidal ideation and behavior, with CAMS-G participants potentially improving slightly faster. CONCLUSION: This description of CAMS-G for veterans adds to the growing literature on suicide-specific interventions and supports the need for additional research to determine if wide-spread rollout is justifiable.

First report of Meris paradoxa Rindge (Geometridae: Ennominae) in the central mountains of Mexico, description of its female and a comparison of caterpillar variation among kin.

Meris paradoxa Rindge, thought to be restricted to southeastern Arizona, is documented in Mexico for the first time. Previously described only from males, we provide the first description of the female from specimens collected as caterpillars and reared to adults. We find female M. paradoxa to have a normal haustellum; an external diagnostic character for this species previously only confirmed in conspecific males. Female genitalia of M. paradoxa are found similar to other Meris, but the absence of a sclerotized signum (present in congeners) may prove autapomorphic. Natural history information for the genus is discussed in light of new data reported here for Mexican M. paradoxa.

Renal Papillary Necrosis Associated With Normocalcemic Primary Hyperparathyroidism.

OBJECTIVES: Renal papillary necrosis (RPN) occurring in primary hyperparathyroidism (PHPT) has not been reported. We present a 50-year-old woman who manifested RPN associated with hypercalciuria and normocalcemic PHPT. METHODS: The diagnosis of RPN was based on imaging studies (ultrasound and computed tomography [CT] scan). PHPT was diagnosed with high parathyroid hormone (PTH) and high/normal serum calcium. RESULTS: A 38-year-old woman was evaluated for hypercalcemia (serum calcium, 11.8 mg/dL; ionized calcium, 6.3 mg/dL; phosphorus, 1.8 mg/dL; intact PTH, 98 pg/mL; and 24-hour urine calcium, 543 mg). Renal ultrasound showed no nephrocalcinosis or nephrolithiasis. A parathyroid scan revealed a left parathyroid adenoma. The patient underwent parathyroidectomy, and she became normocalcemic with normal serum PTH levels postoperatively. One year later, she was diagnosed with a left-sided bronchial carcinoid tumor. Following surgery, a surveillance gallium68 positron emission tomography/CT scan performed 2 years later was negative for metastases. Twelve years later (aged 50 years), she presented for follow-up and reported no symptoms of hypercalcemia, fractures, nephrolithiasis, history of pyelonephritis, diabetes mellitus, analgesic drug use, or hypertension. Her serum calcium level was 9.1 mg/dL, PTH level was 82 pg/mL, 25-OH vitamin D level was 34 ng/mL, and 24-hour urine calcium level was 410 mg. However, renal ultrasound showed bilateral RPN that was confirmed by a CT scan. CONCLUSION: RPN may be associated with hypercalciuria and normocalcemic PHPT. Additional studies with a large number of patients are needed.

Relationship between voluntary ethanol drinking and approach-avoidance biases in the face of motivational conflict: novel sex-dependent associations in rats.

RATIONALE: Aberrant approach-avoidance conflict processing may contribute to compulsive seeking that characterizes addiction. Exploration of the relationship between drugs of abuse and approach-avoidance behavior remains limited, especially with ethanol. OBJECTIVES: To investigate the effects of voluntary ethanol consumption on approach-avoidance conflict behavior and to examine the potential approach/avoidance bias to predict drinking in male and female rats. METHODS: Long-Evans rats consumed ethanol for 5 weeks under the intermittent access two-bottle choice (IA2BC) paradigm. Approach-avoidance tendencies were assessed before and after IA2BC drinking using a previously established cued approach-avoidance conflict maze task and the elevated plus maze (EPM). RESULTS: Female rats displayed higher consumption of and preference for ethanol than males. In the conflict task, males showed greater approach bias towards cues predicting conflict than females. In females only, a median split and regression analysis of cued-conflict preference scores revealed that the more conflict-avoidant group displayed higher intake and preference for ethanol in the first few weeks of drinking. In both sexes, ethanol drinking did not affect cued-conflict preference, but ethanol exposure led to increased time spent in the central hub in the males only. Finally, anxiety levels in EPM predicted subsequent onset of ethanol drinking in males only. CONCLUSIONS: Our results highlight sex and individual differences in both drinking and approach-avoidance bias in the face of cued conflict and further suggest that cued-conflict preference should be examined as a potential predictor of ethanol drinking. Ethanol exposure may also affect the timing of decision-making in the face of conflict.

Effects of Increased Step-Width on Knee Biomechanics During Inclined and Declined Walking.

The purpose of this study was to investigate effects of preferred step width and increased step width modification on knee biomechanics of obese and healthy-weight participants during incline and decline walking. Seven healthy-weight participants and 6 participants who are obese (body mass index ≥ 30) performed 5 walking trials on level ground and a 10° inclined and declined instrumented ramp system at both preferred and wide step-widths. A 2 × 2 (step-width × group) mixed-model analysis of variance was used to examine selected variables. There were significant increases in step-width between the preferred and wide step-width conditions for all 3 walking conditions (all P < .001). An interaction was found for peak knee extension moment (P = .048) and internal knee abduction moment (KAM) (P = .025) in uphill walking. During downhill walking, there were no interaction effects. As step-width increased, KAM was reduced (P = .007). In level walking, there were no interaction effects for peak medial ground reaction force and KAM (P = .007). There was a step-width main effect for KAM (P = .007). As step-width increased, peak medial ground reaction force and peak knee extension moment increased, while KAM decreased for both healthy weight and individuals who are obese. The results suggest that increasing step-width may be a useful strategy for reducing KAM in healthy and young populations.

A Survey of Reported Disease-Related Mutations in the MRE11-RAD50-NBS1 Complex.

The MRE11-RAD50-NBS1 (MRN) protein complex is one of the primary vehicles for repairing DNA double strand breaks and maintaining the genomic stability within the cell. The role of the MRN complex to recognize and process DNA double-strand breaks as well as signal other damage response factors is critical for maintaining proper cellular function. Mutations in any one of the components of the MRN complex that effect function or expression of the repair machinery could be detrimental to the cell and may initiate and/or propagate disease. Here, we discuss, in a structural and biochemical context, mutations in each of the three MRN components that have been associated with diseases such as ataxia telangiectasia-like disorder (ATLD), Nijmegen breakage syndrome (NBS), NBS-like disorder (NBSLD) and certain types of cancers. Overall, deepening our understanding of disease-causing mutations of the MRN complex at the structural and biochemical level is foundational to the future aim of treating diseases associated with these aberrations.

A BULL IN A PILL SHOP: ALPHA-GAL ALLERGY COMPLICATING TREATMENT OPTIONS FOR POSTPROCEDURAL HYPOTHYROIDISM.

OBJECTIVE: The galactose-alpha-1,3-galactose (alpha-gal) allergy, an IgE-mediated response to nonprimate meat, has a singular pathogenesis linked to tick bites and a delayed allergic presentation, which makes it especially cumbersome to diagnose and manage. As a large array of enteral medications contain ingredients derived from meat byproducts, this can affect the care of alpha-gal patients across multiple medical disciplines. Our objective is to present a patient with an alpha-gal allergy, which can complicate hypothyroidism treatment selection. METHODS: In this case of difficulty tailoring thyroid replacement therapy secondary to the alpha-gal allergy, the diagnostic studies included IgE immunoassays for alpha-gal as well as thyroid function tests. RESULTS: A 45-year-old woman with postoperative hypothyroidism and a history of an alpha-gal allergy (diagnosed after an anaphylactic reaction to beef) could not be immediately started on any common thyroid hormone replacement formulation because of our concern regarding the possible presence of nonprimate mammalian meat byproduct components in the thyroid hormone medication. After consulting allergy and immunology specialists and compounding pharmacists and contacting multiple drug companies in an effort to confirm the nature of the inactive ingredients in their thyroid hormone products, she was prescribed a plant-based compounded levothyroxine preparation with good clinical results. CONCLUSION: This case emphasizes the importance of recognizing various risk factors and common drugs which may be associated with the alpha-gal allergy. It is not known how to best tailor enteral medications for patients with an alpha-gal allergy. Further research and pharmaceutical attention to this allergy are needed.

Comparing complications of small-bore chest tubes to large-bore chest tubes in the setting of delayed hemothorax: a retrospective multicenter cohort study.

BACKGROUND: Previous studies have provided initial data suggesting that small-bore (SB, ≤ 14Fr) chest tubes have the same efficacy as large-bore (LB, > 14 Fr) chest tubes for acute hemothorax (HTX), but data continue to be lacking in the setting of delayed HTX. This study compared complications of SB chest tubes to LB tubes in patients with delayed HTX. METHODS: This was a retrospective observational study across 7.5 yrs. at 6 Level 1 trauma centers. Patients were included if 1) diagnosed with a HTX or > 1 rib fracture with bloody effusion from chest tube; 2) initial chest tube placed ≥36 h of hospital admission. Patients were excluded for hemopneumothoraces. The primary endpoint was having at least one of the following chest tube complications: tube replacement, VATS, tube falling out, tube clogging, pneumonia, retained HTX, pleural empyema. Secondary outcomes included chest tube output volume and drainage rate. Dependent/independent and parametric/non-parametric analyses were used to assess primary and secondary outcomes. RESULTS: There were 160 SB patients (191 tubes) and 60 LB patients (72 tubes). Both comparison groups were similar in multiple demographic, injury, clinical features. The median (IQR) tube size for each group was as follows: SB [12 Fr (12-14)] and LB [32 Fr (28-32)]. The risk of having at least one chest tube complication was similar for LB and SB chest tubes (14% vs. 18%, p = 0.42). LB tubes had significantly larger risk of VATS, while SB tubes had significantly higher risk of pneumonia. SB tubes had significantly slower least squares (LS) mean initial output drainage rate compared to LB tubes (52.2 vs. 213.4 mL/hour, p < 0.001), but a non-parametric analysis suggested no significant difference in median drainage rates between groups 39.7 [23.5-242.0] mL/hr. vs. 38.6 [27.5-53.8], p = 0.81. LB and SB groups had similar initial output volume (738.0 mL vs. 810.9, p = 0.59). CONCLUSIONS: There was no clearly superior chest tube diameter size; both chest tube sizes demonstrated risks and benefits. Clinicians must be aware of these potential tradeoffs when deciding on the diameter of chest tube for the treatment of delayed HTXs.