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Abstract Ultrasonic processing of solidifying metals in additive manufacturing can provide grain refinement and advantageous mechanical properties. However, the specific physical mechanisms of microstructural refinement relevant to laser-based additive manufacturing have not been directly observed because of sub-millimeter length scales and rapid solidification rates associated with melt pools. Here, high-speed synchrotron X-ray imaging is used to observe the effect of ultrasonic vibration directly on melt pool dynamics and solidification of Al6061 alloy. The high temporal and spatial resolution enabled direct observation of cavitation effects driven by a 20.2 kHz ultrasonic source. We utilized multiphysics simulations to validate the postulated connection between ultrasonic treatment and solidification. The X-ray results show a decrease in melt pool and keyhole depth fluctuations during melting and promotion of pore migration toward the melt pool surface with applied sonication. Additionally, the simulation results reveal increased localized melt pool flow velocity, cooling rates, and thermal gradients with applied sonication. This work shows how ultrasonic treatment can impact melt pools and its potential for improving part quality.

This study directly compares face-to-face writing center consultations with two closely related variations of Online Writing Instruction (OWI). Although the study takes place in a busy, dynamic writing center, the authors try to make their comparisons as systematic as possible so they can better foreground some of the benefits and disadvantages of various conferencing environments. The study uses qualitative, naturalistic data (transcripts of sessions, surveys) but analyzes them using quasi-experimental methods (expert ratings, patterns of responses) in order to highlight trends across the copious data the authors collected (over 500 transcript pages). Although they realize that some in the writing center community are skeptical of such methods, many others have been calling for systematic, empirical inquiry into writing center concerns (Bergmann quoted in Jaschik; Jones; Hewett, "Synchronous"). Such inquiry both produces insights that may not be readily visible using other methods and can persuade administrators and others across the university of the need to invest more resources and support rigorous research into writing center pedagogy. (Contains 8 tables, 1 figure, and 3 notes.)

Introduction Up to 18% of spontaneous intracerebral hemorrhages are cryptogenic despite a thorough workup, usually noted in a lobar location. Although undetected on DSA, a significant proportion of these represent ruptured micro‐AVM/AVF or cavernous malformations that ultimately are amenable to surgical resection if detected on biopsy. However, occult cerebral amyloid angiopathy can also present similarly, and their management is markedly different. Methods We present a case of recurrent bilateral medial frontal hemorrhage in a patient without known cerebrovascular disease that evaded diagnosis despite hematologic evaluation, MRI, CTA, two DSAs, three clot evacuations with pathology, and brain biopsy. Results The patient is a 60‐year‐old previously healthy woman who presented with sudden onset right hemiparesis and speech arrest. CT revealed a left parasagittal hemorrhage. She was brought to the OR for clot evacuation. Pathology from the clot revealed blood vessels of multiple sizes consistent with meningeal vessels or underlying AVM/AVF. A 6‐vessel cerebral angiogram as unremarkable. The patient’s inpatient course was complicated by new onset Afib with RVR and asymptomatic DVT with PE, however no etiology of coagulopathy was detected. MRI brain showed no evidence of cerebral microbleed or other underlying pathology, noting only DWI + FLAIR hyperintensity in the left ACA territory. The patient was diagnosed with ACA territory stroke complicated by PH2‐type hemorrhagic conversion. She was initially placed on IV Heparin, before transition to apixaban uneventfully. She continued to recover in the hospital and was eventually discharged to rehab. She re‐presented 1 month later with worsening behavioral arrest and right hemiparesis. CT head revealed recurrence of left parasagittal ICH. She underwent clot evacuation in the OR again and repeat pathology was unrevealing. A repeat MRI showed only the evident bleed and a subtle hyperintensity in the right occipital cortex suspicious for an interval subacute occipital lobe stroke with laminar necrosis, ostensibly from Afib. She improved clinically and was discharged to rehab with a diagnosis of recurrent hemorrhage attributed to anticoagulant use and recent stroke. She was discharged this time on no anticoagulant or antiplatelets. She re‐presented 1 month later with sudden onset speech arrest, but now with left hemiparesis. CT revealed a right parasagittal hemorrhage. She was brought to the OR for emergent clot evacuation and parenchymal biopsy – which was initially normal. A repeat 6‐vessel DSA was again unremarkable as was repeat brain MRI. The patient’s parenchymal biopsy was sent for specific congo‐red and immunohistochemistry for beta‐amyloid. IHC revealed beta‐amyloid plaques in the parenchyma and vessel walls, confirming a diagnosis of CAA. Conclusion Apparently cryptogenic lobar hemorrhage may be caused by both occult micro‐AVM/fistula and CAA. As in this case, when a patient experiences recurrent DSA negative lobar hemorrhages, biopsy should be pursued. This case was particularly challenging given the anatomical plausibility of parasagittal AVM/fistula given its midline location and venous drainage, considering the patient’s evident predisposition to systemic venous thrombosis hemorrhagic venous infarction mimicking lobar ICH is also possible. We present this case to raise awareness of the potential need for early biopsy, especially in patients who may also require anticoagulation or antiplatelet medications.

Abstract Nicotinic acetylcholine receptors (nAChRs) are broadly expressed in the central and peripheral nervous systems, playing essential roles in cholinergic neurotransmission. The lynx family proteins, a subset of the Ly6/uPAR superfamily expressed in multiple brain regions, have been shown to bind to nAChRs and modulate their function via allosteric regulation. The binding interactions between lynx and nAChRs, however, have not been systematically quantified and compared. In this work, we characterized the interactions between lynx1 or lynx2 and α3β4‐ or α7‐nAChRs using single‐molecule atomic force microscopy (AFM). The AFM technique allows the quantification of the off‐rate of lynx‐nAChR binding and of the energetic barrier width between the bound state and transition state, providing a biophysical means to compare the selectivity of lynx proteins for nAChR subtypes. Results indicate that lynx1 has a marginal preference for α7‐ over α3β4‐nAChRs. Strikingly, lynx2 exhibits a two order of magnitude stronger affinity for α3β4‐ compared to α7‐nAChRs. Together, the AFM assay serves as a valuable tool for the biophysical characterization of lynx‐nAChR binding affinities. Revealing the differential affinities of lynx proteins for nAChR subtypes will help elucidate how lynx regulates nAChR‐dependent functions in the brain, including nicotine addiction and other critical pathways.

.The article reports on the national survey conducted by the Writing Centers Research Project (WCRP) in response to the needs of an oversimplifying wide range of writing centers nationwide. WCRP survey shows that there are 25 percent of writing centers who have multiple affiliations, and 29 percent average single affiliation accounts. In this connection, most of the writing centers extended their building productive alliances in many institutional units. Through this survey, writing centers as well as their directors will enable to provide improvements and offer better services to their client's in the future.

The four-area project was undertaken to further assess the impact of badger removal on the control of tuberculosis in cattle herds in Ireland. It was conducted between 1997 and 2002 in matched removal and reference areas in four counties, namely Cork, Donegal, Kilkenny and Monaghan, representing a wide range of Irish farming environments. In the removal areas, a proactive programme of badger removal was conducted, on two or three occasions each year, whereas in the reference areas, badger removal was entirely reactive following severe outbreaks of tuberculosis amongst cattle. A detailed statistical analysis of this study has already been presented by Griffin et al. 13; this paper presents further, mainly descriptive, findings from the study. In total, 2,360 badgers were captured in the removal areas of which 450 (19.5%) were considered positive for tuberculosis and 258 badgers were captured in the reference areas, with 57 (26.1%) positive for tuberculosis. The annual incidence of confirmed herd restrictions was lower in the removal area compared to the reference area in every year of the study period in each of the four counties. These empirical findings were consistent with the hazard ratios found by Griffin et al. 13. Further, the effect of proactive badger removal on cattle tuberculosis in the four-area project and in the earlier east-Offaly project, as measured using the number of reactors per 1,000 cattle tested, were very similar, providing compelling evidence of the role of badgers in the epidemiology of tuberculosis in Irish cattle herds. The validity of the four-area project was discussed in detail. Efforts to minimise badger-to-cattle transmission in Ireland must be undertaken in association with the current comprehensive control programme, which has effectively minimised opportunities for cattle-to-cattle transmission.

Abstract Background Maximizing response rates is critically important in order to provide the most generalizable and unbiased research results. High response rates reduce the chance of respondents being systematically different from non-respondents, and thus, reduce the risk of results not truly reflecting the study population. Monetary incentives are often used to improve response rates, but little is known about whether larger incentives improve response rates in those who previously have been unenthusiastic about participating in research. In this study we compared the response rates and cost-effectiveness of a $5 versus $2 monetary incentive accompanying a short survey mailed to patients who did not respond or refused to participate in research study with a face-to-face survey. Methods 1,328 non-responders were randomly assigned to receive $5 or $2 and a short, 10-question survey by mail. Reminder postcards were sent to everyone; those not returning the survey were sent a second survey without incentive. Overall response rates, response rates by incentive condition, and odds of responding to the larger incentive were calculated. Total costs (materials, postage, and labor) and incremental cost-effectiveness ratios were also calculated and compared by incentive condition. Results After the first mailing, the response rate within the $5 group was significantly higher (57.8% vs. 47.7%, p < .001); after the second mailing, the difference narrowed by 80%, resulting in a non-significant difference in cumulative rates between the $5 and $2 groups (67.3% vs. 65.4%, respectively, p = .47). Regardless of incentive or number of contacts, respondents were significantly more likely to be male, white, married, and 50-75 years old. Total costs were higher with the larger versus smaller incentive ($13.77 versus $9.95 per completed survey). Conclusions A $5 incentive provides a significantly higher response rate than a $2 incentive if only one survey mailing is used but not if two survey mailings are used.

Abstract Background Thrombolytic therapy with tissue plasminogen activator (tPA) benefits patients with acute ischemic stroke. However, tPA increases the risk for intracerebral bleeding and enhances post-ischemic neuronal injury if administered 3-4 hours after stroke. Therefore, combination therapies with tPA and neuroprotective agents have been considered to increase tPA's therapeutic window and reduce toxicity. The anticoagulant factor protein S (PS) protects neurons from hypoxic/ischemic injury. PS also inhibits N-methyl-D-aspartate (NMDA) excitotoxicity by phosphorylating Bad and Mdm2 which blocks the downstream steps in the intrinsic apoptotic cascade. To test whether PS can protect neurons from tPA toxicity we studied its effects on tPA/NMDA combined injury which in contrast to NMDA alone kills neurons by activating the extrinsic apoptotic pathway. Neither Bad nor Mdm2 which are PS's targets and control the intrinsic apoptotic pathway can influence the extrinsic cascade. Thus, based on published data one cannot predict whether PS can protect neurons from tPA/NMDA injury by blocking the extrinsic pathway. Neurons express all three TAM (Tyro3, Axl, Mer) receptors that can potentially interact with PS. Therefore, we studied whether PS can activate TAM receptors during a tPA/NMDA insult. Results We show that PS protects neurons from tPA/NMDA-induced apoptosis by suppressing Fas-ligand (FasL) production and FasL-dependent caspase-8 activation within the extrinsic apoptotic pathway. By transducing neurons with adenoviral vectors expressing the kinase-deficient Akt mutant AktK179A and a triple FKHRL1 Akt phosphorylation site mutant (FKHRL1-TM), we show that Akt activation and Akt-mediated phosphorylation of FKHRL1, a member of the Forkhead family of transcription factors, are critical for FasL down-regulation and caspase-8 inhibition. Using cultured neurons from Tyro3, Axl and Mer mutants, we show that Tyro3, but not Axl and Mer, mediates phosphorylation of FHKRL1 that is required for PS-mediated neuronal protection after tPA/NMDA-induced injury. Conclusions PS blocks the extrinsic apoptotic cascade through a novel mechanism mediated by Tyro3-dependent FKHRL1 phosphorylation which inhibits FasL-dependent caspase-8 activation and can control tPA-induced neurotoxicity associated with pathologic activation of NMDA receptors. The present findings should encourage future studies in animal stroke models to determine whether PS can increase the therapeutic window of tPA by reducing its post-ischemic neuronal toxicity.

Abstract Several myelin-associated factors that inhibit axon growth of mature neurons, including Nogo66, myelin-associated glycoprotein (MAG) and oligodendrocyte myelin glycoprotein (OMgp), can associate with a common GPI-linked protein Nogo-66 receptor (NgR). Accumulating evidence suggests that myelin inhibitors also signal through unknown NgR-independent mechanisms. Here we show that MAG, a RGD tri-peptide containing protein, forms a complex with β1-integrin to mediate axonal growth cone turning responses of several neuronal types. Mutations that alter the RGD motif in MAG or inhibition of β1-integrin function, but not removal of NgRs, abolish these MAG-dependent events. In contrast, OMgp-induced repulsion is not affected by inhibition of b1-integrin function. We further show that MAG stimulates tyrosine phosphorylation of focal adhesion kinase (FAK), which in turn is required for MAG-induced growth cone turning. These studies identify β1-integrin as a specific mediator for MAG in growth cone turning responses, acting through FAK activation.

Abstract Background Transient hyperthermic shifts in body temperature have been linked to the endogenous hormone calcitonin gene-related peptide (CGRP), which can increase sympathetic activation and metabolic heat production. Recent studies have demonstrated that these centrally mediated responses may result from CGRP dependent changes in the activity of thermoregulatory neurons in the preoptic and anterior regions of the hypothalamus (POAH). Results Using a tissue slice preparation, we recorded the single-unit activity of POAH neurons from the adult male rat, in response to temperature and CGRP (10 μM). Based on the slope of firing rate as a function of temperature, neurons were classified as either warm sensitive or temperature insensitive. All warm sensitive neurons responded to CGRP with a significant decrease in firing rate. While CGRP did not alter the firing rates of some temperature insensitive neurons, responsive neurons showed an increase in firing rate. Conclusion With respect to current models of thermoregulatory control, these CGRP dependent changes in firing rate would result in hyperthermia. This suggests that both warm sensitive and temperature insensitive neurons in the POAH may play a role in producing this hyperthermic shift in temperature.

Abstract Background Physiological and morphological evidence suggests that activation of the ventromedial preoptic area of the hypothalamus (VMPO) is an essential component of an intravenous LPS-dependent fever. In response to the endogenous pyrogen prostaglandin E2 (PGE2), the majority of temperature insensitive neurons in the VMPO show an increase in firing rate, while warm sensitive neurons are inhibited. We have hypothesized that these PGE2 dependent effects on firing rate are due to changes in the inherent electrical properties of VMPO neurons, which are regulated by the activity of specific ionic currents. Results To characterize the electrical properties of VMPO neurons, whole-cell recordings were made in tissue slices from male Sprague-Dawley rats. Our results indicate that PGE2 dependent firing rate responses were not the result of changes in resting membrane potential, action potential amplitude and duration, or local synaptic input. However, PGE2 reduced the input resistance of all VMPO neurons, while increasing the excitability of temperature insensitive neurons and decreasing the excitability of warm sensitive neurons. In addition, the majority of temperature insensitive neurons responded to PGE2 with an increase in the rate of rise of the depolarizing prepotential that precedes each action potential. This response to PGE2 was reversed for warm sensitive neurons, in which the prepotential rate of rise decreased. Conclusion We would therefore suggest that PGE2 is having an effect on the ionic currents that regulate firing rate by controlling how fast membrane potential rises to threshold during the prepotential phase of the action potential.

Objectives: Studies in the USA, Canada and France have reported higher surgical site infection (SSI) risk in patients with a penicillin allergy label (PAL). Here, we investigate the association between PALs and SSI in the UK, a country with distinct epidemiology of infecting pathogens and range of antimicrobial regimens in routine use., Methods: Electronic health records and national SSI surveillance data were collated for a retrospective cohort of gastrointestinal surgery patients at Cambridge University Hospitals NHS Foundation Trust from 1 January 2015 to 31 December 2021. Univariable and multivariable logistic regression were used to examine the effects of PALs and the use of non-β-lactam-based prophylaxis on likelihood of SSI, 30 day post-operative mortality, 7 day post-operative acute kidney injury and 60 day post-operative infection/colonization with antimicrobial-resistant bacteria or Clostridioides difficile ., Results: Our data comprised 3644 patients and 4085 operations; 461 were undertaken in the presence of PALs (11.3%). SSI was detected after 435/4085 (10.7%) operations. Neither the presence of PALs, nor the use of non-β-lactam-based prophylaxis were found to be associated with SSI: adjusted OR (aOR) 0.90 (95% CI 0.65-1.25) and 1.20 (0.88-1.62), respectively. PALs were independently associated with increased odds of newly identified MRSA infection/colonization in the 60 days after surgery: aOR 2.71 (95% CI 1.13-6.49). Negative association was observed for newly identified infection/colonization with third-generation cephalosporin-resistant Gram-negative bacteria: aOR 0.38 (95% CI 0.16-0.89)., Conclusions: No evidence was found for an association between PALs and the likelihood of SSI in this large UK cohort, suggesting significant international variation in the impact of PALs on surgical patients., (© The Author(s) 2024. Published by Oxford University Press on behalf of British Society for Antimicrobial Chemotherapy.)