Shortcuts to adiabatic soliton compression in active nonlinear Kerr media.

We implement variational shortcuts to adiabaticity for optical pulse compression in an active nonlinear Kerr medium with distributed amplification and spatially varying dispersion and nonlinearity. Starting with the hyperbolic secant ansatz, we employ a variational approximation to systematically derive dynamical equations, establishing analytical relationships linking the amplitude, width, and chirp of the pulse. Through the inverse engineering approach, we manipulate the distributed gain/loss, nonlinearity and dispersion profiles to efficiently compress the optical pulse over a reduced distance with high fidelity. In addition, we explore the dynamical stability of the system to illustrate the advantage of our protocol over conventional adiabatic approaches. Finally, we analyze the impact of tailored higher-order dispersion on soliton self-compression and derive physical constraints on the final soliton width for the complementary case of soliton expansion. The broader implications of our findings extend beyond optical systems, encompassing areas such as cold-atom and magnetic systems highlighting the versatility and relevance of our approach in various physical contexts.

Finite Element Modeling of Quantitative Ultrasound Analysis of the Surgical Margin of Breast Tumor.

Ultrasound is commonly used as an imaging tool in the medical sector. Compared to standard ultrasound imaging, quantitative ultrasound analysis can provide more details about a material microstructure. In this study, quantitative ultrasound analysis was conducted through computational modeling to detect various breast duct pathologies in the surgical margin tissue. Both pulse-echo and pitch-catch methods were evaluated for a high-frequency (22-41 MHz) ultrasound analysis. The computational surgical margin modeling was based on various conditions of breast ducts, such as normal duct, ductal hyperplasia, DCIS, and calcification. In each model, ultrasound pressure magnitude variation in the frequency spectrum was analyzed through peak density and mean-peak-to-valley distance (MPVD) values. Furthermore, the spectral patterns of all the margin models were compared to extract more pathology-based information. For the pitch-catch mode, only peak density provided a trend in relation to different duct pathologies. For the pulse-echo mode, only the MPVD was able to do that. From the spectral comparison, it was found that overall pressure magnitude, spectral variation, peak pressure magnitude, and corresponding frequency level provided helpful information to differentiate various pathologies in the surgical margin.

A Case of Spontaneous Pneumomediastinum Following Ecstasy and Marijuana Use.

Spontaneous pneumomediastinum (SPM) is a benign and self-limiting condition more commonly seen in young adults. Radiology imaging of the chest, including X-ray or CT scan, is the gold standard for diagnosis. Ecstasy, also known as 3,4-methylenedioxymethamphetamine (MDMA) is a synthetic amphetamine derivative widely abused for an increased sense of well-being and euphoria. Marijuana is also abused for recreational purposes. SPM has been reported after both Ecstasy and marijuana use. SPM after these illicit drugs abuse usually has a benign and self-limiting course with supportive management. However, it is always important to rule out serious associated conditions like esophageal perforation. Here, we present a 22-year-old male who developed SPM after Ecstasy ingestion and marijuana inhalation.

Super fragmented: a nationally representative cross-sectional study exploring the fragmentation of inpatient care among super-utilizers.

BACKGROUND: Super-utilizers with 4 or more admissions per year frequently receive low-quality care and disproportionately contribute to healthcare costs. Inpatient care fragmentation (admission to multiple different hospitals) in this population has not been well described. OBJECTIVE: To determine the prevalence of super-utilizers who receive fragmented care across different hospitals and to describe associated risks, costs, and health outcomes. RESEARCH DESIGN: We analyzed inpatient data from the Health Care Utilization Project's State Inpatient and Emergency Department database from 6 states from 2013. After identifying hospital super-utilizers, we stratified by the number of different hospitals visited in a 1-year period. We determined how patient demographics, costs, and outcomes varied by degree of fragmentation. We then examined how fragmentation would influence a hospital's ability to identify super-utilizers. SUBJECTS: Adult patients with 4 or more inpatient stays in 1 year. MEASURES: Patient demographics, cost, 1-year hospital reported mortality, and probability that a single hospital could correctly identify a patient as a super-utilizer. RESULTS: Of the 167,515 hospital super-utilizers, 97,404 (58.1%) visited more than 1 hospital in a 1-year period. Fragmentation was more likely among younger, non-white, low-income, under-insured patients, in population-dense areas. Patients with fragmentation were more likely to be admitted for chronic disease management, psychiatric illness, and substance abuse. Inpatient fragmentation was associated with higher yearly costs and lower likelihood of being identified as a super-utilizer. CONCLUSIONS: Inpatient care fragmentation is common among super-utilizers, disproportionately affects vulnerable populations. It is associated with high yearly costs and a decreased probability of correctly identifying super-utilizers.

Little Earth Strong: A Community-Level, Culturally Appropriate Diabetes Prevention Pilot Targeting Urban American Indians.

PURPOSE: The purpose of this study was to develop a culturally appropriate, community-based diabetes prevention program, named Little Earth Strong, through partnership with an urban, Indigenous, American Indian community and determine its feasibility in lowering diabetes risks. METHODS: Using a community-based participatory research, community-level intervention approach, and after conducting a focus groups with key stakeholders (n = 20), a culturally appropriate health intervention was designed across six stages. This included providing nutrition and physical activity individual, family, and group counseling and conducting individual level biometric tests at a monthly Progress Powwow. Community participants (n = 69) included Indigenous individuals ages 18 to 64 years and their families residing in an urban American Indian housing organization. RESULTS: Findings included the project's feasibility, sustainability, and future needs. Lessons learned included the need the need to situate health interventions within Indigenous culture, engage multiple stakeholders, remain flexible and inclusive of all community members, address cultural concerns regarding biometric testing, and focus on specific ages and groups. The outcome variables included qualitative focus group data regarding feasibility and design and quantitative biometric data including hemoglobin A1C levels and weight in which a significant decrease in A1C values were found among womenConclusions: Little Earth Strong was both feasible and successful in decreasing A1C levels using a community-level approach, especially in high participators who attended most events. These results demonstrate the promise of diabetes prevention fitness and nutrition interventions that are collaboratively designed with the community.

Identifying Perspectives About Health to Orient Obesity Intervention Among Urban, Transitionally Housed Indigenous Children.

Drawing from a socioecological framework of health, this community-based participatory research study examined key cultural health perspectives of transitionally housed, food insecure Indigenous children (aged 8-12 years) by utilizing talking circles and a 4-day photovoice (PV) curriculum. In total, 18 Indigenous children portrayed their health perceptions by taking photographs of their living environment and categorizing photos as healthy, unhealthy, or mixed. And, 10 of the 18 children completed pre- and post-evaluations, where data elucidated that urban Indigenous children experiencing food and housing insecurity demonstrate unique holistic and socioecological perceptions about health. Healthy themes included nutrition, gardening, interpersonal relationships, food sovereignty, water quality, and natural and built environments. Unhealthy themes included cumulative stress, food insecurity, access and cost, screen time, smoking, and violence. We found that implementing these robust insights into urban Indigenous obesity prevention interventions could significantly drive success. This approach may benefit children with similar socioecological strengths and vulnerabilities.

Ode'imin Giizis: Proposing and Piloting Gardening as an Indigenous Childhood Health Intervention.

The Research for Indigenous Community Health Center and the American Indian Housing Organization sought to reduce obesity among Indigenous children and families in a Northern Midwestern urban community who are at risk for homelessness by piloting a gardening health intervention. This community-based participatory research, mixedmethods study examined the feasibility of gardening as an obesity intervention among a school-aged Indigenous population at risk for homelessness through using focus groups, key informant interviews, and valid health measures. The program was found highly feasible and fulfilled a critical need among Indigenous youth and their families, who reportedly suffered from food insecurity and access. This intervention increased healthy food awareness and perceptions, cultural resources, and ancestral food knowledge skills through activities, mentorship, and multigenerational engagement. This study augments the literature on the feasibility of using tribal ecological knowledge and the environment in designing culturally appropriate health interventions.

Variation in Accrual and Race/Ethnicity Reporting in Urological and Nonurological Related Cancer Trials.

PURPOSE: We performed a multiregistry analysis to assess relative differences in accrual sufficiency and race/ethnicity reporting in trials of common urological cancers and other nonurological solid organ tumors. MATERIALS AND METHODS: We queried ClinicalTrials.gov and the ISRCTN (International Standard Randomised Controlled Trial Number) Registry for closed phase III and IV trials focused on prostate, colorectal, kidney, bladder, testicular, breast and lung cancer. Identified trials were cross-verified with appropriate published data sources. Comparative accrual sufficiency and rates of race/ethnicity reporting were calculated. Multivariable logistic regression analysis was performed to determine factors associated with accrual status and race/ethnicity reporting. RESULTS: A total of 326 trials were identified based on our prespecified criteria, of which 63% reported sufficient accrual by time of closure and 58% reported data by race/ethnicity. Nonurological trials were significantly more likely to mention race data than urological trials (OR 3.25, 95% CI 1.24-8.55, p = 0.02). Industry sponsored trials were more likely to meet accrual targets than government funded projects (OR 5.44, 95% CI 1.64-18.20, p = 0.001). Although funding source did not influence race reporting, the reported recruitment of participants of African ethnicity was lower in industry sponsored trials (11.49% vs 3.18%, p <0.01). Two-thirds of the studies did not report baseline characteristics by African American race/ethnicity. CONCLUSIONS: Insufficient accrual and inadequate race/ethnicity reporting are prevalent issues, limiting interpretation of the results of clinical trials of major solid organ malignancies. Addressing these shortcomings would enhance result validity by raising statistical power and improving the transparency of reporting to better evaluate the generalizability of results.

Green synthesis of Nerium oleander-conjugated gold nanoparticles and study of its in vitro anticancer activity on MCF-7 cell lines and catalytic activity.

The phytochemicals present in the stem bark extract of Nerium oleander (commonly known as Karabi) have been utilized for the green synthesis of stable gold-conjugated nanoparticles at room temperature under very mild conditions. The green synthesized gold-conjugated nanoparticles were characterized by surface plasmon resonance spectroscopy, High resolution transmission electron microscopy, X-ray diffraction studies and dynamic light scattering. A mechanism for the synthesis and stabilization of gold-conjugated nanoparticles (AuNPs) has been proposed. Anticancer activity of the stabilized AuNPs studied against MCF-7 breast cancer cell line revealed that the stabilized AuNPs were highly effective for the apoptosis of cancer cells selectively. The antioxidant activity of the stem bark extract of Nerium oleander has also been studied against a long lived 2,2-diphenylpicrylhydrazyl radical at room temperature. Moreover, the utilization of the stabilized AuNPs as a catalyst has also been demonstrated.

Fast and efficient wireless power transfer via transitionless quantum driving.

Shortcut to adiabaticity (STA) techniques have the potential to drive a system beyond the adiabatic limits. Here, we present a robust and efficient method for wireless power transfer (WPT) between two coils based on the so-called transitionless quantum driving (TQD) algorithm. We show that it is possible to transfer power between the coils significantly fast compared to its adiabatic counterpart. The scheme is fairly robust against the variations in the coupling strength and the coupling distance between the coils. Also, the scheme is found to be reasonably immune to intrinsic losses in the coils.

First in situ vesicular self-assembly of 'binols' generated by a two-component aerobic oxidation reaction.

Generation of vesicular self-assemblies from natural and synthetic components has been in the frontiers of research in recent years for an improved understanding of the self-assembly process and also because of its prospective and realized applications in the areas of advanced materials, biotechnology and medicine. In the present work, we report the first example of the in situ generation of vesicular self-assemblies during an aerobic coupling reaction. The two precursor 2-naphthol units, having hydrogen bond donor-acceptor groups with appended alkyl chains, yielded binol (2,2'-dihydroxy-1,1'-binaphthyl) derivatives by aerobic coupling that spontaneously self-assembled in situ, yielding vesicular self-assemblies and gels. The morphology of the self-assemblies has been characterized by various optical, electron and atomic force microscopic techniques. The vesicular self-assemblies obtained in the liquids were capable of entrapping fluorophores such as rhodamine-B and carboxy fluorescein including the anticancer drug doxorubicin. The entrapped fluorophores could also be released by sonication or by rupture of vesicles. The supramolecular gels obtained in binary solvent mixtures showed improved gelation abilities with increase in the alkyl chain lengths as reflected by their minimum gelator concentration (mgcs) values, gel to sol transition temperatures (T gel) and rheology properties. The results described here are also the first demonstration of gelation during an aerobic coupling reaction.

A comprehensive study on landfill site selection for Kolkata City, India.

Kolkata is one of the four major metropolitan cities in India and the capital city of the state of West Bengal. With an area of 187.33 km2 and a population of about 10 million (including a floating population of about 6 million), the city generates about 3500 Metric Ton (MT) of solid waste per day. Currently, Kolkata Municipal Corporation (KMC) disposes its waste at Dhapa (21.47 ha), where the disposal rate exceeds 3000 MT/day, and at Garden Reach (3.52 ha), where the disposal rate is 100 MT/day. Considering the exhaustion of Dhapa land space, city planners are urgently searching for an alternate disposal ground. National Environmental Engineering Research Institute (NEERI), under the sponsorship of Central Pollution Control Board (CPCB), has brought out literature developing the site selection criteria for municipal solid waste disposal ground to suit Indian conditions. The developed criteria encompass environmental conditions, accessibility, geological and hydrogeological conditions, and ecological and societal effects. This paper attempts to locate the most suitable site for disposal of KMC area solid waste using the multicriterion decision analysis as stipulated in CPCB 2003 guidelines and the overlay analysis of geographic information system (GIS). Implications: The paper is based on landfill site selection for dumping of solid waste generated within Kolkata Municipal Corporation (KMC) area. The methodology uses GIS/remote sensing, Site Sensitivity Index (an offshoot of pairwise comparison technique developed in CPCB 2003 guidelines, Government of India), and the Delphi technique. Dhapa landfill site, where solid waste of KMC area is currently being disposed, is exhausted; the authors of this article thus found it relevant to carry out a research on the selection of an alternative landfill site. The study undertaken was comprehensive, yet presented in a lucid way so that policymakers will find easy to comprehend.

A molecular mechanism of direction switching in the flagellar motor of Escherichia coli.

The direction of flagellar rotation is regulated by a rotor-mounted protein assembly, termed the "switch complex," formed from multiple copies of the proteins FliG, FliM, and FliN. The structures of major parts of these proteins are known, and the overall organization of proteins in the complex has been elucidated previously using a combination of protein-binding, mutational, and cross-linking approaches. In Escherichia coli, the switch from counterclockwise to clockwise rotation is triggered by the signaling protein phospho-CheY, which binds to the lower part of the switch complex and induces small movements of FliM and FliN subunits relative to each other. Direction switching also must produce movements in the upper part of the complex, particularly in the C-terminal domain of FliG (FliG(C)), which interacts with the stator to generate the torque for flagellar rotation. In the present study, protein movements in the middle and upper parts of the switch complex have been probed by means of targeted cross-linking and mutational analysis. Switching induces a tilting movement of the FliM domains that form the middle part of the switch and a consequent rotation of the affixed FliG(C) domains that reorients the stator interaction sites by about 90°. In a recently proposed hypothesis for the motor mechanism, such a reorientation of FliG(C) would reverse the direction of motor rotation.

Adjusting the spokes of the flagellar motor with the DNA-binding protein H-NS.

The H-NS protein of bacteria is a global regulator that stimulates transcription of flagellar genes and that also acts directly to modulate flagellar motor function. H-NS is known to bind FliG, a protein of the rotor that interacts with the stator and is directly involved in rotation of the motor. Here, we find that H-NS, well known for its ability to organize DNA, acts in the flagellar motor to organize protein subunits in the rotor. It binds to a middle domain of FliG that bridges the core parts of the rotor and parts nearer the edge that interact with the stator. In the absence of H-NS the organization of FliG subunits is disrupted, whereas overexpression of H-NS enhances FliG organization as monitored by targeted disulfide cross-linking, alters the disposition of a helix joining the middle and C-terminal domains of FliG, and enhances motor performance under conditions requiring a strengthened rotor-stator interface. The H-NS homolog StpA was also shown to bind FliG and to act similarly, though less effectively, in organizing FliG. The motility-enhancing effects of H-NS contrast with those of the recently characterized motility inhibitor YcgR. The present findings provide an integrated, structurally grounded framework for understanding the roughly opposing effects of these motility regulators.

Architecture of the flagellar rotor.

Rotation and switching of the bacterial flagellum depends on a large rotor-mounted protein assembly composed of the proteins FliG, FliM and FliN, with FliG most directly involved in rotation. The crystal structure of a complex between the central domains of FliG and FliM, in conjunction with several biochemical and molecular-genetic experiments, reveals the arrangement of the FliG and FliM proteins in the rotor. A stoichiometric mismatch between FliG (26 subunits) and FliM (34 subunits) is explained in terms of two distinct positions for FliM: one where it binds the FliG central domain and another where it binds the FliG C-terminal domain. This architecture provides a structural framework for addressing the mechanisms of motor rotation and direction switching and for unifying the large body of data on motor performance. Recently proposed alternative models of rotor assembly, based on a subunit contact observed in crystals, are not supported by experiment.

Chemotaxis signaling protein CheY binds to the rotor protein FliN to control the direction of flagellar rotation in Escherichia coli.

The direction of rotation of the Escherichia coli flagellum is controlled by an assembly called the switch complex formed from multiple subunits of the proteins FliG, FliM, and FliN. Structurally, the switch complex corresponds to a drum-shaped feature at the bottom of the basal body, termed the C-ring. Stimulus-regulated reversals in flagellar motor rotation are the basis for directed movement such as chemotaxis. In E. coli, the motors turn counterclockwise (CCW) in their default state, allowing the several filaments on a cell to join together in a bundle and propel the cell smoothly forward. In response to the chemotaxis signaling molecule phospho-CheY (CheY(P)), the motors can switch to clockwise (CW) rotation, causing dissociation of the filament bundle and reorientation of the cell. CheY(P) has previously been shown to bind to a conserved segment near the N terminus of FliM. Here, we show that this interaction serves to capture CheY(P) and that the switch to CW rotation involves the subsequent interaction of CheY(P) with FliN. FliN is located at the bottom of the C-ring, in close association with the C-terminal domain of FliM (FliM(C)), and the switch to CW rotation has been shown to involve relative movement of FliN and FliM(C). Using a recently developed structural model for the FliN/FliM(C) array, and the CheY(P)-binding site here identified on FliN, we propose a mechanism by which CheY(P) binding could induce the conformational switch to CW rotation.

The c-di-GMP binding protein YcgR controls flagellar motor direction and speed to affect chemotaxis by a "backstop brake" mechanism.

We describe a mechanism of flagellar motor control by the bacterial signaling molecule c-di-GMP, which regulates several cellular behaviors. E. coli and Salmonella have multiple c-di-GMP cyclases and phosphodiesterases, yet absence of a specific phosphodiesterase YhjH impairs motility in both bacteria. yhjH mutants have elevated c-di-GMP levels and require YcgR, a c-di-GMP-binding protein, for motility inhibition. We demonstrate that YcgR interacts with the flagellar switch-complex proteins FliG and FliM, most strongly in the presence of c-di-GMP. This interaction reduces the efficiency of torque generation and induces CCW motor bias. We present a "backstop brake" model showing how both effects can result from disrupting the organization of the FliG C-terminal domain, which interacts with the stator protein MotA to generate torque. Inhibition of motility and chemotaxis may represent a strategy to prepare for sedentary existence by disfavoring migration away from a substrate on which a biofilm is to be formed.

The role of the FliK molecular ruler in hook-length control in Salmonella enterica.

A molecular ruler, FliK, controls the length of the flagellar hook. FliK measures hook length and catalyses the secretion-substrate specificity switch from rod-hook substrate specificity to late substrate secretion, which includes the filament subunits. Here, we show normal hook-length control and filament assembly in the complete absence of the C-ring thus refuting the previous 'cup' model for hook-length control. Mutants of C-ring components, which are reported to produce short hooks, show a reduced rate of hook-basal body assembly thereby allowing for a premature secretion-substrate specificity switch. Unlike fliK null mutants, hook-length control in an autocleavage-defective mutant of flhB, the protein responsible for the switch to late substrate secretion, is completely abolished. FliK deletion variants that retain the ability to measure hook length are secreted thus demonstrating that FliK directly measures rod-hook length during the secretion process. Finally, we present a unifying model accounting for all published data on hook-length control in which FliK acts as a molecular ruler that takes measurements of rod-hook length while being intermittently secreted during the assembly process of the hook-basal body complex.

Subunit organization and reversal-associated movements in the flagellar switch of Escherichia coli.

Bacterial flagella contain a rotor-mounted protein complex termed the switch complex that functions in flagellar assembly, rotation, and clockwise/counterclockwise direction control. In Escherichia coli and Salmonella, the switch complex contains the proteins FliG, FliM, and FliN and corresponds structurally with the C-ring in the flagellar basal body. Certain features of subunit organization in the switch complex have been deduced previously, but details of subunit organization in the lower part of the C-ring and the molecular movements responsible for motor switching remain unclear. In this study, we use cross-linking, binding, and mutational experiments to examine subunit organization in the bottom of the C-ring and to probe movements that occur upon switching. The results show that FliN tetramers alternate with FliM C-terminal domains to form the bottom of the C-ring in an arrangement that closely reproduces the major features observed in electron microscopic reconstructions. When motors were switched to clockwise rotation by a repellent stimulus, cross-link yields were altered in a pattern indicating relative movement of FliN and FliM(C). These results are discussed in the framework of a structurally grounded hypothesis for the switching mechanism.

Energy source of flagellar type III secretion.

Bacterial flagella contain a specialized secretion apparatus that functions to deliver the protein subunits that form the filament and other structures to outside the membrane. This apparatus is related to the injectisome used by many gram-negative pathogens and symbionts to transfer effector proteins into host cells; in both systems this export mechanism is termed 'type III' secretion. The flagellar secretion apparatus comprises a membrane-embedded complex of about five proteins, and soluble factors, which include export-dedicated chaperones and an ATPase, FliI, that was thought to provide the energy for export. Here we show that flagellar secretion in Salmonella enterica requires the proton motive force (PMF) and does not require ATP hydrolysis by FliI. The export of several flagellar export substrates was prevented by treatment with the protonophore CCCP, with no accompanying decrease in cellular ATP levels. Weak swarming motility and rare flagella were observed in a mutant deleted for FliI and for the non-flagellar type-III secretion ATPases InvJ and SsaN. These findings show that the flagellar secretion apparatus functions as a proton-driven protein exporter and that ATP hydrolysis is not essential for type III secretion.