Northeastern University
  • Boston, MA, United States
Recent publications
The COVID-19 pandemic has caused a great “reset” and has challenged many assumptions about work and life in general. Our focus in this paper is on the future of global work in the context of multinational enterprises (MNEs). We take a phenomenon-based approach to describe the important trends and challenges affecting the where, who, how and why of global work. As we highlight implications for organizations and individuals, we offer a set of research questions to guide future research and inform IHRM practitioners.
Considerable effort has been put forth to understand mechanisms by which the microbiota modulates and responds to inflammation. Here, we explored whether oxidation metabolites produced by the host during inflammation, sodium nitrate and trimethylamine oxide, impact the composition of a human stool bacterial population in a gut simulator. We then assessed whether an immune-competent in vitro intestinal model responded differently to spent medium from bacteria exposed to these cues compared to spent medium from a control bacterial population. The host-derived oxidation products were found to decrease levels of Bacteroidaceae and overall microbiota metabolic potential, while increasing levels of proinflammatory Enterobacteriaceae and lipopolysaccharide in bacterial cultures, reflecting shifts that occur in vivo in inflammation. Spent microbiota media induced elevated intracellular mucin levels and reduced intestinal monolayer integrity as reflected in transepithelial electrical resistance relative to fresh medium controls. However, multiplexed cytokine analysis revealed markedly different cytokine signatures from intestinal cultures exposed to spent medium with added oxidation products relative to spent control medium, while cytokine signatures of cultures exposed to fresh media were similar regardless of addition of host-derived cues. Further, the presence of immune cells in the intestinal model was required for this differentiation of cytokine signatures. This study indicates that simple in vitro immune-competent intestinal models can capture bacterial-mammalian cross-talk in response to host-derived oxidation products and supports utility of these systems for mechanistic studies of interactions between the gut microbiome and host in inflammation.
We present the magnetic, structural and ⁵⁷Fe Mossbauer characterization of soils collected from an ancient mercury contaminated city named Huancavelica in Peru. The characterization results indicate that silicates and carbonates are the main mineralogical constituents in the samples. In addition, ⁵⁷Fe Mössbauer spectra at room temperature reveal, the presence of two components: a magnetic component related to magnetic Fe-oxides (magnetite, hematite, goethite) and a high non-magnetic component related to Fe⁺³ in high spin configuration and tetrahedral coordination in silicates. The magnetization measurements present screening of paramagnetic, ferromagnetic and antiferromagnetic signals, typical from soils containing different silicates and iron minerals. Remarkably the Verwey and Morin transitions corresponding to magnetite and hematite, respectively, are screened by the paramagnetic signal corresponding to the major silicate components in the samples. Overall, the soils are mainly composed of crystalline and amorphous silicates, calcites and iron bearing which are typical from Andean soils.
Background Little is known about voluntary divestment of firearms among US firearm owners. Here, we aim to estimate the proportion of handgun owners who divest their handguns in the years following their initial acquisition; examine the timing, duration, and dynamics of those divestments; and describe characteristics of those who divest. Methods We use data from the Longitudinal Study of Handgun Ownership and Transfer, a cohort of registered voters in California with detailed information on 626,756 adults who became handgun owners during the 12-year study period, 2004–2016. For the current study, persons were followed from the time of their initial handgun acquisition until divestment, loss to follow-up, death, or the end of the study period. We describe the cumulative proportion who divest overall and by personal and area-level characteristics. We also estimate the proportion who reacquired handguns among persons who divested. Results Overall, 4.5% (95% CI 4.5–4.6) of handgun owners divested within 5 years of their first acquisition, with divestment relatively more common among women and among younger adults. Among those who divested, 36.6% (95% CI 35.8–37.5) reacquired a handgun within 5 years. Conclusions Handgun divestment is rare, with the vast majority of new handgun owners retaining them for years.
Background: Differences in face processing in individuals with ASD is hypothesized to impact the development of social communication skills. This study aimed to characterize the neural correlates of face processing in 12-month-old infants at familial risk of developing ASD by (1) comparing face-sensitive event-related potentials (ERP) (Nc, N290, P400) between high-familial-risk infants who develop ASD (HR-ASD), high-familial-risk infants without ASD (HR-NoASD), and low-familial-risk infants (LR), and (2) evaluating how face-sensitive ERP components are associated with development of social communication skills. Methods: 12-month-old infants participated in a study in which they were presented with alternating images of their mother's face and the face of a stranger (LR = 45, HR-NoASD = 41, HR-ASD = 24) as EEG data were collected. Parent-reported and laboratory-observed social communication measures were obtained at 12 and 18 months. Group differences in ERP responses were evaluated using ANOVA, and multiple linear regressions were conducted with maternal education and outcome groups as covariates to assess relationships between ERP and behavioral measures. Results: For each of the ERP components (Nc [negative-central], N290, and P400), the amplitude difference between mother and stranger (Mother-Stranger) trials was not statistically different between the three outcome groups (Nc p = 0.72, N290 p = 0.88, P400 p = 0.91). Marginal effects analyses found that within the LR group, a greater Nc Mother-Stranger response was associated with better expressive language skills on the Mullen Scales of Early Learning, controlling for maternal education and outcome group effects (marginal effects dy/dx = 1.15; p < 0.01). No significant associations were observed between the Nc and language or social measures in HR-NoASD or HR-ASD groups. In contrast, specific to the HR-ASD group, amplitude difference between the Mother versus Stranger P400 response was positively associated with expressive (dy/dx = 2.1, p < 0.001) and receptive language skills at 12 months (dy/dx = 1.68, p < 0.005), and negatively associated with social affect scores on the Autism Diagnostic Observation Schedule (dy/dx = - 1.22, p < 0.001) at 18 months. Conclusions: In 12-month-old infant siblings with subsequent ASD, increased P400 response to Mother over Stranger faces is positively associated with concurrent language and future social skills.
The primary process in an electrical arc furnace (EAF) during industrial steelmaking results in tons of black slags which cause pollution to the environment. In this work, the iron oxides of black slags generated in the EAF from the SIDERPERU plant, Peru was reduced via the carbothermal reaction. The reduction of the black slag to α-Fe is demonstrated by X-ray diffraction, Mӧssbauer spectroscopy and magnetometry. However, phases with calcium and silicon persist in the sample after the carbothermal process. The thermodynamic calculations of the most probable reactions sequence were performed to understand the reduction process. The magnetometry measurements confirm the presence of ferromagnetic domains, supporting the success of the reduction of the black slag to α-Fe. The reduced black slags were recycled into a HRB335 steel rod by consolidation and extrusion processes and inspected by X-ray fluorescence.
Background Intravitreal injections (IVIs), a common treatment in ophthalmology, result in acute complications and urgent follow-up visits causing significant burden to both patient and physician. We evaluated the incidence of acute complications following IVIs which occurred within seven days of injection. Methods A retrospective cohort study conducted at a private retinal practice, in Cleveland, Ohio. Using the practice management software database, we examined 73,286 injections of patients with unscheduled or urgent visits within 7 days of an injection from August 1st,2018 to August 1st,2020. Data collected included: age, gender, eye, medication injected, diagnosis, reason for urgent follow-up, time between injection and urgent follow-up, and type of anesthesia administered. Data was analyzed using SPSS v.28 (SPSS Inc., Chicago IL). Results Study included 73,286 injections, with 441 injections (n = 441) resulting in urgent follow-up visits (0.60%). Mean patient age was 72.1 (± 30.4) years, with 187 male (42.4%) and 254 female (57.6%) patients. IVI medications included: aflibercept (60.3%), ranibizumab (22.4%), bevacizumab (13.4%), dexamethasone intravitreal implant (2%), triamcinolone acetonide (1.6%) brolucizumab (1.59%), fluocinolone acetonide intravitreal implant 0.19 mg (0.2%), and fluocinolone acetonide intravitreal implant 0.18 mg (0.03%) (Table 1). Medications associated with urgent visits included: aflibercept (42.9%), bevacizumab (37.4%), ranibizumab (7.9%), dexamethasone intravitreal implant (6.8%), brolucizumab (2.7%), and triamcinolone acetonide (2.3%) (Table 2). Days between injection and urgent follow-up was on average 3.96 ± 2.14 days. Urgent follow-ups included blurred vision in 164 patients (37.2% of urgent visits), flashes, floaters or posterior vitreous detachment (PVD) in 55 (12.5%), pain in 42 (9.5%), 43 (9.8%) corneal abrasions, 33 (7.5%) subconjunctival hemorrhages, corneal dryness or foreign body sensation in 30 (6.6%), endophthalmitis in 20 (4.5%), 18 (4.1%)vitreous hemorrhages, iritis or uveitis in 11 (2.5%), miscellaneous complications in 9 (2.0%), 7 (1.6%) elevated intraocular pressures, choroidal neovascular membrane in 4 (0.9%), 4 (0.9%) retinal detachments or tears, and 2 (0.45%) traumatic cataracts (Table 3). Conclusion IVIs resulted in 0.60% urgent/unscheduled follow-up visits within 7 days of injection. Most common causes were blurred vision and symptoms of PVD.
Conventional vision-based systems, such as cameras, have demonstrated their enormous versatility in sensing human activities and developing interactive environments. However, these systems have long been criticized for incurring privacy, power, and latency issues due to their underlying structure of pixel-wise analog signal acquisition, computation, and communication. In this research, we overcome these limitations by introducing in-sensor analog computation through the distribution of interconnected photodetectors in space, having a weighted responsivity, to create what we call a computational photodetector. Computational photodetectors can be used to extract mid-level vision features as a single continuous analog signal measured via a two-pin connection. We develop computational photodetectors using thin and flexible low-noise organic photodiode arrays coupled with a self-powered wireless system to demonstrate a set of designs that capture position, orientation, direction, speed, and identification information, in a range of applications from explicit interactions on everyday surfaces to implicit activity detection.
Nowadays there is a high interest in the recovery of industrial steel waste into useful by-products. For that purpose, it is important to know the physical and chemical properties of steel slag in order to better understand its characteristics and thus seek applications. In this work, we study primary steel slag formed in an electric arc furnace (EAF). Here we present the structural characterization and magnetic properties of the slag performed by X-ray fluorescence spectroscopy (XRF), X-ray diffractometry (XRD), scanning electron microscopy (SEM), magnetic measurements and Mössbauer spectroscopy. The elements Zn, Fe, Cl, Ca, and K and the phases Fe3O4, Zn5(OH)8Cl2.H2O, ZnO, and KCl were identified by XRF and XRD, respectively. Mössbauer spectroscopy at room temperature shows one doublet typical for Fe²⁺, and sextets corresponding to Fe3O4, and Fe2O3. ⁵⁷Fe-Mössbauer spectroscopy appears as a necessary tool in metallurgical slag research.
The steel industry produces large amounts of slag coming from different stages during the steelmaking process every year. Currently, there are numerous attempts to recycle it or to use it in some other industry sectors and to preserve the environment. The characteristics of the slag depends on the steelmaking process and it is crucial to have it before any attempt of recycling. In this work, slag sample produced in the ladle furnace from SIDERPERU steel plant were collected and analyzed by using energy dispersion X-ray (EDX), X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), SQUID magnetometer and Mössbauer spectroscopy. The chemical analysis obtained by EDX and XRF indicate that the main elemental composition of the material is Fe, Ca, Si and Cr. XRD identifies that these elements are in the phases: FeO, Fe3O4, α-Fe2O3, Ca2SiO4, and Ca2,32Mn0,68SiO7. Magnetometry measurements suggest the Verwey transition for magnetite and the Morin transition for hematite are screened by the presence of superparamagnetic phases. The Mössbauer spectrum shows two doublets related to Fe²⁺ and Fe³⁺ ions with hyperfine parameters belonging to that of non-stoichiometric wustite. Also, the presence of hyperfine fields characteristic of the Fe3O4 and Fe2O3 phase identified at room temperature verifies the magnetometry analysis. The analysis of the sample used in this work reveals details connected with the steel fabrication processes and are helpful for posterior recycling attempts.
The axial loading in rockbolts changes due to stress redistribution and rheology in the country rock mass. Such a change may lead to debonding at rockbolt to grout interface or rupture of the rockbolt. In this study, based on laboratory experiments, ultrasonic guided wave propagation in fully grouted rockbolt under different pull-out loads was investigated in order to examine the resultant debonding of rockbolt. The signals obtained from the ultrasonic monitoring during the pull-out test were processed using wavelet multi-scale analysis and frequency spectrum analysis, the signal amplitude and the amplitude ratio ( Q ) of low frequency to high frequency were defined to quantify the debonding of rockbolt. In addition to the laboratory test, numerical simulation on the effect of the embedment lengths on ultrasonic guided wave propagation in rockbolt was conducted by using a damage-based model, and the debonding between rockbolt and cement mortar was numerically examined. It was confirmed that the ultrasonic guided wave propagation in rockbolt was very sensitive to the debonding because of pull-out load, therefore, the critical bond length could be calculated based on the propagation of guided wave in the grouted rockbolt. In time domain, the signal amplitude in rockbolt increased with pull-out load from 0 to 100 kN until the completely debonding, thus quantifying the debonding under the different pull-out loads. In the frequency domain, as the Q value increased, the debonding length of rockbolt decreased exponentially. The numerical results confirmed that the guided wave propagation in the fully grouted rockbolt was effective in detecting and quantifying the debonding of rockbolt under pull-out load.
A compelling demand exists for high-performance high-temperature shape memory alloys (HTSMAs) that can be applied as intelligent components in the rapidly developing aerospace, robotics, manufacturing, and energy exploration industries. However, existing HTSMAs are handicapped by their high cost and unsatisfactory functional properties, which impede their practical application. Here, by using the strategy of creating an oligocrystalline structure, we have developed a high-performance, cost-effective high-temperature shape memory microwire exhibiting an exceptional combination of superb superelasticity with a large recoverable strain of up to 15%, an outstanding one-way shape memory effect with a maximum recoverable strain as high as 13% and a remarkable two-way shape memory effect with a large recoverable strain of 6.3%. These unparalleled comprehensive properties provide this microwire with a high potential for use in high-temperature actuation, sensing, and energy conversion applications, especially in miniature intelligent devices, such as high-temperature microelectromechanical systems. The present strategy may be universally applicable to other brittle phase-transforming alloys for achieving outstanding functional properties at high temperatures.
Every year, the steelmaking industry produces millions of tons of slags resulting in pollution to the environment. Among the waste, secondary metals and scales rich in iron oxides are also thrown away. There is a need to treat the steel waste in a reasonably way to protect the environment and proposing new cheap technologies for producing advanced materials. In this study we report the morphological and structural characterization of waste scales generated during roll milling steel process at JSC “Arcelor Mittal Temirtau”. The raw slag and annealed at 1000 °C were measured by X-ray diffraction (XRD), scanning electron microscopy adapted with energy dispersive X-ray (SEM- EDX), magnetometry and Mössbauer Spectroscopy (MS). Fe and O were detected by EDX as main chemical elements and Si, S, Ca, Mg, C and Al as minimal elemental composition. XDR for the raw sample revealed α-Fe 2 O 3 (hematite) and Fe 3 O 4 (magnetite) as principal and secondary phase, respectively; whereas monophasic α-Fe 2 O 3 is detected for the scales annealed at 1000 °C. Magnetometry measurements show the Verwey transition for the raw sample and the Morin transition for the annealed at 1000 °C; those are fingerprints for the presence of magnetite and hematite, respectively. MS measurements for the raw sample consist of 6 small peaks of absorption and a broad two-lines absorption peak in the central part. The doublets are associated to the hyperfine parameters belonging to wustite. Magnetite is related to the hyperfine parameters for two sextets in octahedral Fe 2.5+ and tetrahedral Fe ³⁺ sites and a small sextet that resembles the Mössbauer parameters of α-Fe 2 O 3 . Only a well crystallized and weakly ferromagnetic sextet confirm the presence of α-Fe 2 O 3 phase for the sample annealed at 1000 °C due to thermal oxidation.
Personalized medicine promises individualized disease prediction and treatment. The convergence of machine learning (ML) and available multimodal data is key moving forward. We build upon previous work to deliver multimodal predictions of Parkinson’s disease (PD) risk and systematically develop a model using GenoML, an automated ML package, to make improved multi-omic predictions of PD, validated in an external cohort. We investigated top features, constructed hypothesis-free disease-relevant networks, and investigated drug–gene interactions. We performed automated ML on multimodal data from the Parkinson’s progression marker initiative (PPMI). After selecting the best performing algorithm, all PPMI data was used to tune the selected model. The model was validated in the Parkinson’s Disease Biomarker Program (PDBP) dataset. Our initial model showed an area under the curve (AUC) of 89.72% for the diagnosis of PD. The tuned model was then tested for validation on external data (PDBP, AUC 85.03%). Optimizing thresholds for classification increased the diagnosis prediction accuracy and other metrics. Finally, networks were built to identify gene communities specific to PD. Combining data modalities outperforms the single biomarker paradigm. UPSIT and PRS contributed most to the predictive power of the model, but the accuracy of these are supplemented by many smaller effect transcripts and risk SNPs. Our model is best suited to identifying large groups of individuals to monitor within a health registry or biobank to prioritize for further testing. This approach allows complex predictive models to be reproducible and accessible to the community, with the package, code, and results publicly available.
Background Mass spectrometry imaging (MSI) derives spatial molecular distribution maps directly from clinical tissue specimens and thus bears great potential for assisting pathologists with diagnostic decisions or personalized treatments. Unfortunately, progress in translational MSI is often hindered by insufficient quality control and lack of reproducible data analysis. Raw data and analysis scripts are rarely publicly shared. Here, we demonstrate the application of the Galaxy MSI tool set for the reproducible analysis of a urothelial carcinoma dataset. Methods Tryptic peptides were imaged in a cohort of 39 formalin-fixed, paraffin-embedded human urothelial cancer tissue cores with a MALDI-TOF/TOF device. The complete data analysis was performed in a fully transparent and reproducible manner on the European Galaxy Server. Annotations of tumor and stroma were performed by a pathologist and transferred to the MSI data to allow for supervised classifications of tumor vs. stroma tissue areas as well as for muscle-infiltrating and non-muscle infiltrating urothelial carcinomas. For putative peptide identifications, m/z features were matched to the MSiMass list. Results Rigorous quality control in combination with careful pre-processing enabled reduction of m/z shifts and intensity batch effects. High classification accuracy was found for both, tumor vs. stroma and muscle-infiltrating vs. non-muscle infiltrating urothelial tumors. Some of the most discriminative m/z features for each condition could be assigned a putative identity: stromal tissue was characterized by collagen peptides and tumor tissue by histone peptides. Immunohistochemistry confirmed an increased histone H2A abundance in the tumor compared to the stroma tissues. The muscle-infiltration status was distinguished via MSI by peptides from intermediate filaments such as cytokeratin 7 in non-muscle infiltrating carcinomas and vimentin in muscle-infiltrating urothelial carcinomas, which was confirmed by immunohistochemistry. To make the study fully reproducible and to advocate the criteria of FAIR (findability, accessibility, interoperability, and reusability) research data, we share the raw data, spectra annotations as well as all Galaxy histories and workflows. Data are available via ProteomeXchange with identifier PXD026459 and Galaxy results via . Conclusion Here, we show that translational MSI data analysis in a fully transparent and reproducible manner is possible and we would like to encourage the community to join our efforts.
Background Multiple myeloma (MM) predominantly affects older patients; many of whom do not undergo autologous hematopoietic stem cell transplant (AHSCT) despite the associated survival benefits. This study was conceived to investigate the patterns of AHSCT among MM patients with due regard to their age and standardized fitness assessments. Methods Fitness scores as per the hematopoietic stem cell transplant-comorbidity index (HSCT-CI) and risk scores as per the revised-myeloma comorbidity index (R-MCI) of MM patients treated between January 2017 and December 2019 were analyzed to assess fitness for AHSCT. Proportions of patients who underwent AHSCT were calculated with regard to age and fitness for AHSCT. Results Of the 81 eligible patient records with a median age of 62 years, the HSCT-CI classified 79.6% and 77.8% of patients aged ≤65 years and >65 years as AHSCT eligible (p 1). Using the R-MCI, 96.3% and 81.5% of patients aged ≤65 years and >65 years, respectively, were classified as eligible for AHSCT ( p 0.0381). Overall, patients aged ≤65 years underwent AHSCT with a greater frequency compared to those aged >65years (38.9 vs. 14.8%, p 0.0402). Irrespective of the age group, there was a statistically significant difference ( p 0.0167) in terms of survival which favored those who underwent AHSCT. Conclusions Both the HSCT-CI and the R-MCI revealed that nearly 80% of patients aged >65 years were fit enough to receive AHSCT. However, far fewer patients of this age group underwent AHSCT. We propose that the routine inclusion of objective fitness assessment could ensure that fit older patients undergo AHSCT and thus do not miss out on the benefits of the same.
The length of flexible manipulators with a telescopic arm alters during movement. The dynamic parameters of telescopic flexible manipulators exhibit significant time-varying characteristics owing to variations in length. With an increase in the manipulators’ length, the nonlinear terms caused by flexibility in the manipulators’ dynamic equations cannot be ignored. The time-varying characteristics and nonlinear terms of telescopic flexible manipulators cause fluctuations in rotation angles, which affect the operation accuracy of end-effectors. In this study, a control strategy based on a combination of fuzzy adjustment and an RBF neural network is utilized to improve the control accuracy of flexible telescopic manipulators. First, the dynamic equation of the manipulators is established using the assumed mode method and Lagrange’s principle, and the influence of nonlinear terms is analyzed. Subsequently, a combined control strategy is proposed to suppress the fluctuation of the rotation angle in telescopic flexible manipulators. The variation ranges of the feedforward PD controller parameters are determined by the pole placement strategy and length of the manipulators. Fuzzy rules are utilized to adjust the controller parameters in real-time. The RBF neural network is utilized to identify and compensate the uncertain part of the dynamic model of the flexible manipulators. The uncertain part comprises time-varying parameters and nonlinear terms. Finally, numerical simulations and prototype experiments prove the effectiveness of the combined control strategy. The results prove that the proposed control strategy has a smaller standard deviation of errors. Therefore, the combined control strategy is more suitable for telescopic flexible manipulators, which can effectively improve the control accuracy of rotation angles.
Sixth-generation wireless networks will aggregate higher-than-ever mobile traffic into ultra-high capacity backhaul links, which could be deployed on the largely untapped spectrum above 100 GHz. Current regulations however prevent the allocation of large contiguous bands for communications at these frequencies, since several narrow bands are reserved to protect passive sensing services. These include radio astronomy and Earth exploration satellites using sensors that suffer from harmful interference from active transmitters. Here we show that active and passive spectrum sharing above 100 GHz is feasible by introducing and experimentally evaluating a real-time, dual-band backhaul prototype that tracks the presence of passive users (in this case the NASA satellite Aura) and avoids interference by automatically switching bands (123.5–140 GHz and 210–225 GHz). Our system enables wide-band transmissions in the above-100-GHz spectrum, while avoiding harmful interference to satellite systems, paving the way for innovative spectrum policy and technologies in these crucial bands.
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15,446 members
A. Das
  • Department of Physics
Sheeba Arnold
  • Department of Psychology
Ana Pastore y Piontti
  • Department of Physics
Edgar Goluch
  • Department of Chemical Engineering
Paolo Ciuccarelli
  • Department of Art and Design
Huntington Ave, 02115, Boston, MA, United States
Head of institution
Daddy Aoun