scholarly journals Design of a Passive Ankle Prosthesis With Energy Return That Increases With Increasing Walking Velocity

Author(s):  
Alexander J. Folz ◽  
Joseph M. Schimmels

An estimated 623,000 individuals are living with a major lower leg amputation in the United States [1]. Of these amputations, 78% were due to peripheral vascular disease (PVD) and 45% were due to PVD in individuals with type I or II diabetes [2]. With diabetes and PVD incidence levels on the rise [1] and those in a depressed socio-economic situation more susceptible to develop type II diabetes [3], the demand for affordable, high quality ankle prostheses has never been higher. Prostheses currently available on the market include both passive and active devices, neither of which fully satisfies user requirements. Passive prostheses, the more commonly prescribed style, are economically priced but lack the powered push-off observed in a natural ankle [4] due to the absence of an actuator. As a result, passive prostheses cause a multitude of quality of life detriments to the end user including asymmetrical gait (for unilateral amputees), slower self-selected walking speeds, higher metabolic cost per distance traveled and increased pain in the residual limb [5–6]. Conversely, active devices can nearly match the functionality and powered push-off of a natural ankle [7] but are cost prohibitive. Among active devices, one of the most successful models is the BiOM. Initially developed at MIT, the BiOM uses an actuator in series with a spring to achieve near natural ankle behavior. In 2013, two years after the product’s official launch, the device cost approximately $50,000 and had only sold about 1,000 units [7]. The limitations of currently available ankle prostheses motivates work on a new solution, the EaSY-Walk (Early Stance Y-deflection), a passive ankle device that mimics several key aspects of a natural ankle joint, especially nonlinear rotational stiffness and rotational work output (powered push-off) that increases with walking velocity while remaining relatively inexpensive.

Around the world, people nearing and entering retirement are holding ever-greater levels of debt than in the past. This is not a benign situation, as many pre-retirees and retirees are stressed about their indebtedness. Moreover, this growth in debt among the older population may render retirees vulnerable to financial shocks, medical care bills, and changes in interest rates. Contributors to this volume explore key aspects of the rise in debt across older cohorts, drill down into the types of debt and reasons for debt incurred by the older population, and review policies to remedy some of the financial problems facing older persons, in the United States and elsewhere. The authors explore which groups are most affected by debt, and they also identify the factors causing this important increase in leverage at older ages. It is clear that the economic and market environments are influential when it comes to saving and debt. Access to easy borrowing, low interest rates, and the rising cost of education have had important impacts on how much people borrow, and how much debt they carry at older ages. In this environment, the capacity to manage debt is ever more important as older workers lack the opportunity to recover for mistakes.


2015 ◽  
Vol 83 (10) ◽  
pp. 3890-3901 ◽  
Author(s):  
Prasun Moitra ◽  
Hong Zheng ◽  
Vivek Anantharaman ◽  
Rajdeep Banerjee ◽  
Kazuyo Takeda ◽  
...  

The intraerythrocytic apicomplexanBabesia microti, the primary causative agent of human babesiosis, is a major public health concern in the United States and elsewhere. Apicomplexans utilize a multiprotein complex that includes a type I membrane protein called apical membrane antigen 1 (AMA1) to invade host cells. We have isolated the full-lengthB. microtiAMA1 (BmAMA1) gene and determined its nucleotide sequence, as well as the amino acid sequence of the AMA1 protein. This protein contains an N-terminal signal sequence, an extracellular region, a transmembrane region, and a short conserved cytoplasmic tail. It shows the same domain organization as the AMA1 orthologs from piroplasm, coccidian, and haemosporidian apicomplexans but differs from all other currently known piroplasmida, including otherBabesiaandTheileriaspecies, in lacking two conserved cysteines in highly variable domain III of the extracellular region. Minimal polymorphism was detected in BmAMA1 gene sequences of parasite isolates from six babesiosis patients from Nantucket. Immunofluorescence microscopy studies showed that BmAMA1 is localized on the cell surface and cytoplasm near the apical end of the parasite. Native BmAMA1 from parasite lysate and refolded recombinant BmAMA1 (rBmAMA1) expressed inEscherichia colireacted with a mouse anti-BmAMA1 antibody using Western blotting.In vitrobinding studies showed that both native BmAMA1 and rBmAMA1 bind to human red blood cells (RBCs). This binding is trypsin and chymotrypsin treatment sensitive but neuraminidase independent. Incubation ofB. microtiparasites in human RBCs with a mouse anti-BmAMA1 antibody inhibited parasite growth by 80% in a 24-h assay. Based on its antigenically conserved nature and potential role in RBC invasion, BmAMA1 should be evaluated as a vaccine candidate.


2014 ◽  
Vol 104 (11) ◽  
pp. 3397-3433 ◽  
Author(s):  
Alberto Alesina ◽  
Eliana La Ferrara

We collect a new dataset on capital punishment in the United States and we propose a test of racial bias based upon patterns of sentence reversals. We model the courts as minimizing type I and II errors. If trial courts were unbiased, conditional on defendant's race the error rate should be independent of the victim's race. Instead we uncover 3 and 9 percentage points higher reversal rates in direct appeal and habeas corpus cases, respectively, against minority defendants who killed whites. The pattern for white defendants is opposite but not statistically significant. This bias is confined to Southern states. (JEL J15, K41, K42)


Plant Disease ◽  
2007 ◽  
Vol 91 (5) ◽  
pp. 517-524 ◽  
Author(s):  
Y. Tosa ◽  
W. Uddin ◽  
G. Viji ◽  
S. Kang ◽  
S. Mayama

Gray leaf spot caused by Magnaporthe oryzae is a serious disease of perennial ryegrass (Lolium perenne) turf in golf course fairways in the United States and Japan. Genetic relationships among M. oryzae isolates from perennial ryegrass (prg) isolates within and between the two countries were examined using the repetitive DNA elements MGR586, Pot2, and MAGGY as DNA fingerprinting probes. In all, 82 isolates of M. oryzae, including 57 prg isolates from the United States collected from 1995 to 2001, 1 annual ryegrass (Lolium multiflorum) isolate from the United States collected in 1972, and 24 prg isolates from Japan collected from 1996 to 1999 were analyzed in this study. Hybridization with the MGR586 probe resulted in approximately 30 DNA fragments in 75 isolates (designated major MGR586 group) and less than 15 fragments in the remaining 7 isolates (designated minor MGR586 group). Both groups were represented among the 24 isolates from Japan. All isolates from the United States, with the exception of one isolate from Maryland, belonged to the major MGR586 group. Some isolates from Japan exhibited MGR586 fingerprints that were identical to several isolates collected in Pennsylvania. Similarly, fingerprinting analysis with the Pot2 probe also indicated the presence of two distinct groups: isolates in the major MGR586 group showed fingerprinting profiles comprising 20 to 25 bands, whereas the isolates in the minor MGR586 group had less than 10 fragments. When MAGGY was used as a probe, two distinct fingerprint types, one exhibiting more than 30 hybridizing bands (type I) and the other with only 2 to 4 bands (type II), were identified. Although isolates of both types were present in the major MGR586 group, only the type II isolates were identified in the minor MGR586 group. The parsimony tree obtained from combined MGR586 and Pot2 data showed that 71 of the 82 isolates belonged to a single lineage, 5 isolates formed four different lineages, and the remaining 6 (from Japan) formed a separate lineage. This study indicates that the predominant groups of M. oryzae associated with the recent outbreaks of gray leaf spot in Japan and the United States belong to the same genetic lineage.


Author(s):  
Melissa Ames

While television has always played a role in recording and curating history, shaping cultural memory, and influencing public sentiment, the changing nature of the medium in the post-network era finds viewers experiencing and participating in this process in new ways. They skim through commercials, live tweet press conferences and award shows, and tune into reality shows to escape reality. This new era, defined by the heightened anxiety and fear ushered in by 9/11, has been documented by our media consumption, production, and reaction. In Small Screen, Big Feels, Melissa Ames asserts that TV has been instrumental in cultivating a shared memory of emotionally charged events unfolding in the United States since September 11, 2001. She analyzes specific shows and genres to illustrate the ways in which cultural fears are embedded into our entertainment in series such as The Walking Dead and Lost or critiqued through programs like The Daily Show. In the final section of the book, Ames provides three audience studies that showcase how viewers consume and circulate emotions in the post-network era: analyses of live tweets from Shonda Rhimes's drama, How to Get Away with Murder (2010--2020), ABC's reality franchises, The Bachelor (2002--present) and The Bachelorette (2003--present), and political coverage of the 2016 Presidential Debates. Though film has been closely studied through the lens of affect theory, little research has been done to apply the same methods to television. Engaging an impressively wide range of texts, genres, media, and formats, Ames offers a trenchant analysis of how televisual programming in the United States responded to and reinforced a cultural climate grounded in fear and anxiety.


1999 ◽  
Vol 2 (2) ◽  
pp. 47-56
Author(s):  
Alberto Zanzi ◽  
Colette Dumas

This comparative study of American and Italian family-owned firms focuses on two key aspects of family business management: succession and governance. This study also explored the impact of generation on these variables.


Author(s):  
Brendan J. Russo ◽  
Emmanuel James ◽  
Cristopher Y. Aguilar ◽  
Edward J. Smaglik

In the past two decades, cell phone and smartphone use in the United States has increased substantially. Although mobile phones provide a convenient way for people to communicate, the distraction caused by the use of these devices has led to unintended traffic safety and operational consequences. Although it is well recognized that distracted driving is extremely dangerous for all road users (including pedestrians), the potential impacts of distracted walking have not been as comprehensively studied. Although practitioners should design facilities with the safety, efficiency, and comfort of pedestrians in mind, it is still important to investigate certain pedestrian behaviors at existing facilities to minimize the risk of pedestrian–vehicle crashes, and to reduce behaviors that may unnecessarily increase delay at signalized intersections. To gain new insights into factors associated with distracted walking, pedestrian violations, and walking speed, 3,038 pedestrians were observed across four signalized intersections in New York and Arizona using high-definition video cameras. The video data were reduced and summarized, and an ordinary least squares (OLS) regression model was estimated to analyze factors affecting walking speeds. In addition, binary logit models were estimated to analyze both pedestrian distraction and pedestrian violations. Ultimately, several site- and pedestrian-specific variables were found to be significantly associated with pedestrian distraction, violation behavior, and walking speeds. The results provide important information for researchers, practitioners, and legislators, and may be useful in planning strategies to reduce or mitigate the impacts of pedestrian behavior that may be considered unsafe or potentially inefficient.


2020 ◽  
Author(s):  
Mbemba Jabbi ◽  
Wade Weber ◽  
Jeffrey Welge ◽  
Fabiano Nery ◽  
Maxwell Tallman ◽  
...  

ABSTRACTOver 2.3 million people in the United States live with bipolar disorder. Sixty percent of those with a bipolar disorder diagnosis attempt suicide at least once in their lifetime, and up to 19% die by suicide. However, the neurobiology of suicide attempts in bipolar disorder remains unclear. Here, we studied the neuroanatomical basis for suicide attempt history in bipolar disorder by measuring gray matter volumes (GMV) to identify differences in brain-volumes in 121 participants with bipolar disorder type I, and healthy participants (n=40). The bipolar group consisted of individuals with suicide attempt history (n=23) and no suicide attempt history (n=58). All participants completed behavioral/diagnostic assessments and MRI measures of GMV. We focused on a predefined frontolimbic circuitry in bipolar disorder versus (vs.) healthy to first identify diagnostic GMV markers and to specifically identify markers for suicide attempt history. We found reduced GMV markers for bipolar diagnosis (i.e., bipolar<healthy) in the anterior cingulate cortex (ACC), and dorsolateral prefrontal cortices (DLPFC). Our observed frontolimbic GMV abnormalities were associated with suicide attempt history and measures of individual variations in current suicidal ideation at the time of scanning. These results identified a frontolimbic-GMV marker for bipolar diagnosis and suicidal behavioral risk tendencies.HighlightsSuicide is a major health problem especially in bipolar disorder but the neurobiological basis for suicide attempts remains obscure. We identified an anterior cingulate and dorsolateral prefrontal cortical volume correlate for suicide attempt history and suicidal ideation and thereby demonstrates a convergent brain marker for suicidal behaviors.


2017 ◽  
Author(s):  
Donna Yates

PurposeTo discuss the key aspects of the international trade in antiquities and the practice of philanthropic donation of object to museums that allow for certain types of tax deduction manipulation using a case of tax deduction manipulation from Australia and a case of tax fraud from the United States as examples.Design/methodology/approachTwo thoroughly researched case studies are presented which illustrate the particular features of current and past antiquities donation incentivization schemes which leave them open to manipulation and fraud.FindingsThe valuation of antiquities is subjective and problematic and the operations of both the antiquities market and the museums sector are traditionally opaque. Because of this tax incentivisation of antiquities donations, is susceptible to fraud.Originality/valueThis paper presents the mechanisms of the antiquities market and museum world to an audience that is not familiar with it. It then clearly demonstrates how the traditional practices of this world can be manipulated for the purposes of tax fraud. Two useful case studies are presented and one of these case studies has never been academically published before, despite it being the cause for a change in Australian tax law.


Vaccines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 1360
Author(s):  
Oluwafemifola Oyedeji ◽  
Jill M. Maples ◽  
Samantha Gregory ◽  
Shauntá M. Chamberlin ◽  
Justin D. Gatwood ◽  
...  

About 45:000 cancers are linked to HPV each year in the United States alone. The HPV vaccine prevents cancer and is highly effective, yet vaccination coverage remains low. Pharmacies can play a meaningful role in increasing HPV vaccination access due to their availability and convenience. However, little is known about pharmacists’ perceived barriers to HPV vaccination. The objective of this systematic review was to summarize existing literature on perceived barriers to administering HPV vaccination reported by pharmacists. Barriers identified from selected studies were synthesized and further grouped into patient, parental, (pharmacist’s) personal, and system/organization barrier groups. Six studies were included in this review. The cost of the HPV vaccine, insurance coverage and reimbursement were commonly reported perceived barriers. Adolescent HPV vaccination barriers related to parental concerns, beliefs, and inadequate knowledge about the HPV vaccine. Perceived (pharmacist’s) personal barriers were related to lack of information and knowledge about HPV vaccine and recommendations. At the system/organization level, barriers reported included lack of time/staff/space; difficulty in series completion; tracking and recall of patient; perceived competition with providers; and other responsibilities/vaccines taking precedence. Future strategies involving pharmacy settings in HPV-related cancer prevention efforts should consider research on multilevel pharmacy-driven interventions addressing barriers.


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