Interventional Assessments of Motor Function in Middle-Aged and Older Adults

This dissertation comprises four experimental studies investigating interventions andassessments for motor performance in dancers, middle-aged, and older adults. Two studies evaluated transcutaneous electrical nerve stimulation (TENS) for influencing motor performance and adaptation and two studies assessed balance control in older adults. In the first study, TENS was applied to the hamstring muscles of high-level dancers as they completed a body-weight resistance training regimen. No greater improvements in balance or strength were observed in dancers who received TENS compared with dancers who received Sham TENS. This finding suggests that the benefits of supplemental TENS may be limited to middle-aged or older adults not engaged in regular physical training as well as individuals with neurological impairments. The subsequent study examined how continuous and bursting TENS applied to the quadriceps and tibialis anterior muscles influenced 6-min walk distance in middle-aged adults. Both forms of bursting TENS resulted in greater distances walked than continuous TENS and no TENS. Additionally, several walking kinematic variables adjusted with changing walking speeds independent of TENS condition. The final two studies assessed how tempo-controlled resistance training of hip abductors or ankle dorsiflexors influence postural control in older adults as well as how muscle function and accelerometer-based variables can predict postural sway measured from center of pressure. Neither training of the hip abductors nor the ankle dorsiflexors improved balance control in older adults. However, there were several tests of muscle function as well as multiple accelerometer-based variables that could significantly predict postural sway in older adults. Further, we have expanded on the application of Romberg Quotients for inferring sensory contributions to postural control by comparing multiple balance conditions and determining the agreement of Romberg Quotients calculated from different balance variables. This dissertation builds on the application of interventions for improving motor performance as well as specific assessments of motor function in middle-aged and older adults.</p

Dimensional perturbation theory of the two-electron atom for states with arbitrary angular momentum.

Dimensional Perturbation Theory (DPT) has been applied to many systems including the hydrogen atom, hydrogen atom in a magnetic field, H+2 molecule and the helium atom. Only S-wave states, and interdimensionally degenerate Pe states, have, up until now, been studied for the helium atom. Here we outline the procedures and discuss the results of a formalism that generalizes the Schwartz expansion of the wavefunction to N-electrons with arbitrary total orbital angular momentum and arbitrary spatial dimension. We present results specifically for 1,3Po states of helium and their interdimensionally degenerate 3,1 Do counterparts

Marcadores hormonales y obesidad en caninos

La obesidad, ya sea canina o humana, ha incrementado su prevalencia en los últimos años a pesar de los esfuerzos realizados por combatirla. Teniendo en cuenta la estrecha relación entre los caninos y los humanos, y que los caninos son un reflejo de los hábitos de los humanos, consideramos que el mejorar e incrementar el conocimiento en obesidad canina es un beneficio tanto para la medicina veterinaria como humana. Por otro lado, hoy en día no contamos con un método objetivo para determinar la adiposidad ni sus repercusiones en la clínica diaria. En este sentido, nuestro trabajo busca contribuir al conocimiento de la regulación endócrina de la obesidad canina y su asociación con el ORMD. Para esto, hemos seleccionado 84 caninos provenientes de tutores particulares, a los cuales clasificamos de acuerdo a su condición corporal en normopesos (CC 4-5/9, n=33), sobrepesos (CC 6-7/9, n=28) y obesos (CC 8-9/9, n=23), determinamos la presión arterial y tomamos muestras de sangre y orina para su estudio hematológico, bioquímico (glucemia, triglicéridos, perfil renal, funcional hepático y fracciones del colesterol) y urianálisis. Por otro lado, valoramos determinaciones hormonales como son perfil tiroideo (T4 total, T4 libre, TSH), cortisol basal, insulina, IGF-1, GLP-1, las adipoquinas leptina, adiponectina y resistina y las citoquinas TNF-α e IL-6. A su vez, de los 84 caninos que formaron parte del estudio seleccionamos a los que obtuvieron una CC entre 7 y 9 inclusive y definimos a los positivos a ORMD como los que presentaban 2 o más de las siguientes características: hipertensión arterial (>160 mmHg), hiperglucemia (>100 mg/dL), hipertrigliceridemia (>200 mg/dL) y/o hipercolesterolemia (>300 mg/dL). Posteriormente, comparamos los caninos positivos y negativos en las variables fisiológicas, hematológicas, bioquímicas, de uroanálisis y hormonales descritas anteriormente. Hemos observado que los pacientes obesos presentan alteraciones a nivel fisiológico y del metabolismo glucídico, lipidico, proteico y del funcionamiento renal. Hallamos que los caninos obesos presentan mayor presión arterial sistólica y concentraciones superiores de resistina, glucemia, insulina, índices HOMA, triglicéridos, proteínas totales, globulinas, VLDL-c, leucocitos y neutrófilos. Por otro lado, presentaron menores concentraciones de HDL-c, relación HDL/LDL, creatinina sérica y densidad urinaria. Los pacientes positivos a ORMD resultaron ser un 18% (teniendo en cuenta que el total son 39 caninos con CC entre 7 y 9). En estos pacientes observamos concentraciones superiores de glucemia, triglicéridos, proteínas totales, globulinas, leucocitos, linfocitos absolutos, PAS, HDL-c, LDL-c y relación HDL/LDL. Podemos concluir que la obesidad canina repercute a varios niveles, principalmente en el metabolismo glucídico y lipídico, generándose un estado de resistencia a la insulina e hiperinsulinemia compensatoria, lo que permite que los caninos mantengan los valores de glucemia dentro de los rangos de referencia. Por otro lado, observamos que el 18% de los caninos obesos presenta ORMD, el cual se asocia a parámetros hematológicos y bioquímicos, principalmente a un aumento de linfocitos absolutos y alteración en las fracciones del colesterol

Temporal integration and 1/f power scaling in a circuit model of cerebellar interneurons

This document is the Accepted Manuscript version of a published work that appeared in final form in Journal of Neurophysiology after peer review and technical editing by the publisher. Under embargo until 1 July 2018. To access the final edited and published work see: https://doi.org/10.1152/jn.00789.2016.Inhibitory interneurons interconnected via electrical and chemical (GABAA receptor) synapses form extensive circuits in several brain regions. They are thought to be involved in timing and synchronization through fast feedforward control of principal neurons. Theoretical studies have shown, however, that whereas self-inhibition does indeed reduce response duration, lateral inhibition, in contrast, may generate slow response components through a process of gradual disinhibition. Here we simulated a circuit of interneurons (stellate and basket cells) of the molecular layer of the cerebellar cortex and observed circuit time constants that could rise, depending on parameter values, to >1 s. The integration time scaled both with the strength of inhibition, vanishing completely when inhibition was blocked, and with the average connection distance, which determined the balance between lateral and self-inhibition. Electrical synapses could further enhance the integration time by limiting heterogeneity among the interneurons and by introducing a slow capacitive current. The model can explain several observations, such as the slow time course of OFF-beam inhibition, the phase lag of interneurons during vestibular rotation, or the phase lead of Purkinje cells. Interestingly, the interneuron spike trains displayed power that scaled approximately as 1/f at low frequencies. In conclusion, stellate and basket cells in cerebellar cortex, and interneuron circuits in general, may not only provide fast inhibition to principal cells but also act as temporal integrators that build a very short-term memory.NEW & NOTEWORTHY The most common function attributed to inhibitory interneurons is feedforward control of principal neurons. In many brain regions, however, the interneurons are densely interconnected via both chemical and electrical synapses but the function of this coupling is largely unknown. Based on large-scale simulations of an interneuron circuit of cerebellar cortex, we propose that this coupling enhances the integration time constant, and hence the memory trace, of the circuit.Peer reviewe

Hybridizing the health education component of healthcare

This disquisition employed a “dissertation in practice” (Carnegie Project on the Education Doctorate, 2021) model, wherein scholar-practitioners in EdD programs lead an organizational improvement initiative that seeks to address an equity-oriented problem of practice. For this disquisition, two interrelated problems were addressed. Problem one (framed as an institutional problem) is related to the suboptimal value offered by the healthcare system in the United States (U.S.). Problem two, (framed as a human problem), explores the lack of access provided to migrant and seasonal agricultural workers (MSAW) to preventative musculoskeletal (MSK) health education. This disquisition suggests that the value of healthcare, defined simply by Porter and Teisberg (2006) as health outcomes per dollar spent, and access to valuable health education could be improved in the U.S. and beyond by systemizing the delivery of health education in a hybridized manner that combines traditional face-to-face (FtF) delivery with digital and electronic mediums. The improvement initiative included the use of a learning management system (LMS) to disseminate the health education/courses intended for MSAW and other stakeholders involved in agricultural health. To explore the effectiveness of the LMS toward increased healthcare access and value, formative and summative data were collected through post course surveys, pretest/posttest assessment of learning, course utilization analytics built into the LMS, and semi-structured interviews with key stakeholders in agricultural health. Implications of the initiative in the global context include the potential to improve the value of healthcare through more effective health education and better health outcomes at lower costs. Implications in the context of MSAW MSK health include the potential to improve (a) knowledge and confidence related to prevention and self-care of musculoskeletal health conditions common in agriculture, (b) access to, awareness of, and utilization of evidence-informed health education that emphasizes prevention and self-care related to musculoskeletal health issues associated with agricultural work, and (c) the value of health education estimated by learning outcomes and learner perceptions

Physiological effects of lung protective ventilation in patients with lung fibrosis and usual interstitial pneumonia pattern versus primary ARDS: a matched-control study.

Background- Although patients with interstitial pneumonia pattern (ILD-UIP) and acute exacerbation (AE) leading to severe acute respiratory failure may require invasive mechanical ventilation (MV), physiological data on lung mechanics during MV are lacking. We aimed at describing the physiological effect of lung protective ventilation in patients with AE-ILD-UIP compared with primary ARDS. Methods- Partitioned lung and chest wall mechanics were assessed in a series of AE-ILD-UIP patients matched 1:1 with primary ARDS as controls (based on BMI and PaO2/FiO2 ratio). Three PEEP levels (zero=ZEEP, 4-8 cmH2O=PEEPLOW, and titrated to achieve positive end-expiratory transpulmonary pressure-PL,EE=PEEPTITRATED) were used for measurements. Results- Ten AE-ILD-UIP patients and 10 matched ARDS were included. In AE-ILD-UIP median PL,EE at ZEEP was - 4.3 [-7.6 – -2.3] cmH2O and lung elastance (EL) 44 [40 – 51] cmH2O/L. At PEEPLOW, PL,EE remained negative and EL did not change (p=0.995) versus ZEEP. At PEEPTITRATED, PL,EE increased to 0.8 [0.3 – 1.5] cmH2O and EL to 49 [43 – 59] (p=0.004 and p&lt;0.001 compared to ZEEP and PEEPLOW, respectively). PL decreased at PEEPLOW (p=0.018) and increased at PEEPTITRATED (p=0.003). In matched ARDS control PEEP titration to obtain a positive PL,EE did not result in significant changes in EL and PL. Conclusions- In mechanically ventilated AE-ILD-UIP patients, differently than in patients with primary ARDS, PEEP titrated to obtain a positive PL,EE significantly worsened lung mechanics

piani di azionariato dei dipendenti in Italia: casi empirici

la tesi tratta del tema dell'azionariato dei dipendenti. Il primo capitolo espone le definizioni di democrazia economica e partecipazione dei lavoratori e le correnti ideologiche e eventi storici caratterizzanti l'evoluzione del tema. il secondo capitolo illustra le normative di riferimento in Italia, attuali e in una prospettiva de iure condendo. Il terzo capitolo tratta del capitalismo condiviso con particolare enfasi data alla descrizione dell'employee ownership. Il quarto capitolo illustra i piani di azionariato di Unicredit, Intesa Sanpaolo, Telecom Italia e Prysmian: da una breve analisi comparativa emerge che sono le variabili economiche ad influenzare maggiormente la decisione dei dipendenti di aderire al piano, allo stesso tempo sembra che la partecipazione alle assemblee ordinarie delle società aumenti in concomitanza dell'implementazione di piani di azionariato per i dipendenti broad-based

Sviluppo di peptidi marcati con Fluoro-18 per una potenziale applicazione nella diagnosi dell'Amiloidosi cardiaca mediante Tomografia ad emissione di positroni

Le amiloidosi sono un insieme eterogeneo di malattie, localizzate o sistemiche, acquisite o ereditarie, caratterizzate dall’accumulo di depositi proteici, chiamati amiloidi, nei tessuti dell’organismo. Le manifestazioni cliniche di questa patologia variano a seconda dell’organo colpito e del precursore proteico implicato nella formazione degli amiloidi. Il coinvolgimento cardiaco si riscontra nelle tre maggiori tipologie di amiloidosi sistemiche: amiloidosi da catene leggere monoclonali (AL), amiloidosi ereditaria da transtiretina (ATTR) e l’amiloidosi senile (SSA). Questa complicanza ha un impatto molto sfavorevole nella prognosi, portando alla morte la maggior parte dei pazienti nel giro di pochi mesi dalla diagnosi. La valutazione clinica dell’Amiloidosi cardiaca (AC) risulta difficile perché i sintomi sono comuni ad altre forme di cardiopatia e si palesano solo nelle fasi più avanzate della malattia. Nel tentativo di rendere la diagnosi sempre più precoce e accurata sono state prese in considerazione molte metodiche diagnostiche strumentali. Tra queste, le metodiche diagnostiche medico- nucleare (PET, SPECT) forniscono uno strumento con notevoli potenzialità per superare i limiti diagnostici attuali e possibilmente identificare e quantificare precocemente i depositi amiloidi. Questo è possibile grazie all’utilizzo di molecole radiomarcate, che forniscono segnali rilevabili al di là della barriera fisica costituita dal corpo umano e consentono di individuare l’infiltrazione miocardica in maniera non invasiva e potenzialmente prima della comparsa di evidenze cliniche. Negli anni molti sforzi sono stati rivolti alla ricerca di marcatori molecolari in grado di rilevare con alta sensibilità e specificità i depositi amiloidi cardiaci, ma, ad oggi, ancora nessun tracciante è stato approvato per l’indagine di AC. Tra le molecole che hanno mostrato un elevata affinità per gli amiloidi cardiaci, spicca l’Aprotinina, marcata con 99mTc per SPECT imaging. Si tratta di una proteina ad attività anti serin-proteasica, le cui proprietà chimiche e strutturali la rendono un ligando selettivo per le fibrille, sia nelle amiloidosi AL che ATTR. Lo scopo della tesi è quello di sviluppare un piccolo peptide (25-mer), costruito sulla base della struttura dell’Aprotinina, opportunamente funzionalizzato in modo da renderlo marcabile con fluoro-18, per valutarne in prospettiva l'impiego nella diagnosi dell’Amiloidosi cardiaca mediamte tomografia ad emissione di positroni (PET). Questa tecnica di imaging consente di ottenere informazioni quantitative dello stato di malattia ed immagini e con una miglior risoluzione spaziale rispetto alla SPECT, soprattutto grazie alle caratteristiche fisiche del radionuclide 18F, che si vuole impiegare. L'attività sperimentale condotta nel lavoro di tesi parte quindi dalla progettazione e de-novo sintesi di una prima sequenza amminoacidica, basata sul frammento ciclico dell’Aprotinina 30-51aa, legato ad una Lisina-azide, tramite una sequenza di tre Glicine. In seguito è stata progettata e sintetizzata una seconda sequenza, simile alla prima, in cui è stata leggermente modificata la sequenza in vista di una migliore stabilità e gestibilità in fase di ciclizzazione. La sintesi peptidica è stata effettuata in fase solida, utilizzando la chimica Fmoc e amminoacidi opportunamente protetti. La prima sequenza è stata sintetizzata usando un approccio manuale, la seconda avvalendosi di un sintetizzatore automatico a microonde. La funzionalizzazione dei peptidi con un'azide ha permesso l'adozione di una strategia di marcatura altamente selettiva attraverso la reazione di cicloaddizione 1,3-dipolare (click-chemistry) catalizzata da rame(I) con un sintone 5-[18F]-fluoro-1-pentino, preparato allo scopo. Il triazolo formatosi nella reazione di click è ottenibile con alte rese ed in tempi brevi, perfettamente adeguati alla breve emivita del fluoro-18 (109 min). Inoltre questa reazione gode di elevato grado di biortogonalità, risultando molto stabile in vivo. La sintesi del 5-[18F]-fluoro-1-pentino è stata messa a punto impiegando una piattaforma di sintesi microfluidica, mediante sostituzione nucleofila del corrispondente tosilato. Tutti i passaggi sintetici sono stati controllati (resa e purezza chimica/radiochimica) mediante analisi HPLC, TLC e MS. L'attività specifica del prodotto finale è stata valutata mediante HPLC impiegando il prodotto freddo (19F) preparato seguendo la stessa procedura