Estimates of persistent inward current in human motor neurons during postural sway

Persistent inward current (PIC) is a membrane property critical for increasing gain of motor neuron output. In humans, most estimates of PIC are made from plantarflexor or dorsiflexor motor units with the participant in a seated position with the knee flexed. This seated and static posture neglects the task-dependent nature of the monoaminergic drive that modulates PIC activation. Seated estimates may drastically underestimate the amount of PIC that occurs in human motor neurons during functional movement. The current study estimated PIC using the conventional paired motor unit technique which uses the difference between reference unit firing frequency at test unit recruitment and reference unit firing frequency at test unit de-recruitment (∆F) during triangular-shaped, isometric ramps in plantarflexion force as an estimate of PIC. Estimates of PIC were also made during standing anterior postural sway, a postural task that elicits a ramped increase and decrease in soleus motor unit activation similar to the conventional seated ramp contractions. For each motor unit pair, ∆F estimates of PIC made during conventional isometric ramps in the seated posture were compared to those made during standing postural sway. Baseline reciprocal inhibition (RI) was also measured in each posture using the post-stimulus time histogram (PSTH) technique. Hyperpolarizing input has been shown to have a reciprocal relationship with PIC in seated posture and RI was measured to examine if the same reciprocal relationship holds true during functional PIC estimation. It was hypothesized that an increase in ∆F would be seen during standing compared to sitting due to greater neuromodulatory input. We found that ∆F estimates during standing postural sway were equal (2.44 ± 1.17, p=0.44) to those in seated PIC estimates (2.73± 1.20) using the same motor unit pair. Reciprocal inhibition was significantly lower when measured in a standing posture (0.0031 ± 0.0251,

Staple Food Consumption Patterns in Urban Zambia: Results from the 2007/2008 Urban Consumption Survey

• The Zambia Urban Consumption Survey, a survey of 1,865 urban households in Lusaka, Kitwe, Mansa, and Kasama, was conducted in August 2007 and February 2008 by the Central Statistical Office in collaboration with the Zambia Food Security Research Project. • Survey results indicate that in Lusaka and Kitwe, wheat has overtaken maize as the most important staple in terms of urban consumer expenditures. Maize is no longer the dominant staple food in urban Zambia, except among the poor. This finding is consistent with broader regional trends toward declining dependence on maize for urban staple food needs. • Hammer-milling services are readily available to the vast majority of urban households and in most cases their cheapest maize meal option is to obtain maize grain and have it custom-milled for a fee. However, maize grain is not consistently available in public markets during the lean season (December-March). GRZ could promote urban food security by ensuring that maize grain is available in public markets at all times. • In Kasama and Mansa, and particularly among relatively poor households, cassava is an important consumption item and serves as a buffer against high maize prices and poor maize grain availability during the lean season. • Supermarkets have only 5-17% of the market share for staple foods and are frequented mainly by wealthier households. Urban consumers are heavily dependent upon non-supermarket, informal retail outlets such as public markets and grocers for their staple food purchases. Policies and public investments to support these traditional retailers, help them operate more efficiently, and reduce the transaction costs they face may have higher payoffs for most urban consumers as well as smallholder farmers than policies presupposing the rapid takeover of supermarkets and other more formal retail channels.Zambia, food security, consumption, household, urban, Agricultural and Food Policy, Community/Rural/Urban Development, Consumer/Household Economics, Food Security and Poverty, International Development, q19,

Task-dependent Modulation of Cortical Excitability and Balance Control in Individuals with Post-concussion Syndrome

In most cases, symptoms resolve between 7-10 days post-concussion. However, in 10-15% of the concussed population, symptoms can remain unresolved for months to years following the head injury. The purpose of this thesis was two-fold, and was broken up into two studies, where the same individuals participated in both studies. The purpose of the first study was to quantify the differences in balance control between individuals with PCS (i.e., had been experiencing symptoms for \u3c30 days) and non-concussed individuals during a lower-limb reaching task. Participants completed a static balance assessment before and after a lower-limb reaching task, which incorporated a Go/No-Go paradigm. Results from this study revealed no differences in the static stability assessments, however, individuals with PCS demonstrated increased medial-lateral COP displacement as well as greater trunk pitch during the reaching task. Overall, the findings reveal persistent balance impairments in individuals with PCS, which may put this population at an increased risk of further injury. The purpose of the second study was to assess task-dependent modulation of cortical excitability prior to planned index finger abduction contractions comparing a non-concussed population to a population with PCS. The protocol in this study consisted of both single and paired-pulse transcranial magnetic stimulation (TMS) which was applied prior to the beginning of 3 different tasks (i.e., a rest condition with no plan to contract, a precision contraction, and a powerful contraction). In addition to the three tasks, participants also had to respond to a Go/No-Go cue. The results of this study revealed an increase in excitability prior to a precision contraction in both non-concussed and PCS groups. No differences in task-dependent modulation were found between the two groups with respect to intracortical facilitation and inhibition, however a negative correlation between number of symptoms reported (SCAT3 symptom evaluation) and intracortical facilitation was revealed. The increase in corticospinal excitability prior to a precision contraction was not explained by the two cortical mechanisms we assessed and may therefore be due to spinal modulation or a different cortical mechanism. Overall, based on the results from this thesis, it appears that individuals with PCS have balance impairments, which may be a result of an inability to maximally activate their postural muscles. Furthermore, it appears that those individuals who reported a higher number of symptoms had greater reductions in intracortical facilitation, likely reflecting the heterogeneity of this clinical group

The Value of a Liberal Arts Education: A Self-Evident Truth

We hold this truth to be self-evident: The best preparation for 21st Century workplace challenges is to earn a liberal arts degree or a professional degree that is grounded in and inspired by the liberal arts

Security of Widows’ Access to Land in the Era of HIV/AIDS: Panel Survey Evidence from Zambia

1. The percentage of households that are headed by widows in rural Zambia increased from 9.4 % to 12.3% between 2001 and 2004. 2. Within 1 to 3 years after the death of their husbands, widow-headed households, on average, controlled 35 percent less land than what they had prior to their husband’s death. 3. To some extent, older widows are protected against loss of land compared to younger widows. 4. Women in relatively wealthy households are particularly vulnerable to losing land after the death of their husbands. 5. Widows whose family has kinship ties to the village authorities are less likely to face a severe decline in landholding size after the death of their husbands. 6. Widows in patrilineal and matrilineal villages are equally likely to lose their rights to land.food security, food policy, Zambia, HIV/AIDS, land, Health Economics and Policy, Land Economics/Use, Q20,

Building the Future - One College Graduate at a Time

The past few weeks have been a time of reflection for me. My father died and my family experienced what all families do when they lose the man who provided for them, guided them, protected them, and — in my case — made sure we fully understood the value of a college education

A Narrative Inquiry into the Influence of School Shooting Survival on College Transition and Experience

There is an extensive body of school-related shooting research exploring causes, how to recognize a threat, and what preparedness measures are effective (Lee et al., 2020; Muchert, 2007). However, there is insufficient research on how the broader context of school-related shootings in American society has influenced college-aged students. The purpose of this study was to tell the story of how students have been influenced by their experience surviving the 2018 Marjory Stoneman Douglas High School shooting during their transition to and performance in higher education. Narrative inquiry provided a deeper understanding through narrative retelling of the perceptions, decisions, and experiences of school shooting survivors. Schlossberg’s transition theory provided a framework by which to analyze participant experiences. This study narrowed a gap in the existing literature by exploring and uncovering school shooting survivor experiences during their transition and time in college. Participants shared important information and perspective on their challenges making friends, processing trauma, and exploring their interests outside of advocacy work. Findings demonstrate the importance of substantial mental health support in college

Native American Indian Perspective of Euroamerican Therapists\u27 Behaviors

The American Psychological Association has identified three areas of skills for cross-cultural competency for psychologists. Those areas are knowledge of self and one\u27s own culture, historical and current knowledge of other cultures and specific technical skills. This study addresses the area of technical skills in a cross-cultural situation, Euroamerican therapists working with Native American Indian clients. Many authors have theorized that individual counseling is not a useful modality to Native American Indians. The method used in this study was a role-play counseling situation between Native American Indians and Euroamerican counseling and clinical psychology doctoral students followed by a post-session interview. The interviews were transcribed and analyzed for recurring themes. The results indicate that therapists must attend to three aspects of an individual: the idiosyncratic, the culture-specific, and the universal. The Native American Indian participants reported that therapist relationship building skills were important. If they did not feel connected to the therapist, they were not willing to disclose their problem nor take any of the therapist\u27s direction. Self-disclosure by the therapist increased the participant\u27s trust of the therapist. Direct eye contact by the therapist was viewed in a variety of ways; some of the participants wanted direct eye contact and other participants felt uncomfortable with it. Consistent with current literature, Native American Indians wanted structure and direction regarding the counseling process from the therapist, but they wanted to define the outcomes, not have outcomes imposed on them. Native Americans in this study reported that although they could see some possible negative consequences of individual therapy, their general belief was that it would be useful in helping them resolve problems