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"Cutter, Mitchell"
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Are Survivors Different? Genetic-Based Selection of Trees by Mountain Pine Beetle During a Climate Change-Driven Outbreak in a High-Elevation Pine Forest
2018
Increased mortality of forest trees, driven directly or indirectly by climate change, is occurring around the world. In western North America, whitebark pine, a high elevation keystone species, and lodgepole pine, a widespread ecologically and economically important tree, have experienced extensive mortality in recent climate-driven outbreaks of the mountain pine beetle. However, even in stands experiencing high levels of mortality, some mature trees have survived. We hypothesized that the outbreak acted as a natural selection event, removing trees most susceptible to the beetle and least adapted to warmer drier conditions. If this was the case, genetic change would be expected at loci underlying beetle resistance. Given we did not know the basis for resistance, we used inter-simple sequence repeats to compare the genetic profiles of two sets of trees, survivors (mature, living trees) and general population (trees just under the diameter preferred by the beetles and expected to approximate the genetic structure of each tree species at the site without beetle selection). This method detects high levels of polymorphism and has often been able to detect patterns associated with phenotypic traits. For both whitebark and lodgepole pine, survivors and general population trees mostly segregated independently indicating a genetic basis for survivorship. Exceptions were a few general population trees that segregated with survivors in proportions roughly reflecting the proportion of survivors versus beetle-killed trees. Our results indicate that during outbreaks, beetle choice may result in strong selection for trees with greater resistance to attack. Our findings suggest that survivorship is genetically based and, thus, heritable. Therefore, retaining survivors after outbreaks to act as primary seed sources could act to promote adaptation. Further research will be needed to characterize the actual mechanism(s) of resistance.
Journal Article
Melanic pigmentation and light preference within and between two Drosophila species
by
Fournier, Eli B.
,
Mayer, Spencer D.
,
Roberts, Stephon
in
behavioral choice experiment
,
Color
,
correlated traits
2021
Environmental adaptation and species divergence often involve suites of co‐evolving traits. Pigmentation in insects presents a variable, adaptive, and well‐characterized class of phenotypes for which correlations with multiple other traits have been demonstrated. In Drosophila, the pigmentation genes ebony and tan have pleiotropic effects on flies' response to light, creating the potential for correlated evolution of pigmentation and vision. Here, we investigate differences in light preference within and between two sister species, Drosophila americana and D. novamexicana, which differ in pigmentation in part because of evolution at ebony and tan and occupy environments that differ in many variables including solar radiation. We hypothesized that lighter pigmentation would be correlated with a greater preference for environmental light and tested this hypothesis using a habitat choice experiment. In a first set of experiments, using males of D. novamexicana line N14 and D. americana line A00, the light‐bodied D. novamexicana was found slightly but significantly more often than D. americana in the light habitat. A second experiment, which included additional lines and females as well as males, failed to find any significant difference between D. novamexicana‐N14 and D. americana‐A00. Additionally, the other dark line of D. americana (A04) was found in the light habitat more often than the light‐bodied D. novamexicana‐N14, in contrast to our predictions. However, the lightest line of D. americana, A01, was found substantially and significantly more often in the light habitat than the two darker lines of D. americana, thus providing partial support for our hypothesis. Finally, across all four lines, females were found more often in the light habitat than their more darkly pigmented male counterparts. Additional replication is needed to corroborate these findings and evaluate conflicting results, with the consistent effect of sex within and between species providing an especially intriguing avenue for further research. Light preference was examined in the light‐bodied Drosophila novamexicana and in three lines of the dark‐bodied Drosophila americana. In both species, female flies are more lightly pigmented than male flies and also show a stronger tendency to select a more brightly lit habitat. Patterns of habitat choice within and between species were mixed, but showed some trends of lighter bodied flies preferring more brightly lit habitats.
Journal Article
Using geotagged tweets to track population movements to and from Puerto Rico after Hurricane Maria
2020
After a disaster, there is an urgent need for information on population mobility. Our analysis examines the suitability of Twitter data for measuring post-disaster population mobility using the case of Hurricane Maria in Puerto Rico. Among Twitter users living in Puerto Rico, we show how many were displaced, the timing and destination of their displacement, and whether they returned. Among Twitter users arriving in Puerto Rico after the disaster, we show the timing and destination of their trips. We find that 8.3% of resident sample relocated during the months after Hurricane Maria and nearly 4% of were still displaced 9 months later. Visitors to Puerto Rico fell significantly in the year after Hurricane Maria, especially in tourist areas. While our Twitter data is not representative of the Puerto Rican population, it provides broad evidence of the effect of this disaster on population mobility and suggests further potential use.
Journal Article
Revealing the Vulnerability of People and Places: A Case Study of Georgetown County, South Carolina
by
Mitchell, Jerry T.
,
Scott, Michael S.
,
Cutter, Susan L.
in
At risk populations
,
Bgi / Prodig
,
Case studies
2000
Losses from environmental hazards have escalated in the past decade, prompting a reorientation of emergency management systems away from simple postevent response. There is a noticeable change in policy, with more emphasis on loss reduction through mitigation, preparedness, and recovery programs. Effective mitigation of losses from hazards requires hazard identification, an assessment of all the hazards likely to affect a given place, and risk-reduction measures that are compatible across a multitude of hazards. The degree to which populations are vulnerable to hazards, however, is not solely dependent upon proximity to the source of the threat or the physical nature of the hazard -social factors also play a significant role in determining vulnerability. This paper presents a method for assessing vulnerability in spatial terms using both biophysical and social indicators. A geographic information system was utilized to establish areas of vulnerability based upon twelve environmental threats and eight social characteristics for our study area, Georgetown County, South Carolina. Our results suggest that the most biophysically vulnerable places do not always spatially intersect with the most vulnerable populations. This is an important finding because it reflects the likely 'social costs' of hazards on the region. While economic losses might be large in areas of high biophysical risk, the resident population also may have greater safety nets (insurance, additional financial resources) to absorb and recover from the loss quickly. Conversely, it would take only a moderate hazard event to disrupt the well-being of the majority of county residents (who are more socially vulnerable, but perhaps do not reside in the highest areas of biophysical risks) and retard their longer-term recovery from disasters. This paper advances our theoretical and conceptual understanding of the spatial dimensions of vulnerability. It further highlights the merger of conceptualizations of human environment relationships with geographical techniques in understanding contemporary public policy issues.
Journal Article
Disease-modifying therapy prescription patterns in people with multiple sclerosis by age
by
Wallin, Mitchell
,
Jin, Shan
,
Cutter, Gary R.
in
Magnetic resonance imaging
,
Multiple sclerosis
,
Original Research
2021
Background:
Disease-modifying therapies (DMTs) for multiple sclerosis (MS) are approved for their ability to reduce disease activity, namely clinical relapses and signal changes on magnetic resonance imaging (MRI). Disease activity appears age dependent. Thus, the greatest benefit would be expected in younger people with MS (PwMS) whereas benefits in the elderly are uncertain.
Methods:
Real-world data were obtained from PwMS from the North American Research Committee on Multiple Sclerosis (NARCOMS) registry and the US Department of Veterans Affairs Multiple Sclerosis Surveillance Registry (MSSR).
Results:
6948 PwMS were surveyed from NARCOMS, and the MSSR had 1719 participants. In younger adult PwMS 40-years old or less, 183 (61.4%) in NARCOMS and 179 (70.5%) in the MSSR were prescribed DMTs. Among PwMS over age 60, 1575 (40.1%) in NARCOMS and 239 (36.3%) in the MSSR were prescribed DMTs. More PwMS in the age group of 31–40 (p = 0.035) and 41–50 (p = 0.001) in the MSSR were using DMTs compared with PwMS of the same age groups in NARCOMS.
Conclusion:
These findings suggest that DMTs are under-utilized in the younger population and continue to be commonly prescribed in the elderly. Broader access may explain the higher prescription rate of DMTs in US veterans.
Journal Article
Aging and efficacy of disease-modifying therapies in multiple sclerosis: a meta-analysis of clinical trials
by
Cutter, Gary
,
Wallin, Mitchell
,
Gonzalez Caldito, Natalia
in
Aging
,
Clinical trials
,
Gadolinium
2020
Background:
Disease-modifying therapies (DMTs) for multiple sclerosis (MS) are approved for the treatment of disease activity and are effective in reducing relapses and new magnetic resonance imaging (MRI) lesions. However, disease activity generally subsides with time, and age-dependent changes in DMT efficacy are not well-established. We aimed to investigate whether age impacts the efficacy of DMTs in treating disease activity in patients with relapsing–remitting MS (RRMS).
Methods:
DMT efficacy related to age was assessed through a meta-analysis of clinical trials that evaluated the efficacy of DMTs in RRMS patients as measured by reductions in the annualized relapse rate (ARR), new T2 lesions, and gadolinium-enhanced lesions on MRI. Using the mean baseline patient age from each trial, a weighted linear regression was fitted to determine whether age was associated with treatment efficacy on a group level.
Results:
Group-level data from a total of 28,082 patients from 26 trials of 14 different DMTs were included in the meta-analysis. There were no statistically significant associations between age and reductions in ARR, new T2 lesions, and gadolinium-enhanced lesions of the treatment group compared with placebo.
Conclusion:
DMTs for RRMS show efficacy in treating disease activity independent of age as demonstrated by group-level data from DMT clinical trials. Nevertheless, clinical trials select for patients with baseline disease activity regardless of age, thereby not representing real-world patients with RRMS, where disease activity declines with age.
Journal Article
3 CI Cognitive Therapy: Initial Application in a Pilot Study to Improve Cognitive Impairment in Chronic Stroke Survivors
by
Ball, Karlene
,
McKay, Staci
,
Cutter, Gary
in
Activities of daily living
,
Cognition & reasoning
,
Cognitive ability
2023
Objective:CI Cognitive Therapy (CICT) is a combination of behavioral techniques derived from CI Movement Therapy (CIMT) modified to apply to the cognitive domain, and Speed of (Cognitive) Processing Training (SOPT). SOPT is effective in improving cognitive function in the treatment setting and driving ability in everyday situations. The data concerning the effect of SOPT on other cognition-based instrumental activities of daily living (IADL) in everyday situations is incomplete. The strengths of CIMT, based on its Transfer Package (TP), are to facilitate 1) transfer of improved function from the treatment setting to IADL in everyday settings, and 2) long-term retention of the improved performance of IADL. This study sought to determine in a preliminary case series whether the TP of CI Movement Therapy combined with SOPT would have the same effect on a wide range of impaired cognition-based ADL.Participants and Methods:Participants were 6 adults with chronic stroke: mean chronicity = 36.2 months, (range, 16-56 months); mean age = 59.7 years, (range, 47-55); 1 female; 3 African American and 3 European American. Five had mild cognitive impairment, while one had moderate impairment. Participants received 35 hours of outpatient treatment in 10-15 sessions distributed over 2-6 weeks, depending on the participants’ availability. Sessions began with 1 hour of SOPT training followed by training of cognition-based ADL by the process of shaping, a common method in the behavior analysis field. Other behavior analysis methods employed in the TP of CI Movement Therapy were used, including: 1) behavior contracting, daily assignment of homework, participation of a family member in the training and monitoring process, daily administration of a structured interview assessing amount and quality of performance of 30 IADL, problem solving to overcome perceived (or real) barriers to performance of IADL. Participants were given daily homework assignments in follow-up and were contacted in periodic, pre-arranged phone calls to determine status, compliance and problem-solve.Results:All six participants showed marked improvement on the SOPT test similar to that in the Ball et al studies. However, here transfer to IADL outside the treatment setting was substantial. On the main real-world outcome, the Canadian Occupational Performance Measure (COPM), there were increases of 2.7±1.3 and 2.1±1.6 on the two scales (d’s = 1.9 & 1.3, respectively). (Changes on the COPM > 2 points are considered clinically meaningful and changes in d’ >.8 are considered large). On two other real-word measures, the Cognitive Task Activity Log (CTAL) and inventory of Improved and New Cognitive Activities (INCA), there was a marked increase during the acquisition phase of training. There was no loss in retention over the 6-16 months (mean = 12.2) of follow-up to date. Instead, the INCA showed strong further improvement after the end of treatment-setting training, especially in the New Activities Not Performed Since Before Stroke Onset category, going from a mean of 8.2 after training to 14.6 at the end of follow-up.Conclusions:These very preliminary results suggest that CICT may be an efficacious therapy for mild to moderate cognitive impairment in chronic stroke and possibly other disorders.
Journal Article
Pregnancy as a risk factor for severe influenza infection: an individual participant data meta-analysis
2019
Background
WHO identifies pregnant women to be at increased risk for severe outcomes from influenza virus infections and recommends that they be prioritized for influenza vaccination. The evidence supporting this, however, is inconsistent. Ecologic studies in particular suggest more severe outcomes from influenza infection during pregnancy than studies based on individual patient data. Individual studies however may be underpowered and, as reported in a previous systematic review, confounding factors could not be adjusted for. We therefore conducted an individual participant data meta-analysis to assess the risk for severe outcomes of influenza infection in pregnant women while adjusting for other prognostic factors.
Methods
We contacted authors of studies included in a recently published systematic review. We pooled the individual participant data of women of reproductive age and laboratory confirmation of influenza virus infection. We used a generalized linear mixed model and reported odds ratios (OR) and 95% confidence intervals (CI).
Results
A total of 33 datasets with data on 186,656 individuals were available, including 36,498 eligible women of reproductive age and known pregnancy status. In the multivariable model, pregnancy was associated with a 7 times higher risk of hospital admission (OR 6.80, 95%CI 6.02–7.68), among patients receiving medical care as in- or outpatients, pregnancy was associated with a lower risk of admission to intensive care units (ICU; OR 0.57, 95%CI 0.48–0.69), and was not significantly associated with death (OR 1.00, 95%CI 0.75–1.34).
Conclusions
Our study found a higher risk of influenza associated hospitalization among pregnant women as compared to non-pregnant women. We did not find a higher mortality rate or higher likelihood of ICU admission among pregnant women who sought medical care. However, this study did not address whether a true community based cohort of pregnant women is at higher risk of influenza associated complications.
Journal Article
The Long Road Home: Race, Class, and Recovery from Hurricane Katrina
2006
Hurricane Katrina was not the strongest of the three storms that reached Category Five intensity in terms of wind speeds or central pressures, but converging factors--primarily its strength and landfall location along the Gulf Coast--made it the most devastating and costly hurricane in US history. Here, Cutter et al highlight the challenging tasks of recovery and the implications of the reconstruction process of the region.
Journal Article
4 Initial Application of Constraint-Induced Cognitive Therapy to Long COVID Brain Fog
by
Knight, Amy
,
Blagburn, Kyli
,
Smith, Morgan
in
Activities of daily living
,
Cognitive ability
,
Cognitive Intervention/Rehabilitation
2023
Objective:Persistent brain fog is common in adults with Post-Acute Sequelae of SARS-CoV-2 infection (PASC), in whom it causes distress and in many cases interferes with performance of instrumental activities of daily living (IADL) and return-to-work. There are no interventions with rigorous evidence of efficacy for this new, often disabling condition. The purpose of this pilot is to evaluate the efficacy, on a preliminary basis, of a new intervention for this condition termed Constraint-Induced Cognitive therapy (CICT). CICT combines features of two established therapeutic approaches: cognitive speed of processing training (SOPT) developed by the laboratory of K. Ball and the Transfer Package and task-oriented training components of Constraint-Induced Movement therapy developed by the laboratory of E. Taub and G. Uswatte.Participants and Methods:Participants were > 3 months after recovery from acute COVID symptoms and had substantial brain fog and impairment in IADL. Participants were randomized to CICT immediately or after a 3-month delay. CICT involved 36 hours of outpatient therapy distributed over 4-6 weeks. Sessions had three components: (a) videogamelike training designed to improve how quickly participants process sensory input (SOPT), (b) training on IADLs following shaping principles, and (c) a set of behavioral techniques designed to transfer gains from the treatment setting to daily life, i.e., the Transfer Package. The Transfer Package included (a) negotiating a behavioral contract with participants and one or more family members about the responsibilities of the participants, family members, and treatment team; (b) assigning homework during and after the treatment period; (c) monitoring participants’ out-of-session behavior; (d) supporting problem-solving by participants and family members about barriers to performance of IADL; and (e) making follow-up phone calls. IADL performance, brain fog severity, and cognitive impairment were assessed using validated, trans-diagnostic measures before and after treatment and three months afterwards in the immediate-CICT group and on parallel occasions in the delayed-CICT group (aka waitlist controls).Results:To date, five were enrolled in the immediate-CICT group; four were enrolled in the wait-list group. All had mild cognitive impairment, except for one with moderate impairment in the immediate-CICT group. Immediate-CICT participants, on average, had large reductions in brain fog severity on the Mental Clutter Scale (MCS, range = 0 to 10 points, mean change = -3.7, SD = 2.0); wait-list participants had small increases (mean change = 1.0, SD = 1.4). Notably, all five in the immediate-CICT group had clinically meaningful improvements (i.e., changes > 2 points) in performance of IADL outside the treatment setting as measured by the Canadian Occupational Performance Measure (COPM) Performance scale; only one did in the wait-list group. The advantage for the immediate-CICT group was very large on both the MCS and COPM (d’s = 1.7, p’s < .05). In follow-up, immediate-CICT group gains were retained or built-upon.Conclusions:These preliminary findings warrant confirmation by a large-scale randomized controlled trial. To date, CICT shows high promise as an efficacious therapy for brain fog due to PASC. CICT participants had large, meaningful improvements in IADL performance outside the treatment setting, in addition to large reductions in brain fog severity.
Journal Article