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Nutrition provides the resources necessary to carry out all the physiological functions organisms require. This has important implications for insect pest management, as polyphagous species can experience considerable nutritional variability, which may impact their response to management tactics.Many studies have shown that dietary protein and carbohydrates play a primary role in insect fitness and that insects regulate their intake of these macronutrients to reach an optimal balance or intake target. Importantly, this intake target can vary across developmental stages, gender, and environmental conditions as physiological requirements change.In this study, we determined the intake target for adult spotted‐wing Drosophila, Drosophila suzukii, an invasive polyphagous fruit pest. We found that adult D. suzukii regulate their intake to meet a 1:4–1:5 protein‐to‐carbohydrate ratio, which is slightly more carbohydrate‐biased than the larval intake target. We also examined the effect of nutritional state on susceptibility to three commonly‐used insecticides by rearing flies on diets with different field‐relevant protein‐to‐carbohydrate ratios and exposing adults to an LC50 dose of zeta‐cypermethrin, spinetoram, or pyrethrin.Overall, female flies had higher survivorship than males, and diet effects varied across insecticides. Diet had no impact in the spinetoram treatments, while the extreme carbohydrate‐ and protein‐biased diets produced the lowest survivorship and reproductive performance in the zeta‐cypermethrin treatments. Survivorship increased with dietary protein in the pyrethrin treatments but reproductive performance did not differ across diets. Our results suggest that tactics, which reduce fly access to dietary protein sources, such as sterilisation, could increase fly susceptibility to insecticides. [ABSTRACT FROM AUTHOR]

Tethered flight mills and free‐flight studies are two common approaches for examining insect flight behavior in the laboratory. Flight behavior studies are significant because they provide information with understanding dispersal and range expansion. Each approach has advantages and drawbacks and can influence the flight behavior of the study organism. However, tethered and untethered flight studies are rarely performed simultaneously to determine whether one technique is better suited for a particular species. Here, we conducted a tethered and untethered flight study to determine the limitations, benefits, and effects the two methods could have on assessing an insect's flight capacity. We focused the study on the global invasive pest, Drosophila suzukii (Matsumura) (Diptera: Drosophilidae). Propensity of flight and flight duration, distance, and velocity were examined for (1) females and males, and (2) summer and winter morphs, as the two morphs differ significantly in body and wing size. The study showed that summer morphs were more likely to fly when untethered than when tethered to a flight mill. Additionally, when comparing the length of time of flight for first take‐off, D. suzukii flew longer when untethered. Outcomes from this study provide information on D. suzukii flight behavior, which could assist with future research on this economically important fruit pest that is rapidly expanding its range. The results also suggest that the flight apparatus can affect D. suzukii flight behaviors, such that future laboratory flight research should be considerate of the flight technique utilized. [ABSTRACT FROM AUTHOR]

Population responses to environmental extremes often dictate the bounds to species' distributions. However, population dynamics at, or near, those range limits may also be affected by sublethal effects. We exposed late instars and pupae of an invasive leafroller, Epiphyas postvittana (Walker) (Lepidoptera: Tortricidae), to cold temperatures and measured the effects of exposure on subsequent survivorship, development, and reproduction. Cold temperature was applied as acute exposure to –10 °C (a low, but not immediately lethal temperature for this species) or the onset of freezing (the peak of the supercooling point exotherm). Survival was defined as the ability to successfully eclose as an adult. We measured immature development times, pupal mass, and adult longevity as proxies of fitness in survivors. Additionally, surviving insects were mated with individuals that had not been exposed to cold to measure fertility. There was no difference between the proportion of larvae or pupae that survived acute exposure to –10 °C and those exposed to the control temperature. Approximately 17% of larvae and 8% of pupae survived brief periods with internal ice formation and continued development to become reproductively viable adults. Importantly, surviving the onset of freezing came with significant fitness costs but not to exposure to –10 °C; most insects that survived partial freezing had lower fertility and shorter adult lifespans than either the –10 °C or control group. These results are discussed within the context of forecasting invasive insect distributions. [ABSTRACT FROM AUTHOR]

Background: Local field potentials (LFPs) represent the summation of periodic (oscillations) and aperiodic (fractal) signals. Although previous studies showed changes in beta band oscillations and burst characteristics of the subthalamic nucleus (STN) in Parkinson's disease (PD), how aperiodic activity in the STN is related to PD pathophysiology is unknown. Objectives: The study aimed to characterize the long‐term effects of STN–deep brain stimulation (DBS) and dopaminergic medications on aperiodic activities and beta bursts. Methods: A total of 10 patients with PD participated in this longitudinal study. Simultaneous bilateral STN‐LFP recordings were conducted in six separate visits during a period of 18 months using the Activa PC + S device in the off and on dopaminergic medication states. We used irregular‐resampling auto‐spectral analysis to separate oscillations and aperiodic components (exponent and offset) in the power spectrum of STN‐LFP signals in beta band. Results: Our results revealed a systematic increase in both the exponent and the offset of the aperiodic spectrum over 18 months following the DBS implantation, independent of the dopaminergic medication state of patients with PD. In contrast, beta burst durations and amplitudes were stable over time and were suppressed by dopaminergic medications. Conclusions: These findings indicate that oscillations and aperiodic activities reflect at least partially distinct yet complementary neural mechanisms, which should be considered in the design of robust biomarkers to optimize adaptive DBS. Given the link between increased gamma‐aminobutyric acidergic (GABAergic) transmission and higher aperiodic activity, our findings suggest that long‐term STN‐DBS may relate to increased inhibition in the basal ganglia. © 2022 International Parkinson and Movement Disorder Society. [ABSTRACT FROM AUTHOR]

Background: Patients with Parkinson's disease might develop treatment‐resistant axial dysfunction after bilateral subthalamic stimulation. Objectives: To study whether lateralized stimulation (unilateral 50% amplitude reduction) for ≥21 days results in ≥0.13 m/s faster gait velocity in the dopaminergic ON state in these patients, and its effects on motor and axial function, quantitative gait and speech measures, quality of life, and selected cognitive tasks. Methods: Randomized, double‐blinded, double‐crossover trial. Results: In 22 participants (51–79 years old, 15 women), there were no significant changes in gait velocity, quality of life, cognitive, and speech measures. Reducing left‐sided amplitude resulted in a 2.5‐point improvement in axial motor Movement Disorder Society Unified Parkinson's Disease Rating Scale (MDS‐UPDRS) (P = 0.005, uncorrected) and a 1.9‐point improvement in the Freezing of Gait Questionnaire (P = 0.024, uncorrected). Conclusions: Lateralized subthalamic stimulation does not result in meaningful improvement in gait velocity in patients with Parkinson's disease who develop treatment‐resistant axial dysfunction after bilateral subthalamic stimulation. Left subthalamic overstimulation may contribute to axial deterioration in these patients. © 2022 International Parkinson and Movement Disorder Society [ABSTRACT FROM AUTHOR]

High-frequency deep brain stimulation ( HFS- DBS) of the subcallosal cingulate ( SCC) region has been investigated as a treatment for refractory forms of depression with a ~50% remission rate in open label studies. However, the therapeutic mechanisms of DBS are still largely unknown. Using anaesthetized Sprague Dawley rats, we recorded neuronal spiking activity in 102 neurons of the dorsal raphe ( DR) before, during and after the induction of a 5-min HFS train in the infralimbic region ( IL) of the medial prefrontal cortex ( mPFC), the rodent homologue of the human SCC. The majority of DR cells (82%) significantly decreased firing rate during HFS ( P < 0.01, 55.7 ± 4.5% of baseline, 35 rats). To assess whether mPFC- HFS mediates inhibition of DR cellular firing by stimulating local GABAergic interneurons, the GABAA antagonist bicuculline ( Bic, 100 μ m) was injected directly into the DR during HFS. Neurons inhibited by HFS recovered their firing rate during Bic+ HFS ( P < 0.01, n = 15, seven rats) to levels not different from baseline. Cells that were not affected by HFS did not change firing rate during Bic+ HFS ( P = 0.968, n = 7, three rats). These results indicate that blocking GABAA reverses HFS-mediated inhibition of DR neurons. As the cells that were not inhibited by HFS were also unaffected by HFS+ Bic, they are probably not innervated by local GABA. Taken together, our results suggest that mPFC- HFS may exert a preferential effect on DR neurons with GABAA receptors. [ABSTRACT FROM AUTHOR]

Minnesota is the state with the strongest winter warming in the contiguous United States. We performed regional climate projections at 10 km horizontal resolution using the Weather Research Forecasting model forced with eight CMIP5 GCMs. The selected GCMs have previously been found to be in relatively good agreement with observations over Minnesota compared to other members of the CMIP5 model ensemble. Our projections suggest ongoing warming in all seasons, especially in winter, as well as shallower snow depth and fewer days with snow cover. We expect significant increases in spring and early summer heavy precipitation events. Our comparisons between different time slices and two different emission scenarios indicate a climate for the state of Minnesota near the end of the 21st century that is significantly different from what has been observed by the end of the 20th century. Winters and summers are expected to be up to 6 and 4°C warmer, respectively, over northern and central Minnesota, and spring precipitation may increase by more than 1 mm d−1 over northern Minnesota. Especially over the central part of the state, winter snow depth is projected to decrease by more than 12 cm, and the number of days per year with snow depth of more than 2.54 cm (one inch) is expected to decrease by up to 55. Plain Language Summary: Minnesota is the state with the strongest winter warming in the contiguous United States. We performed regional projections of the climate across Minnesota for the middle and end of the 21st century. We selected the results from eight recent global climate model projections to calculate climate data over an area of 10 km by 10 km with a regional climate model. Our results indicate that the future climate for the state of Minnesota is likely to be significantly different from what has been observed near the end of the 20th century. Over northern and central Minnesota, winters and summers are expected to be up to 6 and 4°C warmer, respectively, near the end of the 21st century. Spring precipitation may increase by more than 1 mm d−1 over northern Minnesota. Over the central part of the state, winter snow depth is suggested to decrease by more than 12 cm. The number of days per year with snow depth of more than 2.54 cm (one inch) is expected to decrease by up to 55. These results are expected to influence regional decision‐making related to agriculture, infrastructure, water resources, and other sectors. Key Points: Over northern and central Minnesota, winters and summers may be up to 6 and 4°C warmer, respectively, at the end of the 21st centurySpring precipitation may increase by more than 1 mm per day over northern MinnesotaSnow depth may decrease by more than 12 cm. Number of snow days per year may decrease by up to 55 [ABSTRACT FROM AUTHOR]

Parkinson's disease is a neurodegenerative disease affecting the supply of dopamine to basal ganglia nuclei, leading to pathological beta band (13–35 Hz) oscillations in the subthalamic nucleus (STN). STN and beta activity are recognized in motoric functions but their role in cognitive functions remains elusive. We examined single unit and beta local field potential (LFP) activity in the STN during a visual choice preference task in PD patients (n = 12) undergoing deep brain stimulation surgery. Patients viewed 2 of 5 possible animal picture‐pairs and were instructed to choose their favorite ("fav") picture by clicking the left or right mouse key. A block of trials consisted of 50–75 picture‐pair presentations. Single unit histograms and LFP spectrograms were aligned to picture presentation and point of decision for pairs that included the fav and non‐fav pictures, respectively. A total of 58 neurons from 26 blocks of trials were analyzed. Thirty of 58 neurons showed a selective change in spiking activity 0.20–0.65 s to fav picture presentation, which preceded the shortest recorded reaction time (=0.7 s), and 17/58 neurons showed no significant response in our task. Beta LFP significantly desynchronized in response to fav but not non‐fav pictures in all trials, and in 14/26 blocks of trials, the desynchronization was followed by a "beta burst" and ramp‐up to baseline activity. Neurons with choice preference responses were found throughout the dorsoventral extent of the STN. STN single units and beta activity are modulated during visual choice preference, and this suggests a role for STN beta activity in cognitive processing. [ABSTRACT FROM AUTHOR]

Objective: Many lines of evidence suggest that response conflict recruits brain regions in the cortical-basal ganglia system. Within the basal ganglia, deep brain recordings from the subthalamic nucleus (STN) have shown that conflict triggers a transient increase in low-frequency oscillations (LFOs; 2-8Hz). Here, we deployed a new method of delivering short trains of event-related deep brain stimulation (DBS) to the STN to test the causal role of the STN and its associated circuits in conflict-related processing.Methods: In a double-blind design, we stimulated the STN in patients with Parkinson disease by locking brief trains of DBS to specific periods of the trial within a Stroop task.Results: Stimulation had a specific effect on conflict compared to nonconflict trials by relatively speeding responses on conflict trials (ie, reducing the Stroop effect, defined as the difference in reaction time between conflict and nonconflict trials) when it was delivered in the preresponse period in the preparation phase. Stimulation also increased errors when it was delivered early in the response window. This latter result corresponded to the timing of the conflict-induced increase in LFOs observed in the absence of stimulation but was not directly related to the reduction in the Stroop effect.Interpretation: These results support the theory that the time of LFO increase recorded from the STN corresponds to a conflict-processing function. They also provide one of the first demonstrations of event-related DBS of the STN in humans during a cognitive control paradigm. Ann Neurol 2018;84:515-526. [ABSTRACT FROM AUTHOR]

Dexmedetomidine (an alpha-2 adrenergic agonist) sedation is commonly used during subthalamic nucleus ( STN) deep-brain stimulation ( DBS). Its effects on the electrophysiological characteristics of human STN neurons are largely unknown. We hypothesised that dexmedetomidine modulates the firing rates and bursting of human STN neurons. We analysed microelectrode recording ( MER) data from patients with Parkinson's disease who underwent STN DBS. A 'Dex bolus' group (dexmedetomidine bolus prior to MER; 27 cells from seven patients) was compared with a 'no sedation' group (29 cells from 11 patients). We also performed within-patient comparisons with varying dexmedetomidine states. Cells were classified as dorsal half or ventral half based on their relative location in the STN. Neuronal burst and oscillation characteristics were analysed using the Kaneoke-Vitek methodology and local field potential ( LFP) oscillatory activity was also investigated. Dexmedetomidine was associated with a slight increase in firing rate (41.1 ± 9.9 vs. 34.5 ± 10.6 Hz, P = 0.02) but a significant decrease in burstiness (number of bursts, P = 0.02; burst index, P < 0.001; percentage of spikes in burst, P = 0.002) of dorsal but not ventral STN neurons. This was not associated with modulation of beta oscillations in the spike-oscillations analysis(beta peak, P = 0.4; signal-to-noise ratio in the beta range for spikes and bursts, P = 0.3 and P = 0.5, respectively) and LFP analysis (Beta power, P = 0.17). As bursting pattern is often used to identify STN and guide electrode placement, we recommend that high-dose dexmedetomidine should be avoided during DBS surgery. [ABSTRACT FROM AUTHOR]