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Lymphoid priming in human bone marrow begins before expression of CD10 with upregulation of L-selectin.
Expression of the cell-surface antigen CD10 has long been used to define the lymphoid commitment of human cells. Here we report a unique lymphoid-primed population in human bone marrow that was generated from hematopoietic stem cells (HSCs) before onset of the expression of CD10 and commitment to the B cell lineage. We identified this subset by high expression of the homing molecule L-selectin (CD62L). CD10(-)CD62L(hi) progenitors had full lymphoid and monocytic potential but lacked erythroid potential. Gene-expression profiling placed the CD10(-)CD62L(hi) population at an intermediate stage of differentiation between HSCs and lineage-negative (Lin(-)) CD34(+)CD10(+) progenitors. CD62L was expressed on immature thymocytes, and its ligands were expressed at the cortico-medullary junction of the thymus, which suggested a possible role for this molecule in homing to the thymus. Our studies identify the earliest stage of lymphoid priming in human bone marrow
Differences in Load Response of Rotator Cuff and Deltoid Muscles in Younger and Older Adults
Shoulder health is essential for the independence of older adults. Many older adults suffer from impairment of shoulder mobility, yet it is unknown how neuromuscular activation patterns in the shoulder change with age. PURPOSE: To analyze electromyographic (EMG) coherence in the delta band (2-5 Hz) - a measure of common drive from the central nervous system related to force output - to the rotator cuff and deltoid muscles in younger and older adults during low, med and high force levels. METHODS: Eighteen younger adults (YA) (11 males, 25 ± 5 years) and 6 older adults (OA) (3 males, 72.7 ± 8 years) were recruited. Intramuscular EMG was recorded from the supraspinatus muscle (SS); surface EMG was recorded from the middle deltoid (MD) and infraspinatus (IS) muscles. Participants performed 30-sec isometric contractions at 30° scaption at 25%, 50%, and 75% of maximal voluntary contraction (MVC) in random order. Z-transformed pooled coherence of three muscle pairs (SS-IS, SS-MD, IS-MD) were compared using a two-way repeated measures ANOVA (group x force) with Bonferroni post-hoc analysis. RESULTS: There was a significant main effect for the group (p = .014) for the SS-MD pair. YA had greater coherence during the 75% MVC (0.29 ± 0.04) than the 25% MVC (0.18 ± 0.02) (p = 0.001). There were no significant differences between contraction intensities for the OA (OA avg. = 0.12 ± 0.02; [0.11 ± .02 – 0.10 ± .05 – 0.15 ± .04]). For the SS-IS pair, there was a main effect of force (p = .011) and a group x force interaction (p = 0.008): YA had greater coherence at 75% MVC (0.31 ± .025) than at 50% MVC (0.14 ± 0.03, p = .009) and 25% MVC (0.17 ± .03, p = .007); whereas, OA showed no significant differences across force levels (25% MVC: 0.10 ± .03, 50% MVC:0.18 ± .03, 75% MVC: 0.14 ± .03]). No significant differences were found in the IS-MD pair across loads in either group (YA avg.= 0.27 ± .04; OA avg. = 0.14 ± .04). CONCLUSION: Overall, younger adults have more common drive to the rotator cuff and deltoid muscles than older adults across all force levels. The lack of response of common drive to changing force levels in older adults reflects age-related changes in neuromuscular control that could affect shoulder joint integrity
Common Drive to Rotator Cuff and Deltoid Muscles During Fatigue in Individuals With and Without Subacromial Pain Syndrome
Individuals with subacromial pain syndrome have greater superior migration of the humeral head during fatiguing contractions. This may be due to lower common drive across the rotator cuff muscles that stabilize the glenohumeral joint. PURPOSE: To identify intermuscular coherence in the delta band (2-5 Hz), which is a measure of common descending drive to muscles associated with force production, across rotator cuff and deltoid muscle in symptomatic and asymptomatic individuals during an isometric fatiguing contraction. METHODS: Twenty symptomatic (12 F, 8 M, 22 ±3 y/o) and 18 asymptomatic (7 F, 11 M, 25 ± 5 y/o) individuals participated in this study. Surface EMG was recorded from the middle deltoid (MD) and infraspinatus (IS). Intramuscular EMG was recorded with fine-wire electrodes in the supraspinatus (SS). Participants performed an isometric fatiguing contraction at 30° scaption at 25% maximal voluntary contraction until endurance limit. Z-transformed pooled coherence of three muscle pairs (SS-IS, SS-MD, IS-MD) were compared with two-way (time x group) repeated measures ANOVAs with Bonferroni post-hoc analysis. RESULTS: Endurance time did not differ between groups (asymptomatic: 5.7 ±1.1 min symptomatic: 6.5±1.4 min). There was a main effect of time (p\u3c0.01) and a significant group x time interaction for SS-IS coherence (p\u3c0.05). SS-IS coherence did not differ between groups during the initial fatigue phases (avg.=0.16±0.02). SS-IS coherence increased with fatigue in the asymptomatic group (initial = 0.16 ± 0.03, final = 0.22 ± 0.03), but not in the symptomatic group (avg. = 0.15±0.03). There was also a main effect of time on SS-MD coherence (p\u3c0.05), which increased with fatigue in both the asymptomatic (initial=0.11±0.02, final=0.18±0.04) and the symptomatic (initial=0.11±0.01, final=0.13±0.02) groups. IS-MD coherence did not change with fatigue in either group (avg.= 0.22 ± 0.03).CONCLUSION: During neuromuscular fatigue, common drive to the SS and MD increased in individuals with and without subacromial pain. However, common drive to the rotator cuff muscles (SS and IS) only increased with fatigue in the asymptomatic group. Therefore, lower common drive to the SS and IS may be a cause of the decrease in joint stability and narrowing of subacromial space in patients with subacromial pain syndrome
Intermuscular Coherence of Rotator Cuff and Deltoid Muscles Varies with Force Output
Maintaining glenohumeral joint stability requires coordination of the rotator cuff and deltoid muscles. Load changing may alter the neuromuscular control patterns between these two muscle groups. PURPOSE: To identify intermuscular EMG coherence patterns between the rotator cuff and deltoid muscles at different force levels. METHODS: Surface EMG electrodes were used to record activity from the anterior deltoid (AD), middle deltoid (MD), and infraspinatus (IS) muscles of the dominant shoulder in 7 healthy individuals (mean age ± SD = 19±1, 6 females, 1 male). An intramuscular fine-wire EMG electrode was inserted into supraspinatus (SS). Participants performed 30s contractions of isometric shoulder abduction in the scapular plane at 30° at 25% (low-load), 50% (medium-load) and 75% (high-load) of maximum voluntary contraction with visual feedback of the force output. EMG amplitudes and coherence of each muscle pair in the common drive (0-5 Hz), physiological force tremor (5-12 Hz), beta (15-35 Hz), low-gamma (35-60 Hz) and high-gamma (60-100 Hz) bands were compared across the 3 force levels. RESULTS: EMG amplitudes of all muscles increased as force level increased (all pCONCLUSION: Increasing force output led to decreased coherence within the rotator cuff muscles and between supraspinatus and the deltoid muscles, but increased coherence between infraspinatus and the deltoid muscles. This likely serves as a protective mechanism against superior humeral head migration
Implications of Dam Removal: Modeling Streamflow in Lansing, Michigan Using the Soil and Water Assessment Tool
This paper uses hydrologic modeling methods to determine the effects of dam removal in Lansing, Michigan, on the streamflow of the Grand River, flooding risks, and flood mitigation strategies. In Michigan, more than one-half of the state’s dam infrastructure is more than 50 years old, and more than one-third are classified as having a moderate-to high-risk potential. Lansing, Michigan, contains two moderate-to high-risk dams along the Grand River that are a significant hazard to the surrounding community in the event of structural failure. This research utilizes the Soil and Water Assessment Tool (SWAT) to model the impacts of the Moores Park Dam and the North Lansing Dam on streamflow in the greater Lansing area. The purpose of using SWAT was to represent baseline streamflow conditions in the Grand River, compare the differences in streamflow magnitude between baseline conditions and a dam-out environment, and interpret the implications of modeling results for mitigation and management strategies in the study area. Our model exhibited similar streamflow patterns to USGS historical data, with overestimation errors during calibration and validation stemming from groundwater infiltration inaccuracies. The dams-out model for streamflow was higher than the baseline model for streamflow; however, both model iterations require further calibration and validation for the magnitude differences to be considered statistically significant. Despite issues of model calibration and validation, and ongoing model adjustments for accurately representing heavily impounded watershed, the results of this study provide a template for the City of Lansing to adapt their flood mitigation strategies in the study area and further calibrate SWAT with improved sediment, nutrient, and dam attribute data
Imaging Sources with Fast and Slow Emission Components
We investigate two-proton correlation functions for reactions in which fast
dynamical and slow evaporative proton emission are both present. In such cases,
the width of the correlation peak provides the most reliable information about
the source size of the fast dynamical component. The maximum of the correlation
function is sensitive to the relative yields from the slow and fast emission
components. Numerically inverting the correlation function allows one to
accurately disentangle fast dynamical from slow evaporative emission and
extract details of the shape of the two-proton source.Comment: 13 pages, 4 figure
Research collaboration between China and Denmark for development of systemic approaches to agro-ecological pest management without pesticides with focus on vegetable, fruit and berry crops. Proceedings and recommendations from two network workshops
This report is the result of a network project which was established to discuss the potential for collaboration on development of systemic approaches to pest management without pesticides between Chinese and Danish researchers. The focus is on systemic approaches rather than input substitution of synthetic chemicals with agents of natural origin, however, the latter is considered as an integrated tool for the development and design of systemic approaches. The discussions were, furthermore, limited to management of invertebrate pests as well as diseases, while other pests such as weeds have not been included in the discussions. The discussions took place at two workshops and were based on presentations of research from the two countries and field visits in China and Denmark.
After the first workshop that took place in China, it was agreed that Chinese and Danish researchers in this particular field had mutual interests and priorities and that there was a potential for creating collaboration that could yield results beneficial for the agricultural/horticultural sectors in both countries. It was also agreed that in spite of the many differences between variation in climate and ecosystems, as well as in farming systems and their organization in China and Denmark, there were many similarities in the production of high-value crops in the two countries, such as vegetables, fruit and berries and, therefore, an obvious focus for joint research efforts. It was also agreed that joint research efforts could aim at specific crops as well as aiming at the development of specific research approaches.
Based on the observations and the agreements of the first workshop, the second workshop, which took place in Denmark, focused more specifically on the development of a research framework with specified research questions/topics. Two groups were formed – one working with vegetables and one with fruit and berries working in parallel – both looking into what kind of research is needed for development of systemic approaches to pesticide-free pest management should include both well-known practices and new practices.
Although the discussions in the two groups took separate routes and unfolded and described the research topics in each their way, there was a clear consistency between the outputs of the work of the two groups. Each had identified three main research themes that more or less followed the same line and has been merged into three specific recommendations on themes for collaboration, namely:
1) ‘Research to provide the biological foundation and understanding of mechanisms and interactions for development of non-chemical solutions and to improve efficiency of new and existing control methods for severe pest problems’.
2) Research in ‘How best to integrate multifunctional plants (and crops) and use diversification to create a more healthy and productive farming system which is resilient to pests?’
3) Research in ‘How to design and integrate pest management in eco-functional cropping systems at field and farm/landscape level?
Environmental Parameters Associated With Stable Fly (Diptera: Muscidae) Development at Hay Feeding Sites
Substrates composed of hay residues, dung, and urine accumulate around winter hay feeding sites in cattle pastures, providing developmental habitats for stable flies. The objective of this study was to relate physiochemical and microbial properties of these substrates to the presence or absence of stable fly larvae. Properties included pH, temperature, moisture, ammonium concentration, electrical conductivity, and numbers of coliform, fecal coliform, Escherichia coli, and Enterococcus bacteria. Each physiochemical sample was classified as a function of belonging to one of the three 2-m concentric zones radiating from the feeder as well as presence or absence of larvae. In total, 538 samples were collected from 13 sites during 2005–2011. Stable fly larvae were most likely to be found in moist, slightly alkaline substrates with high levels of ammonium and low temperature. The probability of larvae being present in a sample was the highest when the moisture content was 347% relative to dry weight and the average pH was 8.4. Larvae were recovered within all zones, with a nonsignificant, but slightly higher, percentage of samples containing larvae taken 2–4m from the center. All methods used to enumerate bacteria, except total coliform, indicated decreasing concentrations in hay bale residue throughout the summer. In addition to the environmental parameters, cumulative degree day 10˚C had a significant effect on the probability of observing stable fly larvae in a sample, indicating that unidentified seasonal effects also influenced immature stable fly populations
Environmental Parameters Associated With Stable Fly (Diptera: Muscidae) Development at Hay Feeding Sites
Substrates composed of hay residues, dung, and urine accumulate around winter hay feeding sites in cattle pastures, providing developmental habitats for stable flies. The objective of this study was to relate physiochemical and microbial properties of these substrates to the presence or absence of stable fly larvae. Properties included pH, temperature, moisture, ammonium concentration, electrical conductivity, and numbers of coliform, fecal coliform, Escherichia coli, and Enterococcus bacteria. Each physiochemical sample was classified as a function of belonging to one of the three 2-m concentric zones radiating from the feeder as well as presence or absence of larvae. In total, 538 samples were collected from 13 sites during 2005–2011. Stable fly larvae were most likely to be found in moist, slightly alkaline substrates with high levels of ammonium and low temperature. The probability of larvae being present in a sample was the highest when the moisture content was 347% relative to dry weight and the average pH was 8.4. Larvae were recovered within all zones, with a nonsignificant, but slightly higher, percentage of samples containing larvae taken 2–4m from the center. All methods used to enumerate bacteria, except total coliform, indicated decreasing concentrations in hay bale residue throughout the summer. In addition to the environmental parameters, cumulative degree day 10˚C had a significant effect on the probability of observing stable fly larvae in a sample, indicating that unidentified seasonal effects also influenced immature stable fly populations
Current breeding distributions and predicted range shifts under climate change in two subspecies of Black-tailed Godwits in Asia
Habitat loss and shifts associated with climate change threaten global biodiversity, with impacts likely to be most pronounced at high latitudes. With the disappearance of the tundra breeding habitats, migratory shorebirds that breed at these high latitudes are likely to be even more vulnerable to climate change than those in temperate regions. We examined this idea using new distributional information on two subspecies of Black-tailed Godwits Limosa limosa in Asia: the northerly,bog-breeding L. l. bohaii and the more southerly, steppe-breeding L. l. melanuroides. Based on breeding locations of tagged and molecularly assayed birds, we modelled the current breeding distributions of the two subspecies with species distribution models, tested those models for robustness, and then used them to predict climatically suitable breeding ranges in 2070 according to bioclimatic variables and different climate change scenarios. Our models were robust and showed that climate change is expected to push bohaii into the northern rim of the Eurasian continent. Melanuroides is also expected to shift northward, stopping in the Yablonovyy and Stanovoy Ranges, and breeding elevation is expected to increase. Climatically suitable breeding habitatranges would shrink to 16% and 11% of the currently estimated ranges of bohaii and melanuroides, respectively. Overall, this study provides the first predictions for the future distributions of two little-known Black-tailed Godwit subspecies and highlights the importance of factoring in shifts in bird distribution when designing climate-proof conservation strategies.</p
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