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Communication research measures III : a sourcebook
Building on the measures included in the original 1994 volume and subsequent 2009 volume, Communication Research Measures III: A Sourcebook extends its coverage of measurement issues and trends across the entire communication discipline. Volume III features entirely new content and offers an assessment of new measures in mass, interpersonal, instructional, group, organizational, family, health, and intercultural communication and highlights work in emergent subdisciplines in communication, including social media and new communication technologies, sports communication, and public relations. The best of the best from 2009 through today, the profiled research measures in Volume III serve as models for future scale development and constitute the main tools that researchers can use for self-administered measurement of people's attitudes, conceptions of themselves, and perceptions of others. This book is ideal for undergraduate and graduate courses that emphasize quantitative research methods, measurement, and/or survey design across communication studies disciplines.
Book
The impact of developmental stage, tissue type, and sex on DNA double-strand break repair in Drosophila melanogaster
Accurate repair of DNA double-strand breaks (DSBs) is essential for the maintenance of genome integrity, as failure to repair DSBs can result in cell death. The cell has evolved two main mechanisms for DSB repair: non-homologous end-joining (NHEJ) and homology-directed repair (HDR), which includes single-strand annealing (SSA) and homologous recombination (HR). While certain factors like age and state of the chromatin are known to influence DSB repair pathway choice, the roles of developmental stage, tissue type, and sex have yet to be elucidated in multicellular organisms. To examine the influence of these factors, DSB repair in various embryonic developmental stages, larva, and adult tissues in Drosophila melanogaster was analyzed through molecular analysis of the DR- white assay using Tracking across Indels by DEcomposition (TIDE). The proportion of HR repair was highest in tissues that maintain the canonical (G1/S/G2/M) cell cycle and suppressed in both terminally differentiated and polyploid tissues. To determine the impact of sex on repair pathway choice, repair in different tissues in both males and females was analyzed. When molecularly examining tissues containing mostly somatic cells, males and females demonstrated similar proportions of HR and NHEJ. However, when DSB repair was analyzed in male and female premeiotic germline cells utilizing phenotypic analysis of the DR- white assay, there was a significant decrease in HR in females compared to males. This study describes the impact of development, tissue-specific cycling profile, and, in some cases, sex on DSB repair outcomes, underscoring the complexity of repair in multicellular organisms.
Journal Article
A shrinking envelope? Climate warming across the Pacific coastal temperate rainforest and its projected impact on a native defoliator
Temperature regulates the location, frequency, and extent of irruptive forest insect herbivore outbreak cycles. Across the Pacific coastal temperate rainforest, recent outbreaks by a native defoliator, western blackheaded budworm, have impacted the greatest land area recorded since the advent of aerial detection programs and led to widespread losses of canopy leaf area and forest growth. Evidence suggests that the geographic distribution of budworm outbreaks has tracked a poleward shift in suitable temperature across the ecoregion. In this manuscript, we compile aerial observer estimates of insect defoliation, forest inventory data, and historical and projected climate data under three emissions scenarios to hind- and forecast the distribution of budworm outbreaks from 1901 to 2100. Climate data indicate that seasonal temperatures have warmed and are projected to warm further across the ecoregion, while seasonal precipitation has and will remain relatively constant. Models indicate that a range of spring and summer temperatures primarily constrain the biogeography of budworm outbreaks, while minimum host availability, autumn and winter temperatures, and seasonal precipitation further contribute. Projected warming will shift a substantial portion of regional forestland beyond the upper temperature threshold of historic outbreaks. Thus, our forecasts suggest that budworm outbreak distribution will narrow under all three future climatic scenarios tested. Across much of the ecoregion, the distribution of forestlands suitable for budworm outbreaks is projected to shift poleward and upslope, eventually eclipsing its host’s elevational distribution. The possible disruption of periodic defoliator outbreak disturbances in this system may have important ramifications for primary productivity, forest dynamics, and forest structure.
Journal Article
Ancient Maya : archaeology unlocks the secrets to the Maya's past
Explores the world of the Maya, which spans five centuries of history in Mexico, Guatemala, Belize, Honduras, and El Salvador.
Book
Defoliator outbreaks track with warming across the Pacific coastal temperate rainforest of North America
The biogeography of irruptive insect herbivores is determined by host availability and climate conditions. As such, outbreak distributions are sensitive to climatic change, especially across large latitudinal gradients. Here, we investigate the outbreak distributions of two understudied defoliators, hemlock sawfly Neodiprion tsugae (Hymenoptera) and western blackheaded budworm Acleris gloverana (Lepidoptera), that have both recently impacted the greatest land area recorded across the Pacific coastal temperate rainforest since the establishment of aerial survey programs. We compiled polygon‐based estimates of insect damage collected by aerial observers, forest inventory, and downscaled climatic data to develop gridded estimates of bioclimatic conditions across the extent of the Pacific coastal temperate rainforest, including the continental United States, British Columbia and Alaska. We leveraged these data to develop ensemble machine learning models with the goal of predicting the outbreak distribution of each insect. In this manuscript we: 1) describe the historical patterns of defoliator outbreaks, 2) identify and describe climatic conditions associated with outbreaks in both species and 3) assess whether historic outbreaks have tracked geographic shifts in climate conditions across the region. We demonstrate that outbreaks of hemlock sawfly and western blackheaded budworm have been observed across the Pacific coastal temperature rainforests of North America in each decade since the establishment of the Canadian and United States aerial survey programs. The distribution of outbreaks by both insects were best explained by host availability, a limited range of spring, summer, and winter temperatures, and minimum precipitation. Finally, we demonstrate that outbreaks have tracked the poleward shift in suitable climate over the last century. This study establishes a baseline understanding of the climatic constraints and biogeographic patterns of historic sawfly and budworm outbreaks across the Pacific coastal temperate rainforest and emphasizes the overarching importance of climate in driving the irruptive dynamics of these defoliator species. Keywords: climate envelope, defoliators, hemlock sawfly, Pacific coastal temperate rainforest, population dynamics, western blackheaded budworm
Journal Article
المحتال الغاضب : قصة
\"أماندا\" الأبنة الصغيرة والجميلة لعالم بيولوجي يعيش مع زوجته الصغيرة في بيت ويمتلك مزرعة ونهرا يمر من وسطها. هذه الفتاة كانت تعيش مع أختها وزوج أختها .. لكن حادثا وقع جعل أماندا تغادر أختها وهي غضبى لتلجأ إلى بيت أبيها الذي كان في النيبال .. كانت ليلة شتائية عاصفة. حاولت (أماندا) دخول البيت من أحد الشبابيك العلوية .. حين أفزعها صوت \"جبسون\" فسقطت مغمى عليها. شقيقة أماندا المعروفة بغيرتها تعود إلى المنطقة بعد حادث أصيب به الأب .. تعرف أن أحداثا أخرى وقعت خلال الأسبوعين! ماذا وقع ... يا ترى ؟.. هل أحب \"جبسون\" أماندا .. هل كشفت له عن شخصيتها الحقيقية .. هل طلب الزواج منها ؟.. ماذا فعلت الغيورة أختها ؟ هل هربت أماندا من بين والدها، ثانية، كما هربت من بيت شقيقتها... ولماذا؟ ماذا حدث في لندن حين التقى \"جبسون\" وزج شقيقة أماندا في المحطة ... ثم حين ذهب يبحث عن أماندا ؟ هذه الرواية تحكي قصة حب عاصفة وغيرة مقتية، وحياة حافلة بالحوار والمفاجآت. إنها رواية ممتعة بشخصياتها وأجوائها .. لذا ندعوك أن تستمتع بها عزيزنا القارئ الكريم.
BOOK
Is an absolute level of cortical beta suppression required for proper movement? Magnetoencephalographic evidence from healthy aging
Previous research has connected a specific pattern of beta oscillatory activity to proper motor execution, but no study to date has directly examined how resting beta levels affect motor-related beta oscillatory activity in the motor cortex. Understanding this relationship is imperative to determining the basic mechanisms of motor control, as well as the impact of pathological beta oscillations on movement execution. In the current study, we used magnetoencephalography (MEG) and a complex movement paradigm to quantify resting beta activity and movement-related beta oscillations in the context of healthy aging. We chose healthy aging as a model because preliminary evidence suggests that beta activity is elevated in older adults, and thus by examining older and younger adults we were able to naturally vary resting beta levels. To this end, healthy younger and older participants were recorded during motor performance and at rest. Using beamforming, we imaged the peri-movement beta event-related desynchronization (ERD) and extracted virtual sensors from the peak voxels, which enabled absolute and relative beta power to be assessed. Interestingly, absolute beta power during the pre-movement baseline was much stronger in older relative to younger adults, and older adults also exhibited proportionally large beta desynchronization (ERD) responses during motor planning and execution compared to younger adults. Crucially, we found a significant relationship between spontaneous (resting) beta power and beta ERD magnitude in both primary motor cortices, above and beyond the effects of age. A similar link was found between beta ERD magnitude and movement duration. These findings suggest a direct linkage between beta reduction during movement and spontaneous activity in the motor cortex, such that as spontaneous beta power increases, a greater reduction in beta activity is required to execute movement. We propose that, on an individual level, the primary motor cortices have an absolute threshold of beta power that must be reached in order to move, and that an inability to suppress beta power to this threshold results in an increase in movement duration.
Journal Article
Regular cannabis use alters the neural dynamics serving complex motor control
Cannabis is the most widely used recreational drug in the United States and regular use has been linked to deficits in attention and memory. However, the effects of regular use on motor control are less understood, with some studies showing deficits and others indicating normal performance. Eighteen users and 23 nonusers performed a motor sequencing task during high‐density magnetoencephalography (MEG). The MEG data was transformed into the time‐frequency domain and beta responses (16–24 Hz) during motor planning and execution phases were imaged separately using a beamformer approach. Whole‐brain maps were examined for group (cannabis user/nonuser) and time window (planning/execution) effects. As expected, there were no group differences in task performance (e.g., reaction time, accuracy, etc.). Regular cannabis users exhibited stronger beta oscillations in the contralateral primary motor cortex compared to nonusers during the execution phase of the motor sequences, but not during the motor planning phase. Similar group‐by‐time window interactions were observed in the left superior parietal, right inferior frontal cortices, right posterior insular cortex, and the bilateral motor cortex. We observed differences in the neural dynamics serving motor control in regular cannabis users compared to nonusers, suggesting regular users may employ compensatory processing in both primary motor and higher‐order motor cortices to maintain adequate task performance. Future studies will need to examine more complex motor control tasks to ascertain whether this putative compensatory activity eventually becomes exhausted and behavioral differences emerge. Recreational cannabis use is becoming increasingly more common, but the long‐term impact of regular use on the brain is poorly understood. Herein, we investigated how regular cannabis use affects the brain circuitry and dynamics serving motor control in adults. We found that regular cannabis use alters the dynamics serving motor control in primary and higher‐order motor cortices.
Journal Article
Design of Biopolymer-Based Interstitial Therapies for the Treatment of Glioblastoma
Glioblastoma multiforme (GBM) is the most common form of primary brain cancer and has the highest morbidity rate and current treatments result in a bleak 5-year survival rate of 5.6%. Interstitial therapy is one option to increase survival. Drug delivery by interstitial therapy most commonly makes use of a polymer implant encapsulating a drug which releases as the polymer degrades. Interstitial therapy has been extensively studied as a treatment option for GBM as it provides several advantages over systemic administration of chemotherapeutics. Primarily, it can be applied behind the blood–brain barrier, increasing the number of possible chemotherapeutic candidates that can be used and reducing systemic levels of the therapy while concentrating it near the cancer source. With interstitial therapy, multiple drugs can be released locally into the brain at the site of resection as the polymer of the implant degrades, and the release profile of these drugs can be tailored to optimize combination therapy or maintain synergistic ratios. This can bypass the blood–brain barrier, alleviate systemic toxicity, and resolve drug resistance in the tumor. However, tailoring drug release requires appropriate consideration of the complex relationship between the drug, polymer, and formulation method. Drug physicochemical properties can result in intermolecular bonding with the polymeric matrix and affect drug distribution in the implant depending on the formulation method used. This review is focused on current works that have applied interstitial therapy towards GBM, discusses polymer and formulation methods, and provides design considerations for future implantable biodegradable materials.
Journal Article